Airbag device

Abstract

To provide an airbag device which can suppress leakage of inflation gas from an exhaust hole when maintaining closing of the exhaust hole.SOLUTION: An airbag device includes: an airbag 25 which has an exhaust hole 34 which can discharge a part of inflation gas made to flow inside in opening; and a flap material 40 which can close the exhaust hole. The flap material has: a flap body 41 in which a root section 42 side is connected to a peripheral edge of the exhaust hole; and a connection member 47 which is configured to extend from a tip 43 side of the flap body and connect the tip side to an opening / closing control device. The flap body is arranged so that the exhaust hole can be closed from an inner peripheral surface side of the airbag, a width dimension on the root section side is set to be larger than an opening width dimension of the exhaust hole, and the root section side is connected to the peripheral edge of the exhaust hole in the airbag over substantially whole length. The flap body is configured to cover the exhaust hole in a region between straight lines L1, L2 for connecting both ends of a connection portion on the root section side and a portion for connecting the connection member on the tip side, respectively.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an airbag device including an airbag that is folded and stored in a storage area and that inflates so as to protrude from the storage area when inflation gas is introduced therein. [Background technology]

[0002] Conventionally, there has been an airbag device in which an exhaust hole capable of discharging a part of the inflation gas is provided in the airbag, and the opening and closing of the exhaust hole is controlled by an opening and closing control device according to the seating position and physique of the occupant seated in the seat, thereby controlling the internal pressure of the airbag when it is inflated (see, for example, Patent Document 1). In this airbag device, the exhaust hole provided in the airbag can be blocked by a flap material. Specifically, the flap material is configured to include a flap body made of a flexible sheet body, set in a substantially rectangular shape of a size capable of blocking the exhaust hole, and connected at its base to the periphery of the exhaust hole, and a connecting member extending from the flap body and connecting at its connecting end to an opening and closing control device arranged on the storage portion side. In the airbag device described in Patent Document 1, the flap body is arranged from the outer peripheral surface side of the airbag so as to be able to block the exhaust hole, and the connecting member is configured to extend from the flap body so as to connect at its base to an area that is substantially in the center of the flap body and covers the exhaust hole. The flap body was configured to maintain the exhaust hole in a blocked state when the airbag was inflated while maintaining the connection between the connecting member and the opening / closing control device, thereby suppressing the discharge of inflation gas from the exhaust hole. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2009-90965A Summary of the Invention [Problem to be solved by the invention]

[0004] In this conventional airbag device, when the airbag is inflated while maintaining the connection of the connecting member to the opening / closing control device, tension is applied to the flap body between the part where the connecting member is connected and both ends of the base side that are connected to the periphery of the exhaust hole, and this tension maintains the closing state of the exhaust hole by the flap body. However, in the conventional airbag device, the flap body is configured to be disposed on the outer peripheral surface side of the airbag, and the base side of the connecting member is connected to a position that is approximately the center of the flap body (a position that overlaps with the opening surface of the exhaust hole), so even with this configuration that exerts tension, there is a risk that the flap body will rise up due to the inflation gas that has flowed into the airbag, causing the inflation gas to leak from the exhaust hole.

[0005] SUMMARY OF THE PRESENT INVETION The present invention is devised to solve the above-mentioned problems, and has an object to provide an airbag device that is capable of suppressing leakage of inflation gas from the vent hole when the vent hole is kept closed. [Means for solving the problem]

[0006] The airbag device according to the present invention includes an airbag that is folded and stored in a storage area, and that is inflated so as to protrude from the storage area by introducing inflation gas into the airbag, and that has an exhaust hole that can discharge a portion of the inflation gas that has been introduced into the airbag when the airbag is opened; An opening / closing control device that is disposed on the storage portion side and is capable of controlling the opening and closing of the exhaust hole; A flap material capable of blocking the exhaust hole; The present invention is configured to include: The flap material is a flap body made of a flexible sheet body, set to a size capable of blocking the exhaust hole, and a base side of the flap body being joined to the periphery of the exhaust hole at a position closer to the outer periphery of the airbag than the exhaust hole; A connecting member extending from a tip side of the flap body facing the base portion and connecting a connecting end side of the extended tip to an opening / closing control device on the storage portion side; Equipped with An airbag device configured such that the flap body maintains a closed state of the exhaust hole when the airbag is inflated in a state in which the connection of the connecting member to the opening / closing control device is maintained, and opens the exhaust hole when the airbag is inflated in a state in which the connection of the connecting member to the opening / closing control device is released, The flap body is The outer shape is made substantially symmetrical with respect to a center line in the width direction along the longitudinal direction of the connecting member, and the connecting member is configured to extend from substantially the center in the width direction at the tip side, the connecting member is disposed so as to be able to close the exhaust hole from the inner peripheral surface side of the airbag, and the width dimension of the base side is set to be larger than the opening width dimension of the exhaust hole on the side in a direction substantially perpendicular to the longitudinal direction of the connecting member, and the base side is connected to the periphery of the exhaust hole in the airbag over substantially the entire length thereof, It is characterized in that it is configured to cover the exhaust hole in the area between the straight lines connecting both ends of the connecting portion on the base side and the portion connecting the connecting member on the tip side.

[0007] In the airbag device of the present invention, the flap body closes the exhaust hole from the inner peripheral side of the airbag, and the outer shape is configured to cover the exhaust hole in the area between the straight lines connecting both ends of the connecting portion on the base side that is connected to the periphery of the exhaust hole and the portion on the tip side where the connecting member is connected. In the airbag device of the present invention, when the airbag is inflated while the connection of the connecting member to the opening / closing control device is maintained, tension is generated in the flap body so as to extend substantially along the straight line, and the exhaust hole is covered on the inner peripheral side in the area between the tension generating portions in the flap body. Therefore, when the airbag is inflated while the connection to the opening / closing control device is maintained, tension is applied substantially along the straight line, and this tension presses the flap body in the area that is outward from the edge of the exhaust hole. Furthermore, the region between the tension generating portions in the flap body, i.e., the region covering the exhaust hole (middle portion), becomes slack due to the generation of tension substantially along the straight line, but since the flap body covers the exhaust hole from the inner peripheral surface side of the airbag, the flap body receives the internal pressure of the inflation gas flowing into the airbag, and this slackened middle portion becomes pressed against the periphery of the exhaust hole. Therefore, in the airbag device of the present invention, it is possible to accurately prevent the flap body from floating up from the airbag, and to prevent the inflation gas from leaking from the exhaust hole.

[0008] Therefore, in the airbag device of the present invention, leakage of inflation gas from the vent hole can be suppressed when the vent hole is maintained closed.

[0009] In addition, in the airbag device of the present invention, if the flap body has both edges facing each other in the width direction inclined so as to be approximately aligned with the straight lines connecting both ends of the joint part on the base side and the part connecting the joint member on the tip side, when the airbag is inflated while maintaining the connection with the opening / closing control device, tension is generated approximately along the edges facing each other in the width direction of the flap body. In other words, in the airbag device of the above configuration, the flap body is configured not to have a region that extends outward from the tension generating part. Therefore, it is possible to prevent the region extending outward from the tension generating part from floating up, and it is more difficult for a gap to be generated between the flap body and the periphery of the exhaust hole, which is preferable. In addition, the area (size) of the flap body can be made as small as possible, and the material for forming the flap body can be reduced.

[0010] Furthermore, in the airbag device having the above configuration, if the width dimension of the connecting member is set to be smaller than the opening width dimension of the exhaust hole in the direction approximately perpendicular to the longitudinal direction of the connecting member, when the airbag is inflated while maintaining the connection to the opening / closing control device, the tension generated in the flap body can be made to act more stably near the edge of the flap body, which is preferable.

[0011] Specifically, in the airbag device having the above-described configuration, if the exhaust hole is configured to have an opening shape that is approximately circular and the distance from the opening edge of the exhaust hole in the flap body to the edge is at least 3 mm, it is possible to stably block the exhaust hole by the flap body, which is preferable.

[0012] Furthermore, in the airbag device of the above configuration, if the exhaust hole is formed in a region of the airbag which is set to have a small curvature in the cross section at the time of complete inflation and is substantially planar, the exhaust hole and the flap body which blocks the exhaust hole from the inside will be disposed in a region which is substantially planar in the airbag at the time of complete inflation. This is preferable because it makes it possible to prevent a gap from occurring between the tension generating portion and the airbag when tension is applied to the flap body when the airbag is inflated while maintaining the connection between the connecting member and the opening / closing control device. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing an area where an airbag device for a steering wheel according to an embodiment of the present invention is mounted; [Diagram 2] 1 is a schematic plan view of a steering wheel equipped with an airbag device according to an embodiment; [Diagram 3] 2 is a schematic enlarged cross-sectional view of the airbag device according to the embodiment in the front-rear direction. FIG. [Figure 4] FIG. 2 is a bottom view of the airbag used in the airbag device of the embodiment in a flat deployed state. [Diagram 5] 5 is a vertical cross-sectional view of the airbag of FIG. 4, showing the VV area of ​​FIG. [Figure 6] FIG. 5 is a plan view showing a base fabric constituting the airbag of FIG. 4. [Figure 7] 5 is a schematic plan view showing the airbag and the flap material of FIG. 4 as viewed from the inner peripheral surface side of the airbag. [Figure 8] 1 is a schematic cross-sectional view showing a state in which the airbag has completed inflation with the flap material and the fastening member still connected to each other in the airbag device of the embodiment. FIG. [Figure 9] 10 is a partially enlarged cross-sectional view showing the vicinity of the vent hole and the flap material at the completion of inflation of the airbag in the airbag device of the embodiment, with the flap material and the fastening member kept connected to each other; FIG. [Figure 10]10 is a partially enlarged cross-sectional view showing the vicinity of the vent hole and the flap material at the completion of inflation of the airbag in the airbag device of the embodiment with the flap material and the fastening member released from their connected state; FIG. [Figure 11] 4 is a schematic partially enlarged cross-sectional view showing the state of the vent hole and the flap material when the airbag is inflated with the flap material and the fastening member kept connected in the airbag device according to the embodiment. FIG. [Figure 12] 1 is a schematic perspective view showing an inflated state of an airbag in an airbag device according to an embodiment, in a state in which the connected state between the flap material and the locking member is maintained, and in a state in which the connected state between the flap material and the locking member is released. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] An embodiment of the present invention will be described below with reference to the drawings. In the embodiment, an airbag device M mounted on a steering wheel W will be described as an example. As shown in Figs. 2, 3 and 8, the steering wheel W includes a steering wheel main body 1 and an airbag device M arranged on an upper part of a boss portion B in the center of the steering wheel main body 1. In the embodiment, the steering wheel main body 1 includes a ring portion R that is gripped when steering, a boss portion B that is arranged approximately in the center of the ring portion R and connected to the steering shaft SS, and a plurality of spoke portions (four in the embodiment) that connect the boss portion B and the ring portion R. In terms of components, the steering wheel W is composed of the airbag device M and the steering wheel main body 1.

[0015] In the embodiments, unless otherwise specified, the front-rear, up-down, and left-right directions are based on the steering wheel W mounted on the vehicle being steered straight ahead, and the up-down direction is the up-down direction along the axial direction of the steering shaft SS (see Figures 3 and 8) to which the steering wheel W is attached, the front-rear direction is the front-rear direction of the vehicle which is perpendicular to the axis of the steering shaft SS, and the left-right direction is the left-right direction of the vehicle which is perpendicular to the axis of the steering shaft SS.

[0016] The steering wheel body 1 comprises a core metal 2 made of a metal such as an aluminum alloy and arranged to connect each part such as the ring portion R and the boss portion B, a synthetic resin coating layer 3 which coats the core metal 2 in the areas of the ring portion R and the spoke portion S, and a synthetic resin lower cover 4 which covers the lower part of the boss portion B (see Figures 2, 3 and 8).

[0017] 2 and 3, the airbag device M includes an airbag 25, a flap material 40 capable of blocking an exhaust hole 34 (described later) formed in the airbag 25, an inflator 9 for supplying inflation gas to the airbag 25, a case 11 as a storage portion for storing and holding the folded airbag 25 and the inflator 9, an airbag cover 20 for covering the folded airbag 25, a retainer 7 for attaching the airbag 25 and the inflator 9 to the case 11, and a holding release means 15 as an opening / closing control mechanism for controlling the opening and closing of the exhaust hole 34 of the airbag 25. In the airbag device M of the embodiment, the inflator 9 and the holding release means 15 are configured to be controlled in operation by a control device 70 shown in FIG.

[0018] 1, the control device 70 is electrically connected to an occupant detection sensor capable of detecting the physique and seating position of the driver MD as an occupant seated in the seat (driver's seat) DS, for example, a position detection sensor 75 capable of detecting the distance between the steering wheel W and the driver MD, and a weight detection sensor 76 capable of detecting the weight of the driver MD, and is also electrically connected to a collision detection sensor 77 capable of detecting the acceleration and acceleration direction of the vehicle, and inputs electric signals from the position detection sensor 75, the weight detection sensor 76, or the collision detection sensor 77 to operate the inflator 9 and to operate the holding release means 15. In the embodiment, the holding release means 15 is controlled by the control device 70 to exhaust the inflation gas G that has flowed into the airbag 25 to the outside of the airbag 25 so as to control the increase in the internal pressure of the airbag 25 when the airbag 25 is inflated during the operation of the inflator 9, thereby inflating the airbag 25 in a suitable inflation mode.

[0019] 3, the inflator 9 includes a substantially cylindrical main body 9a having a plurality of gas discharge ports 9b, and a flange 9c for mounting the inflator 9 to the case 11. The flange 9c is formed with through holes (not shown) for passing bolts (not shown) of the retainer 7 through. The inflator 9 is electrically connected to the control device 70.

[0020] The case 11 as the storage portion is made of sheet metal and includes a bottom wall portion 12 in the shape of a substantially rectangular plate into which the inflator 9 is inserted from below and a peripheral wall portion 13 extending vertically from the outer periphery of the bottom wall portion 12, as shown in Fig. 3. In the bottom wall portion 12, a through hole 12a is formed in a region in front of an opening (reference numeral omitted) through which the main body portion 9a of the inflator 9 is inserted, through which a connecting end 48 side of a connecting belt 47 as a connecting means of the flap material 40 described later can be inserted. An attachment piece 13a extending outward is formed at the upper end of the peripheral wall portion 13 (see Fig. 2). The airbag device M of the embodiment is configured to be mounted on the upper part of the boss portion B of the steering wheel main body 1 already attached to the steering shaft SS by attaching and fixing the case 11 to the core metal 2 of the steering wheel W using an attachment board of a horn switch mechanism (not shown) attached to the attachment piece 13a. Also, a side wall 20c of the airbag cover 20 is attached to the peripheral wall 13 of the case 11 using rivets 21 or the like (see FIG. 3). In the case of this embodiment, the airbag 25 and the inflator 9 are attached to the bottom wall 12 of the case 11 by using a bolt (not shown) of the retainer 7 arranged in the airbag 25 as an attachment means, passing the bolt through the periphery of the inlet opening 29 of the airbag 25, the bottom wall 12 of the case 11, and the flange 9c of the inflator 9, and fastening it with a nut.

[0021] Further, at a portion on the lower side of the bottom wall portion 12 near the through hole 12a, a release means 15 is disposed as an opening / closing control device that connects the connecting end 48 of the connecting belt 47 of the flap material 40. The release means 15 is composed of a locking pin 16 inserted into a connecting hole 48a formed in the connecting end 48 of the connecting belt 47, and an actuator 17 fixed to the lower surface side of the bottom wall portion 12 and operable to retract the locking pin 16. When the actuator 17 operates to retract the locking pin 16, the locking pin 16 transitions from a state in which it locks the connecting end 48 of the connecting belt 47 to a state in which it releases the lock, thereby releasing the connected and held state of the connecting end 48. This actuator 17 is electrically connected to the control device 70, and as long as the locking pin 16 can be moved by an electric signal from the control device 70, a piston cylinder using hydraulic pressure, water pressure, air pressure, or fluid pressure including a case where an inflator generates expanding gas pressure, a motor using these fluid pressures or electricity, an electromagnetic solenoid, a spring using a biasing force at the time of restoration, or the like can be used. Note that, on the periphery of the through hole 12a on the lower surface of the bottom wall portion 12, on the edge side facing the actuator 17 (the rear edge side of the through hole 12a in the case of the embodiment), as shown in Fig. 3, a support base 12b is disposed to support the tip of the locking pin 16 of the retention release means 15 and prevent the connecting belt 47 from coming off the locking pin 16 when locked (maintaining the connected and held state of the connecting belt 47). In the embodiment, this retention release means 15 and the flap material 40 to which the connecting end 48 side of the connecting belt 47 is connected to the retention release means 15 constitute an internal pressure adjustment mechanism capable of adjusting the internal pressure when the airbag 25 is fully inflated.

[0022] The airbag cover 20 is made of synthetic resin and includes a ceiling wall portion 20a that covers the upper part of the airbag 25 stored in the case 11, and a substantially rectangular tubular side wall portion 20c that extends downward from near the outer periphery of the ceiling wall portion 20a. The ceiling wall portion 20a is formed with two doors 20b, 20b that are pushed by the inflating airbag 25 to open forward and backward.

[0023] As shown in Figs. 4 and 5, the airbag 25 in this embodiment includes a bag-shaped bag body 26 and a tether 38 that regulates the shape of the bag body 26 after it has been fully inflated.

[0024] The bag body 26 is configured so that it can cover the upper surface side of the steering wheel W over the entire surface when it is fully inflated, and has a substantially circular shape when viewed from above that can cover the entire ring portion R, and a substantially elliptical spherical shape when viewed from the side, as shown by the two-dot chain line in Figs. 1 and 2 and Fig. 8. As shown in Figs. 4 and 5, the bag body 26 includes a driver side wall portion 36 that is disposed on the driver MD side when it is fully inflated, and a vehicle body side wall portion 28 that is disposed on the steering wheel W (vehicle body) side, and is formed into a bag shape by connecting the outer peripheries 55a, 56a of the driver side panel 56 and the vehicle body side panel 55, which have substantially the same outer shape, to each other, as shown in Fig. 6. The driver side panel 56 and the vehicle body side panel 55 that constitute the bag body 26 are formed from flexible woven fabric made of polyamide yarn, polyester yarn, or the like.

[0025] In the bag body 26, an inflow opening 29 through which the inflation gas can flow is formed in a circular shape at approximately the center of the vehicle body side wall portion 28, as shown in Fig. 4. The main body portion 9a of the inflator 9 is inserted from below into this inflow opening 29, and four mounting holes 30 through which bolts (not shown) formed in the retainer 7 are inserted are formed on the periphery of the inflow opening 29. In addition, on the periphery of the inflow opening 29, on the front edge side of the inflow opening 29 in the case of the embodiment, an insertion hole 31 through which the connecting end 48 of the connecting belt 47 of the flap material 40 can be inserted is formed in the shape of a slit approximately along the left-right direction.

[0026] Further, the vehicle body side wall 28 of the bag body 26 is formed with a vent hole 33 for discharging excess inflation gas that has flowed into the inside. In the case of the embodiment, the vent hole 33 is formed in two positions that are substantially circular and symmetrical with respect to a line that passes through the center of the inlet opening 29 along the front-rear direction as a reference line CL1 (see FIG. 4). More specifically, the vent hole 33 is formed at a position on the inlet opening 29 side between the inlet opening 29 and the outer peripheral edge 28a (specifically, at a position about 1 / 3 from the inlet opening 29) on the vehicle body side wall 28 of the bag body 26 in a flatly deployed state. The vent hole 33 is disposed in an area that is more inward than the ring portion R when the airbag 25 (bag body 26) is fully inflated (see the two-dot chain line in FIG. 2 and FIGS. 9 and 12).

[0027] Further, in the bag body 26, an exhaust hole 34 that is opened and closed by a flap material 40 is formed in addition to the vent holes 33, 33 that are always open. The exhaust hole 34 is configured to have an opening shape that is approximately circular, and in the case of the embodiment, is disposed at a position between the vent holes 33, 33 and in front of the inflow opening 29 when the bag body 26 is in a flatly deployed state. In detail, the exhaust hole 34 and the vent holes 33, 33 disposed on both the left and right sides of the exhaust hole 34 are disposed so as to be approximately radially around the inflow opening 29. Similarly to the vent holes 33, 33, the exhaust hole 34 is also formed in a position on the inflow opening 29 side between the inflow opening 29 and the outer peripheral edge 28a in the vehicle body side wall portion 28 of the bag body 26 in a flatly deployed state (specifically, a position about 1 / 3 from the inflow opening 29). In the vehicle body side wall 28 of the bag body 26, the region in which the exhaust hole 34 is arranged is a portion that is located at a position that is more inward than the ring portion R when the bag body 26 is fully inflated (see the two-dot chain line in FIG. 2 and FIGS. 9 to 12). More specifically, as shown in FIGS. 9 and 10, the region is a portion that is set to have a small curvature in a cross section when the bag body 26 is fully inflated, and is substantially flat. In the embodiment, the exhaust hole 34 is set to have a larger opening area than each vent hole 33. Specifically, the inner diameter dimension d1 of the exhaust hole 34 is set to about 40 mm, and the inner diameter dimension d2 of each vent hole 33 is set to about 28 mm (see FIG. 4). That is, the inner diameter dimension d1 of the exhaust hole 34 is set to about 1.4 times the inner diameter dimension d2 of each vent hole 33. Incidentally, in the embodiment, the outer diameter dimension OD (see FIG. 4) of the bag body 26 when flatly deployed is set to about 650 mm. In the airbag 25 of this embodiment, the exhaust hole 34 and each vent hole 33 are reinforced at their peripheries by approximately annular reinforcing cloth pieces 62, 63, respectively.

[0028] The tether 38 that regulates the shape of the bag body 26 after inflation is completed is disposed so as to connect the periphery of the inflow opening 29 in the vehicle body side wall 28 with the vicinity of the center of the driver side wall 36, and regulates the distance between the vicinity of the center of the driver side wall 36 and the periphery of the inflow opening 29 when inflation is completed, and in this embodiment, is formed at two locations on both the left and right sides of the inflow opening 29. The tether 38 is composed of two tether substrates 58U and 58D as shown in FIG. 6. The tether substrates 58U, 58D are each configured to include an attachment side portion 59U, 59D that is joined to the vehicle body side wall portion 28 side and the driver side wall portion 36 side, and two tether constituent portions 60U, 60D that extend from the outer periphery of the attachment side portion 59U, 59D, and the tether 38 is formed by joining the ends of the corresponding tether constituent portions 60U, 60D to each other in a state in which the attachment side portions 59U, 59D are joined to the vehicle body side wall portion 28 side and the driver side wall portion 36 side. The tether substrates 58U, 58D that constitute the tether 38 are formed from flexible woven fabric made of polyamide yarn, polyester yarn, or the like, similar to the bag body 26.

[0029] The flap material 40 capable of blocking the exhaust hole 34 of the airbag 25 is disposed on the inner peripheral surface side of the airbag 25 (bag body 26) and includes a flap body 41 that blocks the exhaust hole 34 and a connecting belt 47 that serves as a connecting member extending from the flap body 41. In the case of the embodiment, the flap body 41 and the connecting belt 47 are integrally formed from a flexible sheet body as shown in Figs. 6 and 7. Specifically, the flap body 41 and the connecting belt 47 are formed from a flexible woven fabric made of polyamide yarn, polyester yarn, or the like, similar to the bag body 26 and the tether 38.

[0030] The flap body 41 is set to a size capable of blocking the exhaust hole 34 from the inner peripheral surface side of the bag body 26, and in the case of the embodiment, the outer shape is a substantially isosceles triangle having a widest width at a base 42 side connected to the peripheral edge of the exhaust hole 34 and a narrower width toward a tip 43 side. The base 42 side of the flap body 41 is connected to the peripheral edge of the exhaust hole 34 at a position closer to the outer peripheral edge 26a of the airbag 25 (bag body 26) than the exhaust hole 34, and specifically, when the bag body 26 is deployed flat, the center in the width direction (left-right direction) is aligned substantially with the center of the exhaust hole 34, and the edge 42a on the base 42 side is positioned substantially along the left-right direction, and the base 42 side is sewn to the front edge side of the exhaust hole 34 in the vehicle body side wall 28 over the entire left and right area with a sewing thread (see Figs. 4 and 7). That is, the flap body 41 has an outer shape that is approximately symmetrical with respect to a center line CL2 in the width direction (left-right direction) that is a direction along the front-rear direction (the longitudinal direction of a connecting belt 47 described later) (see FIG. 7), and is configured so that a tip 43 is positioned on this center line CL2. In the flap body 41, edges 41a, 41b that are arranged opposite each other on the width direction (left-right direction) side are formed to be symmetrical and inclined with respect to the front-rear direction.

[0031] In detail, the flap body 41 is configured such that the width dimension on the base 42 side is set larger than the inner diameter dimension of the exhaust hole 34 (the opening width dimension on the left-right side of the exhaust hole 34 (the side in the direction substantially perpendicular to the longitudinal direction of the connecting belt 47)) so that the exhaust hole 34 can be completely blocked, and the edges (edges 41a, 41b) on both sides facing each other on the width direction side (left-right side) are positioned to the left and right of the exhaust hole 34, and the tip 43 is positioned behind the exhaust hole 34. Specifically, the width dimension W1 on the base 42 side of the flap body 41 (the length dimension of the connecting portion 45, see FIG. 7) is set to about three times the inner diameter dimension d1 of the exhaust hole 34. Also, the inclination angle θ (see FIG. 7) of the edges 41a, 41b of the flap body 41 with respect to the left-right direction is set to about 60°. Furthermore, the flap body 41 is configured such that, when overlapped on the periphery of the exhaust hole 34 so as to close the exhaust hole 34, the separation distance D1 (overlap amount, see FIG. 7) from the opening edge 34a of the exhaust hole 34 to each edge portion 41a, 41b is at least 3 mm. In the case of the embodiment, the separation distance D1 (overlap amount) from the opening edge 34a of the exhaust hole 34 to each edge portion 41a, 41b is set to about 15 mm (about 3 / 8 of the inner diameter dimension d1 of the exhaust hole 34). In the embodiment, the separation distance D2 (see FIG. 7) from the opening edge 34a of the exhaust hole 34 to the joining portion 45 is also set to be approximately equal to the separation distance D1 from the opening edge 34a of the exhaust hole 34 to the edge portions 41a, 41b. Incidentally, in the flap body 41, it is desirable to set the separation distance D1 (overlap amount) from the opening edge 34a of the exhaust hole 34 to each edge 41a, 41b within the range of 10 mm to 20 mm. By setting it within this range, it is possible to prevent the flap body 41 from becoming unnecessarily large, and to enable the flap body 41 to stably block the exhaust hole 34.

[0032] That is, the flap main body 41 in the embodiment is configured to cover the exhaust hole 34 in the area between straight lines L1, L2 connecting the ends 45a, 45b which are the two ends of the connecting portion 45 on the base portion 42 side and the portion where the connecting belt 47 is connected on the tip 43 side (in the embodiment, the boundary portion 50 between the flap main body 41 and the connecting belt 47), and each edge portion 41a, 41b of the flap main body 41 is arranged approximately along these straight lines L1, L2 (see Figure 7).

[0033] In the embodiment, the connecting belt 47 as the connecting member is a belt-like body integrally formed with the flap body 41, and has a connecting end 48 extending from the tip 43 side of the flap body 41, which is the extended tip 47a, and a connecting hole 48a through which the locking pin 16 of the retention release means 15 as the opening / closing control device can be inserted and connected (see Figs. 4 and 6). The connecting belt 47 is configured so that the connecting end 48 protrudes outside the bag body 26 through an insertion hole 31 formed on the front edge side of the inflow opening 29 in the bag body 26. The connecting belt 47 has a width dimension W2 (see Fig. 7) set smaller than the inner diameter dimension d1 of the exhaust hole 34 (the opening width dimension on the left and right sides of the exhaust hole 34 (the sides in the direction substantially perpendicular to the longitudinal direction of the connecting belt 47)). Specifically, the width dimension W2 of the connecting belt 47 is set to about 3 / 8 of the inner diameter dimension d1 of the exhaust hole 34. In addition, the length dimension of the connecting belt 47 (more precisely, the distance between the boundary portion 50 and the connecting hole 48a) is set to a dimension that enables the bag body 26 to be expanded without hindrance when the bag body 26 is expanded while the connection with the retention release means 15 is maintained (while the exhaust hole 34 is maintained blocked by the flap body 41), and that enables tension T (see Figure 7) to be generated on straight lines L1, L2 that respectively connect the ends 45a, 45b of the connecting portion 45 on the base portion 42 side of the flap body 41 to the boundary portion 50 with the connecting belt 47 on the tip 43 side.

[0034] Next, the manufacture of the airbag 25 of the embodiment will be described. The base portion 42 side of the flap body 41 of the flap material 40 is sewn to the vehicle body side panel 55 in advance using a sewing thread so as to form the joining portion 45. In addition, the attachment side portion 59D of the tether substrate 58D is overlapped to the vehicle body side panel 55, and the portion that will become the periphery of the inflow opening 29 is sewn to the vehicle body side panel 55 using a sewing thread, and the inflow opening 29, the attachment hole 30, and the insertion hole 31 are formed by a hole punching process. The attachment side portion 59U of the tether substrate 58U is sewn to the driver side panel 56. Next, the vehicle body side panel 55 and the driver side panel 56 are overlapped in a flat developed state with the outer surface sides in contact with each other, and the outer peripheral edges 55a, 56a are sewn to each other using a sewing thread, whereby the bag-shaped bag body 26 in a state in which the flap material 40 is connected can be formed. The bag body 26 is inverted using the inflow opening 29 so as not to expose the seam to the outside, and then the ends of the tether constituent parts 60U, 60D are joined together to form the tether 38, thereby manufacturing the airbag 25.

[0035] The airbag 25 thus manufactured can be mounted on a vehicle as follows. First, the airbag 25 is folded so as to be stored in the case 11 with the retainer 7 disposed inside so that the bolts (not shown) protrude from the mounting holes 30. Although not shown in detail, the airbag 25 is folded from a flatly deployed state in which the vehicle body side wall portion 28 and the driver side wall portion 36 overlap each other to be stored in the case 11 so as to reduce the front-rear and left-right width dimensions. At this time, the flap material 40 is also folded together with the airbag 25 from a flatly deployed and disposed state inside the bag body 26 while the connecting end 48 on the tip end 47a side of the connecting belt 47 protrudes to the outside from the insertion hole 31. Then, the folded airbag 25 is stored in the case 11. At this time, the connecting end 48 of the connecting belt 47 protruding to the outside from the insertion hole 31 is caused to protrude from the through hole 12a of the bottom wall portion 12 of the case 11. The locking pin 16 of the retention release means 15 is inserted into the connection hole 48a formed in the connection end 48, and the tip side of the locking pin 16 is supported by the support base 12b, so that the connection end 48 of the connection belt 47 is locked to the retention release means 15. The main body 9a of the inflator 9 is inserted from below, and the inflator 9 and the airbag 25 are attached to the case 11 using bolts and nuts (not shown) protruding from the bottom wall 12. Furthermore, the airbag cover 20 is placed on the case 11, and the airbag cover 20 is attached to the case 11 using rivets 21 or the like, and a horn switch mechanism (not shown) is attached to the mounting piece 13a of the case 11, whereby the airbag device M can be assembled. This airbag device M can be mounted on a vehicle by using a mounting board (not shown) of the horn switch mechanism to the steering wheel main body 1 previously fastened to the steering shaft SS.

[0036] In the airbag device M of the embodiment, when inflation gas is discharged from the gas discharge port 9b of the inflator 9, the airbag 25 inflates by allowing the inflation gas to flow into the airbag 25, pushes open the door portions 20b, 20b of the airbag cover 20, protrudes from the case 11, and completes its inflation so as to cover almost the entire upper surface of the steering wheel W, as shown by the dashed double-dashed lines in Figures 1 and 2 and in Figure 8.

[0037] In the airbag device M of the embodiment, the flap body 41 closes the exhaust hole 34 from the inner peripheral surface side of the airbag 25, and has an outer shape configured to cover the exhaust hole 34 in a region between straight lines L1 and L2 connecting both ends 45a and 45b of the joint portion 45 on the base portion 42 side that is joined to the periphery of the exhaust hole 34 and a portion where the connecting belt 47 as a connecting member is connected on the tip end 43 side (in the embodiment, a boundary portion 50 between the flap body 41 and the connecting belt 47) (see FIG. 7). In the airbag device M of the embodiment, when the airbag 25 is inflated while maintaining the connection of the connecting belt 47 with the holding release means 15 as the opening / closing control device, a tension T is generated in the flap body 41 so as to be approximately along the straight lines L1 and L2, and the inner peripheral side of the exhaust hole 34 is covered in the region between the tension generating portions in the flap body 41. Therefore, when the airbag 25 is inflated while maintaining the connection with the holding release means 15, tension T acts generally along the straight lines L1 and L2, and this tension T presses the flap body 41 at a portion outside the opening edge 34a of the vent hole 34. Conversely, the region between the tension generating portions in the flap body 41, i.e., the region covering the vent hole 34 (middle region 44), becomes loose due to the generation of tension T generally along the straight lines L1 and L2 (see A in FIG. 11). However, since the flap body 41 covers the vent hole 34 from the inner peripheral surface side of the airbag 25, the middle region 44 in this loose state is pressed against the peripheral edge of the vent hole 34 under the internal pressure of the inflation gas G that has flowed into the airbag 25, as shown in B in FIG. Therefore, in the airbag device M of the embodiment, the flap body 41 can be appropriately prevented from floating up from the airbag 25, and leakage of the inflation gas G from the vent hole 34 can be suppressed.

[0038] Therefore, in the airbag device M of the embodiment, leakage of the inflation gas G from the vent hole 34 can be suppressed when the vent hole 34 is kept closed.

[0039] Specifically, in the airbag device M of the embodiment, the opening / closing control device that controls the opening and closing of the exhaust hole 34 is composed of a retention release means 15 that can retain or release the connection state of the connecting end 48 of the connecting belt 47, which serves as a connecting member in the flap material 40.

[0040] In the airbag device M of the embodiment, when the control device 70, which receives signals from the predetermined sensors 75, 76, 77, detects, for example, that a small driver MD1 is seated or that the driver MD is seated in a position close to the steering wheel W, it outputs an actuation signal to the actuator 17 of the retention release means 15 at substantially the same time as the inflator 9 is actuated so as to retract the locking pin 16, thereby releasing the retained state of the connecting end 48 of the connecting belt 47. Then, the airbag 25 is inflated in an opening mode such that the exhaust hole 34 is opened, as shown in Figs. 10 and 12B, The tip side of the flap body 41 and the connecting member 47 are exposed to the outside while being opened. From exhaust hole 34 、 Inflation is completed by exhausting the excess inflation gas G. Therefore, the airbag 25 exhausts the excess inflation gas G from the exhaust hole 34 and completes inflation in a state in which an increase in internal pressure is suppressed, so that the small driver MD1 or the driver MD seated close to the steering wheel W can be gently protected by the airbag 25, the internal pressure of which is set low, without applying more pressure than necessary.

[0041] Conversely, when the control device 70 detects, for example, that a large driver MD2 is seated or that the driver MD is seated at a position relatively far from the steering wheel W, the control device 70 does not output an activation signal to the actuator 17, and the airbag 25 is inflated in a closed mode in which the connection end 48 of the connecting belt 47 is held by the holding release means 15 and the exhaust hole 34 is closed by the flap body 41, and as shown in A of Figs. 8, 9, and 12, the airbag 25 completes inflation while the exhaust hole 34 is kept closed. Therefore, the airbag 25 completes inflation in a high internal pressure state that does not allow the inflation gas to be discharged from the exhaust hole 34, and therefore the large driver MD2 or the driver MD seated at a position relatively far from the steering wheel W can be protected by the airbag 25 inflated with sufficient internal pressure and with good cushioning without bottoming out.

[0042] In the airbag device M of the embodiment, the flap body 41 is inclined so that the edges 41a, 41b on both sides facing each other on the width direction side (left and right direction side) are approximately aligned with the straight lines L1, L2. That is, in the embodiment, when the airbag 25 is inflated while maintaining the connection with the holding release means 15, the tension T is generated approximately along the edges 41a, 41b facing each other on the width direction side of the flap body 41, and in other words, in the airbag device M of the embodiment, the flap body 41 is configured not to have a region that extends outward from the tension generation portion. Therefore, it is possible to prevent the region extending outward from the tension generation portion from lifting up, and it is even more difficult for a gap to be generated between the flap body 41 and the periphery of the exhaust hole 34. In addition, the area (size) of the flap body 41 can be made as small as possible, and the material for forming the flap body 41 can also be reduced. Of course, if such a point is not taken into consideration, the flap main body may be, for example, substantially rectangular in shape without inclining the edges facing each other in the width direction. In the embodiment, the flap main body 41 is joined to the vehicle body side wall 28 by the joining portion 45 formed at a position substantially coinciding with the ends of the edges 41a, 41b on the base 42 side, but the joining portion 45' may be formed at a position slightly shifted toward the base 42 side from the ends of the edges 41a, 41b as shown by the two-dot chain line in Fig. 7.

[0043] Furthermore, in the airbag device M of the embodiment, the width dimension W2 of the connecting belt 47 as the connecting member is set to be smaller than the opening width dimension (inner diameter dimension d1 of the exhaust hole 34 in the embodiment) in the direction side (left and right direction side) substantially perpendicular to the longitudinal direction of the connecting belt 47 in the exhaust hole 34. Therefore, when the airbag 25 is inflated while the connection with the retention release means 15 is retained, the tension T generated in the flap main body 41 can be applied more stably to the vicinity of the edge portions 41a, 41b of the flap main body 41. Of course, if such a point is not taken into consideration, a connecting member set to be wider than the opening width dimension of the exhaust hole may be used. Note that, in the airbag device M of the embodiment, the connecting belt 47 is configured as an integral part of the flap main body 41, but the connecting belt may be configured as a band-shaped body separate from the flap main body and sewn to the flap main body. Furthermore, the shape of the connecting member is not limited to a belt-like shape as in the embodiment. For example, the connecting member may be a string-like body having a loop portion at the tip side through which the locking pin of the holding release means can be inserted.

[0044] Furthermore, in the airbag device M of the embodiment, the exhaust hole 34 is configured to have an opening shape that is approximately circular, and the flap body 41 is configured so that the separation distance D1 from the opening edge 34a of the exhaust hole 34 to the edges 41a, 41b is at least 3 mm, thereby making it possible to stably block the exhaust hole 34 by the flap body 41.

[0045] Furthermore, in the airbag device M of the embodiment, the exhaust hole 34 is formed in a region of the airbag 25 that is set to have a small curvature in a cross section at the time of complete inflation and is generally planar. Specifically, the airbag device M of the embodiment is for a steering wheel, and the exhaust hole 34 is formed in a region of the vehicle body side wall 28 of the bag main body 26 that is located at a position more inward than the ring portion R of the steering wheel W at the time of complete inflation. The region located at a position more inward than the ring portion R of the vehicle body side wall 28 is located generally planar in the bag main body 26 at the time of complete inflation (see FIGS. 9 and 10). Therefore, in the airbag device M of the embodiment, the exhaust hole 34 and the flap body 41 that blocks the exhaust hole 34 from the inside are disposed in a region that is disposed in a substantially flat shape in the vehicle body side wall 28 of the airbag 25 (bag body 26) at the time of complete inflation, and when the airbag 25 is inflated while maintaining (holding) the connection of the connecting belt 47 with the retention release means 15, when tension T is applied to the vicinity of the edges 41a, 41b of the flap body 41, it is possible to suppress the occurrence of a gap between the tension generating portion (the portion on the edge portions 41a, 41b side) and the vehicle body side wall 28. If such a point is not taken into consideration, the exhaust hole may be disposed in a region of the airbag where the curvature in the cross section at the time of complete inflation is set to be large, which in the case of the embodiment is a region on the outer circumferential edge side that is located on the outer circumferential side of the ring portion R. When the exhaust hole is disposed in such a position, it is true that the airbag inflates in such a way that the peripheral area of ​​the exhaust hole is significantly bent in the cross-sectional shape, which makes it easy for a gap to form between the area on the edge side of the flap body that generates tension (which will be arranged in a substantially straight line in cross section) and the peripheral area of ​​the exhaust hole. However, because the flap body is configured to cover the exhaust hole from the inner surface side of the airbag, the internal pressure of the inflation gas flowing into the airbag causes it to be pressed against the peripheral area of ​​the exhaust hole, and gas leakage from the exhaust hole can be stably suppressed.

[0046] In the airbag device M of the embodiment, the airbag 25 is configured to have two vent holes 33, 33 that are always open in addition to the exhaust hole 34, but the presence or absence of vent holes that are always open is not particularly limited, and the presence or absence, size, number, etc. of the vent holes can be appropriately changed depending on the protection mode of the occupant. Also, in the embodiment, the airbag device M for the steering wheel is taken as an example for explanation, but the airbag device to which the present invention can be applied is of course not limited to the steering wheel, and the present invention may be applied to, for example, an airbag device for the passenger seat. [Explanation of symbols]

[0047] 9...inflator, 11...case (storage portion), 15...retention release means (opening / closing control device), 20...airbag cover, 25...airbag, 26...bag body, 28...vehicle body side wall portion, 34...exhaust hole, 34a...opening edge, 40...flap material, 41...flap body, 41a, 41b...edge portion, 42...base portion, 43...tip, 44...middle portion, 45...connecting portion, 45a, 45b...end portion, 47...connecting belt (connecting member), 47a...tip, 48...connecting end, 48a...connecting hole, 70...control device, G...inflating gas, W...steering wheel, M...airbag device.

Claims

1. an airbag that is folded and stored in a storage area, that is inflated by introducing inflation gas into the airbag so as to protrude from the storage area, and that has an exhaust hole that can discharge a portion of the inflation gas introduced into the airbag when the airbag is opened; an opening / closing control device that is disposed on the storage portion side and is capable of controlling the opening and closing of the exhaust hole; A flap material capable of blocking the exhaust hole; The present invention is configured to include: The flap material is a flap body made of a flexible sheet body, set to a size capable of blocking the exhaust hole, and a base side of the flap body being joined to the periphery of the exhaust hole at a position closer to the outer periphery of the airbag than the exhaust hole; A connecting member extending from a tip side of the flap body facing the base portion and connecting a connecting end side of the extended tip to the opening / closing control device on the storage portion side; Equipped with an airbag device configured such that the flap body maintains the exhaust hole in a closed state when the airbag is inflated with the connection member maintained in connection with the opening / closing control device, and opens the exhaust hole when the airbag is inflated with the connection member released from the opening / closing control device, The flap body is The outer shape is generally symmetrical with respect to a center line in a width direction along the longitudinal direction of the connecting member, and the connecting member is configured to extend from approximately the center in the width direction at the tip side, a connecting member that is disposed so as to be able to close the exhaust hole from an inner peripheral surface side of the airbag, and that has a width dimension on a base side set larger than an opening width dimension on a side of the exhaust hole in a direction substantially perpendicular to a longitudinal direction of the connecting member, and that is connected to a periphery of the exhaust hole in the airbag over substantially the entire length of the base side, The exhaust hole is covered in an area between straight lines connecting both ends of the connecting portion on the base side and a portion connecting the connecting member on the tip side, an airbag device characterized in that, when the airbag is inflated with the connecting member disconnected from the opening / closing control device, the tip side of the flap body and the connecting member are released from the exhaust hole to the outside of the airbag.

2. The airbag device according to claim 1, characterized in that the flap body is configured such that the opposite edges on both sides in the width direction are inclined so as to be approximately aligned with straight lines connecting both ends of the joining portion on the base side and the portion on the tip side where the connecting member is connected.

3. 3. The airbag device according to claim 2, wherein the connecting member has a width dimension set smaller than an opening width dimension of the vent hole on a side in a direction substantially perpendicular to the longitudinal direction of the connecting member.

4. The exhaust hole has an opening shape that is substantially circular, 4. The airbag device according to claim 2, wherein the flap body is configured such that a distance from an opening edge of the exhaust hole to the edge portion is at least 3 mm.

5. 5. The airbag device according to claim 1, wherein the exhaust hole is formed in a region of the airbag that is set to have a small curvature in a cross section at the time of complete inflation and is generally planar.

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