JP7745832B2 - Occupant protection devices - Google Patents

Description

The present invention relates to an occupant protection device for protecting an occupant seated in a seat.

Conventionally, a known occupant protection device includes an airbag folded and positioned in the lap belt portion of a seatbelt. When activated, the airbag inflates with the inflow of inflation gas. When fully inflated, the lower support surface rests against the thighs of the seated occupant, while the rear occupant restraint surface receives and protects the occupant's upper body as it moves forward (see, for example, Patent Document 1). The seatbelt is retracted from a retractor located on one of the upper left and right ends of the seat backrest. The leading end of the seatbelt is fixed to the side of the seat cushion where the retractor is located. The left and right ends of the seat are connected to the left and right sides of the seat by fastening a tongue attached to a buckle located on the opposite side of the seat cushion from the fixed end, thereby positioning the lap belt portion in front of the hips of the seated occupant. The airbag was configured with a bag body that inflates to accommodate an occupant, and a gas supply passage that connects its tip to a gas supply device for inflation gas located at the fixed end of the seatbelt and supplies inflation gas to the bag body. This occupant protection device can be worn by an occupant seated in a seat by unwinding the seatbelt, fastening the tongue to the buckle, and positioning the shoulder belt portion from the retractor to the tongue in front of the occupant's upper body and the lap belt portion in front of the occupant's waist. Subsequently, when inflation gas is supplied to the bag body of the airbag via the gas supply passage in the event of a vehicle collision, the bag body inflates, and with the support surface on the underside of the bag body supporting the thighs of the seated occupant, the occupant restraint surface on the rear side of the bag body can receive and protect the upper body of the occupant moving forward.

Japanese Patent Application Laid-Open No. 2020-66425

However, with conventional occupant protection devices, when fastening the seatbelt tongue to the buckle, for example, if the occupant is small, the length of the lap belt portion from the fixed end to the buckle is shorter than for a larger occupant, and the folded storage portion of the bag main body of the airbag stored in the lap belt portion is shifted toward the buckle, making it difficult to inflate the bag main body when facing the occupant (small occupant). Conversely, if the occupant is large, when fastening the seatbelt tongue to the buckle, the folded storage portion of the bag main body is shifted toward the fixed end of the seatbelt, making it difficult to inflate the bag main body when facing the occupant (large occupant).

The present invention aims to solve the above-mentioned problems by providing an occupant protection device that can smoothly protect an occupant with an inflated airbag even if the folded storage portion of the airbag shifts along the lap belt portion due to differences in occupant physique when the seat belt is fastened.

In the occupant protection device according to the present invention, the seat belt is unwound from a retractor disposed on one upper end side of the backrest of the seat in the left-right direction, and has a fixed end at its tip that is fixed to the side of the seat bottom where the retractor is disposed in the left-right direction. By fastening an assembled tongue to a buckle disposed on the opposite side of the seat bottom from the fixed end side in the left-right direction, the left and right ends of the seat belt are connected to the left and right sides of the seat bottom, and a lap belt portion is disposed in front of the waist of an occupant seated in the seat.
an airbag that is folded and disposed in the lap belt portion, and that, when activated, is inflated by the inflow of inflation gas and is capable of receiving and protecting the upper body of an occupant moving forward;
The airbag,
a bag body that inflates to accommodate an occupant;
a gas supply passage portion having a tip end connected to a gas supply device for inflation gas disposed on the fixed end side of the seat belt, the gas supply passage portion having a base end connected to the bag main body portion so as to be able to supply inflation gas to the bag main body portion;
An occupant protection device comprising:
the airbag is configured to include knee-front inflatable portions that are in communication with the bag main body, are disposed at a front end lower portion of the bag main body, and are disposed in front of the left and right knees of the occupant,
Position adjustment tethers are provided on both the left and right sides of the knee front inflation section when inflation is complete, and are connected to the left and right sides of the seat, respectively, to position the knee front inflation section near the center in the left-right direction on the front side of the seat, so that the rear surface of the knee front inflation section serves as a knee contact surface that contacts the left and right knees of the occupant,
The bag main body and the knee front inflation portion, which communicate with the base side of the gas supply path portion, are folded and covered together with the left and right position adjustment tethers and the base side of the gas supply path portion by a bag cover that allows the bag main body and the knee front inflation portion to protrude when inflated, and are stored in a storage portion of the lap belt portion of the seat belt,
The tether on one of the left and right position adjustment tethers on the buckle side has an end side farther from the knee front expansion portion connected to the tongue,
The other of the left and right tethers is characterized in that the end side of the other tether that is farther from the knee-front expansion portion is connected to the vicinity of the fixed end of the seat belt.

In the occupant protection device of the present invention, after an occupant fastens a seat belt, the device is activated by a vehicle collision or other event. When inflation gas flows from the gas supply passage into the bag main body, the bag cover is pushed open, inflating the bag main body and inflating the knee front inflation section. The left and right edges of the knee front inflation section are pulled by the left and right position adjustment tethers, causing the rear surface to contact the knees and inflating in front of the occupant's left and right knees. The left and right position adjustment tethers position the knee front inflation section so that it is positioned near the center of the front side of the seat cushion. Therefore, even if the occupant wearing the lap belt is small and the folded storage section of the bag main body is shifted toward the lap belt buckle, the left and right position adjustment tethers adjust the knee front inflation section's position so that it inflates near the center of the front side of the seat cushion. The adjusted knee front inflation section also shifts the bag main body, which is inflating near the buckle. In other words, even if the bag main body tends to inflate misaligned toward the buckle, the adjusted knee front inflation portion corrects this misalignment and moves toward the left-right center of the seat cushion, the side away from the buckle, so that it faces the small occupant. As a result, the bag main body inflates to face the small occupant, thereby providing good protection for the small occupant. Also, even if the occupant wearing the lap belt is large and the folded storage portion of the bag main body is misaligned toward the fixed end of the lap belt, if the knee front inflation portion inflates, the left and right position adjustment tethers will adjust the position of the knee front inflation portion so that it inflates near the left-right center on the front side of the seat cushion, and the adjusted knee front inflation portion will also move misaligned as the bag main body inflates at the fixed end. In other words, even if the bag main body attempts to inflate misaligned toward the fixed end, the position-adjusted knee-front inflation portion corrects this misalignment and moves toward the center of the seat, away from the fixed end, so that it faces the large occupant. As a result, the bag main body inflates to face the large occupant, thereby providing excellent protection. Of course, the left and right position-adjustable tethers of the knee-front inflation portion are not directly connected to the seat, but are connected to the tongue or the fixed end of the seat belt. Simply by fastening the lap belt, the left and right position-adjustable tethers' ends away from the knee-front inflation portion can be smoothly positioned on both the left and right sides of the seat. Furthermore, since the fully inflated knee-front inflation portion covers the front sides of the occupant's left and right knees, it can protect the occupant's knees from vehicle body elements in front of the knees (e.g., the instrument panel, front seats, etc.).

Therefore, with the occupant protection device according to the present invention, even if the folded storage portion of the airbag shifts along the lap belt portion due to differences in the occupant's physique when the seat belt is fastened, the inflated airbag can smoothly protect the occupant and also protect the occupant's knees.

1 is a perspective view of a seat equipped with an occupant protection device according to an embodiment of the present invention; 1 is a left side view of a seat equipped with an occupant protection device according to an embodiment; FIG. 1 is a front view of a seat equipped with an occupant protection device according to an embodiment, showing the state in which the seat belt is fastened to the occupant, and also showing the airbag when inflated by a two-dot chain line, and further showing a schematic longitudinal cross-sectional view of the location where the airbag is installed. 2 is a schematic perspective view showing an inflated state of an airbag of the occupant protection device according to the embodiment, as viewed from the rear side; FIG. FIG. 2 is a diagram showing constituent materials of the airbag according to the embodiment. 3 is a front view showing the state where the airbag has completed inflation when the occupant protection device of the embodiment is activated; FIG. 1 is a left side view showing the state in which the airbag has completed inflation when the occupant protection device of the embodiment is activated; FIG. 1 is a right side view showing the state in which the airbag has completed inflation when the occupant protection device of the embodiment is activated; FIG. 10A and 10B are explanatory diagrams illustrating the operation of the passenger protection device according to the embodiment in the case of a small passenger; 10A and 10B are explanatory diagrams illustrating the operation of the occupant protection device according to the embodiment in the case of a large occupant.

One embodiment of the present invention will now be described with reference to the drawings. As shown in Figures 1 to 4, the occupant protection device 10 of this embodiment is mounted on a vehicle seat 1 and comprises a seat belt 11, an airbag 29, and an inflator 24 as a gas supply device that supplies inflation gas to the airbag 29. The seat 1 comprises a backrest 2 and a seat portion 5.

The seat belt 11 is arranged on one side of the seat 1 (the left side in this embodiment) in the left-right direction, so that the upper end 11a can be retracted from a retractor 15 arranged inside the left edge 3a of the upper end 3 of the backrest 2, and the lower end 11b, which serves as the tip, is fixed to an anchor member 16 arranged on the left side 6 of the seat portion 5.

A tongue 18 is disposed in the middle of the seat belt 11, and the tongue 18 is fastened to a buckle 17 disposed on the right side 7 of the seat cushion 5 on the other left-right side of the seat 1 (the right side in this embodiment). When the tongue 18 is fastened to the buckle 17, the portion of the seat belt 11 extending from the tongue 18 toward the retractor 15 forms a shoulder belt portion 12 positioned in front of the upper body MU of the occupant MP, and the portion extending from the tongue 18 toward the fixed end 11b forms a lap belt portion 13 positioned in front of the waist MW of the occupant MP. The buckle 17 is provided with a release button (not shown), and when the fastened tongue 18 is to be released, the tongue 18 can be removed from the buckle 17 by pressing the release button. The retractor 15 also includes a pretensioner that stops the seat belt 11 from being pulled out if it is suddenly pulled out, and can retract the pulled-out belt 11 in the event of a vehicle collision or other accident.

The inflator 24, which serves as a gas supply device, comprises a generally cylindrical inflator body 25 that discharges inflation gas, and a pipe portion 26 that protrudes from the inflator body 25 and is bent in a generally L-shape. The inflator 24 is attached and fixed to the rear side of the left side 6 of the seat 5, where the retractor 15 is located (see Figures 1 and 2). The distal end 47 of the gas supply passage 45 (described below) of the airbag 29 is fitted onto the pipe portion 26, which is further fastened and connected by a clamp 27.

As shown in FIG. 4 , the airbag 29 comprises a bag body 30 that is inflated by the introduction of inflation gas; a gas supply path 45 that is connected to the lower end 30a of the bag body 30 and supplies inflation gas from an inflator 24 (a gas supply device) to the bag body 30; a knee-front inflation section 53 that is connected to the front end (front edge) 32c of the underside 32a of the bag body 30; position adjustment tethers 61, 62 that extend from both left and right edges 53a, 53b of the knee-front inflation section 53; and a tubular belt insertion section 66 that is connected to the lower surface 46b of the gas supply path 45 and through which the lap belt section 13 is inserted. The bag body 30, gas supply path 45, knee-front inflation section 53, position adjustment tethers 61, 62, and belt insertion section 66 are made of flexible woven fabric such as polyester.

When fully inflated, the bag body 30 is configured so that the peripheral wall 31 inflates into a generally triangular prism shape when viewed from the side. The bag body 30 includes a bottom wall 32 on the bottom side, a rear wall 33 on the rear side, a front wall 34 on the front side, and left and right side walls 35 (L, R). When fully inflated, the lower surface 32a of the bottom wall 32, excluding the front edge 32c, forms a support surface 37 that supports the thighs MF of the occupant MP, and the rear surface 33a of the rear wall 33 forms an occupant restraint surface 38 that receives the upper body MU of the occupant MP as they move forward (see Figures 7 and 8).

Across the rear edge 32b of the bottom wall 32, an inlet section 40 is provided, which has multiple inlets 40a (two, arranged side by side, in this embodiment) through which inflation gas flows in from the gas supply passage 45. Additionally, vent holes 43 are provided on the front sides of the left and right side walls 35L, 35R to exhaust excess inflation gas flowing into the bag body 30. Furthermore, along the front edge 32c of the bottom wall 32, two gas supply ports 41 are arranged side by side to supply inflation gas to the knee-front inflation section 53.

As shown in Figure 5, the peripheral wall 31 of the bag body 30 is formed by sewing together two sheets of material: a front section 31a and a rear section 31b. The front section 31a is configured to include a front wall section 34 and the front sides of the left and right side walls 35 (L, R), while the rear section 31b is configured to include a rear wall section 33, a bottom wall section 32, and the rear sides of the side walls 35 (L, R).

The gas supply passage 45 has its base 46 connected to the inlet 40 of the bag body 30 of the airbag 29, through which inflation gas flows, and its tip 47 connected to the pipe 26 of the inflator 24. The gas supply passage 45 is formed by sewing together the outer peripheral edges of an outer material 49 and a bag side material 50, which have identical external shapes (see Figure 5). The base 46 of the gas supply passage 45 has a communication port 46c that communicates with the inlet 40a of the inlet 40 of the bag body 30. The periphery of the communication port 46c is sewn to the periphery of the inlet 40a, connecting the gas supply passage 45 to the rear edge 32b of the bottom wall 32, which forms the lower end 30a of the bag body 30. As previously mentioned, the gas supply passage 45 is configured so that its tip 47 is connected to the pipe 26 of the inflator 24, and supplies inflation gas from the inflator body 25 to the bag body 30.

The gas supply passage 45 is formed by sewing together the outer peripheral edges of an outer material 49 on the lower surface side and a bag side material 50 on the bag main body 30 side, both of which have the same external dimensions. Before sewing together the outer peripheral edges of the outer material 49 and the bag side material 50, the periphery of the communication opening 46c of the bag side material 50 is sewn to the periphery of the inlet 40a of the bag main body 30.

As shown in Figures 4, 6-8, the knee-front inflation section 53 has a generally rectangular parallelepiped shape that, when fully inflated, is able to cover the left and right knees MK (L, R) of a seated occupant MP. When fully inflated, the knee-front inflation section 53 comprises a ceiling wall 54 connected to the front edge 32c of the bottom wall 32 of the bag main body 30, a rear wall 56 extending downward from the rear edge of the ceiling wall 54, left and right side walls 57 (L, R) extending downward from the left and right edges of the ceiling wall 54, a front wall 55 extending downward from the front edge of the ceiling wall 54, and a bottom wall 58 disposed opposite the ceiling wall 54. Two communication ports 54a are provided in the ceiling wall 54, corresponding to the gas supply ports 41 of the bag main body 30, through which inflation gas flows in from the bag main body 30.

In addition, position adjustment tethers 61, 62 are connected to the left and right edges 53a, 53b of the knee front inflation section 53 so that the rear surface 56a of the knee front inflation section 53, when fully inflated, serves as a knee contact surface that contacts the left and right knees MKL, MKR of the occupant MP, and is positioned near the left-right center 8a on the front surface 8 of the seat 5.

The base portion 61a of the position adjustment tether 61 is connected to the left edge 53a of the knee-front inflation portion 53 when inflation is complete, and the end portion 61b away from the knee-front inflation portion 53 is connected near the fixed end 11b of the seat belt 11.

The base 62a of the position adjustment tether 62 is connected to the right edge 53b of the knee front inflation section 53 when inflation is complete, and the end 62b away from the knee front inflation section 53 is connected to the tongue 18.

The length dimensions LL, LR from the bases 61a, 62a of the tethers 61, 62 to the ends 61b, 62b are set so that when the knee-front inflation section 53 has completed inflation in conjunction with inflation of the bag body 30, the rear knee-contact surface 56a is in contact with the knees MK (L, R) of the occupant MP, and the knee-front inflation section 53 is positioned near the center 8a in the left-right direction on the front side 8 of the seat 5.

As shown in Figure 5, the knee front inflation section 53 is formed from a sheet-like knee inflation section material 59 having a shape in which a ceiling side section 59a forming the ceiling wall 54 extends to a front side section 59b forming the front wall 55, a left side section 59d and a right side section 59e forming the left and right side walls 57 (L, R), and a rear side section 59f forming the rear wall 56, and further a bottom side section 59c forming the bottom wall 58 extends from the front side section 59b. The knee front inflation section 53 is formed by sewing the periphery of the communication port 54a of the knee inflation section material 59, and further the front edge 59aa and rear edge 59ab of that periphery, to the front edge 32c of the bottom wall 32 of the bag main body 30, and sewing the corresponding edges of the knee inflation section material 59 together to form the knee front inflation section 53 having a substantially rectangular parallelepiped shape. When sewing the adjacent left side section 59d and right side section 59e of the rear section 59f together, the base 61a side of the position adjustment tether 61 is sewn to the left side connecting section 59fl on the left side, and the base 62a side of the position adjustment tether 62 is sewn to the right side connecting section 59fr on the right side. The ends 61b, 62b of the tethers 61, 62, which are farther from the bases 61a, 62a, are connected to the vicinity of the fixed end 11b and the tongue 18 when the bag body 30 and the knee-front inflation section 53 of the airbag 29 are folded and attached to the folding storage area 22 of the lap belt section 13.

The belt insertion portion 66 is formed into a cylindrical shape by connecting the front and rear edge portions 67a, 67a of a substantially rectangular insertion portion material 67 (see Figure 5) and is arranged to enclose the folded storage area 22 of the airbag 29 (bag main body 30) of the lap belt portion 13. The belt insertion portion 66 is sewn and connected to the outer material 49 of the gas supply path portion 45 before the edge portions 67a, 67a are connected to each other in a loop shape. After the folded bag main body 30 is placed in the folded storage area 22 of the lap belt portion 13, the edge portions 67a, 67a are connected to each other to form a cylindrical (loop) shape.

When the airbag 29 is assembled into the folding storage area 22 of the lap belt portion 13, the bag main body 30, which communicates (connects) the base 46 side of the gas supply path 45, and the knee-front inflation portion 53 are folded together to form the bag assembly 75 together with the left and right position adjustment tethers 61, 62 and the base 46 side of the gas supply path 45. This assembly is then covered by a bag cover 69, which allows the bag main body 30 and the knee-front inflation portion 53 to protrude when inflated, and assembled into the folding storage area 22.

That is, the airbag 29 is made by folding the bag main body 30, to which the gas supply path 45 and the belt insertion portion 66 (before the edges 67a, 67a are sewn together) are attached, and the knee-front inflation portion 53. Next, the folded portion is partially wrapped in a strip-shaped wrapping material (not shown) to prevent the folded portion from collapsing. Then, the belt insertion portion 66 (before it is formed into a cylindrical shape) is used to wrap the folded storage portion 22 of the lap belt portion 13, and the edges 67a, 67a are sewn together to attach the belt insertion portion 66 to the lap belt portion 13. When the ends 61b, 62b of the position adjustment tethers 61, 62 extending from the knee front inflation portion 53 are connected to the vicinity of the fixed end 11b and the tongue 18, and the bag body 30 of the airbag 29, the base portion 46 of the gas supply passage 45, the knee front inflation portion 53, the belt insertion portion 66, and the tethers 61, 62 are covered with the bag cover 69 so that they are not exposed, the airbag 29 is disposed as a bag assembly 75 in the folded storage area 22 of the lap belt portion 13.

The bag cover 69 is formed from a sheet-like cover material 70 that is folded in half (see Figure 5). It wraps around the folded bag body 30 and other parts, and is attached by sewing the overlapping edges 70a together (see Figure 3).

In the occupant protection device 10 of this embodiment, the bag assembly 75 is assembled to the folded storage portion 22 of the lap belt portion 13 of the seat belt 11 already fastened to the seat 1 while the ends 61b, 62b of the tethers 61, 62 are connected to the vicinity of the fixed end 11b or the tongue 18, and the tip 47 of the gas supply passage portion 45 of the airbag 29 is connected to the pipe portion 26 of the inflator 24 using the clamp 27, allowing the device to be mounted on the seat 1.

The occupant protection device 10 of this embodiment is activated after being installed in the seat 1 when a vehicle collision occurs while an occupant MP is seated in the seat 1 and fastening their seatbelt 11 (see Figures 6-8). In this instance, inflation gas from the inflator 24 flows through the gas supply passage 45 and into the bag body 30 from the inlet 40a of the inlet 40, causing the bag body 30 to inflate. When the bag body 30 inflates, the support surface 37 on the lower surface 32a is supported by the thighs MF of the occupant MP, and the occupant restraint surface 38 on the rear surface 33a is positioned to support the upper body MU of the occupant MP. Furthermore, as the bag body 30 inflates, the knee-front inflation portion 53 is also inflated by the inflation gas flowing in from the communication port 54a via the gas supply port 41 of the bag body 30. The inflating knee front inflation section 53 is pulled at its left and right edges 53a, 53b by the left and right position adjustment tethers 61, 62, and inflates in front of the left and right knees MKL, MKR of the occupant MP, with its rear surface acting as the knee contact surface 56a. At this time, the left and right position adjustment tethers 61, 62 cause the knee front inflation section 53 to inflate so that it is positioned near the left-right center 8a on the front side 8 of the seat 5.

In the occupant protection device 10 of this embodiment, even if the occupant wearing the lap belt portion 13 is a small occupant MPS and the folding storage area 22 of the bag main body 30 shifts toward the buckle 17 of the lap belt portion 13, as shown in A of Figure 9, when the knee front inflation portion 53 inflates, the left and right position adjustment tethers 61, 62 adjust the position of the knee front inflation portion 53 so that it inflates near the left-right center 8a on the front side 8 of the seat 5, and the adjusted position of the knee front inflation portion 53 causes the bag main body 30, which is inflating toward the buckle 17, to shift. In other words, even if the bag main body 30 attempts to inflate in a misaligned manner toward the buckle 17, this misalignment is corrected by the position-adjusted knee-front inflation section 53, and the bag main body 30 moves toward the center in the left-right direction of the seat 5, on the side away from the buckle 17, so that it faces the small occupant MPS. As a result, the small occupant MPS can be well protected by the bag main body 30 inflated so that it faces the small occupant MPS.

Also, as shown in Figure 10A, even if the occupant wearing the lap belt portion 13 is a large occupant MPL and the folding storage area 22 of the bag main body portion 30 shifts toward the fixed end 11b of the seat belt 11 in the lap belt portion 13, when the knee front inflation portion 53 inflates, as shown in Figure 10B and 10C, the left and right position adjustment tethers 61, 62 adjust the position of the knee front inflation portion 53 so that it inflates near the left-right center 8a on the front side 8 of the seat 5, and the bag main body portion 30, which inflates toward the fixed end 11b, also shifts due to the adjusted position of the knee front inflation portion 53. In other words, even if the bag main body 30 attempts to inflate in a misaligned manner toward the fixed end 11b, the adjusted position of the knee-front inflation section 53 corrects this misalignment and moves it toward the center in the left-right direction of the seat section 5, the side away from the fixed end 11b, so that it faces the large occupant MPL. As a result, the large occupant MPL can be well protected by the bag main body 30 that inflates to face the large occupant MPL.

Of course, the left and right position adjustment tethers 61, 62 of the knee front inflation portion 53 are not directly connected to the seat 1 at their ends 61b, 62b, which are farther from the knee front inflation portion 53. Instead, they are connected to the tongue 18 or the fixed end 11b of the seat belt 11. Simply fastening the lap belt portion 13 allows the left and right position adjustment tethers 61, 62's ends 61b, 62b, which are farther from the knee front inflation portion 53, to be smoothly positioned on both the left and right sides of the seat cushion 5. Furthermore, when fully inflated, the knee front inflation portion 53 covers the front sides of the left and right knees MK(L, R) of the occupants MP, MPS, MPL, thereby protecting the occupants' knees MKL, MKR from areas of the vehicle body in front of the knees MK(L, R) (e.g., the instrument panel, front seats, etc.).

Therefore, with the occupant protection device 10 of this embodiment, even if the folded storage portion 22 of the airbag 29 shifts along the lap belt portion 13 due to differences in the physiques of the occupants MP, MPS, and MPL when the seat belt 11 is fastened, the inflated airbag 29 can smoothly protect the occupants MP, MPS, and MPR, and can also protect the occupants' knees MK (L, R).

In the embodiment, the end 61b of the position adjustment tether 61 is connected to the seat belt 11 itself near the fixed end 11b of the seat belt 11. However, instead of the seat belt 11 itself, it may be connected to the left side 6 of the seat cushion 5 of the seat 1, or, as with tether 61A shown by the two-dot chain line in Figure 7, the end 61b may be connected near the tip 47 of the gas supply passage portion 45, which is near the fixed end 11b.

1...seat, 2...backrest portion, 3...upper end, 3a...left edge, 5...seat portion, 8...front, 8a...center, 10...occupant protection device, 11...seat belt, 11a...upper end, 11b...(fixed end) lower end, 13...lap belt portion, 15...retractor, 17...buckle, 18...tongue, 22...folded storage portion, 24...(gas supply device) inflator, 29...airbag, 30...bag main body portion, 32a...lower surface, 32c...leading edge, 37...support surface, 38...occupant restraint surface, 45...gas supply path portion, 46...base portion, 47...tip portion, 53...knee front inflation portion, 53a...left edge, 53b...right edge, 56a...rear surface/knee contact surface, 61...(fixed end side) position adjustment tether, 61a...(bag side) base portion, 61b...end portion, 62...(buckle side) position adjustment tether, 62a...(bag side) base portion, 62b...end portion, 69...bag cover,
MP...crew member, MPS...small crew member, MPL...large crew member, MW...waist, MF...thigh, MK (L, R)...knee, MU...upper body.

Claims (1)

The seat belt is unwound from a retractor disposed on one upper end side of the backrest of the seat in the left-right direction, and has a fixed end at its tip that is fixed to the side of the seat bottom where the retractor is disposed in the left-right direction. By fastening an assembled tongue to a buckle disposed on the opposite side of the seat bottom from the fixed end side in the left-right direction, the left and right ends of the seat belt are connected to the left and right sides of the seat bottom, and a lap belt portion is disposed in front of the waist of an occupant seated in the seat.
an airbag that is folded and disposed in the lap belt portion, and that, when activated, is inflated by the inflow of inflation gas and is capable of receiving and protecting the upper body of an occupant moving forward;
The airbag,
a bag body that inflates to accommodate an occupant;
a gas supply passage portion having a tip end connected to a gas supply device for inflation gas disposed on the fixed end side of the seat belt, the gas supply passage portion having a base end connected to the bag main body portion so as to be able to supply inflation gas to the bag main body portion;
An occupant protection device comprising:
the airbag is configured to include knee-front inflatable portions that are in communication with the bag main body, are disposed at a front end lower portion of the bag main body, and are disposed in front of the left and right knees of the occupant,
a gas supply port for supplying inflation gas to the knee-front inflation section is disposed on a bottom wall portion on the bottom side of the bag body, and when the bag body is inflated, the knee-front inflation section is inflated by the inflation gas flowing in through the gas supply port of the bag body;
Position adjustment tethers are provided on both the left and right sides of the knee front inflation section when inflation is complete, and are connected to the left and right sides of the seat, respectively, to position the knee front inflation section near the center in the left-right direction on the front side of the seat, so that the rear surface of the knee front inflation section serves as a knee contact surface that contacts the left and right knees of the occupant,
The bag main body and the knee front inflation portion, which communicate with the base side of the gas supply path portion, are folded and covered together with the left and right position adjustment tethers and the base side of the gas supply path portion by a bag cover that allows the bag main body and the knee front inflation portion to protrude when inflated, and are stored in a storage portion of the lap belt portion of the seat belt,
The tether on one of the left and right position adjustment tethers on the buckle side has an end side farther from the knee front expansion portion connected to the tongue,
An occupant protection device characterized in that the other of the left and right tethers is arranged with its end side farther from the knee-front expansion portion connected to the vicinity of the fixed end of the seat belt.