JP7533232B2 - Side airbag device for vehicle seat - Google Patents

Description

The present invention relates to a side airbag device for a vehicle seat.

The following Patent Document 1 discloses a side airbag that is installed inside the seat back of a seat and inflated and deployed by gas supplied from an inflator. This side airbag has a lower chamber that faces the waist of an occupant seated in the seat when inflated and deployed, and an upper chamber that faces the head. This side airbag has a bag body having a lower chamber and an upper chamber, and an inner tube that is installed inside the bag body and into which an inflator is inserted. Gas ejected from the inflator is supplied to the lower chamber and upper chamber from openings at both ends of the inner tube.

JP 2011-105107 A

It is possible to configure a side airbag so that the inflator is connected to the inner tube on the outside of the bag body. This side airbag can be manufactured, for example, by inserting most of the inner tube into the bag body through a hole formed in the bag body after the bag body is manufactured, and sewing the part of the inner tube inserted into the bag body and the bag body together. In this case, the inflator is connected to the part of the inner tube located on the outside of the bag body.

However, it is difficult to insert the flexible inner tube through the hole into the bag body so as to position it at the desired location within the bag body. This task becomes even more difficult when the overall length of the inner tube is increased in order to position one end of the inner tube within the upper chamber.

Furthermore, unless the entire inner tube is sewn to the bag body, the inner tube will swing significantly when gas is supplied from the inflator. In this case, it will be difficult to quickly inflate and deploy the upper chamber at the specified position.

In consideration of the above, the present invention aims to provide a side airbag device for a vehicle seat in which an inner tube, without an inflator inserted therein, can be easily positioned at a desired position within the bag body, and in which the inner tube is less likely to swing when gas is supplied.

The vehicle seat side airbag device according to claim 1 is provided on a side of a seat back of a seat installed in a vehicle in a seat width direction, and includes a bag body having a lower chamber facing the waist of an occupant seated on the seat and an upper chamber facing the head of the occupant when the bag body is inflated and deployed by gas supplied from an inflator to the inside during a side collision of the vehicle, an inner tube with an open end disposed inside the lower chamber, an inflator insertion part located outside the bag body, connected to the bag body and the inner tube so that its internal space communicates with the internal space of the inner tube, and into which a part of the inflator located outside the bag body is inserted, and the tube-constituting fabric that constitutes the outer shape of the inner tube by sewing, the bag base fabric that constitutes the outer shape of the bag body by sewing, and the insertion part-constituting fabric that constitutes the outer shape of the inflator insertion part by sewing are formed from a single base fabric.

In this specification and claims, a "single base fabric" includes a single base fabric made by cutting a single piece of cloth, and a single base fabric made by sewing together multiple pieces of cloth.

The tube-constituting fabric and the bag base fabric of the vehicle seat side airbag device described in claim 1 are part of a single base fabric. Therefore, if the base fabric is sewn so that one end of the inner tube is positioned inside the lower chamber, the inner tube without an inflator inserted inside can be easily placed inside the bag body.

There is no need to insert the inner tube into the bag body after sewing the bag body. This increases the productivity of the side airbag device and reduces manufacturing costs, even if the overall length of the inner tube is increased.

In addition, because the tube fabric and the bag base fabric are part of the base fabric, the bag body (bag base fabric) suppresses the swinging of the inner tube (tube fabric) when gas is supplied. In other words, the inner tube is less likely to swing. As a result, gas is smoothly supplied from one end of the inner tube to the upper chamber, causing the upper chamber to quickly inflate and deploy.

In this way, the vehicle seat side airbag device according to the present invention has the excellent effect that the inner tube, which does not have an inflator inserted therein, can be easily positioned at a desired position within the bag body, and the inner tube is less likely to swing when gas is supplied.

1 is a schematic side view of a vehicle seat side airbag device according to a first embodiment, a front seat, and an occupant. FIG. 2 is a schematic front view of the front seat and occupant shown in FIG. 1; FIG. 2 is a side view of the side airbag and inflator shown in FIG. 1 . FIG. 4 is a development view of a base fabric which is a component of the side airbag shown in FIG. 3 . FIG. 5 is a development view of the base fabric of FIG. 4 with the lower constituent part folded back. FIG. 6 is an enlarged cross-sectional view taken along the line 6-6 in FIG. 5 . FIG. 7 is an enlarged cross-sectional view similar to FIG. 6 of a modified example of the first embodiment. FIG. 8 is an enlarged cross-sectional view taken along the line 8-8 in FIG. FIG. 9 is an enlarged cross-sectional view taken along the arrow line 9-9 in FIG. FIG. 2 is a schematic perspective view of a portion of a side airbag in an inflated and deployed state, as viewed from the inside of the side airbag. FIG. 11 is a development view of a base fabric which is a component of the vehicle seat side airbag device relating to the second embodiment. FIG. 11 is a development view of the base fabric of the second embodiment when a lower constituent part is folded back. 13 is an enlarged cross-sectional view taken along the arrow line 13-13 in FIG. 12. FIG. 13 is a rear view of the lower component of the base shown in FIG. 12 . 15 is a cross-sectional view taken along the line 15-15 in FIG. 12. FIG. 10 is an enlarged cross-sectional view similar to FIG. 9 of a side airbag according to a second embodiment. FIG. 2 is a schematic perspective view of a portion of a side airbag in an inflated and deployed state, as viewed from the outside of the side airbag. FIG. 11 is a perspective view of a side airbag device for a vehicle seat according to a third embodiment. 19 is a cross-sectional view taken along the line 19-19 in FIG. 18. FIG. 2 is a perspective view of an airbag with gas being supplied thereto.

First Embodiment
A first embodiment of a side airbag device for a vehicle seat according to the present invention will be described below with reference to Figures 1 to 10. The side airbag device for a vehicle seat of this embodiment has a side airbag 10 and an inflator 50. Note that the arrow UP in each drawing indicates the upper side in the vertical direction of the vehicle, the arrow FR indicates the front side in the longitudinal direction of the vehicle, and the arrow LH indicates the left side in the lateral direction of the vehicle (vehicle width direction). In the following description, the vertical direction, the longitudinal direction, and the lateral direction refer to the vertical direction of the vehicle, the longitudinal direction of the vehicle, and the lateral direction of the vehicle, respectively.

As shown in Figures 1 and 2, a front seat 12 (seat) is provided in the passenger compartment of a vehicle equipped with a side airbag 10. The front seat 12 is the left seat. The front seat 12 has a seat cushion 12A, a seat back 12B, and a headrest 12C. Side support parts 12B1 are provided on the inner and outer sides of the seat back 12B in the vehicle width direction. A tear seam (not shown) is provided on the surface of the seat back 12B (i.e., the surface of the seat skin). A seat back frame (not shown) is provided inside the seat back 12B.

In Figures 1 and 2, a crash test dummy P1 is seated in the front seat 12. The dummy P1 is an AM50 (50th percentile American adult male) of the World Side Impact Dummy (WorldSID). Each dummy P1 is seated in the front seat 12 in a manner prescribed by the side impact test method. The dummy P1 is fitted with a webbing 16 of a three-point seat belt device 14. Hereinafter, the dummy P1 may be referred to as an occupant P1. The seat cushion 12A supports the waist P1w and thighs P1t of the occupant P1, the seat back 12B supports the back of the chest P1b, and the headrest 12C supports the head P1h.

The side airbag 10 and the inflator 50 are provided inside the side support portion 12B1 formed on the outer side of the seat back 12B in the vehicle width direction.

As shown in FIG. 3, the side airbag 10 has a bag body 21, an inner tube 26, and an inflator insertion portion 28.

The bag body 21 has a lower chamber 22 and an upper chamber 23 that communicate with each other. A communication hole 24 is formed in the lower part of the rear edge of the bag body 21 (see Figures 3 and 10). An inner tube 26 with both ends open is provided inside the lower chamber 22 and the upper chamber 23. The upper end of the inner tube 26 opens in the upper chamber 23, and the lower end opens in the lower chamber 22. The inner tube 26 is sometimes called a sock or diffuser. A cylindrical inflator insertion part 28 with a substantially L-shaped side shape and both ends open is located outside the bag body 21. As shown in Figure 10, the front end of the inflator insertion part 28 is connected to the communication hole 24. The internal space of the inflator insertion part 28 communicates with the internal space of the inner tube 26. Furthermore, the lower end of the inflator 50 located outside the bag body 21 is inserted into the inflator insertion part 28 from the connection port 28A, which is the upper end opening.

Under normal circumstances when the vehicle is not in a collision, the side airbag 10 is folded and stored inside the side support portion 12B1 on the left side of the seat back 12B. A part of the upper chamber 23 and the lower chamber 22 are stored inside the side support portion 12B1. As shown by the dashed line in FIG. 2, in a front view, the lower chamber 22 of the side airbag 10 is approximately parallel to the up-down direction, and a part of the upper chamber 23 is approximately parallel to the left-right direction.

As shown in FIG. 2, when the tongue 17 of the seat belt device 14 is fastened to the buckle 18 provided on the front seat 12, the shoulder webbing 16A of the webbing 16 is inclined in the vertical direction so as to extend inward in the vehicle width direction as it moves downward in the vertical direction in a front view. In a front view, the inner end of the upper chamber 23 in the vehicle width direction is located more inward in the vehicle width direction than a portion of the shoulder webbing 16A that is located at the same height as the upper chamber 23.

The folded side airbag 10 and the inflator 50 are stored inside the side support portion 12B1 so that the axial direction of the inflator 50 is aligned with the up-down direction of the seat back 12B. Note that the inflator insertion portion 28 and the inflator 50 are not shown in Figs. 1 and 2. A gas outlet is formed at the portion of the inflator 50 inserted into the inflator insertion portion 28. Furthermore, a stud bolt (not shown) is provided at the portion of the inflator 50 inserted into the inflator insertion portion 28, and passes through the inflator insertion portion 28 and the seat back frame, and is fixed to the seat back frame using a nut.

As shown in FIG. 1, the vehicle is provided with an ECU (electric control unit) 55. The inflator 50 is electrically connected to the ECU 55. The ECU 55 is an electronic control circuit having as its main components a microcomputer including a CPU, ROM, RAM, and an interface. The CPU realizes various functions described below by executing instructions stored in the memory (ROM).

The vehicle is further provided with a side collision sensor 57. The side collision sensor 57 is configured to output a side collision signal to the ECU 55 when it detects or predicts a side collision of the vehicle.

Next, the structure and manufacturing method of the side airbag 10 will be explained in detail.

The side airbag 10 is manufactured by sewing a single flexible base fabric 30 made by cutting a single piece of fabric. Figure 4 shows the base fabric 30 in an unfolded state. In Figure 4, the front side of the paper is the "rear side". The base fabric 30 has a bag base fabric 35, a tube constituent fabric 40, and an insertion part constituent fabric 45. The bag base fabric 35 is the part of the base fabric 30 that has the largest area. The center line CL is a line that passes through the center of the base fabric 30 and bisects the base fabric 30 when the base fabric 30 is in the unfolded state. The bag base fabric 35 has a left side portion 36L and a right side portion 36R that are symmetrical about the center line CL and are approximately L-shaped when the base fabric 30 is in the unfolded state.

The tube constituent fabric 40 connecting the left side portion 36L and the right side portion 36R is symmetrical with respect to the center line CL when the base fabric 30 is in an unfolded state. The tube constituent fabric 40 has an upper constituent portion 41 and a lower constituent portion 42 that are vertically separated from each other. The upper constituent portion 41 has a right side portion 41R located to the right of the center line CL, and a left side portion 41L located to the left of the center line CL. The lower constituent portion 42 has a right side portion 42R located to the right of the center line CL, and a left side portion 42L located to the left of the center line CL.

The inserting portion constituent fabric 45 is a portion that connects the left side portion 36L and the right side portion 36R and is located between the upper portion 41 and the lower portion 42. When the base fabric 30 is in an unfolded state, the inserting portion constituent fabric 45 is symmetrical about the center line CL. The inserting portion constituent fabric 45 has a connection port constituent portion 45A that constitutes the center of the inserting portion constituent fabric 45, and a connection end portion 45B that constitutes both the left and right sides and has an approximately V-shaped upper edge.

As shown by the thick line in FIG. 4, a first slit 48A is provided between the lower edge of the upper component 41 and the upper edge of the insertion component fabric 45. A second slit 48B is provided between the lower edge of the insertion component fabric 45 and the upper edge of the lower component 42. A pair of third slits 48C are provided on the left and right sides between the left edge of the lower component 42 excluding its upper end and the left side 36L, and between the right edge of the lower component 42 excluding its upper end and the right side 36R.

When manufacturing the side airbag 10 from the base fabric 30 in the deployed state, first, as shown in Figs. 5 and 6, the portion of the lower component 42 where the third slit 48C is formed is folded upward to be positioned on the front side of the insertion part component fabric 45, and is positioned immediately behind the upper component 41 through the first slit 48A. Hereinafter, the folded portion of the lower component 42 is referred to as the folded portion 42A, the portion between the folded portion 42A and the second slit 48B is referred to as the lower tube forming portion 42B, and the portion located below the folded portion 42A is referred to as the overlapping portion 42C. In Fig. 6, the lower tube forming portion 42B is located rearward of the folded portion 42A. However, as shown in Fig. 7, the lower tube forming portion 42B may be located forward of the folded portion 42A.

Next, as shown by the dashed lines in Figures 5 and 6 (Figure 7), the overlapping portions of the lower end of the upper component 41 and the overlapping portion 42C are sewn together with the first sewing thread 49A. Hereinafter, in this specification, "sewing" using the first sewing thread 49A and the second sewing thread 49B described below refers to sewing together the multiple portions (cloths) to be sewn together using the first sewing thread 49A (second sewing thread 49B) so that gas does not leak between them.

Next, as shown in FIG. 3, the left side portion 36L and the right side portion 36R of the base fabric 30 are folded back around the center line CL so that they approach each other. At this time, as shown in FIG. 8 and FIG. 9, the upper component portion 41 and the lower component portion 42 are folded along the center line CL so that they are positioned forward of the rear edges of the left side portion 36L and the right side portion 36R.

Furthermore, as shown in FIG. 9, the inserting portion constituent fabric 45 is folded about the center line CL so that the inserting portion constituent fabric 45 is positioned rearward of the rear edges of the left side portion 36L and the right side portion 36R. As a result, the inserting portion constituent fabric 45 is formed with a right side portion 45R positioned to the right of the center line CL and a left side portion 45L positioned to the left of the center line CL.

As shown by the dashed lines in Figures 3 and 10, the left side portion 36L and the right side portion 36R, the left side portion 36L and the right side portion 36R and the tube constituent fabric 40, and the left side portion 45L and the right side portion 45R are sewn together using the second sewing thread 49B. When the left side portion 36L and the right side portion 36R are sewn together using the second sewing thread 49B, the bag base fabric 35 forms the bag body 21, and the lower chamber 22 and the upper chamber 23 surrounded by the second sewing thread 49B are formed between the left side portion 36L and the right side portion 36R.

8 and 10, the second sewing thread 49B sews the left side portion 36L, the right side portion 36R, the left side portion 41L, the right side portion 41R, and the left side portion 42L and the right side portion 42R at the top of the overlapping portion 42C along the rear edge of the left side portion 36L and the right side portion 36R between the top end of the upper portion 41 and the bottom end of the upper portion 41 (the top end of the communication hole 24). As a result, the left side portion 41L, the right side portion 41R, and the left side portion 42L and the right side portion 42R at the top of the overlapping portion 42C constitute the upper portion 26A of the inner tube 26. Note that FIG. 3 omits the portion above the middle of the upper portion 26A.

The second sewing thread 49B sews the left side portion 36L, the right side portion 36R, the left side portion 42L, and the right side portion 42R along the rear edge of the left side portion 36L and the right side portion 36R between the lower end of the communication hole 24 and the folded portion 42A. As a result, the left side portion 42L and the right side portion 42R form the lower portion 26C of the inner tube 26 located below the communication hole 24. The second sewing thread 49B sews together the parts located at the same height as the communication hole 24 of the overlapping portion 42C, the left side portion 36L, and the right side portion 36R along the communication hole 24. As a result, the part located at the same height as the communication hole 24 of the overlapping portion 42C forms the middle portion 26B that connects the upper portion 26A and the lower portion 26C. The inner tube 26 is then formed by the upper portion 26A, the middle portion 26B, and the lower portion 26C. As shown in FIG. 3, the upper end opening of the upper portion 26A is located in the upper chamber 23, and the lower end opening of the lower portion 26C is located in the lower chamber 22.

The second sewing thread 49B sews the upper edges of the connection ends 45B of the left side portion 45L and the right side portion 45R together, and the lower edges of the left side portion 45L and the right side portion 45R together. This allows the insertion portion constituent fabric 45 to form the inflator insertion portion 28. The front end of the inflator insertion portion 28 is connected to the left side portion 36L, the right side portion 36R, and the middle portion 26B.

In this manner, the side airbag 10 is formed from the base fabric 30. A connection port 28A is formed at the rear end of the inflator insertion portion 28. The lower end of the inflator 50 is inserted into the inflator insertion portion 28 from the connection port 28A. The interior of the inflator insertion portion 28 and the interior of the middle portion 26B are in communication with each other via the communication hole 24.

(Action and Effects)
Next, the operation and effects of the first embodiment will be described.

For example, when a side collision occurs on the left side of a moving vehicle, the side collision sensor 57 outputs a side collision signal to the ECU 55. This causes gas to be ejected from the gas outlet of the inflator 50, and the ejected gas flows from inside the inflator insertion portion 28 into the inside of the inner tube 26. The gas then flows from the upper end opening of the upper portion 26A into the upper chamber 23, and from the lower end opening of the lower portion 26C into the lower chamber 22. This causes the side airbag 10 to inflate and deploy forward, downward, and upward of the side support portion 12B1 while tearing the tear seam of the seat back 12B of the front seat 12, as shown by the phantom lines in Figures 1 and 2.

The bag base fabric 35 constituting the bag body 21 and the tube constituent fabric 40 constituting the inner tube 26 are part of the base fabric 30. Therefore, when gas is supplied into the inner tube 26, the swinging of the inner tube 26 (tube constituent fabric 40) is suppressed by the bag body 21 (bag base fabric 35). This makes it difficult for the inner tube 26 to swing. Therefore, gas is smoothly supplied from both ends of the inner tube 26 to the lower chamber 22 and the upper chamber 23, and the lower chamber 22 and the upper chamber 23 are quickly inflated and deployed.

As shown in FIG. 2, when the side airbag 10 is fully deployed, the upper chamber 23 is inflated and deployed between the rear surface of the shoulder webbing 16A that restrains the upper body of the occupant P1 and the side of the head P1h above the outer shoulder P1s of the occupant P1. Therefore, when the head P1h of the occupant P1 is displaced to the left during a side collision, the upper chamber 23 is sandwiched between the left side of the head P1h and the rear surface of the shoulder webbing 16A. As a result, the upper chamber 23 restrains the head P1h while receiving a reaction force from the rear surface of the shoulder webbing 16A. As a result, the upper chamber 23 faces the head P1h while receiving a reaction force from the rear surface of the shoulder webbing 16A in a direction approaching the head P1h. The inflated lower chamber 22 faces the waist P1w and chest P1b of the occupant P1 from the left side. The side airbag 10 thus inflated and deployed restrains the waist P1w, chest P1b, and head P1h of the occupant P1, who has moved relatively to the left side of the vehicle.

Furthermore, the inner tube 26 and the bag body 21 are part of the base fabric 30. Therefore, by sewing the base fabric 30 using the first sewing thread 49A and the second sewing thread 49B, the inner tube 26, which has a large overall length and does not have an inflator 50 inserted therein, can be easily positioned within the bag body 21 so that the upper end of the upper portion 26A is located within the upper chamber 23 and the lower portion 26C is located within the lower chamber 22.

Furthermore, the task of inserting the inner tube 26 into the bag body 21 after sewing the bag body 21 is eliminated. Therefore, even if the overall length of the inner tube 26 is increased in order to place both ends of the inner tube 26 inside the lower chamber 22 and the upper chamber 23, respectively, the productivity of the side airbag 10 (side airbag device for a vehicle seat) can be increased and the manufacturing cost can be reduced.

Furthermore, the intermediate portion 26B is formed by folding the overlapping portion 42C of the lower component 42 upward around the folding portion 42A. The intermediate portion 26B of the inner tube 26 prevents gas that has flowed into the inside of the inner tube 26 from flowing into the lower chamber 22 between the lower end of the upper portion 26A and the upper end of the lower portion 26C.

Second Embodiment
Next, a second embodiment of the side airbag device for a vehicle seat according to the present invention will be described with reference to Figures 11 to 17. Note that the same components as those in the first embodiment are given the same reference numerals, and the description thereof will be omitted as appropriate. The side airbag device for a vehicle seat of this embodiment has a side airbag 60 and an inflator 50.

As shown in FIG. 11, the flexible base fabric 61 of the side airbag 60 of the second embodiment has a main component 62 and a lower component 40A that is separate from the main component 62. The main component 62 and the lower component 40A are both made by cutting a single piece of fabric. The main component 62 has a bag base fabric 35, an upper component 41, and an insertion component fabric 45. The upper component 41 and the lower component 40A are components of the tube component fabric.

As shown in Figures 11 and 14, the lower component 40A has a base 40A1 that has the same shape as the lower component 42, and a pair of reinforcing parts 40A2 that protrude from both sides of the base 40A1. Each reinforcing part 40A2 has a connection port component 40A3 and a connection end 40A4. The connection port component 40A3 has a shape obtained by bisecting the connection port component 45A of the insertion part component fabric 45 along the center line CL. The connection end 40A4 that connects to the base 40A1 has approximately the same shape as the connection end 45B.

Next, the structure and manufacturing method of the side airbag 60 will be explained in detail.

When manufacturing the side airbag 60 from the main component 62 and the lower component 40A in the deployed state, first, as shown in FIG. 14, each reinforcing portion 40A2 of the lower component 40A is folded inward so as to overlap the base portion 40A1.

12 and 13, the folded lower component 40A is positioned on the front side of the insertion part fabric 45, and the upper part of the lower component 40A is positioned immediately behind the lower part of the upper component 41 through the first slit 48A. That is, when the unfolded base fabric 61 is viewed from behind, the main component 62 and the lower component 40A are placed in substantially the same state as the unfolded base fabric 30 shown in FIG. 5. At this time, as shown in FIG. 15, the reinforcing part 40A2 is positioned immediately before the insertion part fabric 45. More specifically, the upper edge of each connection port component 40A3 is positioned immediately before the upper edge of the connection port component 45A of the insertion part fabric 45, and the lower edge of each connection port component 40A3 is positioned immediately before the lower edge of the connection port component 45A. Furthermore, the upper edge of each connection end 40A4 is positioned immediately before the upper edge of each connection end 45B, and the lower edge of each connection end 40A4 is positioned immediately before the lower edge of each connection end 45B. Furthermore, as shown in Figures 12 and 13, the overlapping portions of the lower end of the upper constituent part 41 and the base part 40A1 are sewn together with a first sewing thread 49A to form a single base fabric 61 that is an integral body of the main constituent part 62 and the lower constituent part 40A.

The manufacturing procedure thereafter is the same as in the first embodiment. That is, the right side 36R and left side 36L of the main component 62 are folded around the center line CL so that they approach each other, the upper component 41 and lower component 40A are folded along the center line CL, and the insertion component fabric 45 is folded around the center line CL. Furthermore, the left side 36L and right side 36R, the left side 36L and right side 36R and the upper component 41 and lower component 40A, and the left side 45L and right side 45R are sewn together using the second sewing thread 49B.

16 and 17, the second sewing thread 49B sews together the upper edges of the connection ends 45B of the left side portion 45L and the right side portion 45R and the upper edges of the connection ends 40A4 of the reinforcing portions 40A2, and also sews together the lower edges of the left side portion 45L and the right side portion 45R and the lower edges of the reinforcing portions 40A2. As a result, the inflator insertion portion 28 is formed by the insertion portion forming fabric 45 and the reinforcing portions 40A2.

When the base fabric 61 is sewn in this manner using the first sewing thread 49A and the second sewing thread 49B, a side airbag 60 having the same outer shape as the side airbag 10 shown in FIG. 3 is completed.

(Action and Effects)
Next, the operation and effects of the second embodiment will be described.

In the side airbag 60 of the second embodiment, the inflator insertion section 28 is formed by the insertion section fabric 45 and the reinforcing section 40A2. Therefore, the insertion section fabric 45 of the second embodiment has a higher mechanical strength than the insertion section fabric 45 of the first embodiment, which is formed only by the inflator insertion section 28. Therefore, the insertion section fabric 45 of the second embodiment is less likely to break than the insertion section fabric 45 of the first embodiment.

Third Embodiment
Next, a third embodiment of the side airbag device for a vehicle seat according to the present invention will be described with reference to Figures 18 to 20. The same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted as appropriate. The side airbag device for a vehicle seat of this embodiment has a side airbag 70 and an inflator 50.

The basic structure of the side airbag 70 of the third embodiment is the same as that of the side airbag 10. However, a folded protrusion 70A that protrudes toward the left side is formed at the boundary between the upper chamber 23 and the lower chamber 22 of the side airbag 70. Furthermore, the rear ends of the upper protrusion 70A1, which is the upper part of the folded protrusion 70A, and the lower protrusion 70A2, which is the lower part of the folded protrusion 70A, are sewn together with a third sewing thread 49C. The rear ends of the upper protrusion 70A1 and the lower protrusion 70A2 maintain contact with each other regardless of whether gas flows into the lower chamber 22 and the upper chamber 23.

(Action and Effects)
Next, the operation and effects of the third embodiment will be described.

The rear ends of the upper protrusion 70A1 and the lower protrusion 70A2 of the side airbag 70 of the third embodiment are sewn together by a third sewing thread 49C. Therefore, when gas flows into the lower chamber 22 and the upper chamber 23, the rear ends of the upper protrusion 70A1 and the lower protrusion 70A2 tend to maintain the shape they had before the gas flowed in. Therefore, as shown in FIG. 20, when gas flows into the lower chamber 22 and the upper chamber 23, the rear end of the upper chamber 23 tends to fall farther to the right than the front end of the upper chamber 23. Therefore, the upper chamber 23 as a whole tends to fall to the right relative to the lower chamber 22.

Therefore, in the third embodiment, when the upper chamber 23 of the side airbag 70 is inflated and deployed due to a side collision, the upper chamber 23 is likely to be inflated and deployed between the rear surface of the shoulder webbing 16A and the side surface of the head P1h. In other words, the upper chamber 23 is likely to face the head P1h while receiving a reaction force from the rear surface of the shoulder webbing 16A in a direction approaching the head P1h.

Although the above describes various embodiments of the present invention, the present invention is not limited to these embodiments.

The side airbag 60 of the second embodiment may be provided with the folded protrusion 70A of the third embodiment.

The side airbag of the present invention may be installed in the right front seat.

The front seat (rear seat), seat belt device 14, and side airbag may be configured so that the upper chamber 23 does not inflate and deploy between the rear surface of the shoulder webbing 16A and the side of the head P1h when the side airbag is fully inflated and deployed as viewed from the front-rear direction.

The upper end of the inner tube 26 may open within the lower chamber 22.

10 Side airbag (vehicle seat side airbag device)
12 Front seats (seats)
12B Seat back 21 Bag body 22 Lower chamber 23 Upper chamber 26 Inner tube 28 Inflator insertion part 30 Base fabric 35 Bag base fabric 40 Tube constituent fabric 40A Lower constituent part (Tube constituent fabric)
45 Insertion part forming fabric 50 Inflator (side airbag device for vehicle seat)
60 Side airbag (vehicle seat side airbag device)
61 Base fabric 70 Side airbag (vehicle seat side airbag device)
P1 Dummy (passenger)
P1h Head P1w Waist

Claims (1)

a bag body provided on a side portion in a seat width direction of a seat back of a seat installed in a vehicle, the bag body having a lower chamber facing a waist of an occupant seated in the seat and an upper chamber facing a head of the occupant when the bag body is inflated and deployed by gas supplied from an inflator to an inside of the bag body in the event of a side collision of the vehicle;
an inner tube having an open end disposed within the lower chamber;
an inflator insertion portion located outside the bag body, connected to the bag body and the inner tube such that an internal space of the inflator insertion portion communicates with an internal space of the inner tube, and into which a part of the inflator located outside the bag body is inserted;
Equipped with
A side airbag device for a vehicle seat, in which a tube constituent fabric which is sewn to define the outer shape of the inner tube, a bag base fabric which is sewn to define the outer shape of the bag body, and an insertion portion constituent fabric which is sewn to define the outer shape of the inflator insertion portion are all formed from a single base fabric.