Crew protection devices

Abstract

To provide an occupant protection device which can suppress that an airbag arranged at a lap belt part of an occupant is hardly expanded due to an interference existing in front of a seat, and can effectively suppress a burden imposed on a lower abdomen of the occupant by the expanded airbag.SOLUTION: An occupant protection device 10 comprises an airbag 30 which is arranged at a lap belt part 13. An airbag main body 30a of the airbag 30 has a rear wall part 30a1 at which a penetration hole 30a1b penetrating in a fore-and-aft direction is formed, a front wall part 30a2 arranged with an interval between the rear wall part 30a1 and itself in front of the rear wall part 30a1, and connected with the other end of a tither 30c whose one end is connected to the rear wall part 30a1, and an upper wall part 30a3 for connecting the rear wall part 30a1 and the front wall part 30a2 at an upper part of the tither 30c. The occupant protection device is supported to a handle 80 via the tither 30c by the hang and lock of the tither 30c to the handle 80 which is a support body.SELECTED DRAWING: Figure 6

Description

Technical Field

[0004] , , ,

[0005] , , ,

[0001] The present invention relates to an occupant protection device for protecting an occupant seated on a vehicle seat.

Background Art

[0002] Conventionally, as a configuration for protecting an occupant seated in the driver's seat, a configuration in which an airbag is provided on the steering wheel is widely known. On the other hand, Patent Document 1 describes a configuration for protecting an occupant by providing an airbag in a lap belt portion that restrains the waist of the occupant in a seat belt. Further, Patent Document 1 describes a configuration in which a concave portion is provided at the lower rear end of the airbag to reduce the load applied to the lower abdomen of the occupant by the inflated airbag.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the driver's seat is generally configured to be movable in the front-rear direction, the distance between the occupant seated on the driver's seat and the steering wheel changes according to the position of the driver's seat. Here, when the distance between the occupant seated on the driver's seat and the steering wheel is large, it is possible to more accurately protect the occupant with an airbag provided in the lap belt portion as in the configuration described in Patent Document 1 than with an airbag provided on the steering wheel. In particular, this configuration is effective when a configuration that allows the driver's seat to be moved further rearward than before is adopted in order to secure a wide space in front of the occupant seated on the driver's seat due to the automation of the vehicle or the like.

[0005] On the other hand, the airbag described in Patent Document 1 is shaped to expand without gaps in front of the occupant when inflation is complete. Therefore, if the distance between the driver's seat and the steering wheel is short when the airbag inflates, there is a risk that the airbag may interfere with the steering wheel and become difficult to expand. Furthermore, in the airbag described in Patent Document 1, if the depth of the recess is not sufficiently deep relative to the waist circumference of the occupant's lower abdomen, there is a risk that the load on the occupant's lower abdomen by the inflated airbag may not be sufficiently reduced.

[0006] Therefore, the present invention aims to provide an occupant protection device that can prevent interference in the front of the seat from hindering the deployment of the airbag provided in the lap belt area, and that can effectively reduce the load applied to the occupant's lower abdomen by the inflated airbag. [Means for solving the problem]

[0007] A typical configuration of the occupant protection device according to the present invention for solving the above problems is an occupant protection device for protecting an occupant seated in a vehicle seat, comprising: a seat belt having at least a tongue; a buckle to which the tongue is connected; and a lap belt portion that restrains the waist of the occupant seated in the seat when the tongue is connected to the buckle; an inflator that generates inflation gas; an airbag provided in the lap belt portion, the airbag having a main body portion that inflates when the inflation gas is supplied and catches the occupant; and a device connected to the inflator that guides the inflation gas generated from the inflator to the main body portion and allows the inflation gas to flow into the main body portion. The airbag comprises a conduit portion and a tether connected to the outer circumferential surface of the main body, wherein the main body, upon completion of inflation, has a rear wall portion that contacts the occupant, the rear wall portion being positioned in the center in the left-right direction of the rear wall portion and extending upward from the lower end in the vertical direction, and having a through hole formed therein that penetrates in the front-rear direction, a front wall portion positioned in front of the rear wall portion at a distance from the rear wall portion and to which the other end of the tether, one end of which is connected to the rear wall portion, is connected, and an upper wall portion above the tether that connects the rear wall portion and the front wall portion, the main body portion being supported by the support via the tether, by the tether being hooked and locked to the support.

[0008] According to the present invention, in an occupant protection device, it is possible to suppress the difficulty of the airbag provided in the lap belt section from being hindered by an obstruction in front of the seat, and to effectively suppress the load applied to the occupant's lower abdomen by the inflated airbag. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a seat equipped with an occupant protection device. [Figure 2] This is a left side view of the seat. [Figure 3] This is a front view of the seat. [Figure 4] This is a left-side view of the seat when the airbag is inflated. [Figure 5] This is a cross-sectional view of the bag assembly after section AA, shown in Figure 3, has been cut. [Figure 6] This is a perspective view of the airbag assembly with the airbag inflated, seen from below. [Figure 7] This is a plan view of the airbag's deployment. [Figure 8] This is a view from the left side of the area around the seat when the airbag is inflated. [Figure 9] This is a view from the left side of the area around the seat when the airbag is inflated. [Figure 10] This is a view from the left side of the area around the seat when the airbag is inflated. [Figure 11] This is a perspective view of the airbag assembly with the airbag inflated, seen from below. [Figure 12] This is a plan view of the airbag's deployment. [Figure 13] This is a view from the left side of the area around the seat when the airbag is inflated. [Figure 14] This diagram shows the area around the seat when the airbag inflates, viewed from the left side, in a configuration where the occupant protection device is installed in the passenger seat. [Modes for carrying out the invention]

[0010] (First Embodiment) The overall configuration of the occupant protection device 10 according to the first embodiment of the present invention will be described below with reference to the drawings. Unless otherwise specifically stated, the dimensions, materials, shapes, and relative arrangements of the components described below are not intended to limit the scope of this invention to those specific components. Furthermore, in the following description, the left-right direction refers to the left and right directions of the seat 1 on which the occupant protection device 10 is mounted, specifically the left and right directions as seen from the perspective of an occupant M seated on the seat 1. The front-rear direction refers to the front and rear directions of the seat 1, specifically the front and rear directions as seen from the perspective of an occupant M seated on the seat 1. The up-down direction refers to the upward and downward directions in the vertical direction.

[0011] Figure 1 is a perspective view of seat 1 equipped with occupant protection device 10. Figure 2 is a left side view of seat 1. Figure 3 is a front view of seat 1, showing occupant M seated on seat 1 with seat belt 11 fastened and the inflated airbag 30 of occupant protection device 10 with dashed lines. Figure 4 is a left side view of seat 1 when airbag 30 is inflated, showing occupant M seated on seat 1 with seat belt 11 fastened with dashed lines.

[0012] As shown in Figures 1 to 4, the occupant protection device 10 is mounted on the driver's seat 1 of the vehicle and is provided to protect the occupant M seated in the seat 1. The occupant protection device 10 consists of a seat belt 11, a bag assembly 29 equipped with an airbag 30, and an inflator 24 that supplies inflation gas to the airbag 30. The seat 1 has a backrest 2 and a seat 5. The seat 1 is also configured to slide in the front-rear direction by a seat slide (not shown). The seat slide has two rails attached to the vehicle body on the underside of the seat 1, and a rail that engages with these two rails is attached to the seat frame 4, with a locking mechanism provided between them. Although the vehicle in this embodiment is not equipped with an automatic driving mode, the seat 1 is configured to move significantly rearward by a seat slide (not shown) so that it can also be used in vehicles equipped with an automatic driving mode, thereby ensuring ample legroom for the occupant M.

[0013] The seat belt 11 is formed of a belt-shaped material woven from polyester fibers or the like with good sliding performance. The seat belt 11 is configured to be able to be drawn out from a winding mechanism 15 provided inside the vicinity of the upper left edge of the backrest portion 2 on the upper end 11a side near the left shoulder of the occupant M seated on the seat 1. The lower end 11b side of the seat belt 11 is a fixed end fixed to an anchor member 17 provided on the left side of the seat portion 5. Also, a tongue 20 is provided at an intermediate portion of the seat belt 11. The tongue 20 is fastened to a buckle 19 provided on the right side of the seat portion 5 of the seat 1. The state where the occupant M is seated on the seat 1 and the tongue 20 is fastened to the buckle 19 is the state where the occupant M is wearing the seat belt 11.

[0014] The seat belt 11 in the state of being worn by the occupant M extends from the tongue 20 toward the winding mechanism 15 side, is disposed on the front side of the upper body MU of the occupant M, and has a shoulder belt portion 12 which is a portion capable of restraining the upper body MU of the occupant M, and a lap belt portion 13 which extends from the tongue 20 toward the lower end 11b side, is disposed on the front side of the waist MW of the occupant M, and is a portion capable of restraining the waist MW. Incidentally, the occupant M can release the fastening state of the tongue to the buckle 19 by pressing a release button (not shown) provided on the buckle 19 and remove the tongue 20 from the buckle 19.

[0015] The winding mechanism 15 has a pretensioner mechanism 16 configured to stop the drawing out in the case of a sudden drawing out of the seat belt 11 and to be able to wind up the drawn out seat belt 11 in the case of a collision of the vehicle or the like. The pretensioner mechanism 16 is a general-purpose one which operates a built-in gas generator to rotate the shaft around which the seat belt 11 was wound and instantaneously winds up the seat belt 11.

[0016] The inflator 24 is composed of an inflator main body 25 that discharges inflation gas and a pipe section 26 that guides the inflation gas discharged from the inflator main body 25 to the airbag 30. The inflator main body 25 is attached to a seat frame 4 that supports the seat portion 5 of the seat 1. The pipe section 26 extends from the inflator main body 25 and has a shape that is bent substantially L-shaped along the side surface from the bottom surface of the seat portion 5.

[0017] The bag assembly 29 includes an airbag 30 having a bag main body portion 30a and a conduit portion 30b, a bag connection portion 52, and a bag cover 59. The bag main body portion 30a is housed inside the bag cover 59 in a folded state before the airbag 30 operates. The conduit portion 30b of the airbag 30 is connected to the pipe section 26 of the inflator 24, takes in the inflation gas discharged from the inflator 24, and guides it to the bag main body portion 30a. The proximal end portion 30bx2 of the conduit portion 30b of the airbag 30 and the pipe section 26 of the inflator 24 are connected by being fastened with a clamp 27.

[0018] Next, the protection operation of the occupant M by the occupant protection device 10 will be described. First, when the vehicle collides, the pretensioner mechanism 16 of the retractor mechanism 15 operates, and the seat belt 11 worn by the occupant M is retracted to stabilize the seating posture of the occupant M on the seat 1. As a result, the lap belt portion 13 of the seat belt 11 is drawn toward the tongue 20 side, and the shoulder belt portion 12 connected to the lap belt portion 13 is drawn toward the shoulder side of the occupant M. After that, when the inflator 24 operates and the inflation gas is supplied from the inflator main body 25 to the bag main body portion 30a of the airbag 30 via the pipe section 26 and the conduit portion 30b of the airbag 30, the bag main body portion 30a expands. As a result, the upper body MU of the forward-moving occupant M is received by the bag main body portion 30a, and the occupant M is protected.

[0019] Next, the configuration of the bag assembly 29 will be described. Figure 5 is a cross-sectional view of the bag assembly 29 with section AA shown in Figure 3 cut off. Figure 6 is a perspective view of the bag assembly 29 with the airbag 30 inflated, viewed from below, with the bag cover 59 omitted. Figure 7 is a plan view of the unfolded airbag 30. As shown in Figures 5, 6, and 7, the bag assembly 29 comprises the airbag 30, the bag connecting section 52, and the bag cover 59.

[0020] The airbag 30 consists of a bag body 30a, which inflates with inflation gas to catch the occupant M; a conduit 30b, which is connected to the pipe 26 of the inflator 24 and guides the inflation gas released from the inflator 24 to the inlet 30a1a of the bag body 30a, allowing the inflation gas to flow into the bag body 30a; and a tether 30c connected to the outer surface of the bag body 30a. The bag body 30a and the conduit 30b are connected by stitching.

[0021] When inflation is complete, the bag body 30a is positioned directly in front of the occupant M and has a rear wall portion 30a1 that contacts and supports the upper body MU of the occupant M as it moves forward, a front wall portion 30a2 positioned in front of the rear wall portion 30a1 and spaced apart from the rear wall portion 30a1, and an upper wall portion 30a3 that connects the upper part of the rear wall portion 30a1 and the upper part of the front wall portion 30a2. The front wall portion 30a2 is positioned on the opposite side of the rear wall portion 30a1 from the occupant M side. Furthermore, since the rear wall portion 30a1 and the front wall portion 30a2 are spaced apart in the front-rear direction, a gap 35 is formed between the rear wall portion 30a1 and the front wall portion 30a2 below the upper wall portion 30a3. In addition, two inlets 30a1a are provided at the lower part of the rear wall portion 30a1, which are openings for allowing the inflation gas in the conduit portion 30b to flow in. The shape of the bag body 30a is created by bending the roughly rectangular bag body 30a due to the tension of the tether 30c.

[0022] Furthermore, a through-hole 30a1b is formed in the rear wall portion 30a1 of the bag body portion 30a, extending in the front-to-back direction. The through-hole 30a1b is provided to reduce the load on the occupant M's lower abdomen MB (Figure 3) when the bag body portion 30a is inflated. The through-hole 30a1b is located in the center of the rear wall portion 30a1 in the left-right direction and extends upward from the lower end in the vertical direction. The upper end of the through-hole 30a1b is positioned above the tether 30c in the vertical direction. The width of the through-hole 30a1b in the left-right direction is tapered, narrowing from bottom to top. The width L1 of the lower end of the through-hole 30a1b in the left-right direction is preferably set to 100 mm or more to facilitate the occupant M's lower abdomen MB, and in this embodiment it is set to 100 mm. Furthermore, the inner circumferential surface 30a1bx of the through-hole 30a1b is curved. In other words, the through-hole 30a1b has a roughly inverted U-shape with the opening on the lower side when viewed from the front or back direction.

[0023] Furthermore, within the gap 35 below the upper wall portion 30a3, one end 30c1 of the tether 30c is connected to the rear wall portion 30a1, and the other end 30c2 is connected to the front wall portion 30a2. In other words, the upper wall portion 30a3 connects the front wall portion 30a2 and the rear wall portion 30a1 above the tether 30c. Also, in this embodiment, as will be described later, the tether 30c is formed from the base fabric 61 which constitutes a part of the bag body portion 30a, so one end 30c1 of the tether 30c is integrally formed with the rear wall portion 30a1. That is to say, when the tether 30c is said to be connected, it includes not only the configuration in which the tether 30c is connected to the rear wall portion 30a1 or the front wall portion 30a2 by methods such as sewing, but also the configuration in which it is integrally formed with the rear wall portion 30a1 or the front wall portion 30a2. Furthermore, the other end 30c2 of the tether 30c is connected to a position closer to the upper wall portion 30a3 than the tip portion 30a2a of the front wall portion 30a2.

[0024] Furthermore, the bag body portion 30a is formed by sewing together the edges 61a and 62a of two roughly rectangular base fabrics 61 and 62, which are woven fabrics made of polyester fibers in a plain weave or the like. Base fabric 61 is configured to be longer in the longitudinal direction and the same in the short direction as base fabric 62. The portion 61d of base fabric 61 that is longer than base fabric 62 is sewn at its tip 61d1 to the tether stitching portion 61e of base fabric 61 outside the bag body portion 30a, thereby forming a tether 30c. By forming the tether 30c using the base fabric 61 used to form the bag body portion 30a, the amount of material required to form the airbag 30 can be reduced. If this point is not considered, the tether 30c may be formed by connecting a different base fabric or other material to the outer surface of the bag body portion 30a. Furthermore, the tethered suture portion 61e of the base fabric 61 is the connecting portion to the other end 30c2 of the tether 30c in the front wall portion 30a2, and is positioned inward from the end portion 61g of the base fabric 61 which corresponds to the tip portion 30a2a of the front wall portion 30a2.

[0025] Furthermore, the base fabrics 61 and 62 are provided with cutouts 61f and 62f, which are cut out to form through holes 30a1b. In addition, to ensure the thickness of the rear wall 30a1, the front wall 30a2, and the upper wall 30a3, multiple approximately rectangular internal tethers 63 and 64 of two types are provided inside the bag body 30a to separate the two base fabrics 61 and 62. The internal tethers 63 are configured to be longer in the longitudinal direction and the same in the short direction as the internal tethers 64. The internal tethers 63 are sewn to the tether seams 61b and 62b of the base fabrics 61 and 62, and the internal tethers 63 are sewn to the tether seams 61c and 62c of the base fabrics 61 and 62.

[0026] The conduit section 30b is a cylindrical member that is connected to the pipe section 26 of the inflator 24 and the bag body section 30a, respectively, and extends along the longitudinal direction of the wrap belt section 13. The conduit section 30b has two communication ports 30b1 that communicate with the two inlets 30a1a of the bag body section 30a, respectively. The expansion gas inside the conduit section 30b flows into the bag body section 30a through the communication ports 30b1 and the inlets 30a1a.

[0027] Furthermore, the conduit section 30b is formed by sewing together the edges 67a and 68a of the lower material 67 and upper material 68, which are made of the same bag base fabric as the bag body section 30a. The lower material 67 is sewn to the bag connecting section 52 at the seam 67b. The upper material 68 has a communication opening 30b1, and the peripheral edge 68b of the communication opening 30b1 is sewn to the peripheral edge 62e of the inlet 30a1a formed in the base fabric 62 that forms the bag body section 30a, thereby connecting it to the bag body section 30a. The outer dimensions of the lower material 67 and the upper material 68 are the same.

[0028] The bag connecting portion 52 is a cylindrical member made of the same material as the base fabric for the airbag 30, and is a member that connects the airbag 30 to the wrap belt portion 13. The space inside the cylinder of the bag connecting portion 52 is a belt insertion portion 52a through which the wrap belt portion 13 is inserted. After the wrap belt portion 13 is inserted through the belt insertion portion 52a, the two are sewn together to connect the bag connecting portion 52 and the wrap belt portion 13. In addition, the upper surface of the bag connecting portion 52 is sewn to the stitching portion 67b of the lower material 67 that forms the conduit portion 30b of the airbag 30.

[0029] The bag cover 59 is a cylindrical member made of a fabric similar to the material used for the seat 1. The bag cover 59 houses the folded bag body 30a, a portion of the conduit 30b, the bag connecting portion 52, and the portion of the wrap belt 13 that is attached to the bag assembly 29 inside the cylinder. When the bag body 30a of the airbag 30 inflates, the bag cover 59 receives pressure from the bag body 30a, causing a portion of it to rupture and the bag body 30a to be released from the bag cover 59.

[0030] Next, the positional relationship between the airbag body 30a and the occupant M and surrounding components when the airbag 30 is inflated will be explained. Figure 8 is a view from the left of the area around the seat 1 when the seat 1 is positioned towards the rear and the distance between the seat 1 and the steering wheel 80 is large, and the airbag 30 is inflated. Figure 9 is a view from the left of the area around the seat 1 when the seat 1 is positioned towards the front and the distance between the seat 1 and the steering wheel 80 is small, and the airbag 30 is inflated, and the view from the left of the area around the seat 1 is shown, and the occupant M, who has a large waist circumference in the lower abdomen MB, such as a pregnant woman, is seated on the seat 1.

[0031] As shown in Figure 8, when the distance between the seat 1 and the steering wheel 80 is large, the main body 30a of the airbag 30 first inflates upward and forward, and then the tip 30a2a of the front wall 30a2 sags due to gravity. As a result, the tether 30c hooks onto the occupant M's knee MK (support) from above and locks in place, and the main body 30a of the airbag is supported by the occupant M's knee MK via the tether 30c. In this way, the tether 30c hooks onto the knee MK and locks in place, and the main body 30a of the airbag is supported via the tether 30c, which allows the occupant M's knee MK to stably support the main body 30a of the airbag, making it easier to position the main body 30a of the airbag in the desired location, and also makes it easier for the main body 30a to receive reaction force from the knee MK and the thigh connected to the knee MK. In other words, if the upper wall portion 30a3, which is the connection point between the rear wall portion 30a1 and the front wall portion 30a2, is located below the tether 30c, when the upper wall portion 30a3 into which the expansion gas flows comes into contact with the knee portion MK, the upper wall portion 30a3 is easily repelled from the knee portion MK by the repulsive force of the upper wall portion 30a3, and the bag body portion 30a may not be stably supported by the knee portion MK. On the other hand, if the upper wall portion 30a3 is positioned above the tether 30c, as in this embodiment, the tether 30c, into which the expansion gas has not flowed, catches and locks along the upper surface of the knee portion MK, thereby increasing the contact area between the tether 30c and the knee portion MK and increasing the frictional force, allowing the bag body portion 30a to be stably supported by the knee portion MK via the tether 30c. As a result, it becomes easier to position the bag body portion 30a in the intended position, and the bag body portion 30a can more easily obtain reaction force from the knee portion MK and the thigh portion connected to the knee portion MK. Furthermore, since the other end 30c2 of the tether 30c is connected to the front wall portion 30a2 at a position on the upper wall portion 30a3 side from the tip portion 30a2a, the tip region 30a2b of the front wall portion 30a2 between the connection portion and the tip portion 30a2a can be positioned just in front of the occupant M's knee portion MK. This makes it easier to protect the occupant M's knee portion MK with the bag body portion 30a, and also makes it easier to hook the tether 30c onto the knee portion MK.Furthermore, in order to position the front wall portion 30a2 of the bag body portion 30a in front of the knee portion MK of the occupant M so that the tether 30c can easily catch on the knee portion MK and to accurately protect the knee portion MK of the occupant M, it is preferable that the length L2 (Figure 6) between one end 30c1 and the other end 30c2 of the tether 30c is 300 mm or more.

[0032] As shown in Figure 9, when the distance between the seat 1 and the handle 80 is short, the main body portion 30a of the airbag 30 first inflates upward and forward so as to go over the handle 80, and then the tip portion 30a2a of the front wall portion 30a2 hangs down due to gravity. At this time, since the handle 80 is positioned in the gap 35 formed between the rear wall portion 30a1 and the front wall portion 30a2 of the main body portion 30a, the main body portion 30a and the handle 80 are less likely to interfere with each other when the main body portion 30a inflates and expands, and the expansion of the main body portion 30a is not easily hindered. Thus, according to the occupant protection device 10 of this embodiment, even when there is an interfering object, the handle 80, in front of the seat 1, interference between the main body portion 30a and the handle 80 is suppressed, and the handle 80 can prevent the main body portion 30a of the airbag 30 from being hindered from expanding.

[0033] Furthermore, the bag body 30a that has passed over the handle 80 is supported by the ring portion 80a of the handle 80 via the tether 30c, as the tether 30c hooks onto the upper surface of the ring portion 80a of the handle 80 (support) that the occupant M grips and rotates for steering, and locks into place from above. In this way, the tether 30c hooks onto the handle 80 and locks into place, and the bag body 30a is supported via the tether 30c, allowing the handle 80 to stably support the bag body 30a, making it easier to position the bag body 30a in the intended location, and also making it easier for the bag body 30a to receive a reaction force from the handle 80. In other words, if the upper wall portion 30a3, which is the connection point between the rear wall portion 30a1 and the front wall portion 30a2, is located below the tether 30c, when the upper wall portion 30a3 into which the expansion gas flows comes into contact with the handle 80, the upper wall portion 30a3 is easily repelled by the handle 80 due to the repulsive force of the upper wall portion 30a3, and the bag body portion 30a may not be stably supported by the handle 80. On the other hand, if the upper wall portion 30a3 is positioned above the tether 30c as in this embodiment, the tether 30c, into which the expansion gas has not flowed, catches and locks along the upper surface of the ring portion 80a of the handle 80. This ensures a large contact area between the tether 30c and the handle 80, increasing the frictional force and allowing the bag body portion 30a to be stably supported by the handle 80 via the tether 30c. As a result, it becomes easier to position the bag body portion 30a in the intended location, and the bag body portion 30a can more easily receive a reaction force from the handle 80. Furthermore, since the other end 30c2 of the tether 30c is connected to the front wall portion 30a2 at a position closer to the upper wall portion 30a3 than the tip portion 30a2a, it becomes easier to position the tip region 30a2b of the front wall portion 30a2 just in front of the handle 80, making it easier to hook the tether 30c onto the handle 80.

[0034] Furthermore, as shown in Figure 10, since a through hole 30a1b is formed in the rear wall portion 30a1 of the bag body portion 30a at the aforementioned position, when the bag body portion 30a expands, the area of ​​the bag body portion 30a that contacts the area of ​​the lower abdomen MB of the occupant M becomes smaller, thereby reducing the load on the lower abdomen MB of the occupant M. In other words, if a recess were formed in the rear wall portion 30a1 instead of a through hole 30a1b, and the depth of the recess was not sufficiently deep relative to the waist circumference of the lower abdomen MB of the occupant M, the lower abdomen MB of the occupant M would come into contact with the bottom surface of the recess, and the load on the lower abdomen MB of the occupant M would not be sufficiently reduced. In contrast, in this embodiment, the rear wall portion 30a1 has a through hole 30a1b, and a gap 35 is formed between the rear wall portion 30a1 and the front wall portion 30a2, so that the space in which the lower abdomen MB of the occupant M is accommodated is extended to the position of the front wall portion 30a2. Therefore, compared to a configuration in which a recess is formed in the rear wall portion 30a1, the bag body portion 30a is less likely to come into contact with the lower abdomen MB of the occupant M, thereby effectively reducing the load on the lower abdomen MB of the occupant M due to the inflation of the airbag 30. This configuration is particularly effective for occupants M who have a large waist circumference, such as pregnant women, and who require protection of their lower abdomen MB.

[0035] Furthermore, the bag body 30a has a rear wall 30a1 and a front wall 30a2 connected by an upper wall 30a3 above them, and the inlet 30a1a is located in the rear wall 30a1. As a result, as described above, the bag body 30a first extends upward when the inflation gas flows in, which reduces the load on the lower abdomen MB of the occupant M when the bag body 30a starts to inflate, compared to a configuration in which the bag body 30a expands without gaps in front of the occupant M.

[0036] Furthermore, since the bag body 30a has a gap 35 and through holes 30a1b, the volume of the portion of the bag body 30a into which the inflation gas flows can be reduced compared to a shape in which the bag body 30a expands without gaps in front of the occupant M. As a result, the time from when the bag body 30a starts to inflate until it is completed can be shortened, and the bag body 30a can protect the occupant M more safely.

[0037] (Second Embodiment) Next, the occupant protection device 10 according to the second embodiment of the present invention will be described. Parts that overlap with the description of the first embodiment will be simplified or omitted by using the same drawings or reference numerals.

[0038] Figure 11 is a perspective view from below of the bag assembly 29 in the occupant protection device 10 according to this embodiment, with the airbag 30 inflated, and the bag cover 59 is omitted. Figure 12 is a plan view of the deployed airbag 30. Figure 13 is a view from the left side of the area around the seat 1 when the seat 1 is positioned towards the rear and the distance between the seat 1 and the steering wheel 80 is large, and the airbag 30 is inflated, showing an occupant M, such as a pregnant woman, with a large waist circumference in the lower abdomen MB, seated on the seat 1.

[0039] As shown in Figure 11, the occupant protection device 10 of this embodiment differs from the configuration of the first embodiment only in the shape of the bag body portion 30a of the airbag 30. Specifically, the occupant protection device 10 of this embodiment lacks the through-hole 30a1b formed in the rear wall portion 30a1 of the bag body portion 30a of the occupant protection device 10 of the first embodiment, and instead is provided with a non-inflatable portion 30a1c that restricts the inflow of inflation gas. The other configurations of the occupant protection device 10 according to this embodiment are the same as those of the occupant protection device 10 of the first embodiment, so their description is omitted.

[0040] In the rear wall portion 30a1, the non-expanding portion 30a1c is formed at the same position as the through-hole 30a1b in the occupant protection device 10 of the first embodiment. That is, the non-expanding portion 30a1c is in the center in the left-right direction of the rear wall portion 30a1 and extends upward from the lower end in the vertical direction. The upper end of the non-expanding portion 30a1c is positioned above the tether 30c in the vertical direction. The width of the non-expanding portion 30a1c in the left-right direction is tapered, narrowing from bottom to top.

[0041] As shown in Figure 12, the bag body 30a is formed by sewing together the edges 61a and 62a of two roughly rectangular base fabrics 61 and 62, which are woven fabrics made of polyester fibers in a plain weave, similar to the first embodiment. Base fabric 61 is configured to be longer in the longitudinal direction and the same in the short direction as base fabric 62. The portion 61d of base fabric 61 that is longer than base fabric 62 is sewn at its tip 61d1 to the tether stitching portion 61e of base fabric 61 outside the bag body 30a, thereby forming a tether 30c. By forming the tether 30c using the base fabric 61 used to form the bag body 30a, the amount of material required to form the airbag 30 can be reduced. If this point is not considered, the tether 30c may be formed by connecting a different base fabric or other material to the outer surface of the bag body 30a.

[0042] Furthermore, the base fabric 61 and base fabric 62 are sewn together at the seams 61z and 62z. This separates the space where the inlet 30a1a is formed in the bag body 30a from the space inside the seams 61z and 62z, forming a non-expansion section 30a1c where the inflow of expansion gas is restricted. In addition, to ensure the thickness of the rear wall 30a1, the front wall 30a2, and the upper wall 30a3, multiple approximately rectangular internal tethers 63 and 64 of two types are provided inside the bag body 30a to separate the two base fabrics 61 and 62. The internal tether 63 is configured to be longer in the longitudinal direction and the same in the short direction as the internal tether 64. The internal tether 63 is sutured to the tether seams 61b and 62b of the base fabrics 61 and 62, and the internal tether 63 is sutured to the tether seams 61c and 62c of the base fabrics 61 and 62.

[0043] According to the occupant protection device 10 of this embodiment, when the distance between the seat 1 and the steering wheel 80 is large, the airbag 30 inflates, and the tether 30c hooks onto the upper surface of the occupant M's knee MK, securing it in place, and the bag body 30a is supported via the tether 30c (Figure 8). This allows the occupant M's knee MK to stably support the bag body 30a, making it easier to position the bag body 30a in the intended location, and also makes it easier for the bag body 30a to receive reaction force from the knee MK and the thigh connected to the knee MK. Furthermore, since the tip region 30a2b of the front wall portion 30a2 is positioned just in front of the occupant M's knee MK, the bag body 30a can more easily protect the occupant M's knee MK, and the tether 30c can be more easily hooked onto the knee MK.

[0044] Furthermore, as shown in Figure 9, when the distance between the seat 1 and the handle 80 is short, the handle 80 is positioned in the gap 35 formed between the rear wall portion 30a1 and the front wall portion 30a2 of the bag body portion 30a by the same mechanism as in the first embodiment when the airbag 30 inflates. Therefore, even if the handle 80, which is an interfering object, is in front of the seat 1, interference between the bag body portion 30a and the handle 80 is suppressed, and the handle 80 can prevent the bag body portion 30a of the airbag 30 from becoming difficult to expand. In addition, the tether 30c is hooked from above onto the upper surface of the ring portion 80a of the handle 80 and secured, thereby being supported by the ring portion 80a of the handle 80 via the tether 30c. This allows the handle 80 to stably support the bag body portion 30a, making it easier to position the bag body portion 30a in the intended position, and also makes it easier for the bag body portion 30a to receive a reaction force from the handle 80. Furthermore, since the tip area 30a2b of the front wall portion 30a2 is positioned directly in front of the handle 80, the tether 30c can be easily hooked onto the handle 80.

[0045] Furthermore, as shown in Figure 13, since a non-expandable portion 30a1c is formed at the aforementioned position on the rear wall portion 30a1 of the bag body portion 30a, when the bag body portion 30a expands, the non-expandable portion 30a1c with low internal pressure comes into contact with the lower abdomen MB of the occupant M. Also, since a gap 35 is formed between the rear wall portion 30a1 and the front wall portion 30a2, the non-expandable portion 30a1c that comes into contact with the lower abdomen MB of the occupant M receives a reaction force from the occupant M and bends slightly towards the gap 35. As a result of these actions, the force with which the bag body portion 30a presses against the lower abdomen MB of the occupant M is reduced, and therefore, the occupant protection device 10 of this embodiment can effectively reduce the load applied to the lower abdomen of the occupant M. This configuration is particularly effective for occupants M who have a large waist circumference, such as pregnant women, and who require protection of their lower abdomen MB.

[0046] Furthermore, the non-expanding portion 30a1c formed in the rear wall portion 30a1 can be easily formed by sewing the base fabrics 61 and 62 together, without having to cut out the base fabrics 61 and 62 as in the through-hole 30a1b of the first embodiment. This improves the productivity of the bag body portion 30a.

[0047] Furthermore, the bag body 30a has a rear wall 30a1 and a front wall 30a2 connected by an upper wall 30a3 above them, and the inlet 30a1a is located in the rear wall 30a1. As a result, as described above, the bag body 30a first extends upward when the inflation gas flows in, which reduces the load on the lower abdomen MB of the occupant M when the bag body 30a starts to inflate, compared to a configuration in which the bag body 30a expands without gaps in front of the occupant M.

[0048] Furthermore, since the bag body 30a has an air gap 35 and a non-inflatable portion 30a1c, the volume of the portion of the bag body 30a into which the inflation gas flows can be reduced compared to a shape in which the bag body 30a expands without gaps in front of the occupant M. As a result, the time from when the bag body 30a starts to inflate until it is completed can be shortened, and the bag body 30a can protect the occupant M more safely.

[0049] Although the first and second embodiments describe a configuration in which the occupant protection device 10 is installed in the driver's seat of a vehicle, the present invention is not limited to this, and it can also be installed in the rear seat or passenger seat of a vehicle. For example, when installed in the passenger seat of a vehicle, as shown in Figure 14, if the airbag 30 inflates when the distance between the seat 1 and the instrument panel 95 in front of the seat 1 is large, the tether 30c hooks onto the knee portion MK of the occupant M sitting in the passenger seat from above and is secured, and the bag body portion 30a is supported by the knee portion MK of the occupant M via the tether 30c.

[0050] Furthermore, although the occupant protection device 10 was described using a so-called three-point seat belt 11, which comprises a shoulder belt portion 12 and a lap belt portion 13, as an example in the first and second embodiments, the present invention is not limited thereto. That is, even if the present invention is applied to a so-called two-point seat belt 11, which has a lap belt portion 13 but no shoulder belt portion 12, the same effects as described above can be obtained. [Explanation of Symbols]

[0051] 1...Seat, 10...Occupant protection device, 11...Seat belt, 13...Wrap belt section, 15...Retraction mechanism, 19...Buckle, 20...Tongue, 24...Inflator, 30...Airbag, 30a...Bag body (main body), 30a1...Rear wall section, 30a1b...Penetration hole, 30a1c...Non-inflatable section, 30a2...Front wall section, 30a3...Top wall section, 30b...Conduit section, 30c...Tether, 61, 62...Base fabric, 80...Handle (support), M...Occupant, MK...Knee section (support), MW...Waist section

Claims

1. An occupant protection device for protecting occupants seated in vehicle seats, A seat belt having at least a tongue, a buckle to which the tongue is attached, and a lap belt portion that restrains the waist of the occupant seated in the seat when the tongue is attached to the buckle, An inflator that generates expansion gas, An airbag provided in the lap belt section, comprising: a main body that inflates when the inflation gas is supplied and catches the occupant; a conduit connected to the inflator, which guides the inflation gas generated from the inflator to the main body and allows the inflation gas to flow into the main body; and a tether connected to the outer circumferential surface of the main body; Equipped with, When the expansion is complete, the main body is The rear wall portion that contacts the occupant, the rear wall portion having a through hole formed therein, which is located in the center of the rear wall portion in the left-right direction and extends upward from the lower end in the vertical direction, and penetrates in the front-rear direction, A front wall portion is positioned in front of the rear wall portion, spaced apart from the rear wall portion, and to which the other end of the tether, one end of which is connected to the rear wall portion, is connected; An upper wall portion connecting the rear wall portion and the front wall portion above the tether, It has, The occupant protection device is characterized in that the main body is supported by the support via the tether, by the tether being hooked and locked to the support.

2. The occupant protection device according to claim 1, characterized in that the through hole has a substantially inverted U-shape with the lower side as the opening when viewed from the front-rear direction.

3. The occupant protection device according to claim 1, characterized in that the other end of the tether is connected to a position closer to the upper wall than the tip of the front wall.

4. The main body is formed from a base fabric, The occupant protection device according to claim 1, characterized in that the tether is formed from a part of the base fabric that forms the main body.

5. The aforementioned seat belt is equipped with a retraction mechanism capable of being retracted, The occupant protection device according to claim 1, characterized in that the inflator and the winding mechanism are mounted on the seat.

6. The occupant protection device according to any one of claims 1 to 5, characterized in that the support is a handle mounted on the vehicle.

7. The occupant protection device according to any one of claims 1 to 5, characterized in that the support is the knee of the occupant.

8. An occupant protection device for protecting occupants seated in vehicle seats, A seat belt having at least a tongue, a buckle to which the tongue is attached, and a lap belt portion that restrains the waist of the occupant seated in the seat when the tongue is attached to the buckle, An inflator that generates expansion gas, An airbag provided in the lap belt section, comprising: a main body that inflates when the inflation gas is supplied and catches the occupant; a conduit connected to the inflator, which guides the inflation gas generated from the inflator to the main body and allows the inflation gas to flow into the main body; and a tether connected to the outer circumferential surface of the main body; Equipped with, When the expansion is complete, the main body is A rear wall portion that contacts the occupant, the rear wall portion having a non-expansion portion formed therein, which is located in the center of the rear wall portion in the left-right direction and extends upward from the lower end in the vertical direction, and in which the inflow of the expansion gas is restricted. A front wall portion is positioned in front of the rear wall portion, spaced apart from the rear wall portion, and to which the other end of the tether, one end of which is connected to the rear wall portion, is connected; An upper wall portion connecting the rear wall portion and the front wall portion above the tether, It has, The occupant protection device is characterized in that the main body is supported by the support via the tether, by the tether being hooked and locked to the support.

9. The occupant protection device according to claim 8, characterized in that the other end of the tether is connected to a position closer to the upper wall than the tip of the front wall.

10. The main body is formed from a base fabric, The occupant protection device according to claim 8, characterized in that the tether is formed from a part of the base fabric that forms the main body.

11. The aforementioned seat belt is equipped with a retraction mechanism capable of being retracted, The occupant protection device according to claim 8, characterized in that the inflator and the winding mechanism are mounted on the seat.

12. The occupant protection device according to any one of claims 8 to 11, characterized in that the support is a handle mounted on the vehicle.

13. The occupant protection device according to any one of claims 8 to 11, characterized in that the support is the knee of the occupant.

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