JP4569310B2 - Knee airbag device for vehicle - Google Patents

Description

  The present invention relates to a knee airbag device for a vehicle that is interposed between an instrument panel and an occupant's knee during a frontal collision.

  Conventionally, various knee airbag devices for vehicles have been proposed for the purpose of protecting the occupant's knee (see the following patent documents and the like).

  For example, in Patent Document 1, a long mounting bracket having a longitudinal direction in the vehicle width direction is hung between a front pillar and a center bracket, each having a longitudinal direction in the vehicle vertical direction, in the instrument panel. A vehicle knee airbag device in which a knee airbag module storing a knee airbag is attached to and supported by the mounting bracket is disclosed.

According to the above configuration, when the front collision occurs, the folded knee airbag is inflated, and the under cover lid provided on the lower side of the steering column cover in the instrument panel is deployed. As a result, the knee airbag is deployed along the steering column cover and is interposed between the instrument panel and the occupant's knee. And the deployment reaction force of the knee airbag at this time is reliably supported by the mounting bracket, thereby preventing the deployment direction of the knee airbag from deviating.
JP 09-123857 A JP 09-123862 A JP 2004-330959 A

  However, according to the above prior art, there is room for improvement in the following points.

  That is, in general, since the occupant seated in the front seat is inertially moved to the front side of the vehicle at the time of a frontal collision, the distance between the occupant's knees and the instrument panel is narrower than in the seated state. Therefore, in the above prior art in which the knee airbag is deployed so as to rise from bottom to top along the steering column cover, there is a possibility that the knee airbag may come into contact with the shin portion before covering the kneecap of the occupant. In the frontal collision, the request to effectively protect the occupant's knees and thighs seated in the front seat has not been fully met.

  In view of the above facts, an object of the present invention is to provide a vehicle knee airbag device that can effectively protect the occupant's knees to thighs seated in the front seat during a frontal collision.

The knee airbag device for a vehicle according to the first aspect of the present invention includes a frontal collision detection means for detecting a frontal collision of the vehicle and a gas that operates when a frontal collision of the vehicle is detected by the frontal collision detection means. An inflator that blows out, a knee airbag that is deployed and inflated by gas ejected from the inflator, and a module case that is disposed in the instrument panel and stores the knee airbag in a folded state. A knee airbag device for a vehicle in which a knee airbag is interposed between an instrument panel and an occupant's knee at the time of a collision, and the knee airbag has an originally flattened shape and is a seated occupant a first expansion unit which initially developed as pushed out to the indoor rearward toward a position corresponding to between the knees, on the side of the first expansion portion Is configured to include a second expansion unit which secondary expansion toward the vehicle transverse direction outer side after the first communicates with the inflatable portion mutually and initial deployment of the first expansion unit with the location, the and the The knee airbag is partitioned into a central air chamber constituting the first inflating portion and a left and right air chamber constituting the second inflating portion by a partition provided in the vehicle up-down direction in the knee air bag, and the whole As shown in the figure, the partition is formed in the vehicle width direction, and a communication portion is provided in the partition or in the vicinity thereof to connect the adjacent air chambers to each other. Further, the gas from the inflator is supplied to the central air chamber. It is characterized by being ejected .

  According to a second aspect of the present invention, in the knee airbag device for a vehicle according to the first aspect of the present invention, in the first aspect, the knee airbag secondarily deploys outward in the vehicle width direction and simultaneously deploys downward in the vehicle. It is characterized by that.

  According to the first aspect of the present invention, when a frontal collision occurs, the seated occupant moves inertially toward the front side of the vehicle. For this reason, a passenger | crew's knee will approach relatively with respect to the instrument panel of a vehicle.

Here, in the present invention, the knee airbag is configured to include the first inflating portion and the second inflating portion, and in the initial stage of the frontal collision , the gas from the inflator first configures the first inflating portion. The first expansion portion is initially deployed by being ejected into the central air chamber. At this time, the first inflatable portion is initially deployed so as to protrude toward the rear side of the room toward a position corresponding to between the knees of the seated occupant. Therefore, the first inflating portion can be quickly interposed between the occupant's knees and the instrument panel as compared with the configuration in which the entire knee airbag is deployed from the beginning. In addition, since the initial deployment direction is the rear side of the room toward the position corresponding to between the knees of the seated occupant, that is, the first inflating portion toward the rear side of the vehicle with respect to the knee of the occupant moving inertially toward the front side of the vehicle Therefore, the first inflating portion can be quickly interposed between the knees of the occupant and the instrument panel as compared with the configuration in which the initial deployment direction is the vehicle upper side or the vehicle lower side.

Then, after the initial expansion of the first expansion portion, the second expansion portion that is disposed on the side of the first expansion portion and communicates with the first expansion portion is secondarily expanded outward in the vehicle width direction. . Specifically, the gas in the central air chamber is introduced into the left and right air chambers that are formed at both ends of the central air chamber and constitute the second inflating portion, and the second inflating portion is secondarily expanded. . As a result, both knees of the occupant are substantially covered (note that the knee airbag according to the present invention has a flat original deployment shape, and therefore, when the second inflating portion is deployed outward in the vehicle width direction, The narrow gap between the knee and the instrument panel is quickly deployed.) Therefore, the occupant's kneecaps do not come into direct contact with the instrument panel, and the occupant's knees are gently received by the knee airbag. It is done.

That is, according to the present invention, the knee airbag is quickly interposed between the occupant's knee and the instrument panel by the first inflating portion that is initially deployed rearwardly in the interior, and then secondarily deployed outward in the vehicle width direction. The occupant's knees can be substantially covered and gently received by the second inflating portion.
Furthermore, in the present invention, the air chamber constituting the first inflating portion and the air chamber constituting the second inflating portion can be formed by setting the partition in the vehicle up-down direction in the knee airbag. It is possible to arbitrarily tune the deployment speed of the first and second inflatable parts and the protection range (area) for the occupant's knee by appropriately changing the position and size (range) to be set and the area of the communicating part. it can.

  According to the second aspect of the present invention, the knee airbag is deployed to the vehicle lower side at the same time as the secondary deployment to the outer side in the vehicle width direction. Therefore, the knee airbag is moved from the upper side to the lower side of the passenger's kneecap. Will be extended.

As described above, the knee airbag device for a vehicle according to the first aspect of the present invention is such that the original deployed shape is a flat shape, and the interior of the vehicle is directed toward a position corresponding to between the knees of a seated occupant. A first inflatable portion that is initially deployed so as to protrude toward the rear side, and a vehicle that is disposed on a side of the first inflatable portion and communicates with the first inflatable portion and after the first inflated portion is initially deployed. Since the knee airbag is configured to include the second inflating portion that is secondarily deployed outward in the width direction, the first inflating portion that is initially deployed toward the rear side of the cabin is provided between the occupant's knee and the instrument panel. The second inflatable part that quickly interposes the knee airbag and then secondarily deploys outward in the width direction of the vehicle can cover the occupants' knees and gently receive them. Effective from knee to thigh It has an excellent effect that it is possible to protect.
Furthermore, in the knee airbag device for a vehicle according to the first aspect of the present invention, the knee airbag includes a central air bag that forms the first inflating portion with a partition provided in the knee airbag in the vehicle vertical direction. A communication portion that is partitioned into a chamber and a left and right side air chamber that constitutes the second inflating portion and is formed long in the vehicle width direction as a whole, and communicates between adjacent air chambers in the partition or in the vicinity thereof In addition, since the gas from the inflator is jetted into the central air chamber, the deployment speed of the first and second inflatable parts and the protection range (area) for the occupant's knee are arbitrary. As a result, it has an excellent effect that the protection performance of the occupant legs can be easily adjusted.

  According to a second aspect of the present invention, there is provided a knee airbag device for a vehicle according to the first aspect of the present invention, wherein the knee airbag is secondarily deployed outward in the vehicle width direction and simultaneously deployed to the vehicle lower side. As a result, the knee airbag extends from the upper side to the lower side of the occupant's kneecap. As a result, even if the kneecap is in the vicinity of the knee airbag deployment opening, It has the outstanding effect that it can prevent pushing hard to the vehicle rear side.

[First Embodiment]
Hereinafter, a first embodiment of a vehicle knee airbag device according to the present invention will be described with reference to FIGS. In these drawings, an arrow FR appropriately shown indicates the vehicle front side, an arrow UP indicates the vehicle upper side, and an arrow OUT indicates the vehicle width direction outer side.

  FIG. 1 is an external perspective view showing the overall configuration of a vehicle knee airbag device 10 according to the present embodiment as viewed from the vehicle interior side. FIG. 2 is an external perspective view showing the overall configuration of the vehicle knee airbag device 10 on the driver's seat side as viewed obliquely from the rear outside the vehicle.

  As shown in these drawings, a knee airbag device 10 for a vehicle is disposed on the lower back side of the instrument panel 12 of the vehicle corresponding to the driver seat 14 and the passenger seat 16. The vehicle knee airbag device 10 for the driver's seat 14 is disposed on the lower side of the steering column cover 18 in the instrument panel 12, and the vehicle knee airbag device 10 for the passenger seat 16 includes the glove box 20. (See FIG. 2).

  FIG. 3 is an exploded perspective view of the vehicle knee airbag device 10. FIG. 4 shows the process of operation of the vehicle knee airbag device 10. As shown in these drawings, the vehicle knee airbag device 10 includes a cylindrical module case 22 whose both ends are closed. The module case 22 is disposed on the lower back side of the instrument panel 12 with the vehicle width direction as the longitudinal direction, and is arranged along the vehicle width direction in the instrument panel 12 and is an instrument panel reinforcement (not shown) that is a high-strength member. (A member indicated by reference numeral 82 in FIG. 9 of the second embodiment) via a mounting bracket (not shown).

  A slit-like opening 24 is formed on the rear surface side of the peripheral wall portion of the module case 22. The module case 22 is assembled so that the opening 24 faces substantially the vehicle lower side. Furthermore, a circular connection hole 28 for connecting the inflator 26 is formed on the front side of the peripheral wall portion of the module case 22. A small diameter portion 26A of the inflator 26 formed in a substantially cylindrical shape in the connection hole 28 is inserted from the direction perpendicular to the axis (the vehicle front side) and fixed to the peripheral wall portion of the module case 22. Accordingly, when the module case 22 and the inflator 26 are viewed in plan view, they are arranged in a substantially T shape.

  The inflator 26 is electrically connected to a controller 32 as a frontal collision detection means installed in an area where the vehicle body is not deformed at the time of a frontal collision, such as the lower part of the center console 30 (see FIGS. 1 and 2). . The controller 32 is connected to an airbag sensor (not shown) that is disposed at a predetermined position in the front of the vehicle and detects a frontal collision of the vehicle, and whether or not a frontal collision has occurred based on an electrical signal input from the airbag sensor. If it is determined that a frontal collision has occurred, a predetermined current is supplied to the inflator 26. The inflator 26 may be either a high-pressure gas-filled type or a gas generating agent-filled type. However, the inflator 26 is activated when a predetermined current is supplied from the controller 32 and jets gas from the gas outlet 34 of the tip small-diameter portion 26A. It has become.

  In the module case 22, a knee airbag 36 that is expanded and inflated by the gas ejected from the gas ejection port 34 of the inflator 26 is stored in a folded state. The knee airbag 36 includes two fabrics (base fabrics) 38 and 40 that are cut into a substantially rectangular shape whose dimension in the vehicle width direction is longer than the width of the opening 24 formed in the module case 22. These two fabrics 38 and 40 are overlapped and stitched at the periphery to form a bag shape. In FIG. 3, sutures are drawn on the peripheral portions of the fabrics 38 and 40 by broken lines.

  A convex bonding margin 42 is provided at the center of the upper edge of the knee airbag 36, and a rectangular non-sewn portion 44 that is not sewn is formed at the center of the bonding margin 42. The bonding allowance 42 is bonded so that the non-sewn portion 44 of the two fabrics 38 and 40 covers the connecting hole 28 for connecting the inflator described above in the module case 22. Further, a pair of vent holes 46 are formed near the center of the fabric 40 located on the back side (the vehicle front side), and a thin film 48 that is broken when a certain pressure is exceeded is attached to the vent holes 46. Yes.

  Further, as shown in FIGS. 3 and 4, three air bubbles 36 are formed in the knee airbag 36 on both sides (near the outside of the vent hole 46) of the two fabrics 38, 40 of the knee airbag 36 described above. A pair of partitions 50 and 52 for partitioning into chambers are provided substantially in parallel. The partitions 50 and 52 are formed in a narrow band shape, and the front end edge thereof is sewn to the fabric 38 constituting the front surface of the bag, and the rear end edge is sewn to the fabric 40 constituting the rear surface of the bag. As a result, the knee airbag 36 is disposed adjacent to the outer side in the vehicle width direction of the first inflating portion 54 and the first inflating portion 54 that is disposed in the central portion and communicates directly with the gas outlet 34 of the inflator 26. And a pair of left and right second inflating portions 56.

  The setting range of the partitions 50 and 52 is, for example, about the lower half of the knee airbag 36. Accordingly, the first inflating portion 54 and the second second portion of the knee airbag 36 are provided in a portion where the partitions 50 and 52 do not exist. Communication ports 58 and 60 are formed as communication portions that allow the expansion portion 56 to communicate with each other. Further, the width of the first inflating portion 54 substantially matches the opening width of the opening 24 of the module case 22 and is stored in the module case 22 so that the whole is folded before unfolding.

(Operation and effect of this embodiment)
Next, the operation and effect of this embodiment will be described.

  When a frontal collision occurs, the seated passenger moves inertially toward the front side of the vehicle. For this reason, a passenger | crew's knee will approach relatively with respect to the instrument panel 12 of a vehicle, and the clearance gap 62 (refer FIG. 5 (A)) with the instrument panel 12 narrows.

On the other hand, when a frontal collision occurs, a frontal collision is detected by an airbag sensor (not shown), and a collision signal is output to the controller 32. The controller 32 determines whether or not a frontal collision has occurred based on the input collision signal. If it is determined that a frontal collision has occurred, a predetermined current is supplied to the inflator 26. As a result, the inflator 26 is actuated, and the high-pressure gas is ejected into the folded knee airbag 36.

  More specifically, in the state where the knee airbag 36 is stored in the module case 22, the first inflating portion 54 and the second inflating portion 56 are partitioned by the left and right partitions 50, 52, so that the high pressure gas First, the gas flows into the first inflating portion 54 that is in direct communication with the gas outlet 34 of the inflator 26. As shown in FIGS. 5A and 5B, the gas hits the inner wall of the first inflatable portion 54, and the first inflatable portion 54 passes through the opening 24 of the module case 22 in both knees of the seated occupant. The initial deployment is performed so as to protrude toward the rear side of the room toward a position corresponding to the interval. At this time, the knee airbag 36 is in the state shown in FIG. 4A, and since the partitions 50 and 52 are present in the first inflating portion 54 bulged from the opening 24, the left and right second airbags 36 are present. The expansion part 56 does not spread outward in the vehicle width direction, and does not hinder the expansion of the first expansion part 54 from the opening 24.

  Subsequently, when the first inflating part 54 passes through the opening 24 of the module case 22 to some extent, the knee airbag 36 enters the state of FIG. 4B, and the gas ejected from the inflator 26 exceeds the partitions 50 and 52. It flows into the left and right second expansion portions 56 from the communication ports 58 and 60. For this reason, as shown in FIGS. 6A and 6B, the left and right second inflating portions 56 are secondarily expanded outward in the vehicle width direction. Simultaneously with the secondary deployment of the second inflating portion 56, the entire knee airbag 36 is deployed to the vehicle lower side. Finally, the knee airbag 36 is deployed to the state shown in FIG. 4C, so that the flat, substantially rectangular knee airbag 36 that is long in the vehicle width direction has a portion extending from the knee to the shin of the occupant and the instrument. It is interposed in the gap 62 with the ment panel 12. As a result, as shown in FIGS. 7A and 7B, both the knees and shins of the occupant who has moved inertially to the front side of the vehicle due to the frontal collision are gently received.

  When the knee airbag 36 is completely deployed, the thin film 48 of the vent hole 46 provided on the back side is broken by the increase of the bag internal pressure, and the gas is gradually discharged, so that the bag internal pressure is lowered.

  As described above, in the vehicle knee airbag device 10 according to the present embodiment, the knee airbag 36 is divided into the three chambers of the first inflatable portion 54 and the left and right second inflatable portions 56, and the first inflatable portion 54 is provided at the time of a frontal collision. Since it is configured to initially deploy toward the rear side of the room toward a position corresponding to between the knees of a seated occupant, the left and right second inflatable portions 56 are then deployed outward in the vehicle width direction. The first inflatable portion 54 can be quickly interposed in the gap 62 between the occupant's knees and the instrument panel 12 as compared with the configuration in which the whole is expanded. In other words, even if the distance (gap 62) between the occupant's knees and the instrument panel 12 is reduced due to the inertial movement of the occupant, the first inflatable portion 54 of the knee airbag 36 is securely connected to the occupant's knees and the instrument. It can be interposed between the panel 12.

  Further, since the initial deployment direction of the first inflating portion 54 of the knee airbag 36 is set on the rear side in the room toward the position corresponding to between the knees of the seated occupant, that is, it moves inertially toward the front side of the vehicle. In order to initially deploy the first inflatable portion 54 to the vehicle rear side substantially with respect to the occupant's knee, both the knees of the occupant and the instrument are compared to the configuration in which the initial deployment direction of the knee airbag is the vehicle upper side or the vehicle lower side. The first inflatable portion 54 can be quickly interposed in the gap 62 with the ment panel 12.

  Further, after the initial expansion of the first expansion portion 54, the second expansion portion 56 disposed adjacent to both sides of the first expansion portion 54 is secondarily expanded outward in the vehicle width direction. The occupant's knees are quickly and substantially covered by the portion 56. Accordingly, the occupant's kneecap does not directly contact the instrument panel 12, and both the occupant's knees are gently received by the knee airbag 36.

  As described above, according to the present embodiment, it is possible to effectively protect the occupant's knees to thighs seated in the front seat at the time of a frontal collision. In addition, if the occupant inertially moves to the front side of the vehicle during a frontal collision, the load flow at that time flows from the waist through the thigh to the knee. Can effectively protect the thigh.

  In particular, as shown in FIGS. 8A and 8B, the occupant seated in the driver's seat 14 has a relatively small physique, and the seat position of the driver's seat 14 has been shifted to the front side of the vehicle in advance or moved forward. The distance between the knee and the instrument panel 12 (gap 62) becomes narrower from the beginning, but in such a case, by using the vehicle knee airbag device 10 configured as described above, The following effects can be obtained.

  That is, since the first inflating part 54 of the knee airbag 36 is slightly deployed between the knees of the occupant at the initial stage of the frontal collision, the second inflating part 56 spreads outward in the vehicle width direction. Even if it is close to the instrument panel 12, the kneecap is moved outwardly in the vehicle width direction (in the direction of arrow A in FIG. 8B) so that the crotch is slightly opened without strongly pushing the kneecap or shin portion toward the vehicle rear side. It acts to push out (release the kneecap outward in the vehicle width direction). When the kneecap is displaced (rotated) outward in the vehicle width direction, a gap is formed between the kneecap and the instrument panel 12 (the gap 62 is widened), so that the second inflating portion 56 is secondarily extended outward in the vehicle width direction without difficulty. The knee airbag 36 can be substantially covered with the knees when deployed.

  Supplementally, from an image point of view, the first inflatable portion 54 interrupts both occupants' knees in the state of FIG. 4A, and the second inflatable portion 56 inflated slightly in the state of FIG. 4B. The knees of the occupant are slightly opened, and the knee airbag 36 that is completely inflated in the state of FIG.

  That is, when the vehicle knee airbag device 10 according to this embodiment is used, the occupant sits forward with respect to the instrument panel 12 without using a special algorithm or the like, and both knees and the instrument panel 12 are seated. Even when the gap 62 is originally narrow, the occupant's knees are slightly opened by initial deployment of the first inflating portion 54 to form a gap between the knee and the instrument panel 12 (the gap 62 is Since the second inflatable portion 56 can be deployed in the gap 62, the knee airbag 36 can be reliably interposed between the occupant's knee and the instrument panel 12.

  Here, the case where a small occupant is seated has been described as an example, but even if the physique is not small, the distance between the seated occupant's knee and the instrument panel 12 is small due to the relationship with the seat position, etc. In some cases the same applies.

  In the vehicle knee airbag device 10 according to the present embodiment, the second inflating portion 56 of the knee airbag 36 is secondarily deployed outward in the vehicle width direction, and at the same time, the first inflating portion 54 of the knee airbag 36 is used. And since the 2nd expansion part 56 is united and expand | deploys also to the vehicle downward side, the knee airbag 36 will extend from the upper side of a passenger | crew's kneecap to the downward side. As a result, according to the present embodiment, even if the kneecap is in the vicinity of the deployment opening of the knee airbag 36, the knee airbag 36 can be prevented from pushing the shin toward the vehicle rear side.

  Furthermore, in the vehicle knee airbag device 10 according to the present embodiment, by setting two partitions 50 and 52 in the knee airbag 36, the air chamber and the second inflation portion 56 that constitute the first inflation portion 54. Therefore, the position and size (range) for setting the partitions 50 and 52 and the area of the communication ports 58 and 60 are appropriately changed, so that the first inflating portion 54 and the second inflating chamber 54 can be formed. The deployment speed of the inflatable portion 56 and the protection range (area) of the occupant's knee can be arbitrarily tuned. As a result, according to the present embodiment, the protection performance of the occupant legs can be easily adjusted.

  Further, in the vehicle knee airbag device 10 according to the present embodiment, the inflator 26 is disposed substantially at the upper end portion of the knee airbag 36, and the opening 24 of the module case 22 that houses the knee airbag 36 is located below. Since the module case 22 is disposed so as to face the side, the gas ejection direction from the inflator 26 and the bulging direction of the first inflating portion 54 of the knee airbag 36 substantially coincide. For this reason, it is possible to initially deploy the first inflating portion 54 between the knees of the occupant by making maximum use of the kinetic energy of the gas ejected from the inflator 26. Therefore, the initial deployment time of the first inflating part 54 can be shortened.

  In the first embodiment described above, the communication ports 58 and 60 are provided by lowering the positions of the upper ends of the two partitions 50 and 52. However, the present invention is not limited to this, and the two partitions are made of the fabrics 38 and 40. A configuration may be adopted in which the communication portion is secured by extending to the upper edge of the partition and providing an opening in the partition itself.

[Second Embodiment]
Hereinafter, the second embodiment will be described with reference to FIGS. 9 to 11. The second embodiment is a reference example. Further, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in these drawings, the vehicle knee airbag device 70 according to the present embodiment has a main feature in the configuration of the knee airbag 72.

  More specifically, as shown in FIGS. 10 and 11, the knee airbag 72 stitches the peripheral portions of the two fabrics 74 and 76 that are cut into a substantially rectangular shape that is long in the vehicle width direction as a whole. There are no separate parts such as the partitions 50 and 52 used in the first embodiment and the strap 94 described in the third embodiment to be described later.

  A rectangular intake port 78 is formed in the upper half of the fabric 76 constituting the bag front surface at a position slightly offset to the right side from the left and right center. Corresponding to this, the module case 22 is also arranged vertically on the lower back side of the instrument panel 12. A connection hole 28 is formed on the back side of the module case 22 to which the small diameter portion 26A of the inflator 26 is connected. The peripheral edge of the air inlet 78 is bonded to the inner surface of the module case 22 so as to surround the connection hole 28. It is fixed.

  In the vicinity of the steering column cover 18 in the instrument panel 12, the module case 22 is arranged via a mounting bracket 80 such that the longitudinal direction is substantially the vehicle vertical direction (diagonal direction) and the opening 24 faces downward. It is fixed to the instrument panel reinforcement 82. The instrument panel reinforcement 82 is a high-strength member such as a pipe disposed with the vehicle width direction as a longitudinal direction.

  Furthermore, the knee airbag 72 has its longitudinal ends 72B (corresponding to the second inflating part) folded back to the back side of the substantially central part 72A (corresponding to the first inflating part) in the longitudinal direction. It is stored in the module case 22 in a folded state.

  According to the above configuration, when a frontal collision occurs, the gas from the inflator 26 is first jetted into the substantially central portion 72A (first inflating portion) in the longitudinal direction of the knee airbag 72. For this reason, the substantially central portion 72A in the longitudinal direction of the knee airbag 72 is initially initially deployed toward the rear side of the room. Subsequently, both end portions 72B (second inflating portions) in the longitudinal direction of the knee airbag 72 stored in the module case 22 in a state of being folded back are pulled out from the module case 22, and the vehicle width direction Secondary deployment to the outside.

  Thus, in the vehicle knee airbag device 70 according to the present embodiment, the substantially central portion 72A of the knee airbag 72 is initially deployed due to the folding method of the knee airbag 72 and the setting of the gas ejection destination of the inflator 26. In addition, since a configuration is adopted in which the longitudinal end portions 72B are secondarily developed, there is no need to set separate parts such as left and right partitions 50 and 52 as in the first embodiment described above. Therefore, the knee airbag 72 having the effects described in the first embodiment can be manufactured with the minimum necessary manufacturing steps. As a result, according to the present embodiment, the manufacturing cost of the vehicle knee airbag device 70 can be greatly reduced.

  Further, in the vehicle knee airbag device 70 according to the present embodiment, the module case 22 is vertically installed, and therefore can be disposed at a position slightly offset from the front of the occupant to the vehicle width direction outside (right side). Therefore, even when the space near the steering column cover 18 is narrow, it can be easily installed. The deployment shape of the knee airbag 72 is asymmetrical when viewed from the opening 24 of the module case 22, but the deployment performance of the knee airbag 72 in the longitudinal direction at both ends 72 </ b> B is left and right. There is no special impact.

[Third Embodiment]
Hereinafter, the third embodiment will be described with reference to FIG. The third embodiment is a reference example. Further, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 12A and 12B, in the vehicle knee airbag device 90 according to the third embodiment, a long strap 94 is disposed inside the knee airbag 92. There are features.

  More specifically, the knee airbag 92 as a whole is formed long in the vehicle width direction, and a long strap 94 is stretched between the inner surfaces of both ends in the longitudinal direction. Both end portions of the strap 94 are fixed to the inner surfaces of both end portions in the longitudinal direction of the knee airbag 92 by sewing or the like.

  Further, a slack portion 94A that is temporarily fixed by stitching is formed at an intermediate portion of the strap 94 in the longitudinal direction. When a deployment load of a predetermined value or more acts on the suture thread 96 existing at the base of the slack portion 94A, the suture thread 96 breaks, and the temporary fastening state of the slack portion 94A is released, so that the strap 94 extends. ing.

  According to the above configuration, when a frontal collision occurs, gas is ejected from the inflator 26 into the knee airbag 92. For this reason, as shown in FIG. 12A, the knee airbag 92 is initially deployed from the opening 24 of the module case 22 toward the indoor rear side. At this time, the suture thread 96 of the slack portion 94A is cut. Therefore, the knee airbag 92 is initially deployed in the widthwise dimension when the slack portion 94A is maintained, that is, when the tension is applied to the strap 94. At this time, the deployed portion 92A of the knee airbag 92 shown in FIG. 12A corresponds to a “first inflating portion”.

  Thereafter, when the internal pressure of the knee airbag 92 reaches a predetermined value or more, as shown in FIG. 12B, the suture thread 96 is cut and the slack portion 94A is expanded. That is, when the secondary deployment load to the outside in the vehicle width direction acting on the knee airbag 92 reaches a predetermined value or more, the suture thread 96 forming the slack portion 94A of the strap 94 is cut and the temporarily fixed state is released. The strap 94 is extended. Thereby, the knee airbag 92 is largely deployed outward in the vehicle width direction. The left and right deployed portions of the knee airbag 92 at this time correspond to a “second inflatable portion”.

  As described above, in the vehicle knee airbag device 90 according to the present embodiment, the length of the slack portion 94A relative to the entire length of the strap 94, the setting of the release load in the temporarily fixed state of the slack portion 94A, the number of straps 94 disposed, and slackness. By appropriately changing the set number of the portions 94A and the like, the deployment speed of the first inflatable portion and the second inflatable portion and the protection range (area) of the occupant's knee can be arbitrarily tuned.

  Also, in terms of cost, since the strap 94 usually has a small stitching range, the cost is lower than that of the partition 50 or 52 type of the first embodiment described above.

  As described above, according to the present embodiment, the protection performance of the occupant legs can be easily adjusted with a simple and low-cost configuration.

  In each of the above-described embodiments, the vehicle knee airbag device 10, 70, 90 is activated by a frontal collision. However, the frontal collision detecting the frontal collision of the vehicle according to claim 1 is described. The "detection means" includes "a frontal collision detection (prediction) means that detects a frontal collision by predicting a frontal collision of the vehicle (by a pre-crash sensor or the like disposed near the front end of the vehicle)" Is also included.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view showing an overall configuration of a vehicle knee airbag device according to a first embodiment as viewed from the vehicle interior side. It is an external appearance perspective view which shows the whole structure of the knee airbag apparatus for vehicles by the side of a driver | operator shown by FIG. FIG. 2 is an enlarged exploded perspective view of the vehicle knee airbag device on the driver's seat side shown in FIG. 1. It is a perspective view which shows the expansion | deployment process of a knee airbag. (A) is a side view which shows the state which the 1st expansion | swelling part of the knee airbag developed initially, (B) is the top view. (A) is a side view which shows the state which the 2nd expansion | deployment part of knee airbag developed secondary, (B) is the top view. (A) is a side view showing a state in which an occupant is inertially moved and both knees and shins are received by a knee airbag, and (B) is a plan view thereof. (A) is a side view showing a state where the first inflating portion is initially deployed when a small occupant sits close to the instrument panel, and (B) is a plan view thereof. It is an external appearance perspective view which shows the whole structure of the vehicle knee airbag apparatus by the side of the driver seat which concerns on 2nd Embodiment seeing from the diagonally back outside. FIG. 10 is an enlarged exploded perspective view of the vehicle knee airbag device on the driver's seat side shown in FIG. 9. It is a perspective view which shows the expansion | deployment process of a knee airbag. It is a perspective view which shows the expansion | deployment process of the knee airbag which is the principal part of the knee airbag apparatus for vehicles which concerns on 3rd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle knee airbag apparatus 12 Instrument panel 22 Module case 24 Opening part 26 Inflator 32 Controller (front collision detection means)
36 knee airbag 50 partition 52 partition 54 first inflatable portion 56 second inflatable portion 58 communication port (communication portion)
60 communication port (communication part)
62 Clearance

Claims (2)

Frontal collision detection means for detecting a frontal collision of the vehicle;
An inflator that operates when a frontal collision of the vehicle is detected by the frontal collision detection means and ejects gas;
A knee airbag that is deployed and inflated by the gas ejected from the inflator;
A module case that is arranged in the instrument panel and stores the knee airbag in a folded state;
A knee airbag device for a vehicle in which a knee airbag is interposed between an instrument panel and an occupant's knee in a frontal collision,
The knee airbag has a first inflated portion that is initially deployed so that its original deployed shape is a flat shape, and is pushed out toward the rear of the room toward a position corresponding to a position between both knees of a seated occupant. A second inflating portion disposed on the side of the first inflating portion and in communication with the first inflating portion and secondarily deploying outward in the vehicle width direction after the initial inflating of the first inflating portion. Configured ,
The knee airbag is partitioned into a central air chamber constituting the first inflating portion and a left and right air chamber constituting the second inflating portion by a partition provided in the vehicle up-down direction in the knee airbag. And is formed long in the vehicle width direction as a whole, and in the partition or in the vicinity thereof, there is provided a communication portion for communicating adjacent air chambers with each other,
Furthermore, gas from the inflator is jetted into the central air chamber.
A knee airbag device for a vehicle. The knee airbag is deployed to the vehicle lower side simultaneously with the second deployment to the vehicle width direction outer side,
The vehicle knee airbag device according to claim 1.

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