JP7215385B2 - passenger protection device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection device provided with a loop-shaped airbag that protrudes rearward from a storage portion on the front side of a seated occupant and inflates so as to receive the occupant moving forward when inflation gas is introduced.

Conventionally, as an occupant protection device, an airbag that protects a seated occupant can quickly complete inflation, and also completes inflation in a loop shape so as to suppress an increase in reaction force when the occupant is received. known (see, for example, Patent Literatures 1 and 2). These airbags have a loop shape in which a hollow portion is provided in the intermediate portion in the front-rear direction to prevent the inflow of inflation gas when inflation is completed. Moreover, when receiving the occupant, the hollow portion disposed in the intermediate portion in the front-rear direction is crushed to suppress the rise of the reaction force, and the occupant can be received and protected.

JP-A-6-344844 JP 2017-222331 A

However, in any of the occupant protection devices, the airbag when inflation is completed has a hollow portion in the middle portion in the front-rear direction, and is configured to be easily crushed forward. There is a possibility that a stable reaction force cannot be secured.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an occupant protection system in which an airbag can quickly complete inflation and secure a stable reaction force when receiving an occupant. and

The occupant protection device according to the present invention is housed in a housing portion disposed in a vehicle body side portion in front of a seated occupant, and projects rearward from the housing portion and moves forward when inflation gas flows in. An occupant protection device comprising a loop-shaped airbag that is inflated to receive an occupant and has a hollow portion that does not allow inflation gas to flow in the vicinity of the center of the inflated portion, comprising:
The shape of the airbag when inflation is completed is as follows:
A first inflatable portion extending in a substantially columnar shape along the vehicle body side portion from the storage portion and supported by the vehicle body side portion; A second inflatable portion extending in a substantially columnar shape rearward of the part side, and a third inflatable portion extending in a substantially columnar shape from the rear end of the second inflatable portion and intersecting the other end in the vertical direction of the first inflatable portion. and an inflatable portion having a substantially triangular ring shape surrounding the hollow portion,
When the airbag completes inflation,
The vicinity of the rear end of the second inflatable portion is arranged at the rearmost end and serves as a receiving portion for a portion to be protected of the occupant moving forward,
When receiving the part to be protected of the occupant in the vicinity of the rear end of the second expansion part,
The second expansion portion is compressively deformable such that the rear end side approaches the front end side along the axial direction of the substantially columnar shape in the completed expansion shape,
The vicinity of the rear end of the second expansion portion is supported by the third expansion portion, and the vicinity of the front end of the second expansion portion is supported by the first expansion portion so as to ensure a reaction force from the vehicle body side portion. It is characterized in that it is connected with

In the occupant protection device according to the present invention, when the airbag completes inflation, the vicinity of the rear end of the second inflatable portion serves as a receiving portion of the portion to be protected of the occupant, and when the occupant moves forward, A portion of the occupant to be protected is received near the rear end of the second inflatable portion as a receiving portion. At this time, the second expansion portion is compressively deformable such that the rear end side approaches the front end side along the axial direction of the substantially columnar shape in the expansion completion shape, and the vicinity of the rear end of the second expansion portion is moved to the third expansion portion. The vicinity of the front end of the second inflatable portion is connected to the first inflatable portion so that the second inflatable portion is supported by the portion and the reaction force from the vehicle body side portion can be secured. Therefore, the second expansion portion is in a state of buckling deformation, in other words, a state of compression deformation (second expansion portion) in which the rear end side approaches the front end side along the axial direction of the substantially columnar shape of the expanded shape. In such a state that the inflatable portion is compressed in the lengthwise dimension in the front-rear direction, it becomes a behavior that receives the part to be protected of the occupant. That is, the fully inflated airbag deforms not by bending deformation but by compressive deformation such as buckling deformation of the second inflatable portion that can ensure a high reaction force. It is possible to secure the above reaction force and receive the part to be protected of the occupant. Of course, since the airbag is provided with a hollow portion, compared with the case where the entire outer shape is used as the inflation region, the volume into which the inflation gas flows is smaller, and the inflation can be completed quickly. .

Therefore, in the occupant protection system according to the present invention, the airbag can quickly complete inflation, and can secure a stable reaction force when receiving the occupant.

In the occupant protection system according to the present invention, the second inflation portion of the airbag extends in a direction extending from a front end to a rear end when the inflation is completed. It is desirable that the direction is along the direction opposite to the direction of movement of the .

With such a configuration, the second inflatable portion of the airbag moves forward when the occupant protection device is actuated. , so that when the occupant is subjected to buckling deformation by receiving the part to be protected of the occupant, a more accurate and stable reaction force can be ensured.

In the occupant protection system according to the present invention, the occupant's knees and head can be exemplified as the occupant's protection target portion received by the vicinity of the rear end of the second inflatable portion of the airbag. For example, in an occupant protection device in which the knees of an occupant are to be protected, the storage portion for the airbag is disposed on the rear side of the vehicle body side portion in front of the lower legs of the seated occupant, When the airbag is inflated, the airbag protrudes rearward from the housing portion and is inflated so as to receive an occupant moving forward. and is supported on the rear surface side of the vehicle body side portion, and the second expansion portion when expansion is completed extends rearward from the vicinity of the upper end of the first expansion portion to the vicinity of the rear end. as a receiving portion for receiving the knees of the occupant moving forward.

Further, as a passenger protection device in which the head of a rear-seat passenger is to be protected, the storage part of the airbag is placed on the rear side of the front seat as the vehicle-body-side part in front of the seated passenger, and the airbag, when inflated, protrudes rearward from the storage portion and inflates so as to receive an occupant moving forward; along the rear surface side of the front seat and supported by the rear surface side of the front seat; , and the vicinity of the rear end thereof may be provided as a receiving portion for receiving the head of the occupant moving forward.

As an occupant protection device in which the knees of an occupant are to be protected, and a occupant protection device in which the head of a rear seat occupant is to be protected, the airbag is in the second position at the time of completion of inflation. It is preferable to dispose an upper and lower tether that connects the inflatable portion and the third inflatable portion to restrict the movement of the second inflatable portion and the third inflatable portion in the mutually separating direction. In such a configuration, the upper and lower tethers can stabilize the separation state between the second inflation portion and the third inflation portion when the inflation of the airbag is completed, and the substantially triangular annular shape of the airbag when inflation is completed. Stabilizing the shape can contribute to stabilizing the occupant protection performance of the airbag.

Furthermore, as an occupant protection device when the head of an occupant in the front passenger seat is to be protected, the storage portion of the airbag is placed on the upper surface side of the instrument panel as the vehicle body portion in front of the seated occupant. When inflated, the airbag protrudes rearward from the storage portion so as to block the space between the instrument panel and the windshield above the instrument panel, and receives the occupant moving forward. As a configuration for stopably inflating, the first inflatable portion at the completion of inflation is arranged along the upper surface of the instrument panel as the vehicle body side portion and supported by the instrument panel. The second inflatable portion at the time of completion of inflation extends obliquely upward and rearward from the vicinity of the front end of the first inflatable portion, and the vicinity of the rear end of the occupant's head moves forward. It may be disposed as a receiving portion for receiving the portion.

When the head of the occupant on the front passenger seat is the part to be protected, the occupant protection device is such that when the airbag is fully inflated in a vehicle-mounted state,
The length dimension in the front-rear direction from the front end portion of the second expansion portion intersecting the first expansion portion to the rear end portion intersecting the third expansion portion in the state of protruding from the housing portion is
a length dimension from a portion of the first expansion portion that intersects with the second expansion portion to a portion that intersects with the third expansion portion; shorter than the sum of the length dimension up to the lower end portion that intersects with the first expansion portion, and
It is desirable that the length dimension from the portion of the first expansion portion that intersects with the second expansion portion to the portion that intersects with the third expansion portion is longer than the length dimension.

With such a configuration, when the airbag is inflated, the first, second and third inflation sections are substantially columnar and complete inflation in a substantially triangular annular shape. The first expansion portion has a length dimension shorter than that of the second expansion portion extending in the front-rear direction, and expands while extending rearward and downward along the upper surface side of the instrument panel, and the length dimension of the second expansion portion is Although the length dimension is longer than that of the first expansion part, it is smaller than the total length dimension of the first expansion part and the third expansion part. is placed forward (that is, a shape in which the upper end portion is placed behind the lower end portion) can be ensured. As the rearmost end of the bag, the head of the occupant in the passenger's seat moving forward can be received favorably.

Further, as an occupant protection device in which the head of an occupant in a front passenger seat is to be protected, the airbag connects the third inflatable portion and the storage portion when the inflation is completed, thereby It is preferable that a front and rear tether capable of restricting rearward movement of the third inflatable portion away from the housing portion is provided.

With such a configuration, the third inflatable portion, which is arranged substantially in the vertical direction between the first inflatable portion and the second inflatable portion, is restricted from moving backward wholly or partially by the front and rear tethers. Therefore, the substantially triangular annular shape of the airbag is stabilized when the inflation is completed, which contributes to stabilizing the occupant protection performance of the airbag.

Further, as an occupant protection device in which the head of an occupant in the front passenger seat is to be protected, the airbag connects the second inflation portion and the first inflation portion when inflation is completed. , and an upper and lower tether for restricting the movement of the second expansion portion and the first expansion portion in the mutually separating direction.

In such a configuration, the upper and lower tethers can stabilize the separation state between the second inflation portion and the first inflation portion when the inflation of the airbag is completed. Stabilizing the shape can contribute to stabilizing the occupant protection performance of the airbag.

Further, as an occupant protection device in which the head of an occupant in the front passenger seat is to be protected, the airbag connects the upper surface side of the second inflation portion and the storage portion side when the inflation is completed. and an upper outer tether for restricting the downward movement of the second inflatable portion away from the windshield.

With such a configuration, the airbag at the completion of inflation can maintain a state in which the upper surface side of the second inflatable portion is in contact with the windshield by the upper outer tether. Since the upper surface side of the second inflatable portion is supported by the windshield, the behavior of bending deformation can be suppressed and the behavior of the buckling deformation state can be stabilized. Capable of occupant restraint performance.

1 is a schematic side view showing an operating state of an occupant protection system according to a first embodiment of the present invention; FIG. FIG. 4 is a schematic longitudinal sectional view of the airbag when the occupant protection system of the first embodiment is activated; FIG. 4 is a schematic longitudinal sectional view of the airbag when the occupant protection system of the first embodiment is activated; FIG. 3 is a schematic vertical cross-sectional view of the airbag when the occupant protection system of the first embodiment is in operation, showing the IV-IV portion of FIG. 2; FIG. 4 is a schematic perspective view of the single airbag of the first embodiment when inflation is completed; FIG. 2 is a plan view showing constituent materials of the airbag of the first embodiment; FIG. 4A is a plan view showing a connection state of various tethers of the airbag of the first embodiment; 4A and 4B are diagrams for sequentially explaining the inflated states of the airbag when the occupant protection system of the first embodiment is activated; FIG. 9A and 9B are diagrams for sequentially explaining the inflated states of the airbag when the occupant protection system of the first embodiment is activated, and show the state after FIG. 8 ; FIG. FIG. 11 is a schematic side view showing an operating state of the passenger protection device of the second embodiment; FIG. 11 is a schematic vertical cross-sectional view of the airbag when the occupant protection system of the second embodiment is in operation, showing the XI-XI portion of FIG. 10; FIG. 11 is a schematic side view showing an operating state of the passenger protection device of the third embodiment; FIG. 13 is a schematic vertical cross-sectional view of the airbag when the occupant protection system of the third embodiment is in operation, showing the XIII-XIII portion of FIG. 12; FIG. 11 is a schematic side view showing an operating state of the passenger protection device of the fourth embodiment;

A first embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. It is mounted on the upper surface 2a side of (instrument panel) 2 . The front passenger seat 4 includes a backrest portion 4a and a seat portion 4b, and an occupant OP who wears a shoulder belt 6a and a lap belt 6b of the seat belt 6 sits on the seat 4.

The occupant protection device 10 includes an airbag 20 that protects an occupant OP seated on a front passenger seat 4, and an inflator 16 that supplies inflation gas G to the airbag 20. The airbag 20 includes: The inflator 16 is attached to the case 12 so as to supply inflation gas to the folded airbag 20 .

As shown in FIG. 2, the inflator 16 includes a body portion 16a having a gas discharge port 16b for discharging the inflation gas G, and a flange portion 16c extending from the outer peripheral surface of the body portion 16a. It is

The case 12 is made of sheet metal and includes a rectangular plate-shaped bottom wall portion 13 and a rectangular cylindrical peripheral wall portion 14 extending from the outer peripheral edge of the bottom wall portion 13. It is installed and fixed to a vehicle body side member that does not. An inflator 16 and an airbag 20 are attached and fixed to the bottom wall portion 13 by using a square annular retainer 17 .

The retainer 17 is arranged on the inner peripheral surface side of the inflow opening 22 of the airbag 20 , and a plurality of (four in the first embodiment) bolts 18 extending from the retainer 17 are attached to the periphery of the inflow opening 22 . The bolts 18 are inserted through the holes 23 (see FIGS. 6 and 7), the bottom wall portion 13 of the case 12 and the flange portion 16c of the inflator 16, and the nuts 19 are fastened to the bolts 18, thereby tightening the case 12. The peripheral edge of the inflow opening 22 of the airbag 20 and the flange portion 16c of the inflator 16 are attached and fixed to the bottom wall portion 13 .

As for the operation of the inflator 16, when a control device (not shown) receives a signal from a collision detection sensor (not shown) installed in a front bumper or the like for detecting a collision of the vehicle 1 and determines that a collision has occurred, the inflator is operated. 16 is activated.

The airbag 20 is folded and stored in a case 12 as a storage part, and is arranged on the upper surface of the instrument panel 2 so as to block the space between the instrument panel 2 and the windshield 3 above the instrument panel 2 when the inflation gas G flows in. While pushing open the door of the instrument panel 2 (not shown), the case 12 protrudes rearward from the case 12 disposed on the side 2a and inflates so as to receive the occupant OP moving forward. That is, in the first embodiment, the airbag 20 is configured to deploy and inflate from the case 12 as a storage portion disposed on the upper surface 2a side of the instrument panel 2 .

As shown in FIGS. 1 to 3, when the airbag 20 is completely inflated, the airbag 20 extends in a substantially columnar shape along the upper surface 2a of the instrument panel 2 as a vehicle body side part from the case 12 as a storage part, and extends to the instrument panel 2. From the supported lower inflatable portion 27 as the first inflatable portion and the vertical end portion (upper end or front end) 27a of the lower inflatable portion 27 as the first inflatable portion, the portion H side of the occupant OP to be protected. An upper expansion portion 25 as a second expansion portion extending rearward in a substantially columnar shape, and a lower expansion portion as a first expansion portion extending in a substantially columnar shape from a rear end 25b of the upper expansion portion 25 as a second expansion portion. A rear expansion portion 29 as a third expansion portion that intersects with the other end (lower end or rear end) 27b of the portion 27 in the vertical direction is arranged to surround the hollow portion 32 and has a substantially triangular ring shape. . In other words, when the airbag 20 of the first embodiment is fully inflated, the upper inflation portion 25 extends obliquely upward and rearward from the case 12 in a substantially columnar shape, and the rear end 25b of the upper inflation portion 25 extends downward in a substantially columnar shape. Extends forward in a substantially columnar shape along the upper surface 2a of the instrument panel 2 from the lower end 29b of the rear expansion portion 29 so as to intersect the rear expansion portion 29 and the vicinity of the front end 25a of the upper expansion portion 25 on the case 12 side. A hollow portion 32, which is a non-inflating portion into which the inflation gas G does not flow, is arranged in the center in the front-rear direction. In the case of the first embodiment, when the airbag 20 completes inflation, the upper surface 25c side of the upper inflation portion 25 contacts the lower surface 3a of the windshield 3, and the lower surface 27d side of the lower inflation portion 27 contacts the upper surface of the instrument panel 2. It will be in a state of being supported by 2a.

2, the hollow portion 32 has a substantially triangular shape surrounded by the lower surface 25d of the upper inflatable portion 25, the upper surface 27c of the lower inflatable portion 27, and the front surface 29c of the rear inflatable portion 29. , the front top portion 32a of the front end is a tapered portion that intersects the lower surface 25d of the upper expansion portion 25 and the upper surface 27c of the lower expansion portion 27 in a curved shape, and the upper top portion 32b of the rear upper end is the lower surface 25d of the upper expansion portion 25. and the front surface 29c of the rear expansion portion 29, and the lower top portion 32c of the rear lower end intersects the upper surface 27c of the lower expansion portion 27 and the front surface of the rear expansion portion 29 in a curved shape. It is a tapered part that That is, in the case of the first embodiment, the airbag 20 is configured such that the inflatable portions 25, 27, and 29, which are inflated into a substantially columnar shape, are bent into a substantially triangular annular shape, and the intersection portions 34 of the inflatable portions 25, 27, and 29 are bent. , 35 and 36, the peripheral wall 21 of the airbag 20 is in a kinked state. Therefore, when viewed from the left and right, the hollow portion 32 is a substantially triangular space with tapered apexes 32a, 32b and 32c. and

The rear inflation portion 29 of the airbag 20 at the completion of inflation is configured such that the upper end portion 29a that intersects the upper inflation portion 25 is arranged rearward from the lower end portion 29b that intersects the lower inflation portion 27. It is The rear side inflation portion 29 of the airbag 20 at the completion of inflation has a receiving area 30 that receives the occupant OP on the rear surface 29d side, a head receiving area 30a on the upper side of the receiving area 30, and a chest on the lower side. It becomes the reception area 30b. In particular, in the head receiving area 30a of the airbag 20, the vicinity of the rear end 25b of the upper inflatable portion 25 receives a high reaction force when receiving, and receives the head H as a portion to be protected of the occupant OP. It is used as a receiving part. That is, the upper expansion portion 25 as the second expansion portion extends obliquely upward and rearward from the front end 25a to the rear end 25b of the case 12 as a storage portion when the expansion is completed, and extends in the vicinity of the rear end 25b. , making it possible to receive the head H of the occupant OP moving forward, and to enable compressive deformation such that the vicinity of the rear end 25b approaches the front end 25a side when receiving it, so that the vicinity of the rear end 25b and the vicinity of the front end 25a can be received. It is connected to and supported by a rear expansion portion 29 as a third expansion portion and a lower expansion portion 27 as a first expansion portion. Specifically, the upper end 29a of the rear inflatable portion 29 as the third inflatable portion is connected to the rear end 25b of the upper inflatable portion 25 so as to restrict the vertical movement of the rear end 25b of the upper inflatable portion 25, Further, the front end (upper end) of the lower expansion portion 27 as the first expansion portion is arranged so that the front end 25a of the upper expansion portion 25 can secure the reaction force from the upper surface 2a of the instrument panel 2 as the vehicle body side portion. 27a is connected to the front end 25a of the upper expansion portion 25. As shown in FIG.

The peripheral wall 21 of the airbag 20 has an outer peripheral wall 21a and an inner peripheral wall 21b. As shown in FIGS. 5 to 7, the airbag 20 has a peripheral wall 21 formed of two pieces, an outer peripheral side base fabric 50 forming an outer side wall 21a and an inner peripheral side base fabric 51 forming an inner side wall 21b. ing. In the airbag 20, the lateral side edges 51a and 51b of the inner peripheral side base fabric 51 are joined (stitched) to the lateral side edges 50a and 50b of the outer peripheral side base fabric 50, and the inner peripheral side base fabric 51 The peripheral wall 21 can be formed by stitching the front and rear edges 51c and 51d of the outer peripheral base fabric 50, leaving an unstitched portion 51e, and stitching the front and rear edges 50c and 50d of the outer peripheral base cloth 50. .

Each of the upper inflatable portion 25, the lower inflatable portion 27, and the rear inflatable portion 29 has a connecting piece 38 inside so as to define the separation distance between the outer wall 21a and the inner wall 21b when inflated. , 39 and 40 are arranged. Each connecting piece 38, 39, 40 is composed of inner cloths 38a, 39a, 40a connected to the inner wall 21b and outer cloths 38b, 39b, 40b connected to the outer wall 21a. Then, the inner fabrics 38a, 39a, 40a are sewn to the inner peripheral side base fabric 51 forming the inner wall 21b, and the outer fabrics 38b, 39b, 40b are sewn to the outer peripheral side base fabric 50 forming the outer wall 21a. When stitching the inner peripheral side base fabric 51 and the outer peripheral side base fabric 50, the corresponding inner fabrics 38a, 39a, 40a and outer fabrics 38b, 39b, 40b are sewn together to form connecting pieces. 38 is arranged at the intermediate portion of the upper inflatable portion 25 in the longitudinal direction, the connecting cloth 39 is arranged in the intermediate portion of the lower inflatable portion 27 in the longitudinal direction, and the connecting cloth 40 is arranged in the vertical direction of the rear inflatable portion 29. It is arranged in the intermediate part.

Further, the airbag 20 has an inflow opening 22 through which the inflation gas G is introduced in the outer wall 21a. The inflow opening 22 is formed in a circular shape, and is formed in the outer wall 21a (the outer base fabric 50) on the lower surface side of the intersection 34 between the upper inflatable portion 25 and the lower inflatable portion 27 when the airbag 20 completes inflation. , are arranged. Attachment holes 23 through which the bolts 18 of the retainer 17 are inserted are provided on the periphery of the inflow opening 22, as described above.

Further, vent holes 24, 24 for exhausting surplus inflation gas G are opened in the inner wall 21b near the lower end 29b of the rear inflation portion 29. As shown in FIG.

Reinforcing cloths (not shown) having a predetermined shape are disposed at the portions where the connecting cloths 28, 29, 30, the inflow opening 22, and the vent holes 24 are disposed.

When the airbag 20 is fully inflated in the vehicle-mounted state, the upper inflatable portion 25, the lower inflatable portion 27, and the rear inflatable portion 29 each have a substantially rectangular cross-section with both left and right edges rounded. , and the length dimensions LU, LD, and LU (see FIG. 3) of each part are set so as to maintain the relationships LU < LD + LB and LU > LD. .

The length LU is the length of the upper inflatable portion 25, and extends from the front end portion 25a of the upper inflatable portion 25 protruding from the case 12 as a housing portion to the rear inflatable portion. 29 to a rear end portion 25b that intersects with 29 in the front-rear direction. The length LD is the length in the front-rear direction from the front end portion 27a of the lower expansion portion 27 that intersects the upper expansion portion 25 to the rear end portion 27b that intersects the rear expansion portion 29. As shown in FIG. The length LB is the length in the vertical direction from the upper end portion 29a of the rear expansion portion 29 that intersects with the upper expansion portion 25 to the lower end portion 29b that intersects with the lower expansion portion 27 .

The length LU of the upper inflatable portion 25 is shorter than the sum of the length LD of the lower inflatable portion 27 and the length LB of the rear inflatable portion 29, and the length of the lower inflatable portion 27 is It is longer than the dimension LD.

In the case of the first embodiment, the length LU of the upper expansion portion 25 is approximately 550-650 mm, the length LD of the lower expansion portion 27 is approximately 380-480 mm, and the length LB of the rear expansion portion 29 is approximately 380-480 mm. is about 400-500 mm. The distance LL between the upper end portion 29a and the lower end portion 29b of the rear expansion portion 29 in the front-rear direction is about 50 to 150 mm.

The front end 25a of the upper expansion portion 25 and the front end 27a of the lower expansion portion 27 are arranged above the case 12 on the side of the upper surface 2a of the instrument panel 2, are mutually intersecting portions 34, and coincide with each other. there is Further, the rear end 25b of the upper expansion portion 25 and the upper end 29a of the rear expansion portion 29 are a mutual crossing portion 35 and coincide with each other. Similarly, the rear end 27b of the lower inflatable portion 27 and the lower end 29b of the rear inflatable portion 29 are a mutual crossing portion 36 and coincide with each other.

Also, the connection pieces 38, 39, 40 are not disposed near the intersections 34, 35, 36, and the airbag 20 when inflated is bent at the intersections 34, 35, 36. , the upper inflatable portion 25, the lower inflatable portion 27, and the rear inflatable portion 29 have a predetermined length and are formed in a substantially triangular ring shape so as to complete the inflation smoothly.

Furthermore, in the airbag 20 of the first embodiment, when inflated, the upper inflatable portion 25 as the second inflatable portion extends rearward from the case 12 as the storage portion (from the substantially columnar front end 25a to the rear end 25b). Axial direction LX extending to the side) is an obliquely upward and rearward direction, and is arranged so as to be a direction along a direction opposite to a moving direction HM of the head H of the occupant OP moving forward when the occupant protection device 10 is actuated. is provided (see FIG. 1). In the case of the first embodiment, at the time of a frontal collision of the vehicle 1, the moving direction HM of the head H of the standard male (male dummy AM50) seated on the seat 4 with the seat belt 6 worn is obliquely forward. As the downward direction, the axial direction LX of the upper expandable portion 25 is arranged substantially parallel to the moving direction HM and slightly above the moving direction HM of the head H itself.

In the case of the first embodiment, the upper expansion portion 25 contacts the lower surface 3a of the windshield 3 in the axial direction LX. Therefore, it approximates the projecting direction of the upper expansion portion 25 along the lower surface 3 a of the windshield 3 .

Further, in the airbag 20 of the first embodiment, the rear inflation portion 29 does not protrude so as to curve rearward when inflated, and is easily maintained in a substantially triangular annular shape when inflation is completed. , front and rear tethers 42 are arranged. The front and rear tethers 42 have their rear ends 42c sewn to the inner cloth 40a of the connecting cloth 40 on the inner wall 21b on the front surface 29c side of the rear inflation portion 29, and the narrowed front ends 42a are sewn to the inner cloth 40a. , is fixed to the rear portion 13b side of the bottom wall portion 13 of the case 12 as a storage portion. Specifically, the front end 42a is provided with mounting holes 42b, 42b through which the bolts 18 of the retainer 17 are inserted. It is attached and fixed to the rear portion 13b side of the bottom wall portion 13 of the case 12 (see FIG. 2). Although the front and rear tethers 42 are arranged in the hollow portion 32 on the rear end 42c side, the front end 42a side passes through an unstitched portion 51e where the edges 51c and 51d of the inner peripheral base cloth 51 are not sewn together. It is configured to be inserted through the inside of the lower expansion portion 27 and locked to the bolt 18 of the retainer 17 .

Furthermore, in the airbag 20, the upper inflatable portion 25 and the lower inflatable portion 27 are connected to each other when inflation is completed, and movement of the upper inflatable portion 25 and the lower inflatable portion 27 in the separation direction is restricted. The upper and lower tethers 44 are arranged. The upper and lower tethers 44 are arranged to block the front side of the hollow portion 32 and are connected to the upper cloth 45 connected to the inner wall 21b of the upper expansion portion 25 and the inner wall 21b of the lower expansion portion 27. and a lower fabric 46 that Both the upper cloth 45 and the lower cloth 46 have a trapezoidal shape with a wider width on the rear side. The upper edge 45a of the upper cloth 45 is joined to the inner wall 21b of the upper inflation portion 25, and more specifically, sewn near the sewn portion of the inner cloth 38a of the connecting piece 38 in the inner peripheral side base cloth 51. In addition, the lower edge 46b of the lower cloth 46 is joined to the inner wall 21b of the lower inflatable portion 27. Specifically, the inner cloth 39a of the connecting cloth 39 in the inner peripheral side base cloth 51 is sewn. The lower edge 45b of the upper cloth 45 and the upper edge 46a of the lower cloth 46 are sewn together.

Furthermore, the airbag 20 connects the upper surface 25c side of the upper inflatable portion 25 and the case 12 side of the storage portion at the time of completion of inflation, thereby restricting the downward movement of the upper inflatable portion 25 away from the windshield 3. An outer tether 48 is provided. The upper and outer tether 48 has its rear end 48c sewn to the outer wall 21a of the upper expansion portion 25 near the sewn portion of the connecting piece 38, and its front end 48a to the front portion 13a of the bottom wall portion 13 of the case 12 as a storage portion. side (see Fig. 2). Specifically, the front end 48a is provided with mounting holes 48b, 48b through which the bolts 18 of the retainer 17 are inserted. is attached and fixed to the bottom wall portion 13 of the case 12 .

Further, in the airbag 20, along the periphery of the inflow opening 22, a straightening cloth (not shown) is arranged to flow the inflation gas flowing in from the inflow opening 22 to both left and right sides.

In addition, the outer peripheral side base fabric 50, the inner peripheral side base fabric 51, the connection pieces 38, 39, 40, or various tethers 42, 44, 48 are formed of a flexible woven fabric such as polyamide or polyester. ing.

In the occupant protection device 10 of the first embodiment, the airbag 20 with the retainer 17 arranged on the inner peripheral surface side is folded and stored in the case 12, and the peripheral edge of the inflow opening 22 and the inflator 16 are separated. The retainer 17 is fixed to the bottom wall 13 of the case 12 using the bolts 18 and nuts 19 of the retainer 17, and while the case 12 is fixedly mounted in the instrument panel 2, the inflator 16 is operated by a control device (not shown). It can be mounted on the vehicle 1 by connecting lead wires for signal input. When fixing the airbag 20 to the case 12, the front ends 42a of the front and rear tethers 42 inside the airbag 20 and the front ends 48a of the upper and outer tethers 48 outside the airbag 20 are also secured using the bolts 18 of the retainer 17. It is fixed to the bottom wall portion 13 of the case 12 .

After the occupant protection device 10 is mounted on the vehicle V, the vehicle 1 collides, and if a control device (not shown) detects the collision of the vehicle 1 and activates the inflator 16, the inflator 16 is activated by the airbag 20. Since the inflation gas G is supplied, the airbag 20 is deployed and inflated rearward from the case 12 as a storage portion, as shown in FIGS.

Then, when the airbag 20 completes inflation, the rear inflation portion 29 has the upper end portion 29a positioned rearward of the lower end portion 29b, and as indicated by the two-dot chain line in FIG. When the head H moves forward, the vicinity of the head H will move to the head receiving area 30a on the upper side of the receiving area 30 on the rear surface 29d of the rear inflation section 29, more specifically, the upper inflation section 25 as the second inflation section. is received at a receiving portion near the rear end 25b of the . At this time, since the rear expansion portion 29 has a shape in which the upper end portion 29a side protrudes rearward from the lower end portion 29b, it does not bend and deform so as to narrow the hollow portion 32, but has a substantially columnar shape as a storage portion. The behavior of receiving the occupant OP in a state in which the upper expansion portion 25 extending obliquely upward and rearward from the case 12 is subjected to buckling deformation (a state in which the upper expansion portion 25 compresses the length dimension LU in the front-rear direction). becomes. Therefore, the fully inflated airbag 20 deforms with the buckling deformation of the upper inflating portion 25, which can ensure a higher reaction force than the bending deformation of the rear inflating portion 29, so that a stable reaction force is generated. It is possible to secure and receive the head H of the occupant OP. The chest B of the occupant OP moving forward with the head H received and the kinetic energy reduced is received and protected by the chest receiving area 30b on the lower side of the receiving area 30. . Of course, since the airbag 20 is provided with the hollow portion 32, compared with the case where the entire area of the outer shape is used as the inflatable portion, the volume of the inflating gas G flowing therein is small, and the inflation can be completed quickly. be able to.

Therefore, in the occupant protection device 10 of the first embodiment, the airbag 20 can quickly complete inflation, and can secure a stable reaction force when receiving the occupant OP.

In the occupant protection device 10 of the first embodiment, the upper inflation portion 25 as the second inflation portion of the airbag 20 extends rearward from the case 12 as the storage portion, i. The direction LX extending from 25a to the rear end 25b is the direction along the direction facing the moving direction HM of the head H of the occupant OP moving forward when the occupant protection device 10 is actuated. .

Therefore, in the first embodiment, the upper inflatable portion 25 of the airbag 20 extends along the direction facing the moving direction HM of the head H of the occupant OP moving forward when the occupant protection device 10 is activated. , extends rearward from the case 12, and when it receives the head H of the occupant OP and undergoes buckling deformation, a more accurate and stable reaction force can be ensured. In addition, in the first embodiment, even if the head H of the occupant OP is received immediately before the inflation of the airbag 20 is completed, the upper inflation portion 25 is still inflated as shown in FIGS. 8A and 8B and FIG. The head H of the occupant OP moving forward can be received in the receiving area 30c that is in the middle of inflation including the vicinity of the upper end 29a of the rear inflation portion 29 near the rear end 25b. A constant reaction force can be secured even during restraint, and the initial restraint performance of the airbag 20 can be improved.

Further, in the occupant protection device 10 of the first embodiment, when the airbag 20 is fully inflated in the vehicle-mounted state, the airbag 20 protrudes from the case 12 serving as a housing portion, and the lower inflatable portion 27 of the upper inflatable portion 25 and the lower inflatable portion 27 protrude from the case 12 as a storage portion. The length dimension LU in the front-rear direction from the intersecting front end portion 25a to the rear end portion 25b intersecting the rear expansion portion 29 is defined by 29, and a vertical dimension LD from an upper end portion 29a intersecting the upper inflatable portion 25 to a lower end portion 29b intersecting the lower inflatable portion 27 in the rear inflatable portion 29. It is shorter than the sum of the length dimension LB in the direction and longer than the length dimension LD in the front-rear direction of the lower expansion portion 27 .

Therefore, in the first embodiment, when the airbag 20 is inflated, the upper inflatable portion 25, the lower inflatable portion 27, and the rear inflatable portion 29 are substantially columnar and complete inflation in a substantially triangular ring shape. At this time, the lower expansion portion 27 expands downward and rearward along the upper surface 2a side of the instrument panel 2 with a length dimension LD shorter than the upper expansion portion 25 extending obliquely upward and rearward from the case 12. Although the length LU of the upper expansion portion 25 is longer than the length LD of the lower expansion portion 27, the total length of the lower expansion portion 27 and the rear expansion portion 29 (LD+LB). Since the rear inflation portion 29 is smaller, the rear inflatable portion 29 stably maintains the state in which the lower end portion 29b is arranged forward of the upper end portion 29a (that is, the state in which the upper end portion 29a is arranged behind the lower end portion 29b). As a result, the vicinity of the rear end 25b of the upper inflatable portion 25 as the second inflatable portion at the completion of inflation stably becomes the rearmost end of the airbag 20, and the head of the occupant OP moving forward stably. It is possible to secure a state in which the portion H can be received by a stable reaction force that causes the upper expansion portion 25 to undergo buckling deformation.

Further, in the occupant protection device 10 of the first embodiment, the airbag 20 connects the rear inflation portion 29 as the third inflation portion and the case 12 side as the housing portion when inflation is completed, thereby achieving rear inflation. Front and rear tethers 42 that can restrict rearward movement of the portion 29 away from the case 12 are provided.

Therefore, in the first embodiment, the rear inflation portion 29 is restricted from moving rearward wholly or partially by the front and rear tethers 42, so that the substantially triangular annular shape of the airbag 20 when inflation is completed is stable. As a result, the occupant protection performance of the airbag 20 (the ability to receive the head H of the occupant OP moving forward with a stable reaction force that causes the upper inflatable portion 25 to buckle and deform). can contribute to stabilizing

Further, in the occupant protection device 10 of the first embodiment, the airbag 20 connects the upper inflatable portion 25 as the second inflatable portion and the lower inflatable portion 27 as the first inflatable portion when inflation is completed. An upper and lower tether 44 is provided to restrict the movement of the upper expansion portion 25 and the lower expansion portion 27 in the separation direction.

Therefore, in the first embodiment, the upper and lower tethers 44 can stabilize the mutual separation state between the upper inflatable portion 25 and the lower inflatable portion 27 when the inflation of the airbag 20 is completed. By stabilizing the substantially triangular annular shape of the airbag 20, it is possible to contribute to stabilizing the occupant protection performance of the airbag 20.

Furthermore, in the occupant protection device 10 of the first embodiment, the airbag 20 connects the upper surface 25c side of the upper inflation portion 25 as the second inflation portion at the completion of inflation and the case 12 side as the storage portion. , an upper outer tether 48 for restricting downward movement of the upper expansion portion 25 away from the windshield 3 .

Therefore, in the first embodiment, the airbag 20 at the completion of inflation can maintain the state in which the upper surface 25c side of the upper inflation portion 25 is in contact with the lower surface 3a of the windshield 3 by the upper outer tether 48, and the initial restraint can be maintained. When the occupant is restrained including when the upper inflatable portion 25 is supported by the windshield 3 on the upper surface 25c side, the behavior of bending deformation can be suppressed and the behavior of the buckling deformation state can be stabilized. The bag 20 has a good occupant restraint performance that can secure a stable reaction force (the head H of the occupant OP moving forward can be received by a stable reaction force that causes the upper inflatable portion 25 to buckle and deform). performance) can be exhibited.

In the first embodiment, the upper outer tether 48 arranged on the upper surface 25c side of the upper inflation portion 25 was exemplified as the tether arranged on the outside of the airbag 20 when inflation is completed. The rear end side is connected to the lower surface 27d side of the lower expansion portion 27 so that the lower surface 27d of the lower expansion portion 27 can be in close contact with the upper surface 2a side of the instrument panel 2, and the front end side is a case as a storage portion. A lower outer tether may be arranged to connect to the 12 side.

Next, an occupant protection system 10A of a second embodiment shown in FIGS. . In the occupant protection device 10A, the case 12 as a storage portion for the airbag 60 is disposed on the rear surface 4ab side of the backrest portion 4a of the front seat 4A as the vehicle body portion in front of the seated occupant BP. there is Further, the airbag 60 projects rearward from the case 12 as a storage portion when inflated so as to be inflated so as to receive the occupant BP moving forward. Along the rear surface 4ab side of the front seat 4A as a side portion, and arranged so as to be supported by the rear surface 4ab side of the front seat 4A, and the second expansion portion 64 at the completion of expansion is placed in the first expansion portion 64. Extending rearward from the vicinity of the upper end 62a of the inflatable portion 62, the vicinity of the rear end 64b is disposed as a receiving portion for receiving the head H of the occupant BP moving forward.

That is, the airbag 60 has a substantially columnar shape when it is fully inflated and extends upward along the rear surface 4ab of the seat 4A as the vehicle body side portion from the case 12 as the housing portion. A first inflatable portion 62 supported by the rear surface 4ab of the seat 4A and a vertical end (upper end) 62a of the first inflatable portion 62 extend in a substantially columnar shape toward the rear of the portion H to be protected of the occupant BP. a second inflatable portion 64, a third inflatable portion 66 that extends in a substantially columnar shape from a rear end 64b of the second inflatable portion 64 and intersects the other end (lower end) 62b of the first inflatable portion 62 in the vertical direction; is arranged to surround the hollow portion 32 and has a substantially triangular ring shape. When the airbag 60 is fully inflated, the vicinity of the rear end 64b of the second inflatable portion 64 is positioned at the rearmost end to receive the head H as a protected portion of the occupant BP moving forward. In addition, when the head H of the occupant BP is received near the rear end 64b of the second inflation portion 64, the second inflation portion 64 is moved along the substantially columnar axial direction LX of the inflation completion shape toward the rear end 64b side. The vicinity of the rear end 64b of the second expansion portion 64 is connected to and supported by the upper end 66a of the third expansion portion 66 so as to restrict vertical movement so as to be compressively deformable so as to approach the front end 64a side, and the vehicle body side. The vicinity of the front end 64a of the second inflatable portion 64 is connected to the upper end 62a of the first inflatable portion 62 so as to be in contact with the rear surface 4ab of the seat 4A so that the reaction force from the rear surface 4ab of the seat 4A can be secured. I am letting Each expansion part 62, 64, 66 that expands into a substantially columnar shape has a substantially rectangular cross-section with both left and right edges rounded (see FIG. 11).

Also in this airbag 60, the direction in which the second inflation portion 64 extends from the front end 64a to the rear end 64b at the completion of inflation is the head portion of the occupant BP, which is a portion to be protected, which moves forward when the occupant protection device 10A is operated. It is arranged so as to be in the direction opposite to the movement direction HM of H.

In addition, connecting pieces 38, 39, 40 are arranged to connect the inner peripheral wall side and the outer peripheral wall side of the respective inflatable portions 62, 64, 66, and the substantially triangular annular shape of the airbag 60 after completion of inflation is stabilized. In order to restrict the expansion of the second inflatable portion 64 and the third inflatable portion 66, that is, to restrict the movement of the second inflatable portion 64 and the third inflatable portion 66 in the separation direction from each other. Therefore, the upper and lower tethers 44A connecting the second expansion portion 64 and the third expansion portion 66 are provided.

In the occupant protection system 10A of the second embodiment, when the airbag 60 completes inflation, the vicinity of the rear end 64b of the second inflation portion 64 serves as a receiving portion for the head H of the occupant BP. moves forward, the head H of the occupant BP, which is the part to be protected, is received near the rear end 64b of the second inflatable portion 64, which is the receiving part. At this time, the rear end of the second expansion portion 64 is compressed and deformed such that the rear end 64b side approaches the front end 64a side along the axial direction LX of the generally columnar shape of the expansion completion shape. The vicinity of the front end 64a of the second inflatable portion 64 is supported by the third inflatable portion 66 so as to restrict vertical movement, and the reaction force from the seat 4A as a vehicle body side portion can be secured. It is connected to the first expansion portion 62 so as to contact the rear surface 4ab of the seat 4A. Therefore, the second expansion portion 64 is in a state of buckling deformation, in other words, compression deformation such that the rear end 64b side approaches the front end 64a side along the axial direction LX of the substantially columnar shape of the expanded shape. As a state (a state in which the length dimension in the front-rear direction of the second inflatable portion 64 is compressed), a behavior of receiving the head H as a part to be protected of the occupant BP is performed. That is, the fully inflated airbag 60 deforms not by bending deformation but by compressive deformation such as buckling deformation of the second inflatable portion 64 capable of ensuring a high reaction force. , the head H of the occupant BP, which is a part to be protected, can be received by securing a reaction force of a predetermined level or more. Of course, since the airbag 60 is provided with the hollow portion 32, compared with the case where the entire area of the outer shape is used as the inflatable portion, the volume of the inflating gas G flowing therein is small, and the inflation can be completed quickly. be able to.

Therefore, in the occupant protection system 10A of the second embodiment as well, the airbag 60 can quickly complete its inflation, and can secure a stable reaction force when receiving the occupant BP.

Also in the occupant protection system 10A of the second embodiment, after the fully inflated airbag 60 receives the head H of the occupant BP in the vicinity of the rear end 64b of the second inflation portion 64, the rear end 64b is It moves forward and can receive the vicinity of the chest B of the occupant BP by the area from the vicinity of the upper end 66a to the side of the lower end 66b in the third inflatable portion 66, and can suitably receive and protect the occupant BP.

Further, in the occupant protection device 10A of the second embodiment, the case 12 as a storage portion is disposed on the side of the lower end 62b of the first inflation portion 62 of the airbag 60. The case 12 as a storage portion may be arranged on the side of the upper end 62a of the .

Next, an occupant protection system 10B of a third embodiment shown in FIGS. 12 and 13 will be described. In this occupant protection system 10B, knees K of the occupant OP are to be protected. In the occupant protection device 10B, a case 12 as a storage portion for an airbag 70 is disposed on the rear surface 2bb side of the lower portion 2b of the instrument panel 2 as a vehicle body side portion in front of the leg L of the seated occupant OP. . Further, the airbag 70 projects rearward from the case 12 as a storage portion when inflated, and inflates so as to receive the knees K of the occupant OP moving forward. is disposed along the rear surface 2bb side of the lower portion 2b of the instrument panel 2 as a vehicle body side portion and is supported by the rear surface 2bb side of the lower portion 2b of the instrument panel 2, and the second expansion portion 74 at the completion of expansion is arranged. , extends rearward from the vicinity of the upper end 72a of the first inflation portion 72, and the vicinity of the rear end 74b is disposed as a receiving portion for receiving the knee K of the occupant OP moving forward.

That is, the airbag 70 extends upward in a substantially columnar shape along the rear surface 2bb of the instrument panel lower portion 2b as the vehicle body side portion from the case 12 as the storage portion as a shape at the time of completion of inflation. a first expansion portion 72 supported on the rear surface 2bb of the instrument panel lower portion 2b; and a third inflatable portion 76 that extends in a substantially columnar shape from the rear end 74b of the second inflatable portion 74 and intersects the other end (lower end) 72b of the first inflatable portion 72 in the vertical direction. and are arranged to surround the hollow portion 32 and form a substantially triangular ring. When the airbag 70 is fully inflated, the vicinity of the rear end 74b of the second inflatable portion 74 is arranged at the rearmost end to receive the knee K as a protected portion of the occupant OP moving forward. In addition, when the knee K of the occupant OP is received near the rear end 74b of the second inflation portion 74, the second inflation portion 74 is moved along the substantially columnar axial direction LX of the inflation completion shape toward the rear end 74b side. The vicinity of the rear end 74b of the second expansion portion 74 is connected to and supported by the upper end 76a of the third expansion portion 76 so as to restrict vertical movement so as to be compressively deformable so as to approach the front end 74a side, and the vehicle body side. The upper end 72a of the first expansion portion 72 is arranged so that the vicinity of the front end 74a of the second expansion portion 74 is brought into contact with the rear surface 2bb of the lower instrument panel 2b so that the reaction force from the rear surface 2bb of the lower instrument panel 2b can be secured. is connected with Each expansion part 72, 74, 76 that expands in a substantially columnar shape has a substantially rectangular cross-section with both left and right edges rounded (see FIG. 13).

In this airbag 70 as well, the second inflation portion 74 extends from the front end 74a to the rear end 74b when the inflation is completed. It is arranged so as to be in the direction opposite to the movement direction KM of K. As shown in FIG.

In addition, connecting pieces 38, 39, 40 are provided to connect the inner peripheral wall side and the outer peripheral wall side of each of the inflatable portions 72, 74, 76, and the substantially triangular annular shape of the airbag 70 after completion of inflation is stabilized. In order to restrict the expansion of the second inflatable portion 74 and the third inflatable portion 76, that is, to restrict the movement of the second inflatable portion 74 and the third inflatable portion 76 in the separation direction from each other. Therefore, the upper and lower tethers 44B connecting the second expansion portion 74 and the third expansion portion 76 are provided.

In the occupant protection device 10B of the third embodiment, when the airbag 70 completes inflation, the vicinity of the rear end 74b of the second inflation portion 74 serves as a receiving portion for the knee K of the occupant OP. moves forward, the knee K as a protected part of the occupant OP is received near the rear end 74b of the second inflatable portion 74 as a receiving part. At this time, the rear end of the second expansion portion 74 is compressed and deformed such that the rear end 74b side approaches the front end 74a side along the axial direction LX of the substantially columnar shape of the expansion completion shape. The vicinity of the front end 74a of the second inflatable portion 74 is supported by the third inflatable portion 76 so as to restrict vertical movement, and the reaction force from the lower portion 2b of the instrument panel as a vehicle body side portion can be secured. , is connected to the first expansion portion 72 so as to abut on the rear surface 2bb of the instrument panel lower portion 2b. Therefore, the second expansion portion 74 is in a state of buckling deformation, that is, a state of compression deformation in which the rear end 74b side approaches the front end 74a side along the axial direction LX of the substantially columnar shape of the expansion completed shape ( In such a state that the second expansion portion 74 is compressed in the length dimension in the front-rear direction, the knee portion K of the occupant OP, which is a portion to be protected, is received. As described above, the fully inflated airbag 70 is deformed not by bending deformation but by compressive deformation such as buckling deformation of the second inflatable portion 74 capable of ensuring a high reaction force. It is possible to stably receive a reaction force greater than or equal to a predetermined level, and receive the knees K as the parts to be protected of the occupant OP. Of course, since the airbag 70 is provided with the hollow portion 32, compared with the case where the entire area of the outer shape is used as the inflatable portion, the volume of the inflating gas G flowing therein is small, and the inflation can be completed quickly. be able to.

Therefore, in the occupant protection system 10B of the third embodiment as well, the airbag 70 can quickly complete inflation, and a stable reaction force can be secured when the occupant OP is received.

In addition, in the occupant protection device 10B of the third embodiment, the case 12 as a storage portion is disposed on the side of the lower end 72b of the first inflation portion 72 of the airbag 70. The case 12 as a storage portion may be arranged on the upper end 72a side of the .

In each embodiment, the airbags 20, 60, 70 are configured so that the second inflation portions 25, 64, 74 extend rearward from the upper ends 27a, 62a, 72a of the first inflation portions 27, 62, 72. rear ends 25b, 64b, and 76b of the second expansion portions 25, 64, and 74 are connected to upper ends 29a, 66a, and 76a of the third expansion portions 29, 66, and 76; The lower ends 29b, 66b, 76b of 66, 76 are connected to the lower ends 27b, 62b, 72b of the first expansion portions 27, 62, 72. FIG. However, like the airbag 80 of the occupant protection system 10C of the fourth embodiment shown in FIG. 14, the shape at the time of completion of inflation is the first airbag extending in a substantially columnar shape from the case 12 so as to be supported by the rear surface 4ab of the seat 4A. A second inflatable portion 84 is arranged to extend rearward in a substantially columnar shape from a front end 84a connected to a lower end 82b of the inflatable portion 82, and a third inflatable portion 86 extending in a substantially columnar shape extends the lower end 86b to the second inflatable portion. A hollow portion 32</b>C may be provided to connect the rear end 84 b of the portion 84 and the upper end 86 a to the upper end 82 a of the first inflatable portion 82 . The rear end 84b of the second inflatable portion 84 is arranged to receive the knee K of the occupant BP that is moving forward, with the knee K of the occupant BP as a protection target portion. Further, in the hollow portion 32C, the movement of the second inflation portion 84 and the third inflation portion 86 in the separation direction can be restricted so as to stabilize the substantially triangular ring-shaped inflation completion shape of the airbag 80. As shown, the upper and lower tethers 44C connecting the second expansion portion 84 and the third expansion portion 86 are provided.

DESCRIPTION OF SYMBOLS 1... vehicle, 2... (instrument panel/vehicle side part) instrument panel, 2a... upper surface, 2b... (vehicle side part) lower part of instrument panel, 3... windshield, 4A... seat, 4bb... rear surface (of seat), 10, 10A, 10B, 10C... occupant protection device 12... (housing part) case 20... airbag 25... (second expansion part) upper expansion part 25a... front end part 25b... rear end part 27... (second 1 expansion part) Lower expansion part 27a Front end part 27b Rear end part 29 (Third expansion part) Rear expansion part 29a Upper end part 29b Lower end part 32, 32A, 32B, 32C ... Hollow part 42 ... Front and rear tethers 44, 44A, 44B, 44C ... Upper and lower tethers 48 ... Upper and outer tethers,
60, 70, 80 Airbags 62, 72, 82 First inflatable portion 62a, 72a, 82a Upper end 62b, 72b, 82b Lower end 64, 74, 84 Second inflatable portion 64a, 74a , 84a... front end 64b, 74b, 84b... rear end 66, 76, 86... third expansion portion 66a, 76a, 86a... upper end 66b, 76b, 86b... lower end,
LU...Length dimension (of the upper expansion part) LD...Length dimension (of the lower expansion part) LB...Length dimension (of the rear expansion part) LX...Axial direction (of the upper expansion part) HM ...moving direction (of the occupant's head), KM...moving direction (of the occupant's knee), G...inflating gas,
OP, BP... occupant, H... head, L... lower leg, K... knee.

Claims (8)

It is housed in a storage portion disposed on the rear side of the front seat as a vehicle body side portion in front of the seated occupant, and when inflation gas flows in, it projects rearward from the storage portion to prevent the occupant moving forward. An occupant protection device comprising a loop-shaped airbag that inflates to a receiving degree and has a hollow portion that does not allow inflation gas to flow in the vicinity of the center of the inflated portion, the airbag comprising:
The shape of the airbag when inflation is completed is as follows:
A first inflatable portion extending in a substantially columnar shape along the vehicle body side portion from the storage portion and supported by the vehicle body side portion; A second inflatable portion extending in a substantially columnar shape rearward of the part side, and a third inflatable portion extending in a substantially columnar shape from the rear end of the second inflatable portion and intersecting the other end in the vertical direction of the first inflatable portion. and an inflatable portion having a substantially triangular ring shape surrounding the hollow portion,
When the airbag completes inflation,
the first expansion portion is disposed along the rear surface side of the front seat as the vehicle body side portion and supported by the rear surface side of the front seat;
The vicinity of the rear end of the second inflatable portion is arranged at the rearmost end and serves as a receiving portion for a portion to be protected of the occupant moving forward,
When receiving the part to be protected of the occupant in the vicinity of the rear end of the second expansion part,
The second expansion portion is compressively deformable such that the rear end side approaches the front end side along the axial direction of the substantially columnar shape in the completed expansion shape,
The vicinity of the rear end of the second expansion portion is supported by the third expansion portion, and the vicinity of the front end of the second expansion portion is supported by the first expansion portion so as to ensure a reaction force from the vehicle body side portion. concatenate with
The occupant protection according to claim 1, wherein the second inflatable portion extends rearward from the vicinity of the upper end of the first inflatable portion, and the vicinity of the rear end thereof is disposed as a receiving portion for receiving the head of the occupant moving forward. Device. It is housed in a storage portion disposed on the rear side of the vehicle body side portion in front of the legs of a seated occupant, and projects rearward from the storage portion to receive the occupant moving forward when inflation gas flows in. An occupant protection device comprising a loop-shaped airbag which is inflatable and has a hollow portion near the center of the inflated portion that does not allow inflow of inflation gas,
The shape of the airbag when inflation is completed is as follows:
A first inflatable portion extending in a substantially columnar shape along the vehicle body side portion from the storage portion and supported by the vehicle body side portion; A second inflatable portion extending in a substantially columnar shape rearward of the part side, and a third inflatable portion extending in a substantially columnar shape from the rear end of the second inflatable portion and intersecting the other end in the vertical direction of the first inflatable portion. and an inflatable portion having a substantially triangular ring shape surrounding the hollow portion,
When the airbag completes inflation,
the first expansion portion is disposed along the rear surface side of the vehicle body side portion and supported by the rear surface side of the vehicle body side portion;
The vicinity of the rear end of the second inflatable portion is arranged at the rearmost end and serves as a receiving portion for a portion to be protected of the occupant moving forward,
When receiving the part to be protected of the occupant in the vicinity of the rear end of the second expansion part,
The second expansion portion is compressively deformable such that the rear end side approaches the front end side along the axial direction of the substantially columnar shape in the completed expansion shape,
The vicinity of the rear end of the second expansion portion is supported by the third expansion portion, and the vicinity of the front end of the second expansion portion is supported by the first expansion portion so as to ensure a reaction force from the vehicle body side portion. concatenate with
The occupant protection according to claim 1, wherein the second inflatable portion extends rearward from the vicinity of the upper end of the first inflatable portion, and the vicinity of the rear end of the second inflatable portion is disposed as a receiving portion for receiving the knees of the occupant moving forward. Device. The direction in which the second inflatable portion of the airbag extends from the front end to the rear end when the inflation is completed is along the direction opposite to the moving direction of the part to be protected of the occupant moving forward when the occupant protection device is operated. 3. An occupant protection device according to claim 1 or 2 , characterized in that it is arranged so as to be oriented. The airbag connects the second inflation portion and the third inflation portion to each other when inflation is completed, and restricts movement of the second inflation portion and the third inflation portion in a separation direction from each other. 4. The occupant protection system according to any one of claims 1 to 3 , wherein upper and lower tethers are provided to support the occupant. It is housed in a storage portion disposed on the upper surface side of the instrument panel as a vehicle body side portion in front of the seated occupant, and when the inflation gas flows in, the instrument panel and the upper part of the instrument panel. It protrudes rearward from the storage part so as to block the space between it and the windshield, and inflates so as to receive the occupant moving forward. An occupant protection device comprising a loop-shaped airbag,
The shape of the airbag when inflation is completed is as follows:
A first inflatable portion extending in a substantially columnar shape along the vehicle body side portion from the storage portion and supported by the vehicle body side portion; A second inflatable portion extending in a substantially columnar shape rearward of the part side, and a third inflatable portion extending in a substantially columnar shape from the rear end of the second inflatable portion and intersecting the other end in the vertical direction of the first inflatable portion. and an inflatable portion having a substantially triangular ring shape surrounding the hollow portion,
When the airbag completes inflation,
the first inflatable portion is arranged along the upper surface of the instrument panel as the vehicle body side portion and extends rearward and downward from the storage portion so as to be supported by the instrument panel;
The vicinity of the rear end of the second inflatable portion is arranged at the rearmost end and serves as a receiving portion for a portion to be protected of an occupant moving forward,
When receiving the part to be protected of the occupant in the vicinity of the rear end of the second expansion part,
The second expansion portion is compressively deformable such that the rear end side approaches the front end side along the axial direction of the substantially columnar shape of the completed expansion shape,
The vicinity of the rear end of the second expansion portion is supported by the third expansion portion, and the vicinity of the front end of the second expansion portion is supported by the first expansion portion so as to ensure a reaction force from the vehicle body side portion. concatenate with
the second inflatable portion extends obliquely upward and rearward from the vicinity of the front end of the first inflatable portion, and the vicinity of the rear end of the second inflatable portion is disposed as a receiving portion for receiving the head of an occupant moving forward;
The airbag is provided with an upper outer tether that connects the upper surface side of the second inflatable portion and the storage portion side when the airbag is fully inflated, and restricts the downward movement of the second inflatable portion away from the windshield. An occupant protection device characterized by being installed . When the airbag is fully inflated in a vehicle-mounted state,
The length dimension in the front-rear direction from the front end portion of the second expansion portion intersecting the first expansion portion to the rear end portion intersecting the third expansion portion in the state of protruding from the housing portion is
a length dimension from a portion of the first expansion portion that intersects with the second expansion portion to a portion that intersects with the third expansion portion; shorter than the sum of the length dimension up to the lower end portion that intersects with the first expansion portion, and
6. The occupant protection according to claim 5 , wherein the length from the portion of the first expansion portion that intersects with the second expansion portion to the portion that intersects with the third expansion portion is longer than the length dimension. Device. A front-rear tether is provided that connects the third inflatable portion and the storage portion when the airbag is fully inflated, and is capable of restricting rearward movement of the third inflatable portion away from the storage portion. The occupant protection device according to claim 5 or 6 , wherein The airbag connects the second inflatable portion and the first inflatable portion to each other when inflation is completed, and restricts movement of the second inflatable portion and the first inflatable portion in a direction separating from each other. 8. The occupant protection system according to any one of claims 5 to 7 , wherein upper and lower tethers are provided to support the occupant.

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