JP7223333B2 - passenger protection device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection device configured to deploy and inflate an airbag, which is stored on the roof side in front of and above a seated occupant of a vehicle, downward from the storage portion so as to protect the occupant in the event of a vehicle collision.

A conventional occupant protection device that houses an airbag on the roof side consists of a rectangular plate-shaped first bag that deploys downward from the roof side and is adjacent to the front side of the first bag so as to be able to protect the occupant's head. and a second bag that expands and inflates downward from the roof side (see, for example, Patent Document 1). In this occupant protection device, the second bag when fully inflated is supported by the headrest of the front seat in front of the occupant to be protected, and is configured to support the front side of the upper end of the first bag. Therefore, when the first bag supported by the second bag receives the head of the occupant moving forward, it can suitably receive and protect the head of the occupant without moving forward.

JP 2016-30546 A

However, in the conventional occupant protection system, the second bag is configured to be supported by the headrest of the front seat. This causes a situation in which the second bag is no longer supported by the headrest of the front seat, and the fully inflated first bag cannot adequately support the second bag, and the occupant's head, which should be protected, cannot be properly protected. There is a risk that it will disappear.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an occupant protection system in which an airbag that is deployed downward from the roof side can stably receive and protect the occupant's head. .

The occupant protection device according to the present invention is housed in the front upper roof side of a seated occupant in a vehicle, deploys and inflates downward when inflating gas flows in, and can protect the head of the occupant moving forward in the event of a vehicle collision. An occupant protection device comprising an airbag that receives a
When the airbag completes inflation,
a base expanding portion extending downward from the storage portion;
a receiving expansion portion protruding rearward from the base expansion portion and having a rear end surface thereof as a receiving surface for the occupant's head;
As a configuration comprising
The base expanding portion is
a main body inflatable portion extending downward from the storage portion in a columnar shape and projecting the receiving inflatable portion rearward;
a support expansion portion projecting forward from the main expansion portion and configured to restrict forward movement of the main expansion portion by supporting an upper surface side thereof on a vehicle-body-side member disposed on a front peripheral edge of the storage portion;
It is characterized by being configured with

In the occupant protection system according to the present invention, when the airbag is deployed and inflated downward from the housing portion on the roof side to complete inflation, the base inflatable portion extends downward from the housing portion and the rear surface of the base inflatable portion extends downward from the housing portion. Since the bulging receiving portion protrudes rearward from the side, the head of the occupant moving forward is received near the rear end surface of the bulging receiving portion and protected. At this time, in the airbag, the main inflatable portion of the base inflatable portion, from which the receiving inflatable portion protrudes rearward, tries to move forward, but the support inflatable portion, which protrudes forward from the main inflatable portion of the base inflatable portion, does not move forward. However, the upper surface side is supported not by the seat that moves back and forth, but by the vehicle body side member arranged on the periphery of the front side of the storage part, and the support expansion part composed of a part of the airbag itself is supported. , the forward movement of the main body expansion part (specifically, the forward rotation of the main body expansion part around the upper end of the main body expansion part, which is the storage part side) is restricted. The anti-inflatable portion is also supported by the supporting inflatable portion via the main inflatable portion, and the occupant's head is preferably received by the receiving inflatable portion that is restricted from positional deviation (forward movement). protected and protected.

Therefore, in the occupant protection system according to the present invention, the airbag deployed downward from the roof side can stably receive and protect the occupant's head.

Further, in the occupant protection device according to the present invention, when the expansion of the airbag is completed, the receiving inflation portion of the airbag extends vertically from the rear end portion where the rear end face is provided in a substantially bifurcated columnar shape. An upper branched expansion part and a lower branched expansion part connected to the rear surface side of the main body expansion part are arranged with their front ends separated vertically while providing a hollow part penetrating in the left and right direction in the body expansion part. It is desirable that

In such a configuration, the receiving inflation portion is provided with a hollow portion penetrating in the left-right direction. At the very least, inflation can be completed quickly. Of course, even if the airbag is provided with a hollow portion, when the receiving inflatable portion receives the occupant's head at the rear end surface, the substantially columnar upper branched inflatable portion bifurcates from the vicinity of the rear end surface and the lower inflatable portion. The front end of the side branch expansion portion is connected to the body expansion portion on the rear surface side, and the upper branch expansion portion and the lower branch expansion portion cooperate to counteract the pressing force of the occupant's head moving forward. Thus, the occupant's head can be favorably received and protected by the rear end face of the receiving expansion portion where the upper branch expansion portion and the lower branch expansion portion intersect.

In this case, one of the upper branched inflation portion and the lower branched inflation portion of the receiving inflation portion of the airbag extends in the axial direction extending from the front end to the rear end in the movement direction of the head of the occupant moving forward. , and the rear end face may be arranged at a position facing the head of the occupant moving forward.

In such a configuration, the branch expansion portion arranged along the direction of movement of the occupant's head in one of the upper branch expansion portion and the lower branch expansion portion, that is, the main branch expansion portion, near the rear end face, When receiving the occupant's head, a state of compression deformation in which the rear end side approaches the front end side along the axial direction, in other words, a state of buckling deformation, the reaction force is higher than that of bending deformation. to receive the occupant's head. In addition, the other branch expansion part of the upper branch expansion part and the lower branch expansion part, that is, the auxiliary branch expansion part connects the rear end of the main branch expansion part to the rear end of the main branch expansion part. can be supported so as not to move up and down, the main branch expansion portion that receives the occupant's head by increasing the reaction force can stably receive the occupant's head.

In this case, the upper branched inflatable portion of the receiving inflatable portion of the airbag is disposed so that the rear end face thereof faces the head of the occupant moving forward,
The lower branch expansion portion of the receiving expansion portion of the airbag is arranged so that the front end side extends obliquely forward and downward from the rear end side and is connected to the lower end of the main body expansion portion. is desirable.

With such a configuration, even if the rear end of the upper branch expansion portion moves forward after the upper branch expansion portion (main branch expansion portion) receives the occupant's head and the occupant moves forward, The branched inflation part (auxiliary branched inflation part) can receive the vicinity of the occupant's chest on the rear surface side, and the airbag moves forward with the occupant's head and head moving forward by the upper branched inflation part and the lower branched inflation part. The upper body of the chest can be favorably received and protected.

Further, in the occupant protection device according to the present invention, the base inflatable portion of the airbag includes a partition wall that partitions the main inflatable portion and the support inflatable portion,
The partition wall may be provided with a check valve that allows the inflating gas to flow from the body inflating portion to the support inflating portion side and prevents backflow.

With such a configuration, the support inflation section only allows the inflation gas to flow in from the body inflation section side by means of the check valve and does not flow back, so that a high internal pressure can be maintained and the body inflation section can be stably supported. As a result, the receiving expansion portion protruding rearward from the body expansion portion is also stably supported, so that the occupant's head is stably received by the receiving expansion portion whose forward displacement is suppressed. protected and protected.

1 is a schematic diagram showing a vehicle-mounted state of an occupant protection device according to a first embodiment of the present invention; FIG. FIG. 4 is a schematic diagram showing the occupant protection device of the first embodiment when it is in operation; FIG. 4 is a schematic perspective view of the passenger protection device according to the first embodiment when the airbag alone has completed inflation. FIG. 11 is a schematic diagram showing the occupant protection device of the second embodiment when it is in operation; FIG. 11 is a schematic perspective view for explaining a non-return valve of an airbag and another example in the occupant protection system of the second embodiment; FIG. 11 is a schematic diagram showing the occupant protection device of the third embodiment when it is in operation; FIG. 11 is a schematic diagram showing the occupant protection device of the fourth embodiment when it is in operation;

1 and 2, an occupant protection device 10 according to a first embodiment of the present invention will be described with reference to the drawings. It is mounted on the roof 4 side above and forward of the occupant OP seated on the BS seat 3).

The occupant protection device 10 of the first embodiment includes an airbag 16, an inflator 14 that supplies inflation gas G to the airbag 16, and a case 12 that houses the folded airbag 16. . The case 12 is disposed on the roof 4 side of the front upper part of the vehicle 1 on the rear seat BS side as a storage part for the folded airbag 16 . The operation of the inflator 14 is controlled by a control device (not shown) that receives a signal from a sensor capable of detecting or predicting a collision of the vehicle 1. When a collision of the vehicle 1 is detected or predicted, the operation of the inflator 14 is controlled by the control device. A signal activates the inflation gas G to be generated. The inflator 14 is housed inside the airbag 16 and fixed to the case 12 . In other words, the inflator 14 constitutes a means for attaching the airbag 16 to the case 12, and the airbag 16 is attached and fixed by the inflator 14 to the rear wall 12c side of the case 12, which serves as a housing portion, which will be described later. It will be done.

The case 12 is made of metal and has an approximately rectangular parallelepiped shape with an opening 12a at the bottom through which the airbag 16 protrudes. The opening 12a is covered. The door portion 6a of the cover member 6 is pushed open forward when the airbag 16 is inflated, causing the airbag 16 to protrude downward from the opening 12a.

In addition, the inflator 14 is attached together with the case 12 to the mounting substrate 7 as a rigid body-side member below the roof panel 5 to which the case 12 is attached. The inflator 14 is attached to the mounting board 7 with the rear end side of the case 12, that is, the rear wall 12c side of the ceiling wall 12b facing the opening 12a of the case 12 on the upper side.

The mounting board 7 is also extended to the upper surface side of the cover material 6 on the front side of the case 12, and is arranged as a rigid support plate portion 8 that does not move, and supports the airbag 16, which will be described later. The upper surface 22a side of the inflatable portion 22 can be firmly supported by interposing the cover material 6 (more specifically, by interposing the opened door portion 6a and the cover material 6 around the door portion 6a). ing.

The airbag 16 is formed in a bag shape from an airbag base fabric such as polyamide. and a reception expansion portion 24 that protrudes rearward from the rear end surface 24a and serves as a reception surface 25a for the head H of the occupant OP in the vicinity of the rear end surface 24a. The receiving surface 25a is arranged as a substantially semicircular curved surface so that the head H can be received softly.

The base inflatable portion 18 extends downward from the case 12 in a columnar shape (in the embodiment, in the shape of a substantially square prism), and has a main inflatable portion 20 that protrudes a receiving inflatable portion 24 from the rear side near the lower end 18b, and a main inflatable portion 20. The upper surface 22a side of the main body is supported by the support plate portion 8 made of the above-described mounting board 7 as a vehicle body side member arranged on the periphery of the front side of the case 12 and protruding forward from the upper portion 20c side of the front surface 20a. and a support expansion portion 22 that restricts forward movement of the expansion portion 20 . The support expansion part 22 has a substantially right triangular prism shape when viewed from the side so that the front surface 22b extends forward from the lower end 22c side and is connected to the front edge side of the upper surface 22a.

In the case of the first embodiment, the supporting expansion part 22 is slightly narrower in width in the horizontal direction than the main expansion part 20, and is positioned slightly below the upper end of the front surface 20a of the main expansion part 20. protrudes forward from the

When the inflation of the airbag 16 is completed, the receiving inflation portion 24 of the first embodiment extends vertically from the rear end portion 25 provided with the rear end surface 24a in a bifurcated substantially columnar shape (substantially square columnar shape in the embodiment), An upper branch expansion part 29 and a lower branch expansion part are connected to the rear surface 20b side of the body expansion part 20 with their front ends 29a and 31a separated vertically while providing a hollow part 27 penetrating in the left-right direction between them. 31 and are arranged. The hollow portion 27 has three vertices 27a, 27b, and 27c when viewed from the side: a vertex 27a on the front upper side, a vertex 27b positioned on the rear side from the vertex 27a, and a vertex 27c positioned on the lower side. An opening 28 opening in a substantially right-angled triangular shape is provided.

Further, in the receiving inflation portion 24 at the completion of inflation, one of the upper branch inflation portion 29 and the lower branch inflation portion 31 (in the first embodiment, the upper branch inflation portion 29) extends from the front end 29a to the rear end 29b. A configuration in which the axial direction LX is arranged along the front-rear direction, which is the moving direction MX of the head H of the occupant OP moving forward, and the rear end surface 24a is arranged at a position facing the head H of the occupant OP moving forward. there is

Further, the lower branch expansion portion 31 at the completion of expansion is arranged so that the front end 31a side extends obliquely forward and downward from the rear end 31b side and is connected to the lower end 20da of the main body expansion portion 20. . In the first embodiment, the lower branched inflation portion 31 at the completion of inflation is disposed so as to extend forward so that the front end 31a is positioned near the front and above the knees K of the seated occupant OP. there is

In the airbag 16 of the first embodiment, the front end 29a of the upper branched inflatable portion 29 and the front end 31a of the lower branched inflatable portion 31 are connected to each other. and the front end 31a of the lower branch expansion portion 31, the thickness dimension Td is slightly smaller than the thickness dimension Tu in the front-rear direction of the upper portion 20c (see FIG. 1).

Furthermore, in the airbag 16 of the first embodiment, in order to stabilize the shape of each part when inflation is completed, inside the main inflatable part 20, the upper branch inflatable part 29, and the lower branch inflatable part 31, connecting opposing portions in a thickness direction perpendicular to the axial direction of expansion into a substantially columnar shape (front-to-rear direction for main body inflating portion 20, and substantially vertical direction for upper branch inflatable portion 29 and lower branch inflating portion 31) In addition, in order to increase the reaction force when receiving the occupant OP, the intersection angle between the upper branch expansion portion 29 and the lower branch expansion portion 31 is not widened. A connecting piece 41 that connects the upper branch expansion portion 29 and the lower branch expansion portion 31 is provided on the hollow portion 27 side.

In the occupant protection system 10 of the first embodiment, as shown in FIG. 2, the airbag 16 is pushed downward from the case 12 as a housing portion on the side of the roof 4 by the inflation gas G discharged by the inflator 14 during operation. When expansion is completed by deployment and inflation, the base expansion portion 18 extends downward from the case 12, and the receiving expansion portion 24 protrudes rearward from the rear surface 20b near the lower end 18b of the base expansion portion 18. The head H of the occupant OP moving forward is received near the rear end surface 24a of the receiving inflation portion 24 and protected. At this time, the main inflatable portion 20 of the base inflatable portion 18, from which the receiving inflatable portion 24 protrudes rearward, of the airbag 16 tries to move forward. The cover material 6 is attached to the support plate portion 8 as a vehicle body side member arranged on the peripheral edge of the front side of the case 12 instead of the seat S in which the protruding support expansion portion 22 moves back and forth on the upper surface 22a side. The supporting inflation portion 22, which is supported so as to intervene and abut on the airbag 16 itself, moves forward of the main body inflation portion 20 (specifically, the side of the mounting portion to the case 12). Since the forward rotation of the main body expansion portion 20 about the upper end 20ca side of the main body expansion portion 20 is restricted, the receiving expansion portion 24 projecting rearward from the main body expansion portion 20 is also prevented from moving forward. The head H of the occupant OP is preferably received and protected by the receiving inflation portion 24, which is restricted from positional deviation (forward movement). be.

Therefore, in the occupant protection device 10 of the first embodiment, the airbag 16 deployed downward from the roof 4 can stably receive and protect the head H of the occupant OP.

In particular, in the first embodiment, the inflator 14 is arranged on the rear end side of the case 12 when the inflation of the airbag 16 is completed. is supported by the ceiling wall 12b, and the forward movement of the main inflatable portion 20 itself (more specifically, the forward rotation of the main inflatable portion 20 about the upper end 20ca side of the main inflatable portion 20) is restricted. Furthermore, the upper edge surface 20ab on the upper edge side of the front surface 20a of the main expansion portion 20 is also supported by the ceiling wall 12b of the case 12, and the front of the main expansion portion 20 is rotated about the upper end 20ca side of the main expansion portion 20. Since the rotation is restricted, the receiving inflation portion 24 is further prevented from moving forward, and can preferably receive the head H of the occupant OP.

In addition, the support inflation portion 22, which has completed inflation, presses the opened door portion 6a toward the support plate portion 8 with the cover material 6 interposed on the upper surface 22a side. The opened door portion 6 is sandwiched between the upper surface 22a of the support expansion portion 22 and the support plate portion 8 without scattering.

In the first embodiment, when the inflation is completed, the receiving inflation portion 24 of the airbag 16 extends vertically from the rear end portion 25 provided with the rear end face 24a in a substantially bifurcated columnar shape. An upper branch expansion portion 19 and a lower branch expansion portion 31 are arranged, which are connected to the rear surface 20b side of the main expansion portion 20 with their front ends 29a and 31a separated vertically while providing a hollow portion 27 penetrating in the direction. It is configured by setting

Therefore, in the first embodiment, the receiving inflation portion 24 is provided with a hollow portion 27 penetrating in the left-right direction, and the airbag 16 can be reduced in volume by the hollow portion 27 and is inflated. At least the amount of gas G supplied can complete the expansion quickly. Of course, even if the airbag 16 is provided with the hollow portion 27, when the receiving inflating portion 24 receives the head H of the occupant OP with the rear end surface 24a, the airbag 16 bifurcates from the vicinity of the rear end surface 24a. The front ends 29a and 31a of the columnar upper branch expansion portion 29 and the lower branch expansion portion 31 are connected to the main expansion portion 20 on the rear surface 20b side, and the upper branch expansion portion 29 and the lower branch expansion portion 31 are connected to each other. The rear end surface 24a of the receiving expansion portion 24 where the upper branch expansion portion 29 and the lower branch expansion portion 31 intersect cooperates against the pressing force of the head H of the occupant OP moving forward. Optimally, the head H of the occupant OP can be received and protected.

In particular, in the first embodiment, one of the upper branched inflation portion 29 and the lower branched inflation portion 31 in the receiving inflation portion 24 of the airbag 16 (in the first embodiment, the upper branched inflation portion 29) The axial direction LX extending from 29a to the rear end 29b is arranged along the movement direction MX of the head H of the occupant OP moving forward and at a position facing the head H of the occupant OP moving forward on the rear end surface 24a. It is configured to allow

Therefore, in the first embodiment, the branch expansion portion 29 arranged along the movement direction MX of the occupant OP's head H in one of the upper branch expansion portion 29 and the lower branch expansion portion 31, that is, the main branch expansion portion When the inflatable portion 33 receives the head H of the occupant OP near the rear end surface (24a) 33a, it is compressed and deformed such that the rear end 29b side approaches the front end 29a side along the axial direction LX. For example, in a state of buckling deformation, the head H of the occupant OP can be received with a higher reaction force than bending deformation. In addition, the other branch expansion portion 31 of the upper branch expansion portion 29 and the lower branch expansion portion 31, that is, the auxiliary branch expansion portion 35 connects the rear end 31b to the rear end 29b of the main branch expansion portion 33, Since the rear end 29b of the main branch expansion portion 33 can be supported so as not to move up and down, the main branch expansion portion 33, which receives the head H of the occupant OP by increasing the reaction force, stably supports the head of the occupant OP. can accept H.

In this case, the lower branched inflatable portion 31 of the airbag 16 is arranged such that the front end 31a side extends obliquely forward and downward from the rear end 31b side and is connected to the lower end 20da of the main body inflatable portion 20. there is

Therefore, in the first embodiment, after the upper branch expansion portion 29 (main branch expansion portion 33) has received the head H of the occupant OP, the rear end 29b of the upper branch expansion portion 29 moves forward, thereby Even if the OP moves forward, the lower branched inflatable portion 31 (auxiliary branched inflatable portion 35) can receive the vicinity of the chest B of the occupant OP on the rear surface 35a side, and the airbag 16 is maintained at the upper branched inflatable portion. 29 and the lower branch expansion portion 31 can appropriately receive and protect the head H and the upper half of the chest B of the occupant OP moving forward.

It should be noted that the airbag 16A of the occupant protection system 10A of the second embodiment shown in FIGS.

In the occupant protection device 10A of the second embodiment, the base inflatable portion 18A of the airbag 16A has a partition wall 43 that partitions the main inflatable portion 20A and the support inflatable portion 22A. The partition wall 43 is provided with a check valve 50 that allows the inflation gas G to flow from the main inflation portion 20A to the support inflation portion 22A side and prevents backflow.

The check valve 50, as shown in FIG. 5A, is formed of split cloths 44, 44 that divide the partition wall 43 into left and right halves. The divided cloths 44, 44 are configured by providing a convex portion 45 at a portion to be sewn to each other, and the outer peripheral edge of the divided cloths 44, 44 separated from the convex portion 45 is used as a peripheral sewn portion 46 to support the main body inflatable portion 20A. The outer peripheral edge of the boundary portion with the expansion portion 22A is sewn, and the circumference of the convex portions 45, 45 of the divided cloths 44, 44 is sewn together as a central sewn portion 47 while providing a tubular portion 48, and the tubular portion is sewn. A passage 49 for the inflation gas G is provided inside the cylinder 48 , and the cylindrical portion 48 is configured as a check valve 50 . In this check valve 50, when the inflation gas G from the inflator 14 flows from the main inflation portion 20A toward the support inflation portion 22A, the tip of the cylindrical portion 48 is pushed open so as to form the opening 48a. When the valve 50 is opened, the inflation gas G flows from the main inflation portion 20A side to the support inflation portion 22A side through the passage 49, and when it tries to flow back, the support inflation portion 22A acts on the cylinder portion 48. The side pressure closes the opening 48a, blocking the flow path 49, that is, the check valve 50 is closed, and the backflow of the inflation gas G is prevented.

Therefore, in the occupant protection device 10A of the second embodiment, when the airbag 16A is inflated, the support inflatable portion 22A simply allows the inflatable gas G to flow from the main inflatable portion 20A side through the check valve 50, thereby causing a reverse flow. As a result, a high internal pressure can be maintained, and the main inflatable portion 20A can be stably supported. The head H of the OP is stably received and protected by the receiving expanded portion 24 whose forward displacement is suppressed.

In the second embodiment, the support expansion portion 22A has the upper surface 22a interposed with the cover material 6 (more specifically, with the opened door portion 6a and the cover material 6 around the door portion 6a interposed), As a structure to be supported by the support plate portion 8, the lower end 22c is extended to the vicinity of the lower end 20da of the main inflatable portion 20A so as to improve the supporting force of the main inflatable portion 20A. Not only the upper part 20c side of the part 20A but also the lower part 20d side of the main body inflatable part 20A is protruded from the front surface 20a side. By doing so, the support expansion portion 22 may be lengthened in the vertical direction.

As a check valve, as shown in FIG. 5B, the partition wall 43 is made into a single piece, and an opening 52 is provided to communicate between the main inflatable portion 20A and the support inflatable portion 22A. A check valve 50A may be formed by arranging a closure cloth 53 sewn on both edges (both upper and lower edges in the figure) around the periphery of the opening 52 . In this check valve 50A, when the inflation gas G flows from the body inflation portion 20A side to the support inflation portion 22A side, the closing cloth 53 separates from the peripheral edge of the opening 52 and flows toward the support inflation portion 22A side, causing a reverse flow. As a result, the closing cloth 53 is brought into pressure contact with the periphery of the opening 52, closing the opening 52 and closing the check valve 50A, thereby preventing the inflation gas G from flowing back.

Furthermore, as shown in the occupant protection device 10B of the third embodiment shown in FIG. 6, the main branch inflation portion of the airbag may be composed of the lower branch inflation portion 31B of the airbag 16B.

In this airbag 16B, when inflation is completed, a base inflation portion 18B extending downward from the case 12 and a rear end surface 24a projecting rearward from the base inflation portion 18B serves as a receiving surface 25a for the head H of the occupant OP. and a receiving expansion portion 24B. The base inflatable portion 18B extends downward from the case 12 in a columnar shape, and the main inflatable portion 20B projects the receiving inflatable portion 24B rearward. A support plate portion 8 as a vehicle body side member arranged on the periphery is interposed with a cover material 6 (more specifically, an open door portion 6a and a cover material 6 on the periphery of the door portion 6a are interposed), and the upper surface 22a side is provided. and a support expansion portion 22B for restricting the forward movement of the main body expansion portion 20B.

The receiving inflation portion 24B at the time of completion of inflation includes an upper branched inflation portion 29B and a lower branched inflation portion 31B extending vertically in a bifurcated substantially columnar shape from the rear end portion 25 provided with the rear end face 24a. configured as follows. The upper branched expansion portion 29B and the lower branched expansion portion 31B are provided with a hollow portion 27 penetrating in the left-right direction, and the respective front ends 29a and 31a are vertically separated to form the rear surface 20b of the main expansion portion 20B. connected to the side.

However, in this airbag 16B, the lower branched inflation portion 31B, as the main branched inflation portion 33, extends in the axial direction LX extending from the front end 31a to the rear end 31b in the moving direction MX of the head H of the occupant OP moving forward. The upper branch expansion portion 29B is used as the auxiliary branch expansion portion 35, and the rear end face 33a is arranged at a position facing the head of the occupant moving forward.

Also in this third embodiment, when the airbag 16B completes inflation during operation, the lower branched inflation portion 31B is disposed along the axial direction LX along the moving direction MX of the head H of the occupant OP, That is, when the main branch expansion portion 33 receives the head H of the occupant OP near the rear end surface 33a, it is compressed and deformed such that the rear end 31b side approaches the front end 31a side along the axial direction LX. Then, as a state of buckling deformation, the head H of the occupant OP can be received with a higher reaction force than the bending deformation. Further, the upper branch expansion portion 29B as the auxiliary branch expansion portion 35 connects the rear end 29b to the rear end 31b of the lower branch expansion portion 31B as the main branch expansion portion 33, and the lower branch expansion portion 31 as the main branch expansion portion 33 Since the rear end 31b of the side branch expansion portion 31B can be supported so as not to move up and down, the main branch expansion portion 33 (lower side branch expansion portion 31B) that receives the head H of the occupant OP by increasing the reaction force is stabilized. Then, the head H of the occupant OP can be received.

Of course, like the airbag 16C of the occupant protection system 10C of the fourth embodiment shown in FIG. In order to be able to receive the head H of the occupant OP, the front end is spread upward and downward from the rear end surface 24a so that both axial directions intersect with the moving direction MX of the head H of the occupant OP. The 29a and 31a sides may be connected to the rear surface 20b of the main body expansion portion 20C.

In order not to provide the hollow portion 27 of the airbag 16C, unless the point of reducing the capacity of the airbag is taken into consideration, a substantially triangular prism-shaped airbag extending from the main body inflating portion 20C with its axial direction along the left-right direction is used. The airbag may be constructed by protruding the receiving inflatable portion rearward.

Of course, in the above-described airbags having no hollow portion and the airbags 16, 16B, 16C of the first, third, and fourth embodiments, the main inflatable portions 20B, 20C and the support inflatable portion 22B are provided as in the second embodiment. , 22C may be partitioned by a partition wall 43 provided with check valves 50, 50A.

DESCRIPTION OF SYMBOLS 1... Vehicle 4... Roof 8... (Car body side member) Support plate part 10, 10A, 10B, 10C... Occupant protection device 12... (Storage part) Case, 16, 16A, 16B, 16C... Airbag, 18, 18A, 18B, 18C... base expansion part 20, 20A, 20B, 20C... body expansion part, 20a... front surface, 20b... rear surface, 22, 22A, 22B, 22C... support expansion part, 22a... upper surface, 24, 24B, 24C... Receiving expansion part 24a... Rear end surface 27... Hollow part 29, 29B, 29C... Upper branch expansion part 29a... Front end 29b... Rear end 31, 31B, 31C... Lower side branch expansion part , 31a... front end, 31b... rear end, 43... partition wall, 50, 50A... check valve,
LX... (main support expansion part) axial direction, MX... moving direction (of the head), S... seat, G... inflation gas, OP... occupant, H... head.

Claims (4)

An occupant having an airbag which is housed on the roof side in front of and above a seated occupant in a vehicle, deploys and inflates downward when inflating gas flows in, and receives the head of the occupant moving forward in a vehicle collision so as to be able to protect it. a protective device,
When the airbag completes inflation,
a base expanding portion extending downward from the storage portion;
a receiving expansion portion protruding rearward from the base expansion portion and having a rear end surface thereof as a receiving surface for the occupant's head;
As a configuration comprising
The base expanding portion is
a main body inflatable portion extending downward from the storage portion in a columnar shape and projecting the receiving inflatable portion rearward;
a support expansion portion projecting forward from the main expansion portion and configured to restrict forward movement of the main expansion portion by supporting an upper surface side thereof on a vehicle body side member disposed on a front peripheral edge of the storage portion;
with
When the inflation is completed, the expansion receiving portion extends vertically from the rear end portion where the rear end face is provided in a substantially forked columnar shape, and a hollow portion penetrating in the left-right direction is provided between the two and the front ends of the respective front ends. An occupant protection device comprising: an upper branched expansion portion and a lower branched expansion portion which are vertically separated and connected to the rear surface side of the main body expansion portion. one of the upper branched inflation portion and the lower branched inflation portion of the receiving inflation portion of the airbag extends in an axial direction extending from a front end to a rear end along a moving direction of the head of an occupant moving forward, 2. The occupant protection system according to claim 1 , wherein the rear end surface of the occupant is arranged at a position facing the head of the occupant moving forward. The upper branched inflation portion of the receiving inflation portion of the airbag is arranged such that the rear end face thereof faces the head of the occupant moving forward,
The lower branch expansion portion of the receiving expansion portion of the airbag is arranged so that the front end side extends obliquely forward and downward from the rear end side and is connected to the lower end of the main body expansion portion. The occupant protection device according to claim 2 , characterized in that: The base inflatable portion of the airbag includes a partition wall that partitions the main inflatable portion and the support inflatable portion,
2. The partition wall is provided with a check valve that allows the inflating gas to flow from the body inflating portion toward the support inflating portion and prevents backflow. 4. The occupant protection device according to any one of items 1 to 3 .

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