Lower limb restraint airbag device

Abstract

To obtain a lower limb restraint airbag device which can effectively restrain a knee part of an occupant seated on a vehicle seat even when a wide space exists at the seat front side of the knee part of the occupant.SOLUTION: A lower limb restraint airbag device 30 includes: an airbag 32 which is inflated and deployed to a knee part and a shin part of an occupant P seated on a vehicle seat 12 by a gas jetted from an inflator and comes into contact with at least the knee part; a reaction force plate 34 which is drawn to the seat front side of the airbag 32 as the airbag 32 is inflated and deployed; and a lock mechanism 40 which prevents movement of the drawn reaction force plate 34 to the sheet front side.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a lower limb restraint airbag device.

Background Art

[0002] An occupant protection device having a right knee airbag and a left knee airbag that deploy from both left and right sides of an occupant sitting on a vehicle seat toward the knees of the occupant and press the left and right knees respectively has been conventionally known (for example, see Patent Document 1). The right knee airbag has a right knee front contact surface that contacts the front side of the occupant's right knee in the deployed state, and the left knee airbag has a left knee front contact surface that contacts the front side of the occupant's left knee in the deployed state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the occupant protection device having the above configuration, by simply deploying the pair of left and right knee airbags toward the center in the seat width direction, there is no reaction force surface for each knee airbag. Therefore, for example, when there is a large space in front of the knees of an occupant sitting on a vehicle seat, such as a front seat moved significantly rearward, sufficient restraint force cannot be obtained with the pair of left and right knee airbags. In particular, the restraint force at the initial stage of a collision is small. Thus, there is room for improvement in the lower limb restraint airbag device when there is a large space in front of the knees of an occupant sitting on a vehicle seat.

[0005] Therefore, an object of the present invention is to obtain a lower limb restraint airbag device that can effectively restrain the knees of an occupant even when there is a large space in front of the seat of the knees of the occupant sitting on a vehicle seat.

Means for Solving the Problems

[0006] In order to achieve the above object, the lower limb restraint airbag device according to the first aspect of the present invention inflates and deploys toward the knees and shins of an occupant sitting on a vehicle seat by gas ejected from an inflater, and includes an airbag that contacts at least the knees, a reaction plate that is pulled out toward the front side of the seat of the airbag as the airbag inflates and deploys, and a lock mechanism that prevents the pulled-out reaction plate from moving toward the front side of the seat.

[0007] According to the invention of the first aspect, the airbag inflates and deploys toward the knees and shins of an occupant sitting on a vehicle seat by gas ejected from an inflater, and contacts at least the knees. Along with the inflation and deployment of the airbag, the reaction plate is pulled out toward the front side of the seat of the airbag, and the movement of the pulled-out reaction plate toward the front side of the seat is blocked by the lock mechanism.

[0008] That is, this reaction plate forms a reaction surface against the airbag. Therefore, the load from the knees and shins of the occupant who tries to move toward the front side of the seat due to inertia is effectively received by the airbag supported by the reaction plate. Thus, even when there is a wide space on the front side of the seat of the knees of an occupant sitting on the vehicle seat, the knees of the occupant are effectively restrained.

[0009] Further, the lower limb restraint airbag device according to the second aspect is the lower limb restraint airbag device according to the first aspect, wherein the inflater, the airbag, the reaction plate, and the lock mechanism are respectively mounted on a pair of side walls arranged on both the left and right sides of the vehicle seat, and are for the left knee and the right knee of the occupant.

[0010] According to the invention of the second aspect, an inflator, an airbag, a reaction plate, and a locking mechanism are respectively mounted on a pair of side walls disposed on the left and right sides of a vehicle seat, and are for the left knee and the right knee of an occupant. Therefore, for example, compared with a configuration in which the side wall is disposed on only one of the left and right sides and a single airbag restrains the left and right knees of the occupant, the occurrence of poor restraint on the left knee or the right knee of the occupant is suppressed.

[0011] Further, the lower limb restraint airbag device of the third aspect is the lower limb restraint airbag device of the second aspect, wherein the reaction plate is rotatably supported by the side wall and is connected to the airbag by a strap.

[0012] According to the invention of the third aspect, the reaction plate is rotatably supported by the side wall and is connected to the airbag by a strap. Therefore, it is possible to pull out the reaction plate with a simple configuration as the airbag expands and deploys.

[0013] Further, the lower limb restraint airbag device of the fourth aspect is the lower limb restraint airbag device of the third aspect, wherein the locking mechanism includes a lock bar having one end slidably held in a guide groove formed in the side wall and the other end rotatably attached to the reaction plate, and the guide groove has a recess for non-movably accommodating the one end of the lock bar after the reaction plate is pulled out.

[0014] According to the invention of the fourth aspect, the locking mechanism includes a lock bar having one end slidably held in a guide groove formed in the side wall and the other end rotatably attached to the reaction plate. And the guide groove has a recess for non-movably accommodating the one end of the lock bar after the reaction plate is pulled out. Therefore, it is possible to prevent the pulled-out reaction plate from moving forward of the seat with a simple configuration.

[0015] Further, the lower limb restraint airbag device according to the fifth aspect is the lower limb restraint airbag device according to the third aspect, wherein the locking mechanism includes a striker provided on one of the reaction plates on the left and right, and a hook provided on the other reaction plate on the left and right and locked to the striker, and the reaction plate provided with the hook is configured to rotate later than the reaction plate provided with the striker.

[0016] According to the invention of the fifth aspect, the locking mechanism includes a striker provided on one of the reaction plates on the left and right, and a hook provided on the other reaction plate on the left and right and locked to the striker. And the reaction plate provided with the hook is configured to rotate later than the reaction plate provided with the striker. Therefore, the occurrence of poor locking of the hook to the striker is prevented, and the movement of the pulled-out reaction plate to the front side of the seat can be prevented by a simple configuration.

[0017] Further, the lower limb restraint airbag device according to the sixth aspect is the lower limb restraint airbag device according to the fifth aspect, wherein the reaction plate provided with the hook is heavier than the reaction plate provided with the striker.

[0018] According to the invention of the sixth aspect, the reaction plate provided with the hook is made heavier than the reaction plate provided with the striker. Therefore, it is possible to rotate the reaction plate provided with the hook later than the reaction plate provided with the striker by a simple configuration.

[0019] Further, the lower limb restraint airbag device according to the seventh aspect is the lower limb restraint airbag device according to the fifth aspect, wherein the ignition timing of the inflator that jets gas into the airbag connected to the reaction plate provided with the hook by the strap is later than the ignition timing of the inflator that jets gas into the airbag connected to the reaction plate provided with the striker by the strap.

[0020] According to the invention of the seventh aspect, the ignition timing of the inflator that injects gas into the airbag connected by a strap to the reaction plate provided with a hook is delayed compared to the ignition timing of the inflator that injects gas into the airbag connected by a strap to the reaction plate provided with a striker. Therefore, it is possible to rotate the reaction plate provided with the hook later than the reaction plate provided with the striker with a simple configuration.

[0021] Further, the lower limb restraint airbag device according to the eighth aspect is the lower limb restraint airbag device according to the third aspect, wherein the locking mechanism includes a striker provided on either the left or right reaction plate and a hook rotatably provided on the other reaction plate of the left and right and locked to the striker. After the reaction plate provided with the striker and the reaction plate provided with the hook are pulled out, the hook is configured to rotate and lock to the striker.

[0022] According to the invention of the eighth aspect, the locking mechanism includes a striker provided on either the left or right reaction plate and a hook rotatably provided on the other reaction plate of the left and right and locked to the striker. After the reaction plate provided with the striker and the reaction plate provided with the hook are pulled out, the hook is configured to rotate and lock to the striker. Therefore, it is possible to prevent the occurrence of poor locking of the hook to the striker and to prevent the pulled-out reaction plate from moving forward of the seat with a simple configuration.

[0023] Further, the lower limb restraint airbag device according to the ninth aspect is the lower limb restraint airbag device according to any one of the second to eighth aspects, wherein the side wall is configured to be movable in the front-rear direction of the seat, and during vehicle travel, its rear end is disposed on the front side of the seat relative to the front end of the seat cushion of the vehicle seat, and during passenger boarding and alighting, its front end is disposed at the same position as or behind the front end of the seat cushion of the vehicle seat.

[0024] According to the invention of the ninth aspect, the side wall is configured to be movable in the longitudinal direction of the seat, and when the vehicle is running, the rear end thereof is disposed on the front side of the seat with respect to the front end of the seat cushion of the vehicle seat, and when the occupant gets on and off the vehicle, the front end thereof is disposed at the same position as the front end of the seat cushion of the vehicle seat or on the rear side of the seat with respect thereto. Therefore, when the vehicle is running, the lower limb restraint airbag device is surely standby. Further, even in the configuration where the side wall is provided, the influence on the boarding and alighting performance of the occupant is reduced.

[0025] Further, the lower limb restraint airbag device according to the tenth aspect is the lower limb restraint airbag device according to the ninth aspect, and is configured such that the side wall moves to the front side of the seat in conjunction with the reclining of the seat back of the vehicle seat.

[0026] According to the invention of the tenth aspect, the side wall is configured to move to the front side of the seat in conjunction with the reclining of the seat back of the vehicle seat. Therefore, compared with the case where the side wall is not configured to move to the front side of the seat in conjunction with the reclining of the seat back of the vehicle seat, even when the occupant takes a comfortable posture, the knees and shins of the occupant are surely and effectively restrained.

[0027] Further, the lower limb restraint airbag device according to the eleventh aspect is the lower limb restraint airbag device according to the ninth aspect, and is configured such that the seat back of the vehicle seat is not reclined if the rear end of the side wall is not disposed on the front side of the seat with respect to the front end of the seat cushion of the vehicle seat.

[0028] According to the invention of the eleventh aspect, the seat back of the vehicle seat is configured not to recline if the rear end of the side wall is not disposed on the front side of the seat with respect to the front end of the seat cushion of the vehicle seat. Therefore, when the occupant takes a comfortable posture, the knees and shins of the occupant are surely and effectively restrained.

[0029] Moreover, the lower limb restraint airbag device according to the twelfth aspect is the lower limb restraint airbag device according to the first aspect, wherein the inflator, the airbag, the reaction plate, and the locking mechanism are mounted on the lower part of the instrument panel.

[0030] According to the invention of the twelfth aspect, the inflator, the airbag, the reaction plate, and the locking mechanism are mounted on the lower part of the instrument panel. Therefore, for example, even when the length (thickness) along the up-and-down direction of the seat at the rear end of the instrument panel is reduced and there is a wide space on the front side of the seat of the knees of the occupant sitting on the vehicle seat, the knees of the occupant can be effectively restrained.

[0031] Moreover, the lower limb restraint airbag device according to the thirteenth aspect is the lower limb restraint airbag device according to the twelfth aspect, wherein the reaction plate is rotatably supported on the lower part of the instrument panel and is connected to the airbag by a strap.

[0032] According to the invention of the thirteenth aspect, the reaction plate is rotatably supported on the lower part of the instrument panel and is connected to the airbag by a strap. Therefore, it is possible to realize pulling out the reaction plate along with the inflation and deployment of the airbag with a simple configuration.

[0033] Moreover, the lower limb restraint airbag device according to the fourteenth aspect is the lower limb restraint airbag device according to the thirteenth aspect, wherein the locking mechanism includes a lock bar whose one end is slidably held in a guide groove formed in the lower part of the instrument panel and the other end is rotatably attached to the reaction plate, and the guide groove has a recess for non-movably accommodating the one end of the lock bar after the reaction plate is pulled out.

[0034] According to the invention of the 14th aspect, the locking mechanism includes a lock bar having one end slidably held in a guide groove formed in the lower part of the instrument panel and the other end rotatably attached to a reaction force plate. The guide groove has a recess for non-movably accommodating one end of the lock bar after the reaction force plate is pulled out. Therefore, it is possible to prevent the pulled-out reaction force plate from moving forward to the seat side by a simple configuration.

Effect of the Invention

[0035] As described above, according to the present invention, even when there is a wide space on the seat front side of the knees of the occupant sitting on the vehicle seat, the knees of the occupant can be effectively restrained.

Brief Description of the Drawings

[0036]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Modes for Carrying Out the Invention

[0037] Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. For convenience of explanation, the arrow UP appropriately shown in each figure indicates the upward direction of the vehicle and the vehicle seat, the arrow FR indicates the forward direction of the vehicle and the vehicle seat, and the arrow RH indicates the right direction of the vehicle and the vehicle seat. Therefore, in the following description, when the directions of up and down, front and back, and left and right are described without special mention, they indicate up and down, front and back, and left and right in the vehicle and the vehicle seat. Also, the left and right directions are synonymous with the vehicle width direction and the seat width direction. Further, as the vehicle seat in the present embodiment, the front seat of a vehicle (automobile) is taken as an example.

[0038] <First Embodiment> First, the first embodiment will be described. As shown in FIGS. 5 and 6, a vehicle seat 12 provided as the front seat of a vehicle 10 (see FIG. 10) includes a seat cushion 14 on which an occupant sits (supports the occupant's buttocks and thighs), a seat back 16 provided rotatably about the seat width direction as an axial direction on the rear side of the seat cushion 14 and supporting the occupant's back, and a headrest 18 provided movably up and down at the upper end of the seat back 16 and supporting the occupant's head. The seat back 16 is configured to be tiltable (rearward tilt and forward tilt) by a known electric mechanism (not shown).

[0039] In addition, FIGS. 5 and 6 show a state in which a dummy human figure (anthropomorphic dummy) for a collision test is seated on the seat cushion 14 of the vehicle seat 12 as a model of an occupant (seated person). The dummy human figure is, for example, AM50 (50th percentile of American adult males) of a front collision test dummy (Hybrid III). The dummy human figure is seated in a standard seating posture defined by the collision test method, and the vehicle seat 12 is located at a reference setting position corresponding to the seating posture. Hereinafter, the dummy human figure will be referred to as "occupant P".

[0040] As shown in FIGS. 5 and 6, on both the left and right sides of the vehicle seat 12, a pair of left and right side walls 20 formed in a substantially rectangular shape in side view are provided so as to be movable in the front-rear direction. Specifically described, on both the left and right sides of the vehicle seat 12 on the floor 11 of the vehicle 10 (see FIGS. 1 and 10), rails (not shown) similar to seat rails (not shown) that slidably support the seat cushion 14 of the vehicle seat 12 in the front-rear direction are provided.

[0041] And the bottom portions of the respective side walls 20 are slidably fitted to the respective rails. Note that the rear end portions of the respective rails may be integrally supported by the front end portions of the respective seat rails. In addition, since the configurations of the pair of left and right side walls 20 are symmetric and the same, in the following, there may be cases where only one of the side walls 20 is described.

[0042] As shown in FIG. 5, when the vehicle 10 is running, the rear end 20B of each side wall 20 is arranged on the front side of the front end 14F of the seat cushion 14 of the vehicle seat 12. And as shown in FIG. 6, when the occupant P gets in and out, the front end 20F of each side wall 20 is arranged at the same position as or on the rear side of the front end 14F of the seat cushion 14 of the vehicle seat 12.

[0043] More specifically, on one end side in the longitudinal direction of the rails that slidably support each side wall 20, an electric motor (not shown) and a pinion (not shown) that is rotationally driven by the electric motor are provided. And on the bottom of each side wall 20, a rack (not shown) that meshes with the pinion is provided.

[0044] Furthermore, the electric motor is electrically connected to a control device (not shown) mounted on the vehicle 10. Therefore, when the running of the vehicle 10 is detected by the control device (including sensors etc.), the electric motor is driven under the control of the control device, and each side wall 20 moves forward, and its rear end 20B is disposed on the front side of the front end 14F of the seat cushion 14.

[0045] And when the unlocking of the side door (not shown) is detected by the control device (including sensors etc.), it is determined that there is boarding or alighting of the passenger P, and the electric motor is driven under the control of the control device, and each side wall 20 moves backward, and its front end 20F is disposed at the same position as the front end 14F of the seat cushion 14 or on the rear side thereof. Note that the side wall 20 may be configured to move only on the side door side.

[0046] Also, each side wall 20 may be configured to move forward in conjunction with the recline of the seat back 16 of the vehicle seat 12 by a predetermined angle or more. More specifically, a sensor (not shown) for detecting the angle of the seat back 16 is provided on the vehicle 10, and the sensor is electrically connected to the control device.

[0047] With such a configuration, when the sensor detects the recline of the seat back 16 by a predetermined angle or more, the electric motor is driven under the control of the control device, and the side wall 20 moves forward, and its rear end 20B is disposed on the front side of the front end 14F of the seat cushion 14.

[0048] Further, each side wall 20 may be configured such that if the rear end 20B thereof is not disposed on the front side of the front end 14F of the seat cushion 14 of the vehicle seat 12, the seat back 16 of the vehicle seat 12 will not recline. Specifically described, a sensor (not shown) for detecting the position of each side wall 20 is provided in the vehicle 10, and the sensor is electrically connected to a control device.

[0049] With such a configuration, if the sensor does not detect that the rear ends 20B of the left and right side walls 20 are disposed on the front side of the front end 14F of the seat cushion 14, the energization to the electric mechanism is cut off under the control of the control device, and the recline of the seat back 16 is made impossible. In addition, when the seat back 16 reclines or the seat belt (not shown) is not attached, if the running speed of the vehicle 10 exceeds a predetermined speed while the left and right side walls 20 remain disposed on the rear side, a warning sound may be configured to be generated.

[0050] As shown in FIGS. 1 to 4, on the inner surfaces of the pair of left and right side walls 20 facing each other (facing the inner side in the seat width direction), accommodation recesses 24 having predetermined shapes and sizes are respectively formed. And in each accommodation recess 24, an inflater (not shown) and a lower limb restraint airbag device 30 are respectively mounted (accommodated).

[0051] That is, an inflater for the right knee of the occupant P and the lower limb restraint airbag device 30 are mounted on the right side wall 20, and an inflater for the left knee of the occupant P and the lower limb restraint airbag device 30 are mounted on the left side wall 20 (see FIGS. 5 and 6). Each side wall 20 is covered by a skin 22 (see FIGS. 3 to 6), and normally, the inflater and the lower limb restraint airbag device 30 accommodated in the accommodation recess 24 are not visible from the outside.

[0052] The inflator is, for example, a combustion-type cylinder inflator and is electrically connected to the control device. Therefore, this inflator is configured to generate high-temperature gas by being actuated by the control device when a frontal collision of the vehicle 10 occurs. Here, the frontal collision of the vehicle 10 refers to both when the frontal collision of the vehicle 10 is detected and when the inevitability of the frontal collision of the vehicle 10 is predicted (hereinafter referred to as "predicted"). In addition, the forms of the frontal collision of the vehicle 10 in which the control device actuates the inflator include offset frontal collisions such as oblique collisions and micro-lap collisions, in addition to full-lap frontal collisions.

[0053] The lower limb restraint airbag device 30 mounted on each side wall 20 is inflated and deployed (by splitting the skin 22) toward the knees K and shins S of the occupant P sitting on the vehicle seat 12 by the gas ejected from the inflator, and includes an airbag 32 that contacts at least the knees K from the front side (specifically, obliquely upward and forward).

[0054] The left and right airbags 32 are formed of, for example, a base fabric (fabric material) of a polyamide-based or polyester-based material with a size large enough to cover at least the left and right knees K and shins S of the occupant P from the front side (specifically, obliquely upward and forward). The left and right airbags 32 are housed in the respective accommodation recesses 24 in a folded state with a predetermined folding method.

[0055] In addition, the lower limb restraint airbag device 30 includes a reaction plate 34 that is pulled out to the front side (specifically, obliquely upward and forward) of the airbag 32 as the airbag 32 expands and deploys, and a lock mechanism 40 that prevents the pulled-out reaction plate 34 from moving forward (fixes the pulled-out reaction plate 34 in that position).

[0056] The reaction force plate 34 is made of resin having a certain degree of hardness, for example, and is formed in a substantially rectangular flat plate shape having a predetermined thickness. And this reaction force plate 34 is accommodated in the accommodation recess 24 on the front side (specifically, diagonally upward and forward side) of the airbag 32, and the rear end portion 34B thereof is rotatably supported by a rotation shaft 35 having a substantially vertical direction (specifically, a direction inclined by a predetermined angle with respect to the vertical direction in a side view) as an axial direction on the side wall 20.

[0057] Incidentally, hereinafter, the surface facing the inner side in the sheet width direction of the reaction force plate 34 in the state of being accommodated in the accommodation recess 24 is referred to as the "inner surface", and the surface facing the outer side in the sheet width direction is referred to as the "outer surface". The substantially central portion of the reaction force plate 34 on its inner surface is connected to a predetermined portion (a portion facing the inner side in the sheet width direction when inflated and deployed) of the airbag 32 by a strap 36.

[0058] The locking mechanism 40 includes a pair of upper and lower locking bars 42, one end 42A of which is slidably held in a guide groove 26 formed in the accommodation recess 24 of the side wall 20, and the other end 42B of which is rotatably attached to the outer surface of the reaction force plate 34. Each locking bar 42 has a main body portion 42C formed in a columnar shape, and one end 42A and the other end 42B of each locking bar 42 are each formed to bulge in a spherical shape. That is, the diameters of one end 42A and the other end 42B of each locking bar 42 are made larger than the diameter of the main body portion 42C of each locking bar 42.

[0059] The pair of upper and lower guide grooves 26 extend forward (specifically, diagonally upward and forward) from the portion where the reaction force plate 34 is accommodated, and the width of each guide groove 26 is formed to be the same as or slightly larger than the diameter of one end 42A of each locking bar 42. And at the peripheral edge portion on the open side (inner side in the sheet width direction) of each guide groove 26, an overhanging portion (not shown) that narrows the groove width until it becomes the same width as the diameter of the main body portion 42C of each locking bar 42 is integrally formed.

[0060] Therefore, one end portion 42A of each lock bar 42 is configured to be slidably held by its overhanging portion so as not to come out of each guide groove 26. At a predetermined portion in each guide groove 26, recesses 28 are integrally formed to movably accommodate (immerse) one end portion 42A of each lock bar 42 after the reaction force plate 34 is pulled out. As a result, the reaction force plate 34 is locked by being supported by the pair of upper and lower lock bars 42 so as not to move forward.

[0061] Next, the operation of the lower limb restraint airbag device 30 according to the first embodiment configured as described above will be described.

[0062] When a frontal collision of the vehicle 10 is detected or predicted, the inflator operates to eject gas. Then, the airbag 32 expands and deploys toward the knees K and shins S of the occupant P sitting on the vehicle seat 12 by the gas ejected from the inflator, and contacts at least the knees K. Here, the airbag 32 is connected by the reaction force plate 34 and the strap 36.

[0063] Therefore, as the airbag 32 expands and deploys, the reaction force plate 34 rotates about the rotation shaft 35 provided at its rear end portion 34B and is pulled out to the front side of the airbag 32. Then, the forward movement of the pulled-out reaction force plate 34 is blocked by the locking mechanism 40 (the reaction force plate 34 is fixed). That is, this reaction force plate 34 forms a reaction force surface against the airbag 32.

[0064] Therefore, the load from the knees K and shins S of the occupant P trying to move forward due to inertia can be effectively received by the airbag 32 supported by the reaction force plate 34. Thus, even when there is a large space in front of the knees K of the occupant P sitting on the vehicle seat 12 (far from the reaction force surface such as the instrument panel) when the vehicle seat 12 is moved backward greatly, the knees K of the occupant P can be effectively restrained (in particular, a sufficient restraining force at the initial stage of the collision can be ensured).

[0065] In addition, even when the occupant P sitting on the vehicle seat 12 is not wearing a seat belt, or even when wearing a seat belt but not sufficiently restrained by the lap belt in the seat belt due to a reclined comfortable position with the seat back 16 reclined significantly, the knees K of the occupant P can be effectively restrained.

[0066] Note that since an airbag 32 is interposed between the reaction plate 34 and the knees K of the occupant P, the knees K of the occupant P do not come into direct contact with the reaction plate 34 when the airbag 32 expands and deploys. Therefore, the impact on the knees K of the occupant P by the reaction plate 34 can be minimized or prevented.

[0067] Also, the inflator, the airbag 32, the reaction plate 34, and the lock mechanism 40 are respectively mounted on a pair of side walls 20 disposed on both left and right sides of the vehicle seat 12, and are for the right knee and left knee of the occupant P. Therefore, for example, compared with a configuration in which the side wall 20 is disposed on only one of the left and right sides and a single airbag (not shown) restrains the left and right knees K of the occupant P, the occurrence of poor restraint on the left knee or right knee of the occupant P can be suppressed.

[0068] Also, as described above, the reaction plate 34 is rotatably supported by a rotating shaft 35 on the side wall 20 and is connected by the airbag 32 and the strap 36. Therefore, pulling out the reaction plate 34 along with the expansion and deployment of the airbag 32 can be realized with a simple configuration.

[0069] Furthermore, the lock mechanism 40 includes a pair of upper and lower lock bars 42, one end 42A of which is slidably held in a guide groove 26 formed in the side wall 20, and the other end 42B of which is rotatably attached to the reaction plate 34. Each guide groove 26 has a recess 28 that non - movably accommodates one end 42A of each lock bar 42 after the reaction plate 34 is pulled out. Therefore, preventing the forward movement of the pulled - out reaction plate 34 (fixing the reaction plate 34) can be realized with a simple configuration.

[0070] Further, the side wall 20 is configured to be movable in the front-rear direction, and when the vehicle 10 is running, its rear end 20B is disposed on the front side of the front end 14F of the seat cushion 14 of the vehicle seat 12. Therefore, when the vehicle 10 is running, the lower limb restraint airbag device 30 can be surely put in standby.

[0071] Also, when the occupant P gets on and off the vehicle, its front end 20F is disposed at the same position as the front end 14F of the seat cushion 14 of the vehicle seat 12 or on the rear side thereof. Therefore, even in the configuration where the side wall 20 is provided, the influence on the getting-on and -off performance of the occupant P with respect to the vehicle 10 can be reduced.

[0072] Note that, as described above, the side wall 20 may be configured to move forward in conjunction with the reclining of the seat back 16 of the vehicle seat 12. According to this, when the occupant P takes a comfortable posture, compared with the case where the side wall 20 is not configured to move forward in conjunction with the reclining of the seat back 16 of the vehicle seat 12, the lower limb restraint airbag device 30 can be surely put in standby, so that the knees K and shins S of the occupant P can be surely and effectively restrained.

[0073] Also, as described above, if the rear end 20B of the side wall 20 is not disposed on the front side of the front end 14F of the seat cushion 14 of the vehicle seat 12, the seat back 16 of the vehicle seat 12 may be configured not to recline. According to this, when the occupant P can take a comfortable posture, since the lower limb restraint airbag device 30 is surely put in standby, the knees K and shins S of the occupant P can be surely and effectively restrained.

[0074] <Second Embodiment> Next, the second embodiment will be described. Note that the same reference numerals are given to the parts equivalent to those in the first embodiment, and the detailed description (including the common operations) is appropriately omitted.

[0075] As shown in FIGS. 7 and 8, in this second embodiment, only the configuration of the lock mechanism 40 is different from that of the first embodiment. That is, this lock mechanism 40 includes a striker 44 provided at the front end portion 34F on the outer surface of one (for example, the right side) reaction force plate 34R and a hook 46 provided at the front end portion 34F on the outer surface of the other (for example, the left side) reaction force plate 34L, instead of the pair of upper and lower lock bars 42 and the concave portion 28.

[0076] The striker 44 is formed in a substantially "C" shape in side view, and is integrally attached to the substantially central portion in the vertical direction facing the right knee portion K of the occupant P via the airbag 32 on the right reaction force plate 34R. The hook 46 is formed in a substantially "Σ" shape in plan view, and is integrally attached to the substantially central portion in the vertical direction facing the left knee portion K of the occupant P via the airbag 32 on the left reaction force plate 34L.

[0077] And as shown by the arrow in FIG. 8(A), the hook 46 is configured to be lockable to the striker 44 from the front side. That is, the claw portion 46A, which is the tip portion of the hook 46, is formed in a hook shape in plan view so as not to come off from the cylindrical portion 44A extending substantially in the vertical direction of the striker 44. As shown in FIG. 8(B), this claw portion 46A enters the inside (the reaction force plate 34R side) of the cylindrical portion 44A of the striker 44 from the front right side, and as shown in FIG. 8(C), it is configured to be locked to the cylindrical portion 44A.

[0078] Therefore, the left reaction force plate 34L provided with the hook 46 is configured to rotate later (with a time difference) than the right reaction force plate 34R provided with the striker 44. Specifically, the left reaction force plate 34L provided with the hook 46 is made heavier (a difference is given in the moment of inertia) than the right reaction force plate 34R provided with the striker 44. Therefore, it is possible to prevent the occurrence of a locking failure of the hook 46 with respect to the striker 44.

[0079] Then, by locking the hook 46 to the striker 44, the right reaction plate 34R and the left reaction plate 34L can be fixed, and reaction surfaces for each airbag 32 can be formed by the right reaction plate 34R and the left reaction plate 34L. That is, each airbag 32 supported by the right reaction plate 34R and the left reaction plate 34L can reliably restrain the left and right knees K of the occupant P.

[0080] And, the left reaction plate 34L provided with the hook 46 can be rotated later (with a time difference) than the right reaction plate 34R provided with the striker 44, and the forward movement of the pulled-out right reaction plate 34R and left reaction plate 34L can be blocked (the right reaction plate 34R and the left reaction plate 34L can be fixed) by a simple configuration.

[0081] Note that the configuration in which the left reaction plate 34L provided with the hook 46 is rotated later (with a time difference) than the right reaction plate 34R provided with the striker 44 is not limited to the above configuration.

[0082] For example, the ignition timing of the inflator that jets gas into the left airbag 32 connected by the strap 36 to the left reaction plate 34L provided with the hook 46 may be configured to be later than the ignition timing of the inflator that jets gas into the right airbag 32 connected by the strap 36 to the right reaction plate 34R provided with the striker 44. According to this, the left reaction plate 34L provided with the hook 46 can be rotated later (with a time difference) than the right reaction plate 34R provided with the striker 44 with high accuracy by a simple configuration.

[0083] Further, for example, as shown in FIG. 9, the hook 46 may be provided so as to be rotatable with respect to the left reaction plate 34L. That is, the corner portion 46C on the reaction plate 34L side at the base portion 46B of the hook 46 is rotatably supported by a rotation shaft 48 having a substantially vertical direction as the axial direction at the front end portion 34F on the outer surface of the reaction plate 34L. Then, after the right reaction plate 34R provided with the striker 44 and the left reaction plate 34L provided with the hook 46 are pulled out, the hook 46 rotates around the rotation shaft 48 by the inertial force generated by the pulling-out operation and is locked to the striker 44. It may be configured as follows.

[0084] According to this, it is possible to prevent the occurrence of poor locking of the hook 46 to the striker 44 (easily lock the hook 46 to the striker 44), and to prevent the right reaction plate 34R and the left reaction plate 34L pulled out from moving forward (fix the right reaction plate 34R and the left reaction plate 34L). This can be realized with a simple configuration.

[0085] <Third Embodiment> Finally, the third embodiment will be described. Note that the same reference numerals are given to the parts equivalent to those in the first embodiment, and detailed descriptions (including common operations) are omitted as appropriate.

[0086] As shown in FIG. 10, in this third embodiment, the inflator 38, the airbag 32, the reaction plate 34, and the lock mechanism 40 are mounted not on the pair of left and right side walls 20 but on the lower portion 52 of the instrument panel (hereinafter referred to as "IP") 50, and the single airbag 32 restrains the left and right knees K and shins S of the occupant P. The only difference from the first embodiment is that it is configured as follows.

[0087] Therefore, the size of the airbag 32 is formed to be larger in the left - right direction than the airbags 32 of the first and second embodiments so as to be able to restrain the left and right knee parts K and shin parts S of the occupant P. Also, this instrument panel 50 is a so - called thin - type instrument panel in which the length (thickness) along the vertical direction is reduced compared to the length along the front - rear direction in side view, and there is a wide space in front of the knee part K of the occupant P sitting on the vehicle seat 12.

[0088] In the lower part 52 of the instrument panel 50, a housing recess 54 similar to the housing recess 24 is formed, and the housing recess 54 is covered by a cover (not shown). Thereby, normally, the lower - limb restraint airbag device 30 etc. housed in the housing recess 54 are not visible from the outside. Note that this cover is configured to be cleaved by the inflation pressure when the airbag 32 expands and deployed, and does not inhibit the expansion and deployment of the airbag 32.

[0089] The reaction force plate 34 has its rear end portion 34B rotatably supported by a rotation shaft 35 having the left - right direction as the axial direction on the rear side in the lower part 52 of the instrument panel 50, and the substantially central portion on its lower surface is connected to the substantially central portion in the left - right direction at the lower end portion of the airbag 32 when it expands and deploys by a strap 36.

[0090] And as shown in FIG. 11, this reaction force plate 34 is formed in a substantially "concave" shape in bottom view, and the folded airbag 32 is arranged so as to overlap with a rectangular notch 34C formed in the central portion in the left - right direction of the rear end portion 34B in bottom view. Thereby, the reaction force plate 34 is configured not to inhibit the expansion and deployment of the airbag 32. That is, the airbag 32 can expand and deploy to the rear side of the reaction force plate 34 through the notch 34C.

[0091] The locking mechanism 40 includes a pair of left and right locking bars 42, one end 42A of which is slidably held in a guide groove 56 formed in the lower portion 52 of the instrument panel 50, and the other end 42B of which is rotatably attached to the upper surface of the reaction force plate 34. And at a predetermined portion in the left and right guide grooves 56, after the reaction force plate 34 is pulled out, recesses 58 for non-movably accommodating (immersing) one ends 42A of the respective locking bars 42 are integrally formed. Note that the configuration for preventing one ends 42A of the respective locking bars 42 from coming out of the respective guide grooves 56 is the same as that of the first embodiment.

[0092] According to the third embodiment having such a configuration, even when the length (thickness) along the vertical direction at the rear end portion of the instrument panel 50 is reduced and there is a wide space on the front side of the knees K of the occupant P sitting on the vehicle seat 12, the knees K of the occupant P can be effectively restrained. Moreover, since the reaction force plate 34 is rotatably supported by the lower portion 52 of the instrument panel 50 and is connected by the airbag 32 and the strap 36, pulling out the reaction force plate 34 along with the inflation and deployment of the airbag 32 can be realized with a simple configuration.

[0093] Also, as described above, the locking mechanism 40 includes a pair of left and right locking bars 42, one end 42A of which is slidably held in a guide groove 56 formed in the lower portion 52 of the instrument panel 50, and the other end 42B of which is rotatably attached to the reaction force plate 34. And the left and right guide grooves 56 have recesses 58 for non-movably accommodating one ends 42A of the respective locking bars 42 after the reaction force plate 34 is pulled out. Therefore, preventing the forward movement of the pulled-out reaction force plate 34 (fixing the reaction force plate 34) can be realized with a simple configuration.

[0094] As described above, the lower limb restraint airbag device 30 according to the present embodiment has been described with reference to the drawings. However, the lower limb restraint airbag device 30 according to the present embodiment is not limited to the one shown in the drawings, and can be appropriately designed and changed within the scope not departing from the gist of the present invention. For example, the inflator and the lower limb restraint airbag device 30 may be provided on the door trim (not shown) of the side door and the console box (not shown) instead of the pair of left and right side walls 20.

[0095] According to this, at least in a typical position (position determined by regulations) of the vehicle seat 12, the knee K and the shin S of the occupant P can be restrained. If there is no problem with the boarding and alighting of the occupant P with respect to the vehicle 10, the side walls 20 may be integrally provided via a connecting member (not shown) on both the left and right sides of the vehicle seat 12. According to this, since the side walls 20 move integrally with the vehicle seat 12, the knee K and the shin S of the occupant P can be restrained regardless of the position of the vehicle seat 12.

[0096] Further, in the lock mechanism 40 in the first embodiment and the third embodiment, instead of the pair of upper and lower or left and right lock bars 42, a rectangular flat lock plate (not shown) may be provided. In that case, one end and the other end of the lock plate may be formed to bulge into a columnar shape with a diameter larger than the plate thickness of the lock plate, and the guide grooves 26, 56 and the recesses 28, 58 may also be configured to be able to slide and accommodate one end of the lock plate, respectively.

Explanation of Reference Numerals

[0097] 10 Vehicle 12 Vehicle seat 14 Seat cushion 14F Front end 16 Seat back 20 Side wall 20B Rear end 26 Guide groove 28 Recess 30 Lower limb restraint airbag device 32 Airbag 34 Reaction plate 36 Strap 38 Inflator 40 Lock mechanism 42 Lock bar 42A One end 42B The other end 44 Striker 46 Hook 50 Instrument panel 52 Lower part 56 Guide groove 58 Recess K Knee P Occupant S Shin

Claims

1. An airbag that inflates and expands toward the knees and shins of an occupant sitting on a vehicle seat by gas ejected from an inflater and contacts at least the knees, and A reaction plate that is pulled out toward the front side of the seat of the airbag as the airbag inflates and expands, and A locking mechanism that prevents the pulled-out reaction plate from moving toward the front side of the seat. The inflater, the airbag, the reaction plate, and the locking mechanism are respectively mounted on a pair of side walls arranged on both left and right sides of the vehicle seat and are for the left knee and the right knee of the occupant. The reaction plate is rotatably supported by the side wall and is a lower limb restraint airbag device connected to the airbag by a strap.

2. The locking mechanism includes a lock bar having one end slidably held in a guide groove formed in the side wall and the other end rotatably attached to the reaction plate. The guide groove has a recess that non-movably accommodates the one end of the lock bar after the reaction plate is pulled out. The lower limb restraint airbag device according to Claim 1.

3. The locking mechanism includes a striker provided on either the left or right reaction plate, and a hook provided on the other reaction plate of either the left or right and locked to the striker. The reaction plate provided with the hook is configured to rotate later than the reaction plate provided with the striker. The lower limb restraint airbag device according to Claim 1.

4. The reaction plate provided with the hook is heavier than the reaction plate provided with the striker. The lower limb restraint airbag device according to Claim 3.

5.

6. The ignition timing of the inflator that injects gas into the airbag connected by the reaction plate provided with the hook and the strap is later than the ignition timing of the inflator that injects gas into the airbag connected by the reaction plate provided with the striker and the strap. The lower limb restraint airbag device according to claim 3.

6. The locking mechanism includes a striker provided on either the left or right reaction plate, a hook rotatably provided on the other reaction plate on either the left or right and locked to the striker, and after the reaction plate provided with the striker and the reaction plate provided with the hook are pulled out, the hook rotates and is locked to the striker. The lower limb restraint airbag device according to claim 1.

7. The side wall is configured to be movable in the front-rear direction of the seat. When the vehicle is running, the rear end thereof is disposed on the front side of the seat with respect to the front end of the seat cushion of the vehicle seat. When the occupant gets on or off the vehicle, the front end thereof is at the same position as the front end of the seat cushion of the vehicle seat or disposed on the rear side of the seat. The lower limb restraint airbag device according to any one of claims 1 to 6.

8. The side wall is configured to move toward the front side of the seat in conjunction with the reclining of the seat back of the vehicle seat. The lower limb restraint airbag device according to claim 7.

9. If the rear end of the side wall is not disposed on the front side of the seat with respect to the front end of the seat cushion of the vehicle seat, the seat back of the vehicle seat is configured not to recline. The lower limb restraint airbag device according to claim 7.

10. An airbag that expands and deploys toward the knees and shins of an occupant sitting on a vehicle seat by gas ejected from an inflator and contacts at least the knees, A reaction plate that is pulled out toward the front side of the seat of the airbag as the airbag expands and deploys; A locking mechanism that prevents the pulled-out reaction plate from moving toward the front side of the seat; and is provided with; The inflator, the airbag, the reaction plate, and the locking mechanism are respectively mounted on a pair of side walls arranged on both left and right sides of the vehicle seat and are for the left knee and the right knee of the occupant. The side wall is configured to be movable in the front-rear direction of the seat. When the vehicle is running, the rear end thereof is arranged on the front side of the seat relative to the front end of the seat cushion of the vehicle seat. When the occupant gets on and off the vehicle, the front end thereof is at the same position as the front end of the seat cushion of the vehicle seat or is arranged on the rear side of the seat relative to the front end of the seat cushion of the vehicle seat. A lower limb restraint airbag device.

11. The lower limb restraint airbag device according to claim 10, wherein the side wall is configured to move toward the front side of the seat in conjunction with the reclining of the seat back of the vehicle seat.

12. The lower limb restraint airbag device according to claim 10, wherein the seat back of the vehicle seat is configured not to recline if the rear end of the side wall is not arranged on the front side of the seat relative to the front end of the seat cushion of the vehicle seat.

13. An airbag that expands and deploys toward the knees and shins of an occupant sitting on a vehicle seat by gas ejected from an inflator and contacts at least the knees; A reaction plate that is pulled out toward the front side of the seat of the airbag as the airbag expands and deploys; A locking mechanism that prevents the pulled-out reaction plate from moving toward the front side of the seat; and is provided with; The inflator, the airbag, the reaction plate, and the locking mechanism are mounted on the lower part of the instrument panel. The reaction plate is rotatably supported on the lower part of the instrument panel and is connected to the airbag by a strap. A lower limb restraint airbag device.

14. The locking mechanism is It includes a lock bar with one end slidably held in a guide groove formed at the lower part of the instrument panel and the other end rotatably attached to the reaction force plate. The lower limb restraint airbag device according to claim 13, wherein the guide groove has a recess for non - movably accommodating the one end of the lock bar after the reaction force plate is pulled out.

Images