Occupant protection devices

Abstract

To provide an occupant protection device that can smoothly protect an occupant with an inflated airbag, even if a folded and stored site of the airbag is shifted along a lap belt part due to a physical difference of the occupant, when a seat belt is attached.SOLUTION: An occupant protection device 10 is provided with: a bag body part 30 in which an airbag 29 stored in a lap belt part 13 of a seat belt inflates to be able to receive an occupant; a gas supply passage part 45 through which gas for inflation from a gas supply device is supplied to the bag body part; a knee-front inflation part 53 communicating with the bag body part. In the knee-front inflation part are arranged position adjustment Tethers 61 and 62, connected to vicinities of left and right sides of a seat part 5, which make a knee-contact surface 56a contact knees MK (L and R) of the occupant and arrange the knee-front inflation part in the vicinity of a center 8a at a front surface 8 side of the seat part. An end part 62b of the Tether 62 is connected to a tung 18, and an end part 61b of the Tether 61 is connected to a vicinity of a stationary end 11b of the seat belt.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to an occupant protection device for protecting an occupant seated in a seat. [Background technology]

[0002] A conventional occupant protection device includes an airbag that is folded and disposed in the lap belt portion of a seatbelt, and when activated, it inflates with an inflow of inflation gas, and when inflation is complete, the support surface on the underside is supported by the thighs of the occupant seated in the seat, and the occupant restraint surface on the rear side receives and protects the upper body of the occupant moving forward (see, for example, Patent Document 1). The seatbelt is configured to be unwound from a retractor disposed on one of the upper left and right ends of the seat backrest, with the leading end being a fixed end that is fixed to the side of the seat cushion where the retractor is disposed in the left and right direction, and a tongue attached to a buckle disposed on the opposite side of the left and right fixed end of the seat cushion is fastened to connect the left and right ends of the seat to the left and right, and the lap belt portion is disposed in front of the waist of the occupant seated in the seat. The airbag is configured with a bag body that inflates to accommodate an occupant, and a gas supply passage that connects a tip of the bag body to a gas supply device for inflation gas disposed at the fixed end of the seatbelt and that 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 or the like, the bag body inflates, and the support surface on the lower surface of the bag body is supported by the thighs of the occupant seated in the seat, thereby receiving and protecting the upper body of the occupant moving forward with the occupant restraint surface on the rear surface of the bag body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-66425 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional occupant protection devices, when fastening the tongue of the seat belt 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 that of a large 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 by facing the occupant (small occupant).On the other hand, if the occupant is large, when fastening the tongue of the seat belt to the buckle, the folded storage portion of the bag main body is shifted toward the fixed end of the seat belt, making it difficult to inflate the bag main body by facing the occupant (large occupant).

[0005] The present invention is intended to solve the above-mentioned problems, and aims to provide 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. [Means for solving the problem]

[0006] 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.

[0007] In the occupant protection device according to the present invention, after an occupant seated in a seat fastens a seat belt, the device is activated by a vehicle collision or the like, allowing inflation gas to flow from the gas supply passage into the bag main body, pushing open the bag cover, inflating the bag main body and inflating the knee front inflation portion. The left and right edges of the knee front inflation portion 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 then cause the knee front inflation portion to inflate near the left-right center of the front side of the seat cushion. Therefore, even if the occupant wearing the lap belt is small and the folded storage portion of the bag main body is shifted toward the lap belt buckle, when the knee front inflation portion inflates, the left and right position adjustment tethers adjust the position of the knee front inflation portion so that it inflates near the left-right center of the front side of the seat cushion. The adjusted position of the knee front inflation portion 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 by shifting toward the fixed end, the shift is corrected by the position-adjusted knee-front inflation section, and the bag main body moves toward the center in the left-right direction of the seat part, which is the side away from the fixed end, so that it faces the large occupant.As a result, the large occupant can be well protected by the bag main body that inflates to face the large occupant.Of course, the left and right position-adjustable tethers for the knee front inflation portions are not directly connected to the seat, but are connected to the tongue or near the fixed end of the seat belt, so that simply by fastening the lap belt, the left and right position-adjustable tethers' ends away from the knee front inflation portions can be smoothly positioned on both the left and right sides of the seat cushion. Furthermore, since the knee front inflation portion, once fully inflated, covers the front sides of the occupant's left and right knees, it can protect the occupant's knees from parts of the vehicle body in front of the knees (for example, the instrument panel or front seats).

[0008] Therefore, with the occupant protection device of the present invention, 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, the inflated airbag can smoothly protect the occupant, and can also protect the occupant's knees. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a seat equipped with an occupant protection device according to an embodiment of the present invention; [Figure 2] 1 is a left side view of a seat equipped with an occupant protection device according to an embodiment; [Figure 3] 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. [Figure 4] 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. [Figure 5] FIG. 2 is a diagram showing constituent materials of the airbag according to the embodiment. [Figure 6] 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. [Figure 7] 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. [Figure 8]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. [Figure 9] 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; [Figure 10] 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. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described below with reference to the drawings. As shown in Figures 1 to 4, an occupant protection device 10 of the 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.

[0011] The seat belt 11 is arranged on one side of the seat 1 in the left-right direction (the left side in this embodiment) 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 portion 2, and the lower end 11b as the tip is arranged as a fixed end fixed to an anchor member 16 arranged on the left side 6 of the seat portion 5.

[0012] 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 side in the left-right direction of the seat 1 (the right side in this embodiment). When the tongue 18 is fastened to the buckle 17, the seat belt 11 has a portion extending from the tongue 18 toward the retractor 15 as a shoulder belt portion 12 disposed in front of the upper body MU of the occupant MP, and a portion extending from the tongue 18 toward the fixed end 11b as a lap belt portion 13 disposed 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 is also configured to stop the seat belt 11 from being pulled out if it is suddenly pulled out, and further includes a pretensioner that can retract the pulled out belt 11 if the vehicle crashes or the like.

[0013] The inflator 24 serving as a gas supply device includes a generally cylindrical inflator body 25 that discharges inflation gas, and a pipe portion 26 that projects from the inflator body 25 and is bent in a generally L-shape, and is attached and fixed to the rear side of the left side 6 of the seat portion 5 where the retractor 15 is disposed (see FIGS. 1 and 2). A tip end 47 of a gas supply passage portion 45 of an airbag 29, which will be described later, is fitted onto the pipe portion 26 and further fastened and connected by a clamp 27.

[0014] 4, the airbag 29 is configured to include a bag main body 30 that is greatly inflated by the inflow of inflation gas, a gas supply path 45 that is connected to the lower end 30a of the bag main body 30 and supplies inflation gas from an inflator 24 serving as a gas supply device to the bag main 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 main 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 13 is inserted. The bag main body 30, the gas supply path 45, the knee-front inflation section 53, the position adjustment tethers 61, 62, and the belt insertion section 66 are made of flexible woven fabric such as polyester.

[0015] The bag main body 30 is configured so that, when fully inflated, the peripheral wall 31 inflates into a generally triangular prism shape when viewed from the side, and 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 bag main body 30 has a lower surface 32a of the bottom wall 32, excluding a front edge 32c, which serves as a support surface 37 for supporting the thighs MF of the occupant MP, and a rear surface 33a of the rear wall 33 which serves as an occupant restraint surface 38 that receives the upper body MU of the occupant MP as they move forward (see FIGS. 7 and 8).

[0016] An inlet section 40 having multiple inlets 40a (two arranged side by side on the left and right in this embodiment) is disposed near the rear edge 32b of the bottom wall 32, through which inflation gas flows in from the gas supply passage 45. In addition, vent holes 43 are formed 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, two gas supply ports 41 are disposed side by side on the left and right on the front edge 32c of the bottom wall 32, through which inflation gas is supplied to the knee-front inflation section 53.

[0017] 5, the peripheral wall 31 of the bag body 30 is formed by sewing together two sheets of material, a front region 31a and a rear region 31b. The front region 31a includes a front wall 34 and the front sides of the left and right side walls 35 (L, R), while the rear region 31b includes a rear wall 33, a bottom wall 32, and the rear sides of the side walls 35 (L, R).

[0018] The gas supply path 45 has a base 46 connected to the inlet 40 of the bag body 30 of the airbag 29, through which inflation gas flows, and a tip 47 connected to the pipe 26 of the inflator 24. The gas supply path 45 is formed by sewing together the outer peripheral edges of an outer material 49 and a bag side material 50, which have the same outer shape (see FIG. 5). The base 46 of the gas supply path 45 is provided with a communication port 46c that communicates with the inlet 40a of the inlet 40 of the bag body 30, and the periphery of the communication port 46c is sewn to the periphery of the inlet 40a, so that the gas supply path 45 is connected to the rear edge 32b of the bottom wall 32, which forms the lower end 30a of the bag body 30. As described above, the gas supply passage 45 is configured such that the 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.

[0019] The gas supply path portion 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 portion 30 side, 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 port 46c of the bag side material 50 is sewn to the periphery of the inlet 40a of the bag main body portion 30.

[0020] 4, 6-8, the knee-front inflatable section 53 has a generally rectangular parallelepiped shape that can cover the left and right knees MK (L, R) of a seated occupant MP when fully inflated. When fully inflated, the knee-front inflatable section 53 includes 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.

[0021] 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.

[0022] The position adjustment tether 61 has its base 61a connected to the left edge 53a of the knee-front inflation section 53 when inflation is complete, and its end 61b, which is away from the knee-front inflation section 53, connected near the fixed end 11b of the seat belt 11.

[0023] The position adjustment tether 62 has a base 62a connected to the right edge 53b of the knee front inflatable portion 53 when inflation is complete, and an end 62b away from the knee front inflatable portion 53 connected to the tongue 18.

[0024] The length dimensions LL, LR from the base 61a, 62a of the tethers 61, 62 to the end portions 61b, 62b are set to be length dimensions that position the knee-front inflation portion 53 near the center 8a in the left-right direction on the front 8 side of the seat 5, with the rear knee contact surface 56a in contact with the knees MK (L, R) of the occupant MP, when the knee-front inflation portion 53 has completed inflation in conjunction with the inflation of the bag main body 30.

[0025] As shown in FIG. 5, the knee front inflation portion 53 is formed from a sheet-like knee inflation portion material 59 having a shape in which a ceiling side portion 59a forming the ceiling wall 54 extends to a front side portion 59b forming the front wall 55, a left side portion 59d and a right side portion 59e forming the left and right side walls 57 (L, R), and a rear side portion 59f forming the rear wall 56, and further has a bottom side portion 59c extending from the front side portion 59b to form the bottom wall 58. The knee front inflatable portion 53 is formed by sewing the periphery of the communication port 54a of the knee inflatable 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 inflatable material 59 together to form the knee front inflatable portion 53 having a substantially rectangular parallelepiped shape.When sewing the adjacent left side portion 59d and right side portion 59e of the rear side portion 59f together, the base 61a side of the position adjustment tether 61 is sewn to the left side connecting portion 59fl on the left side, and the base 62a side of the position adjustment tether 62 is sewn to the right side connecting portion 59fr on the right side. In addition, the ends 61b, 62b of the tethers 61, 62 that are farther from the base portions 61a, 62a are connected to the vicinity of the fixed end 11b and the tongue 18 when the bag main body portion 30 and the knee front inflation portion 53 of the airbag 29 are folded and attached to the folding storage portion 22 of the lap belt portion 13.

[0026] The belt insertion portion 66 is formed into a cylindrical shape by connecting front and rear edge portions 67a, 67a of a substantially rectangular insertion portion material 67 (see FIG. 5), and is arranged so as to enclose the folded storage portion 22 of the airbag 29 (bag main body 30) of the lap belt portion 13. Before connecting the edge portions 67a, 67a into a loop shape, the belt insertion portion 66 is connected by sewing to the outer material 49 of the gas supply path portion 45, and after the folded bag main body 30 is placed in the folded storage portion 22 of the lap belt portion 13, the edge portions 67a, 67a are connected to each other to form a cylindrical (loop) shape.

[0027] Furthermore, when the airbag 29 is assembled to the folding storage area 22 of the lap belt portion 13, the bag main body portion 30, which communicates (connects) the base portion 46 of the gas supply path portion 45, and the knee-front inflation portion 53 are folded, and together with the left and right position adjustment tethers 61, 62 and the base portion 46 of the gas supply path portion 45, they are configured as a bag assembly 75, and are further covered by a bag cover 69 which allows the bag main body portion 30 and the knee-front inflation portion 53 to protrude when inflated, and are assembled to the folding storage area 22.

[0028] That is, the airbag 29 is made by folding the bag body 30 and the knee-front inflation section 53, to which the gas supply path 45 and the belt insertion section 66 before sewing the edge sections 67a, 67a together are attached, and then partially wrapping the folded section with a strip-shaped wrapping material (not shown) to prevent the folded section from collapsing. Then, the belt insertion section 66 before being made into a cylindrical shape is wrapped around the folded storage section 22 of the lap belt section 13, and the edge sections 67a, 67a are sewn together to attach the belt insertion section 66 to the lap belt section 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 main body portion 30 of the airbag 29, the base portion 46 of the gas supply path portion 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 portion 22 of the lap belt portion 13.

[0029] The bag cover 69 is formed from a sheet-like cover material 70 that is folded in half (see Figure 5), and is arranged by wrapping around the folded bag main body 30, etc., and sewing the overlapping edges 70a together (see Figure 3).

[0030] In the embodiment of the occupant protection device 10, 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 connecting the ends 61b, 62b of the tethers 61, 62 to the vicinity of the fixed end 11b or the tongue 18, and the tip portion 47 of the gas supply path portion 45 of the airbag 29 is connected to the pipe portion 26 of the inflator 24 using the clamp 27, so that the device can be mounted on the seat 1.

[0031] The occupant protection device 10 of this embodiment is activated after being installed in the seat 1 when a vehicle collision or the like occurs with an occupant MP seated in the seat 1 and wearing a seat belt 11 (see FIGS. 6 to 8 ). At this time, inflation gas from the inflator 24 flows through the gas supply passage 45 and into the bag main body 30 from the inlet 40a of the inlet portion 40, causing the bag main body 30 to inflate. When the bag main 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 so as to be able to support the upper body MU of the occupant MP. Furthermore, when the bag main body 30 inflates, the inflation gas flowing in from the communication port 54a via the gas supply port 41 of the bag main body 30 also inflates the knee-front inflation portion 53. 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 serving 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 surface 8 of the seat 5.

[0032] In the occupant protection device 10 of the embodiment, when the lap belt portion 13 is worn, for example, as shown in A of Figure 9, if the occupant wearing the device is a small occupant MPS and the folding storage area 22 of the bag main body portion 30 shifts toward the buckle 17 of the lap belt portion 13, as shown in B and C of Figure 9, once 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 portion 5, and the bag main body portion 30 inflating toward the buckle 17 also shifts due to the position-adjusted knee front inflation portion 53. In other words, even if the bag main body 30 attempts to inflate by shifting toward the buckle 17, the shift 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, which is 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 that inflates so as to face the small occupant MPS.

[0033] Furthermore, as shown in Figure 10A, even if the occupant wearing the lap belt portion 13 is a large occupant MPL and the folded storage area 22 of the bag main body portion 30 shifts toward the fixed end 11b of the seat belt 11 of the lap belt portion 13, when the knee front inflation portion 53 inflates, as shown in Figures 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 adjusted position of the knee front inflation portion 53 also shifts the bag main body portion 30 that inflates toward the fixed end 11b. In other words, even if the bag main body portion 30 attempts to inflate by shifting toward the fixed end 11b, the shift is corrected by the position-adjusted knee-front inflation portion 53, and the bag main body portion 30 moves toward the center in the left-right direction of the seat portion 5, which is the side away from the fixed end 11b, so as to face the large occupant MPL.As a result, the large occupant MPL can be well protected by the bag main body portion 30 that has inflated so as to face the large occupant MPL.

[0034] Of course, the left and right position adjustable tethers 61, 62 of the knee front inflation portion 53 are not directly connected to the seat 1 at their ends 61b, 62b away from the knee front inflation portion 53, but are connected near the tongue 18 or fixed end 11b of the seat belt 11, and simply by fastening the lap belt portion 13, the ends 61b, 62b of the left and right position adjustable tethers 61, 62 away from the knee front inflation portion 53 can be smoothly arranged on both the left and right sides of the seat 5. Furthermore, the knee front inflation portion 53 that has completed inflation can cover the front sides of the left and right knees MK(L, R) of the occupants MP, MPS, MPL, and therefore can protect the occupants' knees MKL, MKR from parts of the vehicle body in front of the knees MK(L, R) (for example, the instrument panel or front seats).

[0035] Therefore, in the occupant protection device 10 of the 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, MPL when the seat belt 11 is fastened, the inflated airbag 29 can smoothly protect the occupants MP, MPS, MPR, and further protect the knees MK (L, R) of the occupants.

[0036] 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, but it may also be connected to the left side part 6 of the seat portion 5 of the seat 1 instead of the seat belt 11 itself, or, as in the tether 61A shown by the dotted line in Figure 7, the end 61b may be connected near the tip end 47 of the gas supply path portion 45, which is near the fixed end 11b. [Explanation of symbols]

[0037] 1...seat, 2...backrest, 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...folding storage area, 24...(gas supply device) inflator, 29...airbag, 30...bag main body, 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...lower body, MF...thighs, MK(L,R)...knees, MU...upper body.

Claims

[Claim 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.

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