Occupant protection device

Abstract

Disclosed is an occupant protection device that contributes to an increase in waist restraint capability for an occupant. This occupant protection device (30) comprises: a push-up member (40) that can turn to push up a seating surface (26) of a seat cushion (2); and a drive device (50) that applies a force for the push-up member (40) to turn at the time of a vehicle emergency. The push-up member (40) has a front part (42) on a front side of a turn center (41) in the front–rear direction of a vehicle seat (100). The drive device (50) is disposed below the front part (42) of the push-up member (40) in a portion between the front part (42) and the turn center (41) of the push-up member (40) and applies the force to the front part (42) of the push-up member (40).

Description

Occupant protection devices

[0001] The present invention relates to an occupant protection device that is provided inside or below a seat cushion of a vehicle seat.

[0002] When a vehicle is involved in a frontal collision, the occupant tends to move forward due to inertia. Patent Document 1 describes an occupant protection device that, in the event of such a frontal collision, instantly inflates an airbag in the vehicle seat to raise the front end of the seat cushion, thereby restricting the forward movement of the occupant's lower back.

[0003] JP 2007-118820 A

[0004] In Patent Document 1, the airbag is fixed to the seat pan and directly pushes up the lower front end of the seat cushion when inflated. However, depending on the characteristics of the seat cushion (such as softness or thickness), the force or amount of pushing up by the airbag may be insufficient, and the behavior or direction of the pushing up may be unstable.

[0005] In addition, in Patent Document 1, when the airbag inflates, the front end of the seat cushion pushes up the occupant's knees. However, due to the mounting and positioning of the airbag relative to the vehicle seat, the occupant's knees are not sufficiently lifted. In order to effectively lift the occupant's knees, rather than lifting only the occupant's knees as in Patent Document 1, it is more desirable to lift up the area around the occupant's thighs near the buttocks, lifting the entire area from the occupant's thighs to the knees, and thereby applying a force that rotates the occupant's pelvis in a clockwise direction.

[0006] An object of the present invention is to provide an occupant protection device that contributes to improving the performance of restraining the lumbar region of an occupant.

[0007] An occupant protection device according to one aspect of the present invention is an occupant protection device that is provided inside or below the seat cushion of a vehicle seat, and includes a push-up member that can rotate to push up the seat surface of the seat cushion, and a drive device that applies a force to rotate the push-up member in the event of a vehicle emergency, wherein the push-up member has a front portion forward of the rotation center in the fore-and-aft direction of the vehicle seat, and the drive device is positioned below the front portion of the push-up member between the front portion of the push-up member and the rotation center, and is configured to apply the force to the front portion of the push-up member.

[0008] According to this aspect, the drive unit is disposed near (below) the portion (front portion) of the push-up member that receives the force, so the force from the drive unit can be applied immediately (i.e., directly or without dissipating the force) to the front portion of the push-up member, which makes it easier to ensure the force / amount of push-up on the seat surface.

[0009] Furthermore, since the push-up is not caused by the airbag itself as in the conventional case, but by a rotating push-up member, the push-up follows the path of the rotation, which makes it easier to stabilize the behavior or direction of the push-up.

[0010] The direction of this rotation can be a direction in which a force acts to rotate the occupant's pelvis in a clockwise direction. Therefore, if the push-up member is positioned to push up the area near the thighs of an occupant who is seated on the seat cushion in the correct posture and wearing a seat belt, the entire area from the occupant's thighs to the knees can be lifted, and a clockwise rotational force can be applied to the occupant's pelvis. This reduces forward movement of the occupant's waist and prevents the submarine phenomenon, thereby improving the occupant's waist restraint performance.

[0011] Another aspect of the present invention is an occupant protection device that is provided inside or below the seat cushion of a vehicle seat, and includes an inflatable airbag cushion, an inflator that supplies gas for inflation and deployment to the internal space of the airbag cushion in the event of a vehicle emergency, and an inclined portion that is located on the rear side when the seat cushion is divided into front and rear halves at the center position in the fore-and-aft direction and is inclined upward toward the front, and the airbag cushion is located either above or below the inclined portion, or both above and below the inclined portion, and is configured so that when the airbag cushion inflates and deploys, the airbag cushion and / or the inclined portion pushes up the seat surface of the seat cushion diagonally rearward.

[0012] According to this aspect, because the inclined portion is disposed relatively rearward of the seat cushion, the inclined portion, which is inflated and deployed by the airbag cushion, and / or the airbag cushion, which is inflated and deployed using the inclined portion as a reaction force surface, can push up the vicinity of the thighs near the buttocks of the occupant (assuming the occupant is seated on the seat cushion in a normal posture and fastening a seat belt) diagonally rearward. This, as in the case described above, can impart a clockwise rotational force to the occupant's pelvis. Therefore, forward movement of the occupant's lower back can be reduced, and the occurrence of the submarine phenomenon can be suppressed, thereby improving the occupant's lower back restraint performance.

[0013] 1A is a perspective view showing the external shape of a vehicle seat provided with an occupant protection device according to a first embodiment. FIG. 1B is a perspective view showing an internal frame structure of the vehicle seat of FIG. 1A. FIG. 1C is a view showing an occupant protection device according to the first embodiment in a side cross section of the vehicle seat. FIG. 1D is a view explaining the arrangement and operation of the occupant protection device according to the first embodiment in relation to an occupant, where (a) shows a normal state, (b) shows an early stage of a vehicle emergency, and (c) shows a middle or later stage of a vehicle emergency. FIG. 1E is a view showing a modified example of the drive device according to the first embodiment, where (a) is an overall view similar to FIG. 2 and (b) is an enlarged view of part B of (a). FIG. 1F is a view showing an occupant protection device according to a second embodiment in a side cross section of the vehicle seat. FIG. 1G is a view showing an occupant protection device according to a modified embodiment of the second embodiment. FIG. 1H is a view explaining the arrangement and operation of the occupant protection device according to the second embodiment in relation to an occupant, where (a) shows a normal state, (b) shows a middle stage of a vehicle emergency, and (c) shows a later stage of a vehicle emergency. FIG. 1H is a view for explaining the effect of the occupant protection device according to the second embodiment from another perspective, where (a) shows a comparative example and (b) shows the second embodiment. 10 is a diagram showing an occupant protection device according to another modified example of embodiment 2. FIG. 11 is a diagram showing an occupant protection device according to yet another modified example of embodiment 2. FIG. 12 is a diagram showing an occupant protection device according to yet another modified example of embodiment 2.

[0014] An occupant protection device according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In this specification, up / down, left / right, and front / rear are defined as follows. When an occupant is seated in a seat (vehicle seat) in a normal posture, the direction the occupant faces is referred to as the forward direction, and the opposite direction is referred to as the rearward direction, and the axes of coordinates are referred to as the front / rear direction. Furthermore, when an occupant is seated in a vehicle seat in a normal posture, the right side of the occupant is referred to as the right direction, and the left side of the occupant is referred to as the left direction, and the axes of coordinates are referred to as the left / right direction. Similarly, when an occupant is seated in a normal posture, the direction of the occupant's head is referred to as the upward direction, and the direction of the occupant's waist is referred to as the downward direction, and the axes of coordinates are referred to as the up / down direction.

[0015] In addition, in this document, "occupant" refers to a person with a physique equivalent to that of an average American man, conforming to the frontal collision test dummy (Hybrid III AM50 / frontal collision test dummy established by the NHTSA [National Highway Traffic Safety Administration] standard [49CFR Part 572 Subparts E and O]), with approximate dimensions of 175 cm in height, 88 cm in seated height, and 78 kg in weight.

[0016] [Embodiment 1] As described above, a problem with conventional occupant protection devices that are provided inside or below the seat cushion of a vehicle seat is that, for example, the airbag directly pushes the lower front end of the seat cushion upward (vertically), and the force or amount of pushing up by the airbag is insufficient to effectively lift the knees of the occupant.

[0017] To solve this problem, the occupant protection device according to the first embodiment includes a push-up member that can rotate to push up the seat surface of the seat cushion, and a drive device that applies a force to rotate the push-up member in the event of a vehicle emergency. The push-up member has a front portion forward of the rotation center in the front-to-rear direction of the vehicle seat, and the drive device is disposed below the front portion of the push-up member between the front portion of the push-up member and the rotation center, and is configured to apply the force to the front portion of the push-up member.

[0018] A specific example of the occupant protection device according to the first embodiment will be described below with reference to FIGS. 1A to 4. FIG.

[0019] 1A and 1B, a vehicle seat 100 includes a seat back 1 that supports the back of an occupant, a seat cushion 2 on which the occupant sits, and a headrest 3 that supports the head of the occupant. The vehicle seat 100 is, for example, a driver's seat or a passenger seat, but may also be a rear seat.

[0020] A back frame 10 and a seat frame 20, which form the framework of the seat, are provided inside the seat back 1 and the seat cushion 2, respectively. The back frame 10 and the seat frame 20 are made of processed metal parts or hard resin, and are connected to each other via a reclining mechanism 4. The seat frame 20 has a pair of side frames 22, 22 spaced apart on the left and right, and a seat pan 24 (see FIG. 2) is installed between the front portions of the pair of side frames 22, 22. The seat pan 24 is located below the front portion of the seat cushion 2, and springs 25 that support the seat cushion 2 are provided behind the seat pan 24.

[0021] The seat cushion 2 includes, for example, a seat pad made of urethane foam or the like that covers the surface and periphery of the seat frame 20, and a seat cover made of leather, fabric, or the like that covers the surface of the seat pad. The upper surface of the seat cover forms the surface on which the occupant sits, i.e., the seating surface 26 of the seat cushion 2.

[0022] The occupant protection device 30 is provided inside or below the seat cushion 2. For example, the occupant protection device 30 is provided inside the seat cushion 2 and covered by a seat cover. In this case, the occupant protection device 30 may be provided on the upper surface of the seat pan 24. Alternatively, if a seat pan 24 is not provided, the occupant protection device 30 may be provided on the seating frame 20. In another example, the occupant protection device 30 is provided below the seat cushion 2 rather than inside the seat cushion 2. In this case, for example, the occupant protection device 30 is attached to a bracket fixed to the vehicle seat 100 below the seat cushion 2. An example in which the occupant protection device 30 is provided on the upper surface of the seat pan 24 will be described below.

[0023] 2, the occupant protection device 30 includes a push-up member 40 that can rotate to push up the seat surface 26 of the seat cushion 2, and a drive device 50 that applies a force to rotate the push-up member 40 in the event of a vehicle emergency. An example of a vehicle emergency is a frontal collision of the vehicle.

[0024] The push-up member 40 has a front portion 42 located forward of the rotation center 41. The front portion 42 is a portion that includes the front end 42a of the push-up member 40 and refers to the portion of the push-up member 40 that is on the front side. For example, if the push-up member 40 is cut in half at the midpoint in the front-to-rear direction, it can be said that the front half includes at least the front portion 42, and the rear half includes at least the rear portion 43. As will be described in detail later, the force from the drive device 50 to the push-up member 40 is not applied to the rear portion 43, but is applied only to the front portion 42.

[0025] The rear end of the push-up member 40 is rotatably supported by the seat pan 24, and this rear end (supported portion) serves as the rotation center 41. In another embodiment, the rear end of the push-up member 40 may be rotatably supported by the seat frame 20 or the pair of side frames 22, 22 instead of the seat pan 24.

[0026] The push-up member 40 is made of a hard material (e.g., metal or hard resin). For example, the push-up member 40 is formed in a plate shape using a material harder than the seat cushion 2 and an airbag cushion 52 (described later).

[0027] The push-up member 40 is disposed between the seat cushion 2 and the seat pan 24 and extends in the left-right direction. The push-up member 40 is located between the pair of side frames 22, 22, and the length in the left-right direction (i.e., width) of the push-up member 40 is, for example, slightly shorter than the length between the pair of side frames 22, 22.

[0028] The push-up member 40 is bent once in the front-to-rear direction between the rotation center 41 and the front portion 42. This bent point 44 is located above an imaginary line connecting the rotation center 41 and the front end 42a of the front portion 42. In other words, when extending forward from the rotation center 41 toward the front portion 42, the push-up member 40 extends upward from the rotation center 41, and then changes angle at the bent point 44 and extends toward the front end 42a.

[0029] The front portion 42 of the push-up member 40 extends parallel to the support surface 24a of the seat pan 24. Here, the support surface 24a is flat and substantially horizontal. A portion 45 of the front portion 42 from the front end 42a to the bent portion 44 is parallel to the support surface 24a and extends substantially horizontally. On the other hand, a portion 46 from the bent portion 44 to the pivot center 41 is not parallel to the support surface 24a but forms an acute angle with respect to the support surface 24a and is inclined upward toward the front. The former straight portion 45 is longer in the front-to-rear direction than the latter inclined portion 46.

[0030] The front end 42a of the push-up member 40 faces the front wall 24b of the seat pan 24. The front wall 24b extends upward from the front end of the support surface 24a of the seat pan 24, and the push-up member 40 is located lower than the upper end 24c of the front wall 24b. In this example, the front wall 24b has an inverted U-shaped cross section, with the folded-back portion of this U forming the upper end 24c. A space is defined between the push-up member 40 and the support surface 24a, and a drive unit 50 is provided in the front portion of this space.

[0031] The drive unit 50 is disposed below the front portion 42 of the push-up member 40, between the front portion 42 and the rotation center 41. The drive unit 50 is configured to apply a force (hereinafter referred to as a "rotational force") that rotates the push-up member 40 to the front portion 42. In other words, the rotational force from the drive unit 50 to the push-up member 40 is not applied to the rear portion 43, but is applied only to the front portion 42.

[0032] The drive device 50 includes an inflatable airbag cushion 52 and an inflator 54 that supplies gas for inflation into the interior space of the airbag cushion 52 in the event of a vehicle emergency.

[0033] The inflator 54 is electrically connected to the vehicle ECU. For example, the inflator 54 is activated upon receiving a signal from the vehicle ECU detecting an impact during a frontal collision of the vehicle, and instantly supplies gas to the airbag cushion 52. Various inflators can be used as the inflator 54, including those filled with a gas generating agent, compressed gas, or both. For example, the inflator 54 has an ignition device at the open end of a bottomed cylindrical body. The ignition device ignites the gas generating agent inside the cylindrical body to generate gas, which is then supplied to the airbag cushion 52 through multiple nozzles on the circumferential surface of the cylindrical body.

[0034] The airbag cushion 52 is a bag that inflates and deploys when supplied with gas from the inflator 54. The airbag cushion 52 is formed by joining (for example, sewing or gluing) multiple sheets of base fabric, such as nonwoven fabric, at appropriate positions. The airbag cushion 52 is placed on the support surface 24a of the seat pan 24, for example, in a folded state. The airbag cushion 52 may be folded in any manner, such as into an accordion shape, a roll shape, or a combination thereof.

[0035] The airbag cushion 52 can be attached to the seat pan 24 by various methods. For example, the front and rear portions and / or the middle portion of the airbag cushion 52 can be attached to the seat pan 24 using fasteners such as bolts or rivets. In this case, the attachment points of the airbag cushion 52 to the seat pan 24 may also serve as attachment points for attaching the inflator 54 to the seat pan 24. For example, if the inflator 54 is a cylindrical body with a bottom as described above, the axis of the cylindrical body is aligned with the left-right direction and housed inside the airbag cushion 52. Then, stud bolts 54a protruding from the outer periphery of the cylindrical body protrude outside the airbag cushion 52 and are inserted into the seat pan 24 from the mounting surface 24a side, and are fastened to the seat pan 24 by nuts 54b. In this manner, the inflator 54 and the airbag cushion 52 are fastened together to the mounting surface 24a of the seat pan 24 by the stud bolts 54a and nuts 54b.

[0036] The airbag cushion 52 and the inflator 54 are located below the front portion 42 of the push-up member 40. When gas is supplied from the inflator 54, the airbag cushion 52 begins to inflate and deploy below the front portion 42 of the push-up member 40, contacts the underside of the front portion 42, and applies a rotational force to the front portion 42. The push-up member 40 to which the rotational force is applied rotates clockwise about the rotation center 41, and pushes up the lower portion of the seat cushion 2, and pushes up the seat surface 26.

[0037] 3A and 3B are diagrams illustrating the arrangement and operation of the occupant protection device 30 in relation to the occupant P. (a) shows a normal state, (b) shows an early stage of a vehicle emergency, and (c) shows a middle or late stage of a vehicle emergency.

[0038] 3A, an occupant P is seated on the seat cushion 2 in a normal posture and wearing a seat belt (not shown). The occupant protection device 30 is disposed in a position where the push-up member 40 pushes up the vicinity of the thighs near the buttocks of the occupant P. For example, the rotation center 41 of the push-up member 40 is located below the thighs of the occupant P near the buttocks.

[0039] As shown in Figure 3(b) , in the initial stage of a vehicle emergency, the inflator 54 first instantaneously supplies gas to the airbag cushion 52. The airbag cushion 52 then begins to inflate and deploy below the front portion 42 of the push-up member 40. At this time, the airbag cushion 52 inflates and deploys upward, with the support surface 24a of the seat pan 24 serving as a reaction surface. The airbag cushion 52 is also urged to inflate and deploy upward, with the front wall 24b of the seat pan 24 serving as a reaction surface. That is, as the airbag cushion 52 inflates and deploys forward, it comes into contact with the front wall 24b and, receiving a reaction force from the front wall 24b, continues to inflate and deploy upward, which is the direction in which the front wall 24b extends.

[0040] Then, the airbag cushion 52, which is inflating upward, immediately hits the front portion 42 of the push-up member 40 and applies a rotational force to the front portion 42. As a result, the push-up member 40 begins to rotate. The push-up member 40 rotates along an arc trajectory centered on the rotation center 41, pushing up the lower portion of the seat cushion 2 and pushing up the seat surface 26. After the push-up force begins to be input from the front portion 42 of the push-up member 40 to the seat cushion 2, the seat surface 26 of the seat cushion 2 begins to be pushed up by the entire portion of the push-up member 40 that was initially horizontal (portion 45 from the front end 42a of the front portion 42 to the bent portion 44).

[0041] At this time, in relation to the occupant P, the push-up member 40 begins to lift the vicinity of the thighs close to the buttocks of the occupant P via the seat surface 26. Note that in the event of a frontal collision of the vehicle, the occupant P will tend to move forward due to inertia, but the lumbar region is restrained by the seat belt, restricting the forward movement of the lumbar region.

[0042] As shown in Figure 3(c) , as the airbag cushion 52 continues to inflate and deploy, the push-up member 40 rotates further, further pushing up the seat surface 26. The push-up member 40 rotates at an angle of, for example, a maximum of 5 degrees or more, preferably 10 to 20 degrees, relative to the support surface 24a of the seat pan 24. Note that when the airbag cushion 52 inflates and deploys, it does not come into contact with the rear portion 43 of the push-up member 40. In other words, a space is maintained between the rear portion 43 of the push-up member 40 and the seat pan 24.

[0043] In relation to the occupant P, the push-up member 40 further lifts the area near the thighs of the occupant P, close to the buttocks, via the seat surface 26, and lifts the entire portion of the occupant P from the thighs to the knees. This acts to rotate the pelvis of the occupant P in a clockwise direction. This action prevents the vertebrae of the occupant P from being pushed up, and keeps the spine of the occupant P downward. In other words, because the spine is not pushed up, no phase difference occurs in the ribs, and no burden is placed on the chest of the occupant P, while suppressing forward movement of the waist of the occupant P and preventing the submarine phenomenon.

[0044] As described above, the occupant protection device 30 of embodiment 1 comprises a push-up member 40 that can rotate to push up the seat surface 26 of the seat cushion 2, and a drive unit 50 that applies a force to rotate the push-up member 40 in the event of a vehicle emergency, the push-up member 40 has a front portion 42 that is forward of the rotation center 41 in the fore-and-aft direction of the vehicle seat 100, and the drive unit 50 is positioned below the front portion 42 of the push-up member 40 between the front portion 42 of the push-up member 40 and the rotation center 41, and is configured to apply the force to the front portion 42 of the push-up member 40.

[0045] According to this configuration, the drive unit 50 is disposed near (below) the portion of the push-up member 40 that receives the force (the front portion 42), so that the force from the drive unit 50 can be applied immediately (i.e., directly or without dissipating the force) to the front portion 42 of the push-up member 40. This makes it easier to ensure the force / amount of push-up on the seat surface 26. Furthermore, because the push-up is not caused by the airbag itself but by the rotating push-up member 40, the push-up follows the trajectory of the rotation. This makes it easier to stabilize the behavior or direction of the push-up. Furthermore, this rotation direction acts as a force that rotates the pelvis of the occupant P in a clockwise direction, which contributes to improving the lumbar restraint performance of the occupant P, for example by suppressing the occurrence of the submarine phenomenon described above.

[0046] In particular, in one aspect of embodiment 1, the drive unit 50 includes an inflatable airbag cushion 52 and an inflator 54 that supplies gas for inflation to the internal space of the airbag cushion 52 in the event of a vehicle emergency, and the airbag cushion 52 is configured to begin inflation and deployment below the front portion 42 of the push-up member 40 and apply the force to the front portion 42 of the push-up member 40.

[0047] With this configuration, the push-up member 40 functions as a pressure-receiving plate that receives the inflation and deployment force of the airbag cushion 52, and the inflation and deployment force of the airbag cushion 52 can be applied to the front part 42 of the push-up member 40 without being released.

[0048] In one aspect of the first embodiment, the airbag cushion 52 is configured to be out of contact with the rear portion 43 of the push-up member 40 when inflated and deployed.

[0049] With this configuration, the inflation and deployment force of the airbag cushion 52 can be input in a concentrated manner to the front portion 42 of the push-up member 40 .

[0050] In one aspect of the first embodiment, the airbag cushion 52 is disposed on the support surface 24a of the seat pan 24 and is configured to inflate and deploy upward with the support surface 24a as a reaction surface.

[0051] This configuration can promote the rotation of the push-up member 40. In particular, since the mounting surface 24a is a flat surface, it is possible to improve the ease with which the airbag cushion 52 can be inflated and deployed upward and the ease with which the airbag cushion 52 can be positioned.

[0052] In one aspect of the first embodiment, the push-up member 40 has a bent portion 44 above an imaginary line connecting the front end 42 a of the front portion 42 and the rotation center 41 .

[0053] With this configuration, the front portion 42 of the push-up member 40 can start pushing up the seat surface 26 at an earlier timing than when it is not bent. Also, the space below the front portion 42 of the push-up member 40 can be made smaller than when it is not bent. This makes it possible to minimize the distance between the front portion 42 of the push-up member 40 and the input portion of the rotational force from the drive unit 50 (here, the airbag cushion 52), allowing the rotational force to be input to the front portion 42 efficiently, and also allows the front portion 42 to be separated as far as possible from the seat surface 26, thereby minimizing the impact of the push-up member 40 on sitting comfort during normal operation.

[0054] The above-described first embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The elements of the first embodiment, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0055] For example, the drive device 50 may be something other than the combination of the airbag cushion 52 and the inflator 54. For example, the drive device 50 may include various structures such as various actuators such as a motor, a piston, a gear mechanism, a cam mechanism, a slide mechanism, etc. An example will be described below.

[0056] 4 , the drive device 50 includes a power source 72 and a power transmission unit 74 that connects the power source 72 to the lift-up member 40 and transmits power from the power source 72 to the lift-up member 40 to apply a rotational force to the front portion 42 of the lift-up member 40. The power transmission unit 74 includes, for example, a piston connected to the underside of the front portion 42 of the lift-up member 40 and a cylinder that slidably houses the piston. The power source 72 is, for example, a gas generator that can supply high-pressure gas into the cylinder, is electrically connected to the vehicle-side ECU, and, similar to the inflator 54, is activated based on a signal received from the vehicle-side ECU. When the power source 72 is activated, high-pressure gas is supplied into the cylinder, and the high-pressure gas moves the piston, thereby applying a rotational force to the front portion 42 of the lift-up member 40.

[0057] [Embodiment 2] Conventional passenger protection devices have other or related problems. Specifically, because conventional airbag cushions are mounted on flat or low-angle seat pans, the airbag cushions tend to roll toward the front of the vehicle or collapse when an occupant is restrained. When an occupant moves forward in a frontal collision, if the occupant reaches the apex of the inflated portion (e.g., spherical shape) of the airbag cushion, the occupant is less likely to receive reaction force from the airbag cushion when moving further forward. As a result, restraint performance is reduced, allowing the occupant's hips to rotate forward and the upper torso to move forward. The impact of these problems can be greater in conventional configurations in which the airbag cushion is located relatively far forward on the seat cushion.

[0058] To solve this problem, the occupant protection device according to the second embodiment adopts a different approach from that of the occupant protection device according to the first embodiment. Specifically, the occupant protection device according to the second embodiment is an occupant protection device provided inside or below a seat cushion of a vehicle seat, and includes an inflatable airbag cushion, an inflator that supplies inflation gas to the interior space of the airbag cushion in the event of a vehicle emergency, and an inclined portion that is disposed rearward when the seat cushion is divided into front and rear halves at a center position in the front-to-rear direction and inclines upward toward the front. The airbag cushion is disposed above or below the inclined portion, or both above and below the inclined portion. When the airbag cushion inflates and deploys, the airbag cushion or the inclined portion pushes up the seat surface of the seat cushion diagonally rearward.

[0059] 5 to 11, a specific example of an occupant protection device according to the second embodiment will be described below. However, for components related to or similar to those in the first embodiment, the description will be omitted and the same or similar reference numerals will be used.

[0060] 5, the occupant protection device 230 includes an inflatable airbag cushion 252, an inflator 254 that supplies gas for inflation into the internal space of the airbag cushion 252 in the event of a vehicle emergency, and an inclined portion 255 that is disposed on the rear side when the seat cushion 2 is divided into front and rear halves at the center position in the front-to-rear direction and is inclined upward toward the front. Here, the airbag cushion 252, the inflator 254, and the inclined portion 255 are provided inside the seat cushion 2.

[0061] The airbag cushion 252 and the inflator 254 are similar to the airbag cushion 52 and the inflator 54 of the first embodiment. However, the airbag cushion 252 is disposed above the inclined portion 255. Here, the airbag cushion 252 is disposed on the upper surface of the inclined portion 255. The airbag cushion 252 inflates and deploys using the inclined portion 255 as a reaction surface, pushing up the sitting surface 26 of the seat cushion 2. The direction in which the airbag cushion 252 is urged to inflate and deploy is a direction perpendicular to the inclination direction of the inclined portion 255, which is a direction in which the sitting surface 26 is pushed up diagonally rearward.

[0062] The inclined portion 255 can be made of metal, resin, or the like, but is made of a material harder than the airbag cushion 252 and has high rigidity. For example, the inclined portion 255 has strength characteristics similar to those of an iron plate. The inclined portion 255 has enough rigidity to not deform even when subjected to a force from the airbag cushion 252 that is inflating or has already been inflated and deployed.

[0063] The ramp portion 255 can be configured as part of the seat pan 24. In other embodiments, the ramp portion 255 can be separate from the seat pan 24 (see FIG. 6). If separate, the ramp portion 255 can be a plate fixedly or movably attached to the seat pan 24. In still other embodiments, the ramp portion 255 does not need to be attached to the structure of the vehicle seat 100 (e.g., the seating frame 20, the seat pan 24).

[0064] 5, in which the inclined portion 255 is configured as part of the seat pan 24, the seat pan 24 can also be considered to be angled. This angle is larger than that of conventional seat pans. Specifically, the angle of inclination relative to the horizontal plane is, for example, 5 to 15 degrees larger than that of conventional seat pans that are flat or have a low angle. By setting the angle within this range, it becomes easier to achieve both seating comfort in the vehicle seat under normal conditions, reduced hip movement of the occupant P, improved restraint performance, and reduced chest deflection in the event of a vehicle emergency.

[0065] The inclined portion 255 and the airbag cushion 252 are disposed on the rear side of the seat cushion 2 in the front-to-rear direction. In relation to the occupant P, the highest point of the inclined portion 255 and the airbag cushion 252 is forward of the ischial bones of the occupant P and closer to the occupant P's waist. This position can be, for example, about 50 to 100 mm rearward from a conventional position. By setting the inclined portion 255 and the airbag cushion 252 in this manner, in the event of a vehicle emergency, the initial restraint can be accelerated and a ride-down effect can be obtained. In other words, the initial load input to the occupant P's waist is accelerated, which makes it easier to obtain the ride-down effect and accelerates waist rebound.

[0066] Furthermore, the inclined portion 255 and the airbag cushion 252 are positioned relatively high in the vertical direction within the seat cushion 2. This position is preferably closer to the waist, taking into consideration the reaction force and seating comfort. This improves the initial restraint performance in a vehicle emergency, keeps the occupant P's waist at the same height, and suppresses the amount of movement of the upper torso, which is effective in reducing the amount of chest deflection.

[0067] 7A and 7B are diagrams illustrating the arrangement and operation of the occupant protection device 230 in relation to the occupant P. (a) shows a normal state, (b) shows a middle stage of a vehicle emergency, and (c) shows a later stage of a vehicle emergency. In FIG. 7, the left side shows a comparative example, and the right side shows the second embodiment. The comparative example uses a conventional seat pan 24', which has a lower angle than the seat pan 24 (inclined portion 255) according to the second embodiment.

[0068] 7A, an occupant P is seated in the seat cushion 2 in a normal position and wearing a seat belt (not shown). In the event of a vehicle emergency, the inflator 254 first instantaneously supplies gas to the airbag cushion 252. The airbag cushion 252 then begins to inflate and deploy, inflating and deploying diagonally rearward with the inclined portion 255 acting as a reaction surface.

[0069] As shown in FIG. 7B, in the middle stage of a vehicle emergency, the inflating and deploying airbag cushion 252 pushes the seat surface 26 diagonally rearward. In relation to the occupant P, the airbag cushion 252 lifts the area of ​​the occupant P's thighs near the buttocks via the seat surface 26. This acts to rotate the pelvis of the occupant P in a clockwise direction (rotating the waist backward). As shown in FIG. 7C, this lifting force and rotational force are greater than those of the comparative example. As a result, forward movement of the occupant P's waist and chest is reduced in the later stage of a vehicle emergency.

[0070] As described above, according to the occupant protection device 230 of the second embodiment, the inclined portion 255 is disposed relatively rearward of the seat cushion 2, and therefore the inflated and deployed airbag cushion 252 can push up the vicinity of the thighs near the buttocks of the occupant P (assuming the occupant P is seated on the seat cushion in a normal posture and fastening a seat belt) diagonally rearward. This can impart a clockwise rotational force to the pelvis of the occupant P. This can reduce forward movement of the lumbar region of the occupant P and also suppress the occurrence of the submarine phenomenon, thereby improving the occupant lumbar restraint performance.

[0071] In particular, the occupant protection device 230 has an inflatable airbag cushion 252 attached to a seat pan 24 that is angled more than conventional ones, and can reduce the flexion of the occupant's chest by bending the occupant's waist backward when the airbag is inflated and deployed.

[0072] 8A and 8B are diagrams for explaining the effects of the second embodiment from another perspective, where (a) shows a comparative example and (b) shows the second embodiment. The comparative example does not include the occupant protection device 230. Compared to the comparative example, the second embodiment has the following effects.

[0073] That is, when the in-seat airbag cushion 252 deploys to restrain the occupant P's waist, it exerts a force that pushes upward on the waist and the entire spine connected to it. This causes the spine behind the occupant P's sternum to move upward while remaining stationary in the fore-and-aft direction of the vehicle. Since this movement occurs during a frontal collision, a force that moves the occupant P relatively forward is applied to the occupant P. However, as a result of the deployment of the in-seat airbag cushion 252, a force that moves upward from the occupant P's waist to the spine is applied, as described above, and the occupant P's sternum therefore moves downward and forward in front of the occupant P. At this time, the occupant P's sternum falls forward and diagonally downward, which limits the reduction in the distance between the occupant P and the seat belt 300 and airbag cushion 310 relative to the direction of movement of the tip of the sternum (i.e., increases the gap). As a result, chest deflection due to the force applied to the occupant P from the seat belt 300 and airbag cushion 310 can be suppressed.

[0074] Next, some other aspects of the second embodiment will be described.

[0075] As shown in FIG. 9 , in another embodiment, multiple airbag cushions may be provided in the front-to-rear direction. For example, the airbag cushions may include a front airbag cushion 252a and a rear airbag cushion 252b. Correspondingly, inflators 254a and 254b are also provided separately, and the front airbag cushion 252a and the rear airbag cushion 252b are configured to inflate and deploy independently of each other. This configuration allows for restraint and hip rotation to be maintained with two push-ups in the event of a vehicle emergency. In particular, forward bending of the hips and movement of the upper torso of the occupant P can be further reduced during later restraint in the event of a vehicle emergency.

[0076] As shown in Fig. 10, the airbag cushion 252 may be disposed below the inclined portion 255. In this case, the inflated airbag cushion 252 moves the inclined portion 255 so that the inclination angle with respect to the horizontal plane increases, thereby pushing up the sitting surface 26 of the seat cushion 2. The inclined portion 255 may function in the same manner as the push-up member 40 of the first embodiment. For example, the inclined portion 255 is made of a plate separate from the seat pan 24, and is rotatably supported on the seat pan 24. The inclined portion 255 may be formed of a material with higher rigidity than the seat pan 24.

[0077] As shown in Fig. 11 , airbag cushions may be arranged both above and below the inclined portion 255. Specifically, the airbag cushion includes an upper airbag cushion 252-1 arranged above the inclined portion 255 and a lower airbag cushion 252-2 arranged below the inclined portion 255. The upper airbag cushion 252-1 is configured to inflate and deploy using the inclined portion 255 as a reaction force surface to push up the seat surface 26. The lower airbag cushion 252-2 is configured to move the inclined portion 255 by inflating and deploying so that the inclination angle with respect to the horizontal plane increases. In other words, the aspect shown in Fig. 11 corresponds to a combination of the aspect shown in Fig. 6 and the aspect shown in Fig. 10 .

[0078] The upper airbag cushion 252-1 and the lower airbag cushion 252-2 are configured to be inflatable and deployable independently of each other. Therefore, the upper airbag cushion 252-1 and the lower airbag cushion 252-2 are supplied with inflation gas by inflators 254-1, 254-2 provided individually corresponding to the upper airbag cushion 252-1 and the lower airbag cushion 252-2. By providing the upper airbag cushion 252-1 in addition to the lower airbag cushion 252-2, the occupant's hips can be further encouraged to rotate backward in the event of a vehicle emergency.

[0079] The above-described second embodiment and several implementations thereof are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the second embodiment, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0080] <Additional Considerations Regarding Various Embodiments> [Embodiment A-1] An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: a push-up member that can rotate so as to push up the seat surface of the seat cushion; and a drive device that applies a force that causes the push-up member to rotate in the event of a vehicle emergency, wherein the push-up member has a front portion that is forward of the rotation center in the fore-and-aft direction of the vehicle seat, and the drive device is positioned below the front portion of the push-up member between the front portion of the push-up member and the rotation center, and is configured to apply the force to the front portion of the push-up member.

[0081] [Embodiment A-2] The occupant protection device described in embodiment A-1, wherein the drive device includes an inflatable airbag cushion and an inflator that supplies gas for inflation to the internal space of the airbag cushion in the event of a vehicle emergency, and the airbag cushion is configured to begin inflation and deployment below the front portion of the push-up member and apply the force to the front portion of the push-up member.

[0082] [Embodiment A-3] The occupant protection device according to embodiment A-1 or A-2, wherein the airbag cushion is configured so as not to come into contact with the rear portion of the push-up member when inflated and deployed.

[0083] [Embodiment A-4] An occupant protection device according to embodiment A-2 or A-3, wherein the airbag cushion is disposed on a support surface of the seat pan and configured to inflate and deploy upward using the support surface as a reaction force surface.

[0084] [Embodiment A-5] The occupant protection device according to embodiment A-4, wherein the mounting surface is a flat surface.

[0085] [Embodiment A-6] The occupant protection device according to embodiment A-4 or A-5, wherein the front portion of the push-up member extends parallel to the placement surface.

[0086] [Embodiment A-7] An occupant protection device according to any one of embodiments A-4 to A-6, wherein the push-up member is bent once between the front portion and the pivot center, and the portion from the bent point to the front end of the front portion extends parallel to the placement surface.

[0087] [Embodiment A-8] An occupant protection device according to embodiment A-7, wherein the push-up member is inclined upward and forward in the front-to-rear direction of the vehicle seat from the rotation center to the bent portion.

[0088] [Embodiment A-9] An occupant protection device according to embodiment A-8, wherein the portion of the push-up member from the front end of the front portion to the bent point is longer than the portion from the bent point to the pivot center.

[0089] [Embodiment A-10] An occupant protection device according to any one of embodiments A-4 to A-9, wherein the seat pan has a front wall extending upward from the front end of the support surface, and the push-up member is provided at a position lower than the upper end of the front wall.

[0090] [Embodiment A-11] An occupant protection device according to any one of embodiments A-2 to A-10, wherein the airbag cushion is configured so as to be urged to inflate and deploy upward with the front wall of the seat pan as a reaction surface.

[0091] [Embodiment A-12] An occupant protection device according to any one of embodiments A-4 to A-11, wherein the inflator is fixed to the seat pan via a bolt inserted from the mounting surface side.

[0092] [Embodiment A-13] The driving device is an occupant protection device described in embodiment A-1, which has: a power source; and a power transmission unit that connects the power source to the push-up member and transmits power from the power source to the push-up member to apply the force to the front of the push-up member.

[0093] [Embodiment A-14] An occupant protection device according to any one of embodiments A-1 to A-6 or A-13, wherein the push-up member has a bent portion above an imaginary line connecting the front end of the front portion and the pivot center.

[0094] [Embodiment B-1] An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: an inflatable airbag cushion; an inflator that supplies gas for inflation into the internal space of the airbag cushion in the event of a vehicle emergency; and an inclined portion that is arranged on the rear side when the seat cushion is divided into front and rear halves at the center position in the fore-and-aft direction and is inclined upward toward the front, wherein the airbag cushion is arranged either above or below the inclined portion or both above and below the inclined portion, and wherein the occupant protection device is configured such that when the airbag cushion inflates and deploys, the airbag cushion and / or the inclined portion pushes up the seat surface of the seat cushion diagonally rearward.

[0095] [Embodiment B-2] An occupant protection device as described in embodiment B-1, in which the airbag cushion is positioned above the inclined portion and is configured to inflate and deploy using the inclined portion as a reaction force surface to push up the seat surface of the seat cushion.

[0096] [Embodiment B-3] An occupant protection device as described in embodiment B-1, in which the airbag cushion is positioned below the inclined portion, and the inclined portion is configured to be moved by the inflated and deployed airbag cushion so that the inclination angle with respect to the horizontal plane increases, thereby pushing up the seat surface of the seat cushion.

[0097] [Embodiment B-4] The airbag cushion comprises an upper airbag cushion arranged above the inclined portion and a lower airbag cushion arranged below the inclined portion, the upper airbag cushion is configured to inflate and deploy using the inclined portion as a reaction surface to push up the seat surface of the seat cushion, and the lower airbag cushion is configured to move the inclined portion so that the inclination angle with respect to the horizontal plane increases upon inflation and deployment, an occupant protection device as described in embodiment B-1.

[0098] [Embodiment B-5] An occupant protection device according to any one of embodiments B-1 to B-4, wherein the inclined portion is part of a seat pan.

[0099] [Embodiment B-6] An occupant protection device according to any one of embodiments B-1 to B-4, wherein the inclined portion is separate from the seat pan and is configured as a plate attached to the seat pan.

[0100] [Embodiment B-7] An occupant protection device according to any one of embodiments B-1 to B-6, in which a plurality of the airbag cushions are provided in the front-rear direction.

[0101] [Embodiment B-8] An occupant protection device as described in any of embodiments B-1 to B-7, in which, when an occupant is seated on the seat cushion in a normal posture and wearing a seat belt, the inflation and deployment of the airbag cushion encourages the occupant's waist to rotate backward.

[0102] 1...seat back, 2...seat cushion, 3...headrest, 4...reclining mechanism, 10...back frame, 20...seating frame, 22...side frame, 24, 24'...seat pan, 24a...mounting surface, 24b...front wall, 24c...upper end, 25...spring, 26...seat surface, 30...occupant protection device, 40...push-up member, 41...rotation center, 42...front portion, 42a...front end, 43...rear, 44...bending point, 45, 46...portion, 50...drive device, 52 ...airbag cushion, 54...inflator, 54a...stud bolt, 54b...nut, 72...power source, 74...power transmission part, 100...vehicle seat, 230...occupant protection device, 252, 252a, 252b, 252-1, 252-2...airbag cushion, 254, 254a, 254b, 254-1, 254-2, ...inflator, 255...inclined part, 300...seat belt, 310...airbag cushion of front airbag, P...occupant

Claims

1. An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: a push-up member that is rotatable so as to push up the seat surface of the seat cushion; and a drive device that applies a force to rotate the push-up member in the event of a vehicle emergency, wherein the push-up member has a front portion forward of the rotation center in the fore-and-aft direction of the vehicle seat, and the drive device is positioned below the front portion of the push-up member between the front portion of the push-up member and the rotation center, and is configured to apply the force to the front portion of the push-up member.

2. An occupant protection device as described in claim 1, wherein the drive device has an airbag cushion that can be inflated and an inflator that supplies gas for inflation to the internal space of the airbag cushion in the event of a vehicle emergency, and the airbag cushion is configured to begin inflating and deploying below a front portion of the push-up member and apply the force to the front portion of the push-up member.

3. The passenger protection device according to claim 2, wherein the airbag cushion is disposed on a support surface of the seat pan and configured to inflate and deploy upward with the support surface serving as a reaction surface.

4. An occupant protection device as set forth in claim 2, wherein the airbag cushion is configured so that it is urged to inflate and deploy upward with the front wall of the seat pan acting as a reaction surface.

5. An occupant protection device as described in claim 3, wherein the push-up member is bent once between the front portion and the rotation center, and the portion from the bent point to the front end of the front portion extends parallel to the support surface.

6. An occupant protection device as described in claim 1, wherein the drive device has: a power source; and a power transmission section that connects the power source to the push-up member and transmits power from the power source to the push-up member to apply the force to a front portion of the push-up member.

7. An occupant protection device as set forth in claim 1, 2, 3, 4 or 6, wherein the push-up member has a bent portion above an imaginary line connecting the front end of the front portion and the pivot center.

8. An occupant protection device provided inside or below a seat cushion of a vehicle seat, comprising: an inflatable airbag cushion; an inflator that supplies gas for inflating and deploying to the internal space of the airbag cushion in the event of a vehicle emergency; and an inclined portion that is arranged on the rear side when the seat cushion is divided into front and rear at the center position in the fore-and-aft direction and inclines upward toward the front, the airbag cushion is arranged either above or below the inclined portion or both above and below the inclined portion, and the occupant protection device is configured such that when the airbag cushion inflates and deploys, the airbag cushion and / or the inclined portion push up the seat surface of the seat cushion diagonally rearward.

9. An occupant protection device as set forth in claim 8, wherein the airbag cushion is disposed above the inclined portion and configured to inflate and deploy using the inclined portion as a reaction surface to push up the seat surface of the seat cushion.

10. An occupant protection device as described in claim 8, wherein the airbag cushion is disposed below the inclined portion, and the inclined portion is configured to be moved by the inflated and deployed airbag cushion so that the inclination angle with respect to the horizontal plane becomes larger, thereby pushing up the seat surface of the seat cushion.

11. An occupant protection device as described in claim 8, wherein the airbag cushion comprises an upper airbag cushion arranged above the inclined portion and a lower airbag cushion arranged below the inclined portion, the upper airbag cushion is configured to inflate and deploy using the inclined portion as a reaction surface to push up the seat surface of the seat cushion, and the lower airbag cushion is configured to move the inclined portion by inflating and deploying so that the inclination angle with respect to the horizontal plane becomes larger.

12. An occupant protection device according to any one of claims 8 to 11, wherein the inclined portion is part of a seat pan.

13. An occupant protection device as claimed in any one of claims 8 to 11, wherein the inclined portion is separate from the seat pan and is constituted by a plate attached to the seat pan.

14. An occupant protection device according to any one of claims 8 to 11, wherein a plurality of the airbag cushions are provided in the front-rear direction.

15. An occupant protection device as claimed in any one of claims 8 to 11, wherein, when an occupant is seated on the seat cushion in a normal posture and wearing a seat belt, the inflation and deployment of the airbag cushion encourages backward rotation of the occupant's waist.

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