JP7409341B2 - knee airbag device - Google Patents

Description

The present invention relates to a knee airbag device mounted on a vehicle.

Patent Document 1 listed below discloses a knee protection airbag device, a so-called "knee airbag device", which includes an airbag that is inflated and deployed to restrain both knees of an occupant. In this knee airbag device, the airbag has a fold-in part whose tip is folded into the airbag, and a side that faces the vehicle body with the left and right ends of the airbag, whose tip is folded in, facing toward each other. A pair of first roll folding parts that are roll-folded, and a second roll-folding part that is roll-folded on both left and right end sides, with the distal end side in the deployment direction of the airbag facing the base end, and the side facing the vehicle body. It is folded and stored so that it has .

Japanese Patent Application Publication No. 2009-101758

In the case of the above-mentioned knee airbag device, the tip of the airbag is folded into the airbag at the folding part, so when the resistance at the folding part is large when the folding is released, the airbag inflates and deploys. is expected to be hindered. Therefore, a problem may arise in that the smooth inflation and deployment operation of the airbag is hindered. In particular, such problems may become more pronounced when the space in front of the occupant's knees becomes narrower due to variations in occupant physique (e.g., occupant height, leg length, etc.) . Therefore, when designing this type of knee airbag device, effective technology is required to prevent the inflation and deployment operation of the airbag from being hindered even when the space in front of the occupant's knees is narrow. It will be done.

The present invention has been made in view of such problems, and it is an object of the present invention to provide a knee airbag device that can smoothly inflate and deploy an airbag even in a narrow space in front of the knees of an occupant. .

One aspect of the present invention is
a storage section provided in a vehicle interior section located in front of the knees of a passenger;
an airbag housed in the accommodation section so as to be inflated and deployed in a space facing the passenger's knee and the interior of the vehicle;
a gas supply unit that supplies gas for inflation and deployment to the airbag;
Equipped with
When the airbag is inflated and deployed in the opposing space, the surface facing the knees of the passenger is the passenger-side facing surface, and the surface facing the interior of the vehicle is the vehicle-side facing surface. a first folded portion that is folded back in a first direction along a first fold line extending in the width direction of the airbag with either the facing surface or the vehicle-side facing surface facing inward; a plurality of second folding lines extending parallel to each other along the first folding line such that the other of the passenger-side facing surface and the vehicle-side facing surface is on the inside together with the folded first folded portion; a second folded part that is folded back multiple times in a second direction that is opposite to the first direction ; a knee airbag device;
It is in.

In the knee airbag device of the above-described aspect, the airbag is housed in a housing section provided in the interior of the vehicle, which is located forward of the knees of the occupant. The airbag protrudes from the accommodating part and is inflated and deployed in the opposing space between the knees of the occupant and the interior of the vehicle by supplying gas for inflation and deployment from the gas supply part.

This airbag is provided with at least a first folded portion and a second folded portion. Here, the first folded portion is a portion that is folded back along a first fold line extending in the width direction of the airbag so that either the passenger-side facing surface or the vehicle-side facing surface is on the inside. On the other hand, the second folded portion is a portion that is folded back along a second fold line extending along the first fold line so that either the passenger-side facing surface or the vehicle-side facing surface is on the inside.

When the airbag is deployed and inflated, the first folded portion and the second folded portion are released from folding along their respective fold lines. At this time, if the folding direction of the first folding part along the first folding line and the folding direction of the second folding part along the second folding line are in the same direction, the expansion occurs in the airbag. The vector is always formed in a direction biased toward either the passenger side or the vehicle side. For this reason, when the space in front of the occupant's knees is narrow, this may impede the inflation and deployment operation of the airbag.

Therefore, by making the direction of folding at the first folding line of the first folding part and the direction of folding at the second folding line of the second folding part opposite to each other, each folding line The movements of the two folded parts when the folding is released can be made different from each other. As a result, the deployment vector generated in the airbag differs between when the first folded part is unfolded at the first fold line and when the second folded part is folded and released at the second fold line. change to the side.

At this time, by combining the deployment vector in the direction toward the vehicle and the deployment vector in the direction toward the passenger, it becomes possible to obtain the deployment vector in the direction toward the occupant's knees. The directivity of the airbag can be improved. Therefore, even when the space in front of the occupant's knees is narrow, the airbag slips through this narrow space and is smoothly inflated and deployed.

As described above, according to the above-described aspect, it is possible to provide a knee airbag device that can smoothly inflate and deploy an airbag even in a narrow space in front of the knees of an occupant.

1 is a diagram showing an overview of the configuration of a knee airbag device according to a first embodiment; FIG. FIG. 2 is a plan view showing the airbag in FIG. 1 in an unfolded, unfolded state before being folded. FIG. 3 is a sectional view taken along the line III-III in FIG. 2. FIG. 3 is a plan view showing the airbag of FIG. 2 along with a plurality of fold lines. FIG. 5 is a plan view showing the airbag of FIG. 4 in a state folded back along a first fold line. A sectional view taken along the line VI-VI in FIG. 5. FIG. 6 is a plan view showing the airbag of FIG. 5 in a state where it is folded back along a second fold line. A sectional view taken along the line VIII-VIII in FIG. 7. FIG. 8 is a plan view showing the airbag of FIG. 7 in a state folded back along a third fold line. FIG. 2 is a cross-sectional view schematically showing how the airbag in FIG. 1 is inflated and deployed at an initial stage. FIG. 2 is a cross-sectional view schematically showing how the airbag in FIG. 1 is inflated and deployed in a later stage. FIG. 12 is a partially enlarged cross-sectional view of FIG. 11; FIG. 2 is a cross-sectional view schematically showing how the airbag in FIG. 1 is inflated and deployed in its final stage. FIG. 5 is a plan view corresponding to FIG. 4 of the airbag according to the second embodiment.

Preferred embodiments of the above aspects are described below.

In the above embodiment, "inflation and deployment" refers to an operation in which the airbag, which has been folded into a predetermined shape in advance, is inflated in response to gas supply and deployed to release the folded state.

In the knee airbag device of the above aspect, the airbag has a plurality of chambers partitioned by a plurality of tethers,
It is preferable that the first fold line is provided in a knee chamber of the plurality of chambers that is sandwiched between the passenger's knee and the vehicle interior portion in an inflated and deployed state in the opposing space.

According to this knee airbag device, the folding of the first folding portion at the first folding line can be released before the knee chamber of the airbag is completely inflated. Therefore, it is possible to prevent the knee chamber of the airbag from completely inflating and reaching the area above the knee of the occupant.

In the knee airbag device of the above aspect, the airbag has a plurality of chambers partitioned by a plurality of tethers, and the plurality of chambers includes a large-capacity chamber having the largest inflation capacity, Preferably, the first fold line is provided in the large capacity chamber.

According to this knee airbag device, the folding of the first folded portion at the first folding line can be released before the large capacity chamber of the airbag is completely inflated. Therefore, it is possible to prevent the large-capacity chamber from being completely inflated and hindering the inflation and deployment operation of the airbag.

In the knee airbag device of the above aspect, the airbag has a plurality of chambers partitioned by a plurality of tethers, and the plurality of chambers includes a front surface of the lower leg of the occupant when inflated and deployed in the opposing space. It is preferable that the narrowing chamber includes a narrowing chamber located at a location where the gap between the interior portion and the vehicle interior portion is the narrowest, and that the first folding line is provided in the narrowing chamber.

According to this knee airbag device, the folding of the first folding portion at the first folding line can be canceled before the narrowing chamber of the airbag is completely inflated. Therefore, it is possible to prevent the narrowing chamber from being completely inflated and hindering the inflation and deployment operation of the airbag.

In the knee airbag device according to the aspect described above, the first folded portion is folded back along the first folding line so that the passenger side facing surface of the airbag is on the inside, and the second folded portion is folded back along the first folded line such that the passenger side facing surface of the airbag is on the inside. It is preferable that after the first folding portion is folded back, the airbag is folded back along the second folding line so that the surface facing the vehicle side faces inside.

In this knee airbag device, when the airbag is inflated and deployed, the second folded portion is unfolded prior to the first folded portion. At an initial stage when the second folded portion is released from folding, the airbag comes into contact with the interior portion of the vehicle at its vehicle-side facing surface. Thereafter, in a later stage when the first folded portion is unfolded, the airbag comes into contact with the occupant's knee on its passenger side facing surface. Therefore, the contact load that the occupant receives from the airbag in the initial stage can be reduced.

Hereinafter, a specific example of the knee airbag device of this embodiment will be described with reference to the drawings.

In the drawings of this specification, unless otherwise specified, the vehicle width direction is indicated by an arrow X, the vehicle front is indicated by an arrow Y, and the vehicle upper direction is indicated by an arrow Z. Regarding the knee airbag, arrow A indicates the direction of inflation and deployment, arrow B1 indicates the width direction (front-back direction) of the airbag in the unfolded state before folding, and arrow B1 indicates the direction of the airbag in the unfolded state before folding. The vertical and width directions (left and right directions) in this state are shown by arrow B2, and the thickness direction of the airbag is shown by arrow B3.

(Embodiment 1)
As shown in FIG. 1, a knee airbag device 101 according to the first embodiment is installed in a vehicle. This knee airbag device 101 is provided for an occupant C seated on a front seat (not shown) of a vehicle, and serves to protect the occupant C by primarily restraining his or her knees K in the event of a vehicle collision. .

The knee airbag device 101 includes a housing section 10, an airbag 20 as a knee airbag for protecting the knee, and an inflator 30 as a gas supply section.

The accommodating portion 10 is provided in a lower panel 2, which is a vehicle interior portion, of the instrument panel 1 and located in front of the knee region K of the occupant C. This housing part 10 opens at a position facing the front part La of the lower leg of the occupant C, and the opening part is covered by an airbag door 2a provided in the lower part 2 of the panel. At this time, the lower leg front part La refers to the front part of the lower leg L, which is the area from the knee part K of the occupant C to the ankle via the shin part.

The accommodating portion 10 has an accommodating space that accommodates the airbag 20 together with the inflator 30. The housing portion 10 may be configured by forming a part of the instrument panel 1 into the shape of a case, or may be configured by a case separate from the instrument panel 1.

A protrusion 3 that protrudes toward the knee K of the occupant C is provided in a lower panel 2 of the instrument panel 1 at a position facing the knee K of the occupant C. The narrow space Sa between the knee portions K and the protruding portion 3 is a space where the gap in the vehicle longitudinal direction is the smallest in the facing space S between both knee portions K of the occupant C and the panel lower part 2.

The airbag 20 is formed into a bag shape by sewing together a plurality of base fabrics, and is accommodated in the storage section 10 in a state in which it is folded in advance into a predetermined shape so that it can be inflated and deployed in the opposing space S. . This airbag 20 is configured so that, when inflated and deployed, the opposing space S extends diagonally upward in the deployment direction A along the lower panel 2. Inflating and deploying at this time refers to an operation in which the airbag 20, which has been folded in a predetermined shape in advance, expands in response to gas supply and releases the folded state.

The inflator 30 has a gas generation port (not shown) communicating with the interior space of the airbag 20, and is configured to supply gas for inflation and deployment to the interior space of the airbag 20 when activated. This inflator 30 operates in response to a control signal output from a control unit (ECU) 103 when a collision detection sensor 102 detects a vehicle collision. The collision detection sensor 102 and the control unit 103 are both mounted on the vehicle, and together with the knee airbag device 101, construct an occupant protection system for protecting the occupant C.

The airbag 20 receives gas supply from the inflator 30 and begins to inflate and deploy. At this time, the airbag 20 protrudes from the accommodating part 10 by splitting the airbag door 2a due to the load received from the airbag 20, and the airbag 20 protrudes from the housing part 10 in the opposing space S between both knees K of the occupant C and the lower panel 2. Expand and expand. This airbag 20 is tethered from the inside by a plurality of tethers 41, 42, 43, which will be described later, as tethering members so as not to be inflated and deployed beyond a certain size.

The airbag 20 inflated and deployed between both knees K of the occupant C and the lower panel 2 functions to restrain at least both knees K of the occupant C. The restraint mentioned here includes a mode in which the movement of both knees K of the occupant C is restricted from moving forward due to a reaction force due to the internal pressure of the airbag 20, and a mode in which a movement in which both knees K of the occupant C are restricted from opening outwards is restricted. This includes a mode in which the occupant C floats upwards Z of the vehicle, and the like. Thereby, both knee parts K of the occupant C can be suppressed from moving in the vehicle width direction X, in the vehicle front direction Y, and in the vehicle upward direction Z.

In FIG. 2, the airbag 20 is shown in an unfolded, unfolded state C1 before being folded. This airbag 20 has four chambers 20a, 20b, 20c, and 20d partitioned by three tethers 41, 42, and 43.

The three tethers 41, 42, and 43 are all formed in the shape of a long strip (also referred to as a "belt shape" or "thin plate shape"), and both ends of the tethers in the short direction are attached to the airbag by sewing, gluing, or other methods. It is joined to the inner wall surface. Each of the three tethers 41, 42, and 43 is typically made of a base fabric used for the airbag 20 or a webbing material used for a seat belt. Each of the three tethers 41, 42, 43 is provided with a plurality of gas flow openings 41a, 42a, 43a arranged in the width direction B1, and an appropriate amount of gas flows through the plurality of gas flow openings 41a, 42a, 43a. Gas distribution is now possible.

Regarding the airbag 20 in the unfolded state C1, when the end on the side of the inflator 30 in the vertical width direction B2 is taken as the base end, and the end on the side opposite to the inflator 30 in the vertical width direction B2 is taken as the tip part, there are three tethers. 41, 42, and 43 are arranged in the order of the first tether 41, the second tether 42, and the third tether 43 from the base end side to the distal end side in the vertical width direction B2.

The four chambers 20a, 20b, 20c, and 20d are arranged in the order of a first chamber 20a, a second chamber 20b, a third chamber 20c, and a fourth chamber 20d from the base end side to the distal end side in the vertical width direction B2. It is formed. In this embodiment, the three chambers 20a, 20b, 20c are configured to have approximately the same expansion capacity.

On the other hand, the fourth chamber 20d is a large-capacity chamber with the largest expansion capacity among the four chambers 20a, 20b, 20c, and 20d. The fourth chamber 20d is a knee chamber that is sandwiched between the knee K of the occupant C and the lower panel 2 in the inflated and deployed state in the facing space S, and is also a knee chamber that is sandwiched between the knee K of the occupant C and the lower panel 2. This is a narrow chamber located in the narrow space Sa where the gap between the two and the narrow space Sa is the narrowest.

The gas supplied from the inflator 30 first fills the first chamber 20a of the interior space of the airbag 20. As a result, the airbag 20 starts to inflate and deploy. This gas flows into the second chamber 20b through the plurality of gas flow openings 41a of the first tether 41 while filling the first chamber 20a. This gas further flows into the third chamber 20c through the plurality of gas flow openings 42a of the second tether 42 while filling the second chamber 20b. This gas further flows into the fourth chamber 20d through the plurality of gas flow openings 43a of the third tether 43 while filling the third chamber 20c. The fourth chamber 20d is then filled with gas until the airbag 20 is inflated and deployed to a predetermined state.

Note that the number of tethers is not limited to three, and the number of chambers is not limited to four, and each number can be changed as appropriate. For example, it is preferable to set the number of tethers and chambers by assuming the physique of the occupant C (for example, the height of the occupant C, the length of the lower leg L (see FIG. 1), etc.). Thereby, the airbag 20 can be appropriately inflated and deployed according to the assumed physique of the occupant C.

As shown in FIG. 3, the airbag 20 in the unfolded state C1 has a first surface 21 and a second surface 22 that face each other in the thickness direction B3. In this airbag 20, its first surface 21 becomes the passenger-side facing surface that faces the knee region K (see FIG. 1) of the occupant C when it is inflated and deployed in the opposing space S, and its second surface 22 is This becomes the vehicle side facing surface facing the interior portion 2 (see FIG. 1).

As shown in FIG. 4, the airbag 20 is provided with a first folded part 23, a second folded part 24, and a third folded part 25.

The first folded portion 23 is a portion that is folded back along one first fold line F1 extending in the width direction B1 of the airbag 20 so that the first surface 21 is on the inside. The first fold line F1 is set closer to the tip end than the third tether 43 in the vertical width direction B2. When the dimension of the first folded portion 23 in the vertical width direction B2 is defined as the amount of folding, it is preferable to set the amount of folding appropriately for each package. The versatility of the knee airbag device 101 can be increased by changing the folding amount of the first folding portion 23 depending on the type of vehicle in which the knee airbag device 101 is installed.

The second folded portion 24 includes a plurality of (three in FIG. 4) second folded portions extending in parallel along the first folding line F1 with the second surface 22 facing inside after the first folded portion 23 is folded back. This is the part that is folded back along line F2. Each of the plurality of second folding lines F2 is adjacent to the first folding line F1 on the base end side in the longitudinal width direction B2 than the third tether 43 and the first folding line F1, and is spaced from each other in the longitudinal width direction B2. are set apart.

After the second folding part 24 is folded, the third folding part 25 is made of a plurality of pieces (in FIG. This is the part that is folded back at the third fold line F3 of each section.

Next, the folding mode of the airbag 20 will be described with reference to FIGS. 4 to 9.

As shown in FIG. 4, first, the tip of the airbag 20 in the unfolded state C1 in the vertical width direction B2 is folded back in the first direction D1 along the first fold line F1. Thereby, as shown in FIGS. 5 and 6, the airbag 20 changes from the unfolded state C1 to the folded state C2. In the airbag 20 in the folded state C2, a first folded portion 23 is formed on the first surface 21 side.

Next, the tip of the airbag 20 in the folded state C2 in the longitudinal direction B2 is folded back along the second fold line F2 in the second direction D2, which is the opposite direction to the first direction D1 (see FIG. 5). At this time, since the airbag 20 has a plurality of second folding lines F2, the airbag 20 is folded back in a roll shape in the second direction D2. Thereby, as shown in FIGS. 7 and 8, the airbag 20 changes from the folded state C2 to the folded state C3. In the airbag 20 in the folded state C3, a second folded portion 24 is formed on the second surface 22 side.

Finally, both left and right ends of the airbag 20 in the folded state C3 in the width direction B1 are folded back in the third direction D3 along the third fold line F3 (see FIG. 7). At this time, since a plurality of third folding lines F3 are set on the airbag 20, both left and right end portions of the airbag 20 are folded back in a roll shape in the third direction D3. Thereby, as shown in FIG. 9, the airbag 20 changes from the folded state C3 to the folded state C4. In the airbag 20 in the folded state C4, a pair of left and right third folded portions 25 are formed on the second surface 22 side. The airbag 20 is then accommodated in the accommodation section 10 in the folded state C4.

Next, the inflation and deployment operation of the airbag 20 of the knee airbag device 101 of the first embodiment will be explained with reference mainly to FIGS. 10 to 13.

As shown in FIG. 10, gas generated during operation of the inflator 30 is supplied to the internal space of the airbag 20. At this time, the vehicle rear side of the facing area S extends from the shin to the knee K along the front part La of the lower leg of the occupant C, and the vehicle front side of the facing area S extends along the panel lower part 2. Therefore, the airbag 20 starts to deploy and inflate in the deployment direction A below the opposing region S in the initial stage E1.

The airbag 20 in the folded state C4 (see FIG. 9) is expanded to release the previously folded state. Regarding the deployment of the airbag 20, first, the airbag 20 changes from the folded state C4 to the folded state C3 shown in FIG. 7 by releasing the folding of the third folded portion 25 at the third folding line F3. Thereafter, by releasing the folding of the second folding portion 24 at the second fold line F2 from the folded state C3, the airbag 20 becomes the folded state C2 shown in FIG. Then, by releasing the folding of the first folding portion 23 along the first folding line F1 from the folded state C2, the airbag 20 returns to a state close to the unfolded state C1 shown in FIG.

As shown in FIG. 11, the airbag 20 begins to expand and inflate in the order of the first chamber 20a near the inflator 30, the second chamber 20b, the third chamber 20c, and the fourth chamber 20d. At this time, the gas in the first chamber 20a flows into the second chamber 20b through the gas flow opening 41a of the first tether 41. The gas that has flowed into the second chamber 20b flows into the third chamber 20c through the gas flow opening 42a of the second tether 42. The gas that has flowed into the third chamber 20c flows into the fourth chamber 20d through the gas flow opening 43a of the third tether 43. Then, the second chamber 20b expands above the first chamber 20a, the third chamber 20c expands above the second chamber 20b, and the fourth chamber 20d expands above the third chamber 20c.

During the inflation and deployment process in which the airbag 20 changes from the folded state C3 (see FIG. 7) to the folded state C2 (see FIG. 5), the second folded portion 24 is folded back into a roll shape in the second direction D2. The roll unravels in the first direction D1, which is the opposite direction. At this time, since the second folded part 24 is disposed facing the panel lower part 2, it makes a constant movement so as to continue the roll release operation in the first direction D1 while contacting the panel lower part 2.

The later stage E2 of the airbag 20 shown in FIG. 11 is a stage in which the airbag 20 is returning from the folded state C2 (see FIG. 5) to a state close to the unfolded state C1 (see FIG. 4). . In this latter stage E2, the folding of the first folding portion 23 at the first folding line F1 is released before the fourth chamber 20d is completely expanded. The first folded portion 23 changes from a folded state in the first direction D1 (the state indicated by the solid line in FIG. 11) to a folded state in the second direction D2, which is the opposite direction (the two points in FIG. 11). (state shown by the dashed line).

Therefore, the fourth chamber 20d of the airbag 20 can pass upward through the narrow area Sa and move to the area above the knee K of the occupant C before being completely inflated. At this time, since the first folding part 23 is disposed facing the knee part K of the occupant C, the first folding part 23 moves so as to continue the folding operation in the second direction D2 while contacting the knee part K, that is, the second folding part 23 The folding portion 24 moves in the opposite direction.

As shown in FIG. 12, since the airbag 20 is provided with the first folded part 23, in the latter stage E2, when the airbag 20 is inflated and deployed in the opposing space S, the deployment vector Va in the direction toward the lower panel 2 and the occupant A deployment vector Vc in the direction toward the knee K of the occupant C (that is, deployment direction A) is obtained by combining it with the deployment vector Vb in the direction toward the front lower leg portion La of C. Therefore, the directivity in the deployment direction A of the fourth chamber 20d of the airbag 20 can be improved, and it is possible to improve the directivity in the deployment direction A of the fourth chamber 20d of the airbag 20. Even in the case where the fourth chamber 20d is caught on the panel lower part 2 or the lower leg front part La, it can be suppressed.

As shown in FIG. 13, in the final stage E3 of the airbag 20, a fourth A chamber 20d is arranged. Therefore, at the final stage E3 of the airbag 20, it is possible to ensure a desired pressing load applied from the airbag 20 to the knees of the occupant C. At this time, the fourth chamber 20d of the airbag 20 restrains both knee portions K of the occupant C, thereby suppressing movement of both knee portions K in the vehicle width direction X and forward direction Y of the vehicle.

Further, three chambers 20a, 20b, and 20c are arranged between both shins of the occupant C and the lower panel 2 in the facing space S. The three chambers 20a, 20b, and 20c have a smaller inflation capacity than the fourth chamber 20d, and are configured such that the dimension in the thickness direction B3 of the airbag 20 during inflation is smaller than that of the fourth chamber 20d. That is, the airbag 20 has a thinner portion corresponding to the three chambers 20a, 20b, and 20c. Therefore, at the final stage E3 of the airbag 20, the pressing load applied from the airbag 20 to the shin of the occupant C can be suppressed to a small level.

Next, the effects of the first embodiment described above will be explained.

In the knee airbag device 101 having the above configuration, the airbag 20 is housed in the housing section 10 provided in the lower panel 2 located forward of the knee K of the occupant C. The airbag 20 protrudes from the accommodation portion 10 and is inflated and deployed in the opposing space S between the knee part K of the occupant C and the lower panel 2 by supply of gas for inflation and deployment from the inflator 30.

This airbag 20 is provided with at least a first folded part 23 and a second folded part 24. Here, the first folded part 23 is a part that is folded back along the first fold line F1 so that the first surface 21 of the airbag 20 is on the inside. On the other hand, the second folded portion 24 is a portion that is folded back along the second fold line F2 so that the second surface 22 of the airbag 20 is on the inside.

When the airbag 20 is deployed and inflated, the first folded portion 23 and the second folded portion 24 are released from folding at the respective fold lines F1 and F2. At this time, the folding direction of the first folding part 23 at the first folding line F1 (first direction D1) and the folding direction of the second folding part 24 at the second folding line F2 (second direction D2). , are in the same direction, the deployment vector generated in the airbag 20 is always biased towards either the passenger side or the vehicle side. Therefore, when the space in front of the knees K of the occupant C is a narrow space Sa, the inflation and deployment operation of the airbag 20 may be hindered.

Therefore, the folding direction of the first folding part 23 at the first folding line F1 (first direction D1), the folding direction of the second folding part 24 at the second folding line F2 (second direction D2), By making the directions opposite to each other, it is possible to make the movements of the two folded portions 23 and 24 different from each other when the folding is released at the respective folding lines F1 and F2. As a result, the deployment vector generated in the airbag 20 differs between when the first folded portion 23 is unfolded at the first folding line F1 and when the second folded portion 24 is unfolded at the second folded line F2. , changes to the passenger side or the vehicle side.

At this time, by combining the deployment vector Va in the direction toward the vehicle and the deployment vector Vb in the direction toward the passenger, a deployment vector Vc in the direction toward the knee K of the occupant C (upward deployment direction A) is obtained. This makes it possible to increase the directivity of the airbag 20 so that it is directed toward the knees K of the occupant C. Therefore, even when the space in front of the knees K of the occupant C is a narrow space Sa, the airbag slips through the narrow space Sa and is smoothly inflated and deployed.

Therefore, according to the first embodiment described above, it is possible to provide the knee airbag device 101 that can smoothly inflate and deploy the airbag 20 even in the narrow space Sa in front of the knees K of the occupant C. Become.

According to the knee airbag device 101 having the above configuration, the folding of the first folding portion 23 at the first folding line F1 can be canceled before the fourth chamber 20d of the airbag 20 is completely inflated. Therefore, it is possible to prevent the fourth chamber 20d of the airbag 20 from being completely inflated and reaching the area above the knees of the occupant C (ie, the inflation and deployment operation of the airbag 20 is prevented).

According to the knee airbag device 101 having the above configuration, when the airbag 20 is inflated and deployed, the folding of the second folding part 24 is released before the first folding part 23 is released. At an initial stage E1 when the second folded portion 24 is unfolded, the airbag 20 comes into contact with the panel lower part 2 at its second surface 22. Thereafter, in a later stage E2 in which the folding of the first folded portion 23 is released, the airbag 20 comes into contact with the knee K of the occupant C at its first surface 21. Therefore, the contact load that the occupant C receives from the airbag 20 at the initial stage E1 can be reduced.

In a modification particularly related to the first embodiment described above, the first folded portion 23 is folded back along the first fold line F1 so that the second surface 22 of the airbag 20 is on the inside, and the second surface 22 of the airbag 20 is folded back along the first folding line F1. A configuration can be adopted in which the second folded portion 24 is folded back along the second fold line F2 so that the first surface 21 is on the inside.

In the case of this configuration, when the second folded portion 24 unrolls during the inflation and deployment process of the airbag 20, the second folded portion 24 continues the roll release operation while moving along the occupant C. Thereafter, the first folded portion 23 is released from folding along the first fold line F1 while contacting the lower panel 2.

In another modification particularly related to the first embodiment described above, in order to improve the independence of the airbag 20 in the opposing space S, the expansion capacity of at least the first chamber 20a is larger than that of the second chamber 20b and the third chamber. The expansion capacity of the four chambers 20a, 20b, 20c, and 20d can be set to exceed the expansion capacity of the chamber 20c, or the expansion capacity of all the four chambers 20a, 20b, 20c, and 20d can be set to be approximately the same. That is, the relative sizes of the expansion capacities of the four chambers 20a, 20b, 20c, and 20d can be appropriately set as necessary.

In another modification particularly related to the first embodiment described above, at least one of the three chambers 20a, 20b, 20c has a first fold line F1. It is possible to adopt a configuration in which the following is provided. In the case of this configuration, when the second folding line F2 is set closer to the tip end side in the vertical width direction B2 than the first folding line F1, the first folding part 23 is set to the second folding line F2 of the second folding part 24. After being folded back at , it is folded back at the first fold line F1.

Other embodiments related to the first embodiment described above will be described below with reference to the drawings. In other embodiments, the same elements as those in Embodiment 1 are given the same reference numerals, and descriptions of the same elements will be omitted.

(Embodiment 2)
As shown in FIG. 14, the airbag 120 according to the second embodiment is different from the airbag 20 according to the first embodiment. This airbag 120 is provided with a bellows folded portion 123 and a roll folded portion 124.

In the bellows folding portion 123, first folding lines L1 and second folding lines L2 are set alternately in the vertical width direction B2. Therefore, the bellows folding portion 123 is configured not only to be folded back in the first direction D1 along the first folding line L1 but also to be folded back in the second direction D2 along the second folding line L2. At this time, the bellows folded portion 123 has a portion corresponding to the first folded portion 23 of the first embodiment (first folded portion) and a portion corresponding to the second folded portion 24 of the first embodiment (second folded portion). This is a part that combines both. On the other hand, the roll folding portion 124 is a portion corresponding to the second folding portion 24 of the first embodiment.

The other configurations are the same as in the first embodiment.

According to the second embodiment described above, by employing the bellows folded portion 123 in the airbag 120, when the airbag 120 is deployed and inflated, the directionality toward the knee K of the occupant C is changed from the airbag of the first embodiment. It becomes possible to increase the number of times compared to the case of 20.

Other than that, the same effects as in the first embodiment are achieved.

The present invention is not limited to the typical embodiments described above, and various applications and modifications can be made without departing from the purpose of the present invention. For example, the following embodiments that apply the above embodiments can also be implemented.

In the above-described first embodiment, the fourth chamber 20d of the airbag 20 corresponds to all of the knee chamber, the large capacity chamber, and the narrow chamber, but instead of this, the fourth chamber 20d corresponds to the knee chamber At least one of a large-capacity chamber, a large-capacity chamber, and a small-capacity chamber can be configured.

Further, in view of the above embodiment and other modifications, the following aspects are possible.

As one aspect,
"A storage section provided in the interior of the vehicle located in front of the passenger's knees,
an airbag housed in the accommodation section so as to be inflated and deployed in a space facing the passenger's knee and the interior of the vehicle;
a gas supply unit that supplies gas for inflation and deployment to the airbag;
Equipped with
When the airbag is inflated and deployed in the opposing space, the airbag is deployed in the direction toward the knees of the occupant by combining the deployment vector in the direction toward the interior of the vehicle and the deployment vector in the direction toward the front of the occupant's lower legs. A knee airbag device that is folded in a folding manner that provides a vector. ”
This may be the case.

According to this aspect, as in the case of the above-described embodiment, since the deployment vector in the direction toward the knees of the occupant is obtained, the directivity of the airbag can be increased so that it is directed toward the knees of the occupant. Therefore, even when the space in front of the occupant's knees is narrow, the airbag can slip through this narrow space and be smoothly inflated and deployed.

2 Vehicle interior part 10 Storage part 20 Airbag 20a, 20b, 20c Chamber 20d Chamber (knee chamber, large capacity chamber, narrow chamber)
21 First surface (crew side facing surface)
22 Second surface (vehicle side facing surface)
23 First folded part 24 Second folded part 30 Inflator (gas supply part)
41, 42, 43 tether 101 knee airbag device 120 airbag 123 bellows folded part (first folded part, second folded part)
124 Roll folding section (second folding section)
B1 Width direction of airbag C Occupant F1 First fold line F2 Second fold line K Knee area S Opposing space

Claims (5)

a storage section provided in a vehicle interior section located in front of the knees of a passenger;
an airbag housed in the accommodation section so as to be inflated and deployed in a space facing the passenger's knee and the interior of the vehicle;
a gas supply unit that supplies gas for inflation and deployment to the airbag;
Equipped with
When the airbag is inflated and deployed in the opposing space, the surface facing the knees of the passenger is the passenger-side facing surface, and the surface facing the interior of the vehicle is the vehicle-side facing surface. a first folded portion that is folded back in a first direction along a first fold line extending in the width direction of the airbag with either the facing surface or the vehicle-side facing surface facing inward; a plurality of second folding lines extending parallel to each other along the first folding line such that the other of the passenger-side facing surface and the vehicle-side facing surface is on the inside together with the folded first folded portion; A knee airbag device comprising: a second folded portion that is folded back multiple times in a second direction that is opposite to the first direction . The airbag has a plurality of chambers partitioned by a plurality of tethers,
According to claim 1, the first fold line is provided in a knee chamber of the plurality of chambers that is sandwiched between the passenger's knee and the vehicle interior portion in an inflated and deployed state in the opposing space. The described knee airbag device. The airbag has a plurality of chambers partitioned by a plurality of tethers, the plurality of chambers includes a large-capacity chamber having the largest inflation capacity, and the large-capacity chamber includes the first fold line. The knee airbag device according to claim 1, wherein the knee airbag device is provided with: The airbag has a plurality of chambers partitioned by a plurality of tethers, and the plurality of chambers has a gap between the front part of the lower leg of the occupant and the interior part of the vehicle when the airbag is inflated and deployed in the opposing space. The knee airbag device according to claim 1, further comprising a narrowing chamber located at the narrowest point, and wherein the first folding line is provided in the narrowing chamber. The first folded part is folded back along the first folding line so that the passenger side facing surface of the airbag is on the inside, and the second folded part is folded back on the air bag after the first folded part is folded back. The knee airbag device according to any one of claims 1 to 4, wherein the bag is folded back multiple times along the plurality of second fold lines so that the surface facing the vehicle side of the bag is on the inside.

Images