JP5886667B2 - Air bag and air bag device - Google Patents

Description

  The present invention relates to an airbag and an airbag apparatus, and more particularly to an airbag and an airbag apparatus having a vent hole that can be opened and closed.

  It is 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. . Such an airbag device includes an airbag device for a driver seat installed in a steering wheel, an airbag device for a passenger seat installed in an instrument panel, a side airbag device installed in a vehicle side or seat, and an upper door portion. Various types have been developed and adopted, such as an interior curtain airbag device, a knee airbag device corresponding to an occupant's knee, and a pedestrian airbag device installed under a hood.

  These airbag apparatuses generally include 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. Have. In addition, there has already been proposed an airbag in which a vent hole for releasing an internal gas to the outside is formed and the internal pressure of the airbag is adjusted by controlling the opening and closing of the vent hole (for example, Patent Document 1 to Patent Document 3).

  The airbag device described in Patent Document 1 changes a variable vent hole that allows or suppresses the gas flow state inside and outside the airbag according to the deployment state of the airbag, and changes the gas flow state in the variable vent hole. The airbag is deployed in a plurality of directions in stages, and the circulation state changing means is in a permissive state that allows gas to flow in the initial deployment stage of the airbag. In addition, after the initial deployment stage, the permissible state and the suppression state that suppresses the flow of gas can be selectively set according to the deployment state of the airbag.

  An airbag device described in Patent Document 2 includes an opening / closing control device capable of holding and detaching a strap, and a flap member that is connected to the tip of the strap and arranged to cover the vent hole at the peripheral edge of the vent hole When the airbag is inflated, the vent hole is closed by pressing the periphery of the vent hole to keep the vent hole closed, and when the airbag is inflated, the vent hole is released. Is configured to open.

  The airbag apparatus described in Patent Document 3 includes a first strap connected to the periphery of a vent hole and a lower portion of an airbag occupant side base fabric, an edge of the vent hole, and an occupant side base fabric of the airbag. A second strap connected to the rear portion, and the first strap is configured to close the vent hole in accordance with the inflation and deployment of the airbag. When it is restrained, the first strap is pulled together with the edge of the vent hole to open the vent hole.

JP 2005-14861 A JP 2007-307990 A JP 2010-58544 A

  In the airbag apparatus described in Patent Document 1 to Patent Document 3 described above, by covering or sliding the valve body (flap material or the like) on the opening portion of the vent hole, or by narrowing the opening portion of the vent hole, Controls opening and closing of vent holes. However, in this vent hole opening and closing method, in order to control the opening and closing of the vent hole in stages, a complicated mechanism is adopted, and the amount of use of the base fabric increases and the weight increases. There were problems such as difficulty in folding. Further, when the opening / closing control device is arranged, there is a problem that the weight of the airbag device is increased and the cost is increased.

  The present invention was devised in view of such problems, and an object of the present invention is to provide an airbag and an airbag apparatus that can easily control the opening and closing of the vent hole and can suppress an increase in weight and an increase in cost. .

  According to the present invention, in an airbag that is normally folded and accommodated in a vehicle structure and is inflated and deployed by supplying gas in an emergency, the vent hole formed in the base fabric constituting the airbag And having a stitching portion having a width capable of covering the vent hole and having both ends stitched to the surface of the base fabric so as to sandwich the vent hole, and a distance between the stitching portions on the base fabric. A valve body having a long overall length, a strap connected to an intermediate portion of the back surface of the valve body and inserted into the airbag from a slit formed in the base cloth, and one end connected to the strap And a tether connected to an airbag component member whose other end moves as the airbag is inflated and deployed, and when the tether is in a tensioned state, the strap is deformed into a folded state. And closing the vent hole by bringing it into close contact with the surface of the base fabric, and opening the vent hole by releasing the folded state of the valve body when the tether is in a relaxed state. Is provided.

  Further, according to the present invention, the airbag includes a 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 device, the airbag has a vent hole formed in a base fabric constituting the airbag and a width capable of covering the vent hole, and both ends of the base fabric sandwich the vent hole. And a valve body having a total length longer than the distance between the stitched portions on the base fabric, and connected to an intermediate portion on the back surface of the valve body and attached to the base fabric. A strap that is inserted into the airbag from the formed slit, and an airbag that has one end connected to the strap and the other end that moves as the airbag is inflated and deployed. A tether connected to a structural component, and when the tether is in a tension state, the strap deforms the valve body into a folded state and closes the vent hole to close the vent hole, An airbag device is provided, wherein the vent hole is opened by releasing the folded state of the valve body when the tether is in a relaxed state.

  In the airbag and the airbag apparatus described above, the valve body has a widened portion wider than the other portions in the stitched portion on the slit portion side, and the outer periphery of the widened portion is stitched to the base fabric. Accordingly, the folded portion of the valve body that has been transformed into a folded state may be accommodated.

  Moreover, the said valve body may have a crease | fold for making it easy to deform | transform into a folded state. The strap may have a protrusion formed in the width direction. Further, the tether may be configured to be able to expand stepwise in accordance with the inflation and deployment of the airbag.

  The valve body may be accommodated so that the vent hole can be shifted to an open state in a state in which the folded state is released when the airbag is accommodated, or in a state in which the folded state is released. The vent hole may be accommodated in a closed state.

  According to the airbag and the airbag device according to the present invention described above, the vent hole is closed by deforming the valve body into the folded state, and the vent hole can be opened by releasing the folded state of the valve body. Thus, the vent hole can be opened and closed according to the tension and relaxation of the tether, and the opening and closing of the vent hole can be easily controlled. In addition, the vent hole opening and closing mechanism has a simple configuration including a valve body, a strap, and a tether, so that the amount of base fabric used can be reduced and a pyrotechnic product such as an opening and closing control device can be used. There is no need to use it, and the increase in weight and cost of the airbag and airbag device can be suppressed.

  In addition, by accommodating the folded part of the valve body in the wide part of the valve body, it is possible to suppress the looseness of the folded part, improve airtightness, and leak gas from the vent hole and the slit part. Can be suppressed.

  Moreover, when a valve body has a predetermined crease | fold, the folding state of a valve body can be stably deformed to the same shape, and it can be stabilized more functionally.

  In addition, by forming the protrusion on the strap, the timing for pulling the strap into the airbag can be adjusted, and vent hole opening / closing control can be easily performed in accordance with the characteristics of the airbag.

  In addition, by configuring the tether with a tether that can be expanded stepwise, the opening and closing of the vent hole can be controlled according to the stage of inflation and deployment of the airbag. The closed state can be easily maintained.

  Further, by accommodating the airbag in the state in which the folded state of the valve body is released when the airbag is accommodated, the vent hole can be promptly shifted to the open state in the initial stage of inflation and deployment of the airbag. In addition, the vent hole can be held in a closed state by sewing or the like in a state in which the folded state of the valve body is released when the airbag is accommodated. The closed state can be maintained for a certain time.

It is a figure which shows the airbag and airbag apparatus which concern on 1st embodiment of this invention, (A) is a rear view of an airbag, (B) has shown sectional drawing of the airbag apparatus. It is a top view which shows the valve body and strap which were shown in FIG. 1, (A) is a valve body, (B) is a strap, (C) is a modification of a valve body, (D) is a modification of a strap. ing. It is a figure which shows the 1st example of the opening-and-closing control of a vent hole, (A) shows an initial open state, (B) shows a middle period closed state, (C) has shown the late stage open state. It is a figure which shows the 2nd example of the opening-and-closing control of a vent hole, (A) has shown the initial closed state, (B) has shown the middle-stage closed state, (C) has shown the late-stage open state. It is a figure which shows the tether shown in FIG. 1, (A) is 1st embodiment, (B) is a 1st modification, (C) has shown the 2nd modification. It is a figure which shows the effect | action of the airbag apparatus shown in FIG. 1, (A) is the initial stage of inflation deployment, (B) is the middle stage of inflation deployment, (C) is the late stage of inflation deployment, (D) is The occupant contact stage is shown. It is a figure which shows the modification of an airbag apparatus, (A) shows a 1st modification, (B) shows a 2nd modification, (C) shows a 3rd modification, (D) shows a 4th modification. ing.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. Here, FIG. 1 is a view showing the airbag and the airbag apparatus according to the first embodiment of the present invention, in which (A) is a rear view of the airbag, and (B) is a sectional view of the airbag apparatus. Show. 2 is a plan view showing the valve body and the strap shown in FIG. 1, (A) is the valve body, (B) is the strap, (C) is a modification of the valve body, and (D) is a deformation of the strap. An example is shown.

  As shown in FIGS. 1 and 2, the airbag apparatus according to the first embodiment of the present invention is normally folded and expanded and deployed in an emergency, and gas is supplied to the airbag 1. The airbag 1 and the retainer 3 for fixing the inflator 2. The airbag 1 can cover the vent hole 4 formed in the base fabric constituting the airbag 1 and the vent hole 4. And has stitched portions 5a and 5b sewn to the surface of the base fabric (for example, the second base fabric 1b) so as to sandwich the vent hole 4, and the stitched portions 5a and 5b on the base fabric The valve body 5 having a total length Lv longer than the distance Lf between 5b and the slit 61 formed in the base fabric (for example, the second base fabric 1b) is connected to the intermediate portion of the back surface of the valve body 5 and air Stroke inserted into bag 1 And a tether 7 having one end connected to the strap 6 and the other end connected to an airbag component (for example, the inner surface of the airbag 1) that moves as the airbag 1 is inflated and deployed. When the tether 7 is in a tension state, the strap 6 deforms the valve body 5 into a folded state and closes the vent hole 4 by closely contacting the surface of the base fabric (for example, the second base fabric 1b). Sometimes, the vent hole 4 is opened by releasing the folded state of the valve body 5.

  The airbag apparatus shown in FIG. 1 (B) is, for example, an airbag apparatus for a driver's seat, and is disposed on a steering boss portion 12 disposed at a substantially central portion of a steering wheel 11 disposed on the front surface of the driver's seat. It is covered with a resin pad (not shown). The air bag 1 starts inflating and deploying when gas is supplied to the inside by the operation of the inflator 2, the pad is cleaved and released into the passenger compartment, and inflated and deployed in front of the passenger seated in the driver's seat.

  The airbag 1 includes, for example, a first base cloth 1a that forms a contact surface with an occupant and a second base cloth 1b that is disposed on the steering wheel 11 side. A bag body constituting the airbag 1 is formed by sewing the edge with the base fabric 1b. As shown in FIG. 1 (A), an opening 1c for mounting the inflator 2 is formed at a substantially central portion of the second base fabric 1b. The airbag 1 is, for example, a part of the inflator 2 inserted into the opening 1c, a bag ring (not shown) is arranged from the inside, and is fixed to the retainer 3 by a fixing tool (not shown) such as a bolt and a nut. Is done. A width regulating tether 8 that regulates the protruding width (thickness) when the airbag 1 is inflated and deployed may be arranged inside the airbag 1.

  The inflator 2 is a gas generator that generates gas to be supplied to the airbag 1 and has, for example, a substantially disk-shaped outer shape. In FIG. 1B, the case where the disk-type inflator 2 is used is illustrated, but a cylinder-type inflator having a substantially cylindrical outer shape may be used. The inflator 2 is connected to an ECU (electronic control unit) (not shown) and is controlled based on measurement values of an acceleration sensor or the like. When the ECU senses or predicts a vehicle collision or sudden deceleration, the inflator 2 is ignited by the ignition current from the ECU, burns the chemical stored in the inflator 2 to generate gas, and the gas is supplied to the airbag 1. Supply.

  The retainer 3 is a member that fixes the airbag 1 and the inflator 2, and an airbag module is configured by connecting pads. The airbag module is connected to the steering boss portion 12 so as to be relatively movable, and constitutes a horn switch between the pad and the steering boss portion 12. The steering wheel 11 is connected to the steering boss portion 12 through a plurality of spokes. In addition, the basic structure of the airbag apparatus comprised by the airbag 1, the inflator 2, and the retainer 3 mentioned above is a mere example, and is not limited to what was illustrated.

  For example, as shown in FIGS. 1A and 1B, the vent hole 4 is a substantially circular opening formed in the second base fabric 1 b that forms the back side of the airbag 1. With this configuration, the gas released from the vent hole 4 can be prevented from blowing to the occupant. Further, the vent hole 4 is formed, for example, inside the steering wheel 11. With this arrangement, the vent hole 4 can be arranged at a position opposite to the direction in which the occupant contacts the airbag 1 and pressure is applied, and gas can be easily released.

  Here, FIG. 2 is a plan view showing the configuration of the valve body 5 and the strap 6. As shown in FIG. 2A, the valve body 5 has a width Wa that can cover the vent hole 4, and both ends are sewn to the surface of the second base fabric 1b so as to sandwich the vent hole 4. It has parts 5a and 5b and is configured to have a total length Lv that is longer than the distance Lf between the stitched parts 5a and 5b on the second base fabric 1b. Further, the valve body 5 has a widened portion 51 that is wider than the other portions in the stitched portion 5b on the slit portion 61 side, and is folded by sewing the outer periphery of the widened portion 51 to the second base fabric 1b. The folding part F of the valve body 5 deformed into the shape can be accommodated. If necessary, a reinforcing cloth (patch cloth) that is overlapped with the valve body 5 and sewn may be used.

  In addition, the positions of the vent hole 4 and the slit portion 61 indicated by the alternate long and short dash line in FIG. The relative positions of are illustrated. Therefore, the interval between the vent hole 4 and the slit portion 61 on the actual second base fabric 1b is shorter than the interval shown in FIG. 2A by the ratio of Lf / Lv. The total length Lv of the valve body 5 is such that the opening area in a state in which the valve body 5 is separated from the surface of the airbag 1 to form the maximum gas discharge portion is at least twice the opening area of the airbag 4. By setting, the gas in the airbag 1 can be efficiently discharged to the outside.

  The stitching portion 5a on the vent hole 4 side is disposed in the vicinity of the vent hole 4 and is formed in an arc shape along the outer periphery of the vent hole 4 in order to improve the airtightness when the vent hole 4 is closed. The In addition, when the airtightness of the valve body 5 can be ensured sufficiently, or when airtightness does not need to be considered, the stitched portion 5a may be formed in a linear shape instead of the arc shape.

  The stitched portion 5b on the slit portion 61 side is configured by a wide portion 51 having a relationship of width Wb> width Wa. Specifically, the stitched portion 5b is an end of the wide portion 51 on the side opposite to the vent hole 4. And a pair of suture lines 5d and 5d sewn in the vertical width direction at both left and right ends of the wide portion 51. A pocket portion 52 that can accommodate the folded portion F of the valve body 5 is formed in the wide portion 51 by the stitched lines 5c and 5d. As shown in the figure, the pair of suture lines 5d and 5d may be formed so that the interval decreases toward the suture line 5c. With such a configuration, the pocket portion 52 having a wide opening and a narrow back can be formed, the folded portion F of the valve body 5 can be easily accommodated, and the folded state can be easily maintained.

  Further, in the switching portion between the width Wa and the width Wb of the valve body 5, the wide portion 51 may be formed with a cut portion 5 e formed in the extending direction of the valve body 5 having the width Wa. The notch 5e forms a play for smoothly performing the operation of the valve body 5 between the folded state and the released state.

  Moreover, the valve body 5 may have a fold 5f for facilitating deformation into a folded state. The fold 5f is formed by, for example, a suture line obtained by sewing a suture thread on the base fabric constituting the valve body 5 in the lateral width direction. In FIG. 2A, folds 5 f are formed at two locations near the boundary line with the wide portion 51 of the valve body 5 (that is, near the entrance of the pocket portion 52) and near the connection portion of the strap 6. In this embodiment, the valve body 5 is folded so that the fold 5f near the pocket 52 forms a mountain and the fold 5f near the vent hole 4 forms a valley.

  As described above, the crease 5f may be a part partially increased in rigidity by a suture line, or may be a part partially increased in rigidity by an adhesive disposed between the patch cloth. Alternatively, it may be a part where the rigidity is partially lowered by cutting a part of the patch cloth. Further, when the valve body 5 is soft and the valve body 5 can be easily folded without the fold 5f, the fold 5f may be omitted. In FIG. 2A, the two suture lines 5g constitute a connection portion with the strap 6.

  As shown in FIG. 2B, the strap 6 includes a connection portion 62 connected to the valve body 5, two strap main bodies 63 extending from the connection portion 62, and a connection portion 64 connected to the tether 7. And a protrusion 65 formed in the width direction. In addition, you may make it use the reinforcement cloth (patch cloth) which overlaps with the strap 6 and is sewn as needed.

  The connecting portion 62 is a portion that combines the two strap main bodies 63 into one part, and the gray colored portion shown in FIG. 2 (B) is changed to the gray colored portion shown in FIG. A portion for connecting the strap 6 to the valve body 5 by the suture line 5g is formed by matching (without upside down). In addition, when it is not necessary to combine the two strap main bodies 63 into one component, the connection part 62 may be divided | segmented by the approximate center part.

  A notch 66 formed in the extending direction of the strap body 63 may be formed at the boundary between the connection portion 62 and the strap body 63. The cut portion 66 reduces the gap between the slit portion 61 and the strap body 63 when the strap body 63 is pulled into the airbag 1 and presses the valve body 5 against the surface of the second base fabric 1b, and is airtight. It has the function to improve. In addition, you may make it abbreviate | omit the cutting part 66 as needed.

  The connecting portion 62 is a portion that connects the strap 6 to the tether 7 shown in FIG. 1 and may have any shape. As shown in the figure, it may be a shape bent inward from the strap body 63, may be a shape widened on both the left and right sides, or may be a shape in which the strap body 63 is stretched as it is. In addition, the strap 6 may be integrally formed by the same base fabric as the tether 7, and in that case, the connecting portion 62 can be omitted.

  The protrusion 65 is formed wider than the slit 61 through which the strap body 63 is inserted, and is configured such that the protrusion 65 is caught when the strap body 63 passes through the slit 61. Therefore, when the protrusion 65 is pulled out of the airbag 1, the length from the protrusion 65 to the valve body 5 does not change until the protrusion 65 is deformed and passes through the slit 61. This means that the timing for shifting the valve body 5 to the folded state can be delayed. In other words, even when tension is applied to the tether 7 when the airbag 1 is inflated and deployed, the projection 65 constitutes a stopper, and the tension that allows the projection 65 to pass through the slit 61 is sufficient. The bent state of the bent hole 4 can be maintained until it acts on. The protrusion 65 may be formed so as to protrude in the width direction in the lateral width direction, or may be formed so as to protrude in the width direction in the thickness direction.

  The shape of the slit portion 61 is not limited to the illustrated pore shape, and can be arbitrarily changed, for example, a slot shape or a round hole shape, and the cross-sectional shape of the strap body 63 is also changed accordingly. The shape of the projection 65 can be arbitrarily changed according to these shapes.

  In the modification of the valve body 5 shown in FIG. 2C, the valve body 5 does not have the wide portion 51 and therefore does not have the pocket portion 52. Even with such a configuration, the valve body 5 can be folded along the fold 5f. In addition, in the modification of the valve body 5, about another structure, since it is the same as the valve body 5 shown to FIG. 2 (A), detailed description is abbreviate | omitted here.

  The modification of the strap 6 shown in FIG. 2D is applicable to both the valve bodies 5 shown in FIGS. 2A and 2C, and the protrusion 65 is omitted. . When it is not necessary to adjust the timing for shifting the valve body 5 to the folded state, or when the timing for shifting the valve body 5 to the folded state can be adjusted by other means, as shown in the figure, the protrusion 65 May be omitted. Note that in the modification of the strap 6, the other configurations are the same as those of the strap 6 shown in FIG.

  Next, opening / closing control of the vent hole 4 using the valve body 5 described above will be described. Here, FIG. 3 is a diagram illustrating a first example of vent hole opening / closing control, in which (A) shows an initial open state, (B) shows an intermediate closed state, and (C) shows a late open state. . In each figure, the upper part shows a plan view and the lower part shows an XX cross-sectional view of the plan view.

  The initial open state shown in FIG. 3 (A) shows a state in which the vent hole 4 can be shifted to the open state before the airbag 1 is inflated and deployed and at the initial stage of inflation and deployment of the airbag 1. Yes. Specifically, the valve body 5 is pulled out from the pocket portion 52 and is folded or slackened to the suture portion 5a side. At this time, the protrusion 65 of the strap 6 is in a state of being pulled out of the airbag 1. Accordingly, the illustrated initial opened state is maintained until the strap 6 is pulled into the airbag 1 by the inflation and deployment of the airbag 1 and a certain tension is generated and the protrusion 65 is pulled into the airbag 1.

  At this time, since the valve body 5 is pulled out from the pocket portion 52, it is only disposed at the upper part of the vent hole 4, and when the gas pressure is loaded from the vent hole 4. As shown by the alternate long and short dash line in the sectional view, the valve body 5 can be easily pushed outward, separated from the surface of the airbag 1, and gas can be discharged to the outside of the airbag 1. That is, when the airbag 1 is accommodated, the valve body 5 is accommodated so that the bent hole 4 can be shifted to an open state in a state in which the folded state is released.

  The middle-term closed state shown in FIG. 3B shows a state in which a constant tension is generated in the strap 6 as the airbag 1 is inflated and deployed, and the protrusion 65 is drawn into the airbag 1. Specifically, the strap 6 is in a tensioned state in which the connection portion with the valve body 5 reaches the slit portion 61, and the valve body 5 is pulled toward the stitching portion 5b and is pocketed by the fold 5f. 52 is in a folded state. At this time, since the valve body 5 is pulled by the strap 6 and pressed against the surface of the airbag 1, the valve body 5 is in a closed state in which the vent hole 4 is closed.

  As shown in the figure, the valve body 5 is folded and accommodated in the pocket portion 52, so that the looseness of the folded portion can be suppressed, the airtightness is improved, and the vent hole 4 and the slit portion 61 are removed. Gas leakage can be suppressed.

  The final-stage open state shown in FIG. 3C shows a state in which, for example, an occupant comes into contact with the airbag 1 and the internal pressure of the airbag 1 suddenly increases. Specifically, the strap 6 is in a relaxed state by contact of an occupant with the airbag 1, and the valve body 5 is in a state in which it can be pulled out from the pocket portion 52, and the gas pressure is supplied from the vent hole 4. By being loaded on the valve body 5, the valve body 5 is pushed outward and is separated from the surface of the airbag 1. Therefore, the gas in the airbag 1 is released to the outside of the airbag 1 from the gap between the valve body 5 and the vent hole 4, and the impact of the occupant can be mitigated.

  According to the opening / closing control of the vent hole 4 described above, the vent hole 4 can be changed from the open state to the closed state to the open state at a predetermined timing. Therefore, when the occupant is in the state of being close to the airbag 1 (for example, in the case of out-of-position), the airbag 1 is connected to the occupant at the initial stage of inflation and deployment of the airbag 1. Even in the case of contact, the impact of the occupant can be reduced by releasing the gas from the vent hole 4. In addition, the vent hole 4 can be kept closed in the middle stage to the final stage of the inflation and deployment of the airbag 1, and the airbag 1 is connected to the occupant in the middle stage to the final stage of the inflation and deployment of the airbag 1. In the case of contact, the impact of the occupant can be reduced by releasing the gas from the vent hole 4.

  Moreover, in this embodiment, since the vent hole 4 can be shifted to an open state at a necessary timing, it is not necessary to form a so-called normally open type vent hole or to reduce the size to the minimum necessary size. Thus, it is possible to suppress the release of useless gas when the airbag 1 is inflated and deployed, to reduce the size of the inflator 2, and to reduce the weight and cost of the airbag device.

  Next, a second example of the opening / closing control of the vent hole 4 using the valve body 5 described above will be described. Here, FIG. 4 is a diagram showing a second example of vent hole opening / closing control, where (A) shows an initial closed state, (B) shows an intermediate closed state, and (C) shows a late open state. . In each figure, the upper part shows a plan view and the lower part shows an XX cross-sectional view of the plan view.

  The initial closed state shown in FIG. 4A shows a state in which the vent hole 4 is held in a closed state at a stage before the airbag 1 is inflated and deployed and at an initial stage of inflation and deployment of the airbag 1. Specifically, the valve body 5 is pulled out from the pocket portion 52 and is folded to the suture portion 5a side, and the valve body 5 is sewn by the suture line 5h in this state. Yes.

  At this time, since the valve body 5 is sewn in a state where the overall length is shortened, the state can be maintained until the suture line 5h is broken, and the closed state in which the vent hole 4 is closed is maintained. Can do. That is, the valve body 5 is accommodated so that the vent hole 4 can be held in a closed state in a state in which the folded state is released.

  In this way, when the initial closed state is maintained by the suture line 5h, the timing of shifting to the intermediate closed state of the vent hole 4 can be adjusted by the suture line 5h, and thus the protrusion 65 of the strap 6 is omitted. You may do it. However, by forming the protrusion 65 on the strap 6, the illustrated initial closed state can be stably maintained. Further, in order to improve the airtightness of the vent hole 4 in the initial closed state, the valve body 5 may be stitched to the airbag 1 by the stitching line 5h. Instead of the suture line 5h, the initial closed state may be formed by an adhesive, or the suture line 5h may be formed in the vertical width direction instead of the horizontal width direction of the valve body 5.

  The middle-term closed state shown in FIG. 4 (B) and the final-term closed state shown in FIG. 4 (C) are the same as the first example of the opening / closing control of the vent hole 4 shown in FIGS. 3 (B) and 3 (C). Since it is a state, detailed description is abbreviate | omitted here.

  According to the second example of the opening / closing control of the vent hole 4 described above, the vent hole 4 can be changed from the closed state to the open state at a predetermined timing. Therefore, the vent hole 4 can be held in the closed state until the occupant comes into contact with the airbag 1 from the initial stage to the final stage of the inflation and deployment of the airbag 1. Gas emission can be suppressed, the inflator 2 can be reduced in size, and the weight and cost of the airbag device can be reduced.

  Further, when the opening / closing control of the second example is adopted, the airbag 1 is used as in the case where the occupant is present in the vicinity of the airbag 1 (for example, in the case of out-of-position). In consideration of the case where the airbag 1 comes into contact with the occupant in the initial stage of inflation and deployment, a so-called normally open vent hole may be formed in the airbag 1.

  The tether 7 may be any string member that can pull the strap 6 when the airbag 1 is inflated and deployed. The tether 7 has one end connected to the strap 6 and the other end connected to an airbag component that moves as the airbag 1 is inflated and deployed. The airbag constituent member may be, for example, the inner surface of the airbag 1, a width regulation tether 8 disposed inside the airbag 1, a rectifying cloth that controls the flow of gas, or the like.

  Here, FIG. 5 is a figure which shows the tether shown in FIG. 1, (A) is 1st embodiment, (B) is a 1st modification, (C) has shown the 2nd modification. . The tethers 7 shown in FIGS. 5 (A) to 5 (C) are all configured to be able to expand stepwise in accordance with the inflation and deployment of the airbag 1, but the tether 7 is limited to such a configuration. It may be composed of a normal tether that does not expand stepwise.

  The tether 7 shown in FIG. 5 (A) has a widened portion 7a formed at an intermediate portion in the extending direction, and a fracture portion 7b formed in the widened portion 7a substantially perpendicular to the extending direction. The fracture | rupture part 7b is comprised by the some cut | interruption or opening, for example, and is arranged in the shape of a straight line or a curve at predetermined intervals. In addition, the cut may be a simple cut or a narrow slit. Further, the opening may be a so-called pin hole or a circular or polygonal small hole.

  The breaking portion 7b has, for example, a primary breaking portion that breaks evenly at the left and right in the center portion, and a secondary breaking portion that is formed on both sides of the primary breaking portion and alternately breaks right and left. The primary fracture portion is a portion that gives a trigger (starting point) at which the tether 7 breaks at the fracture portion 7b. The secondary fracture portion is configured to be able to fracture alternately left and right when tension is generated in the tether 7 by adjusting the left and right slit widths and slit intervals. In this way, by breaking the break portion 7b as the airbag 1 is inflated and deployed, the length of the tether 7 can be gradually increased while the opening portion 7c is formed.

  By connecting the expandable tether 7 to the strap 6, it is possible to apply an appropriate tension to the strap 6 according to the stage of inflation and deployment of the airbag 1, and to appropriately control the opening / closing of the vent hole 4 described above. Can be done at any time. Further, when the occupant comes into contact with the airbag 1 in the middle stage to the final stage of inflation and deployment of the airbag 1, the tether 7 can be immediately relaxed, and the vent hole 4 is opened by the action of the valve body 5. Can be migrated to. Note that the configuration of the tether 7 described above is merely an example, and the tether 7 may be configured by the modification shown in FIGS. 5B and 5C.

  In the first modification of the tether 7 shown in FIG. 5B, a fracture portion 7 d is formed along the center portion of the tether 7. With this configuration, the tether 7 is configured to be cut in the vertical direction, and the tether 7 can be extended in the arrow direction.

  A second modification of the tether 7 shown in FIG. 5C is obtained by forming a stitched portion 7 e in the folded portion of the tether 7. With this configuration, the tether 7 can be extended in the direction of the arrow by breaking the suture thread of the stitching portion 7e.

  Note that all the configurations of the tether 7 shown in FIGS. 5A to 5C can also be applied to the width regulating tether 8 that regulates the protruding width (thickness) of the airbag 1 when the airbag 1 is inflated and deployed. . By applying such an expandable tether to the width regulating tether 8, the airbag 1 can be easily inflated and deployed in stages, and the airbag 1 can be projected in the initial stage of inflating and deploying and the airbag 1 thereafter. Vibration in the front-rear direction can be suppressed. In addition, when an expandable tether is employed as the width regulating tether 8, the tether 7 can be easily configured with a normal tether that does not expand.

  Next, the operation of the airbag device shown in FIG. 1 will be described. Here, FIG. 6 is a diagram showing the operation of the airbag apparatus shown in FIG. 1, wherein (A) is an initial stage of inflation and deployment, (B) is a middle stage of inflation and deployment, and (C) is a stage of inflation and deployment. The latter stage, (D) shows the passenger contact stage. The operation shown in FIG. 6 is based on the first example of the opening / closing control of the vent hole 4 shown in FIG. Further, in each figure, for convenience of explanation, the strap 6 and the tether 7 are not distinguished from each other.

  As shown in FIG. 6A, in the initial stage of inflation and deployment of the airbag 1, the tether 7 is in a relaxed state or a tension state in which a tension suitable for the protruding width (thickness) of the airbag 1 is applied. At this stage, the valve body 5 is configured to be able to shift the vent hole 4 to an open state, and is configured to be able to discharge gas from the vent hole 4 when a gas pressure is applied to the valve body 5. Yes. Therefore, even when the occupant is approaching the steering wheel 11 (for example, in an out-of-position state), the gas can be immediately released from the vent hole 4, and the impact on the occupant can be reduced. Can do.

  As shown in FIG. 6B, in the middle stage of the inflation and deployment of the airbag 1, a constant tension is generated in the tether 7 according to the inflation and deployment of the airbag 1, and the strap 6 is pulled into the airbag 1. The valve body 5 is folded and accommodated in the pocket portion 52, and the vent hole 4 shifts to the closed state. Even when the occupant collides with the airbag 1 in this state, since the appropriate tension is applied to the tether 7, the vent hole 4 can be immediately shifted to the open state, and the impact of the occupant is reduced. Can be relaxed.

  As shown in FIG. 6C, in the latter stage of the inflation and deployment of the airbag 1, the tether 7 expands in response to the inflation and deployment of the airbag 1, and a constant tension is applied to the tether 7 while vent holes are provided. 4 can be maintained in the closed state. In this state, even if the occupant (dummy P) collides with the airbag 1, as shown in FIG. The hole 4 can be shifted to the open state, and the passenger's impact can be reduced.

  According to the airbag 1 and the airbag apparatus according to the above-described embodiment, the vent hole 4 is closed by deforming the valve body 5 into the folded state, and the vent hole 4 is released by releasing the folded state of the valve body 5. By enabling the opening, the vent hole 4 can be opened and closed according to the tension and relaxation of the tether 7, and the opening and closing of the vent hole 4 can be easily controlled. Moreover, since the opening / closing mechanism of the vent hole 4 has a simple configuration constituted by the valve body 5, the strap 6 and the tether 7, the usage amount of the base fabric can be reduced, and an opening / closing control device like There is no need to use pyrotechnics, and an increase in weight and cost of the airbag 1 and the airbag device can be suppressed.

  Then, the modification of an airbag apparatus is demonstrated. Here, FIG. 7 is a figure which shows the modification of an airbag apparatus, (A) is a 1st modification, (B) is a 2nd modification, (C) is a 3rd modification, (D) is The 4th modification is shown. In addition, about the same component as the airbag apparatus which concerns on 1st embodiment mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  In the first modification shown in FIG. 7A, the vent hole 4 is disposed outside the steering wheel 11. The valve body 5 mentioned above is arrange | positioned at the vent hole 4, and the vent hole 4 can be opened and closed by the effect | action similar to 1st embodiment. Although not shown, the vent hole 4 may be arranged both inside and outside the steering wheel 11.

  In the second modified example shown in FIG. 7B, the tether 7 is connected to the intermediate portion of the width regulating tether 8 of the airbag 1. The width regulating tether 8 corresponds to an airbag component that moves as the airbag 1 is inflated and deployed.

  In the third modification shown in FIG. 7C, a plurality of vent holes 4 are arranged inside the steering wheel 11. By arranging a plurality of vent holes 4, the amount of gas released can be easily increased, and the design according to the capacity of the airbag 1 can be easily performed.

  In the fourth modified example shown in FIG. 7D, the vent hole 4 and the valve body 5 described above are arranged in the airbag 1 of the passenger seat airbag device. Here, the vent hole 4 is arranged on the back side (wind shield W side) of the airbag 1, but it may be arranged on the side surface of the airbag 1. When the vent hole 4 is disposed on the side surface of the airbag 1, the other end of the tether 7 may be connected to a tether or partition wall disposed in the front-rear direction of the airbag 1.

  The present invention is not limited to the above-described embodiment, and the airbag device may be a side airbag device, a curtain airbag device, a knee airbag device, a pedestrian airbag device, etc. in addition to the passenger seat airbag device. Of course, various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Air bag 1a 1st base fabric 1b 2nd base fabric 1c Opening part 2 Inflator 3 Retainer 4 Vent hole 4a, 4b Sewing part 5 Valve body 5a, 5b Sewing part 5c, 5d, 5g, 5h Sewing line 5e Cutting part 5f Fold 6 Strap 7 Tether 7a Widening portion 7b Breaking portion 7c Opening portion 7d Breaking portion 7e Stitching portion 8 Width regulating tether 11 Steering wheel 12 Steering boss portion 51 Wide portion 52 Pocket portion 61 Slit portion 62, 64 Connection portion 63 Strap body 65 Projection 66 Cutting part

Claims (7)

In an airbag that is normally folded and accommodated in a vehicle structure and inflated and deployed by supplying gas in an emergency,
A vent hole formed in a base fabric constituting the airbag;
The vent hole has a width that can be covered, and has a stitched portion that is sewn to the surface of the base fabric so as to sandwich the vent hole, and is longer than the distance between the stitched portions on the base fabric. A valve body having a total length;
A strap that is connected to the middle portion of the back surface of the valve body and is inserted into the airbag from a slit formed in the base fabric;
A tether having one end connected to the strap and the other end connected to an airbag component that moves as the airbag is inflated and deployed;
The strap deforms the valve body into a folded state when the tether is in tension and closes the vent hole by closely contacting the surface of the base fabric, and releases the folded state of the valve body when the tether is in a relaxed state. The vent hole is opened by doing so.   The valve body has a widened portion that is wider than the other portions in the stitched portion on the slit portion side, and is deformed into a folded state by stitching the outer periphery of the widened portion to the base cloth. The airbag according to claim 1, wherein the airbag is configured to be able to accommodate a folded portion of the valve body.   The airbag according to claim 1, wherein the valve body has a fold for facilitating deformation into a folded state.   The airbag according to claim 1, wherein the strap has a protrusion formed in a width direction.   The airbag according to claim 1, wherein the tether is configured to be able to expand stepwise in accordance with the inflation and deployment of the airbag.   The valve body is accommodated so that the vent hole can be shifted to an open state in a state in which the folded state is released when the airbag is accommodated, or the vent hole is in a state in which the folded state is released. The airbag according to claim 1, wherein the airbag is accommodated so as to be held in a closed state. In an airbag apparatus 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,
The said airbag is an airbag in any one of Claims 1-6, The airbag apparatus characterized by the above-mentioned.