Airbag device and occupant protection device

Abstract

The present disclosure provides an airbag device and an occupant protection device. The airbag device includes: an inflator that generates gas at the time of a collision of a vehicle; and an airbag that is supplied with the gas and that inflates and deploys from a seat rear side to a seat front side of an upper portion of a seat of the vehicle. The airbag has a front-rear cavity and an airbag main body. The front-rear cavity has a pair of left and right front-rear extending portions that inflate and deploy from left and right sides of a head of an occupant seated on the seat to the seat front side, and a linking portion that links front end portions of the pair of front-rear extending portions in a seat left-right direction. The airbag main body inflates and deploys to the occupant side later than the front-rear cavity on the seat rear side of the linking portion, and at the time of restraint of the occupant, the airbag main body is compressed in a seat front-rear direction while the front-rear cavity is stretched in the seat front-rear direction.

Description

Technical Field

[0001] This disclosure relates to airbag devices and occupant protection devices equipped with airbag devices. Background Technology

[0002] The airbag device disclosed in Japanese Patent Application Publication No. 2019-018593 includes: an inflation device that generates high-pressure gas upon impact; and a bag that inflates and deploys from the seat back of a vehicle seat upon receiving gas from the inflation device. The bag includes: a torso support that deploys to the side opposite to the seat back, passing over the torso of an occupant seated on the vehicle seat; and a pair of head supports that deploy on both sides of the vehicle seat in the width direction, passing over the occupant's head, and connected to the torso support. An abutment is formed on the bag, which, in the deployed state, passes vertically between the pair of head supports and avoids the occupant's head.

[0003] The airbag device disclosed in Japanese Patent Application Publication No. 2019-218013 includes: an inflation device; and an airbag that deploys by gas supplied from the inflation device. The airbag has a rear inflator that deploys towards the back of the seat, a pair of side inflators extending forward from both sides of the rear inflator in the seat width direction, and a pair of front inflators extending towards the center from the pair of side inflators and connected at the center to cover the front of the occupant. In this airbag, gas flow channels are formed in the order of the rear inflator, side inflators, and front inflators. The front inflator has a pair of restraints extending towards the center from the pair of side inflators and connected at the center to cover the front of the occupant, and a pair of energy-absorbing parts extending forward and outward from the pair of restraints to cover the front of the restraints. Summary of the Invention

[0004] In the airbag device disclosed in Japanese Patent Application Publication No. 2019-018593, when the occupant is restrained by the airbag, a tensile load in the vehicle's longitudinal direction acts on the torso support and a pair of head supports. Similarly, in the airbag device disclosed in Japanese Patent Application Publication No. 2019-218013, when the occupant is restrained by the airbag, a tensile load in the vehicle's longitudinal direction acts on a pair of lateral inflators and a pair of front inflators. Since this tensile load continuously increases from the initial stage of restraint to the later stage of restraint, the load applied to the occupant continuously increases. Therefore, there is room for improvement from the viewpoint of enhancing the energy absorption performance of the airbag.

[0005] In view of the above facts, the purpose of this disclosure is to provide an airbag device and occupant protection device that can improve the energy absorption performance of an airbag that expands and deploys from the rear side of the upper part of the vehicle seat to the front side of the seat.

[0006] The first type of airbag device includes: an inflation device that generates gas upon vehicle collision; an airbag supplied with the gas and inflating and deploying from the rear side of the upper part of the vehicle seat towards the front side of the seat; the airbag having front and rear chambers and an airbag body; the front and rear chambers having a pair of left and right front and rear extensions that inflate and deploy towards the front side of the seat from the left and right sides of the head of an occupant seated on the vehicle seat, and a connecting portion that connects the front ends of the pair of front and rear extensions in the left-right direction of the seat; the airbag body inflates and deploys towards the occupant side at the rear side of the connecting portion of the seat after the front and rear chambers, and when the occupant is restrained, the airbag body is compressed in the left-right direction of the seat while the front and rear chambers extend in the front-back direction of the seat.

[0007] In the first type of airbag device, gas generated from an inflator is supplied to the airbag during a vehicle collision, causing the airbag to inflate and deploy from the rear side of the upper part of the vehicle seat towards the front side. This airbag has front and rear chambers and an airbag body. The front and rear chambers have a pair of left and right front-to-back extensions that inflate and deploy towards the front side of the occupant's head, which is seated in the vehicle seat, and a connecting portion that connects the front ends of the pair of front and rear extensions in the left-to-right direction of the seat. The airbag body inflates and deploys towards the occupant side at the rear side of the connecting portion, following the front and rear chambers, and when the occupant is restrained, the airbag body is compressed in the left-to-right direction of the seat while the front and rear chambers extend in the front-to-back direction. This compression and deformation of the airbag body improves energy absorption performance.

[0008] The second type of airbag device is, in the first type, in which the airbag body is supplied with gas from the inflation device through a connecting hole located at the rear side of the seat in the left-right direction center of the connecting part when the front and rear cavities are inflated and deployed.

[0009] In the second type of airbag device, the airbag body, in its inflated and deployed state, is supplied with gas from the inflation device via a connecting hole located at the rear seat side of the seat in the left-right direction of the connecting portion between the front and rear chambers. That is, gas passing through a pair of front-rear extensions and the connecting portion of the front and rear chambers is supplied to the airbag body from the aforementioned connecting hole towards the rear seat side. This allows the airbag body to inflate and deploy sufficiently later than the front and rear chambers. As a result, for example, it becomes easier for the airbag to inflate and deploy through the narrow gap between the occupant's head and the vehicle's roof.

[0010] The third type of airbag device is that, in the first or second type, the base fabric constituting the front and rear cavities includes a base fabric that is difficult to stretch compared to the base fabric constituting the airbag body.

[0011] In the third type of airbag device, since the base fabric constituting the front and rear cavities includes a base fabric that is difficult to stretch compared to the base fabric constituting the airbag body, the energy absorption achieved by the front and rear cavities extending in the front-rear direction of the seat can be increased.

[0012] The fourth type of airbag device is, in the third type, the front and rear cavities are structures formed by overlapping and sewing multiple base fabrics, a portion of which is the difficult-to-stretch base fabric.

[0013] According to the fourth method of airbag device, multiple base fabrics are overlapped and sewn together during the manufacture of the front and rear cavities. Since some of the base fabrics are base fabrics that are less stretchable compared to the base fabrics that constitute the main body of the airbag, the effect of the third method can be obtained.

[0014] The fifth type of airbag device is, in any one of the first to fourth types, the airbag body is shaped such that it is clamped between the occupant's thigh and chest when restrained.

[0015] According to the fifth type of airbag device, when the occupant is restrained by the airbag, the airbag body is sandwiched between the occupant's thighs and chest. Therefore, since the occupant's upper body can contact the airbag body with a larger area, the load applied to the occupant can be effectively reduced.

[0016] The sixth type of airbag device includes a pair of left and right rear straps in any one of the first to fifth types. One end of each of the left and right rear straps is respectively secured to the pair of front and rear extensions, and the other end of each is respectively secured to the seat back or body of the vehicle seat at the rear side relative to the occupant. When restrained, the left and right rear straps pull the pair of front and rear extensions backward and diagonally downward toward the seat.

[0017] According to the sixth type of airbag device, when the airbag restrains the occupant, one end of each airbag is secured to a pair of front and rear extensions in the front and rear chambers, and the other end of each airbag is secured to a pair of left and right rear straps that engage with the seat back or body of the vehicle seat at a position relative to the occupant. These rear straps pull the pair of front and rear extensions backward and diagonally downward towards the seat. The pair of rear straps, together with the front and rear chambers, bear the load applied to the airbag body by the occupant, thus acting as support members. Furthermore, the aforementioned pulling action achieved by the pair of rear straps suppresses the vertical and longitudinal swaying of the airbag in the seat direction when inflation is complete.

[0018] The seventh type of airbag device is, in the sixth type, configured such that, when restrained, the lower surfaces of the pair of front and rear extensions abut against the left and right shoulders of the occupant.

[0019] According to the seventh type of airbag device, when the airbag restrains the occupant, the lower surfaces of the pair of front and rear extensions of the front and rear chambers are pulled backward and diagonally downward by a pair of rear straps, thus abutting against the left and right shoulders of the occupant. Therefore, regardless of the occupant's body size, the vertical position of the airbag body relative to the occupant's head in the seat can be stabilized.

[0020] The eighth type of airbag device is that, in the sixth type, the vehicle seat is a long seat, and a pair of slits extending in the vertical direction along the left and right sides of the seat of the occupant are formed on the back of the long seat. In the state before the airbag is inflated and deployed, a portion of each of the rear straps is inserted into each of the slits.

[0021] According to the eighth type of airbag device, a pair of slits extending vertically along both sides of the seat back of the long seat are formed. Before the airbag inflates, a portion of a pair of rear seat straps is inserted into these slits. When the airbag inflates, these rear seat straps, along with a pair of forward and backward extensions of the front and rear chambers, extend forward toward the seat. Because of this structure, a pair of rear seat straps can be provided even when the vehicle seat is a long seat.

[0022] The ninth type of airbag device is that, in the sixth type, the vehicle seat is a long seat, and a pair of slits extending in the vertical direction of the seat are formed on the back of the long seat. The upper end of each slit is provided as a widening portion that increases the width of each slit toward the upper side of the seat. When the airbag inflates and deploys, a portion of each rear seatbelt passes through each widening portion and is inserted into each slit.

[0023] According to the ninth type of airbag device, a pair of slits extending vertically along both sides of the seat back of a long seat are formed. The upper end of each slit is configured as a widening portion that increases the width of each slit towards the upper side of the seat. When the airbag inflates, a pair of rear seat straps, along with a pair of front and rear extensions of the front and rear chambers, extend forward towards the seat. At this time, a portion of each rear seat strap is inserted into each slit through the widening portion. Because of this structure, a pair of rear seat straps can be provided even when the vehicle seat is a long seat.

[0024] The tenth type of airbag device is that, in the sixth type, the vehicle seat is a long seat, and a pair of left and right slits extending along the vertical direction of the seat are formed on the back of the long seat, on both sides of the occupant's seat in the left-right direction, and the other end of each of the rear straps is fixed to the frame of the seat back in each of the slits.

[0025] According to the tenth type of airbag device, a pair of slits extending vertically along both sides of the seat back of the long seat are formed on the seat back. The other ends of each of the pair of rear straps are fixed to the frame of the seat back within each slit. When the airbag inflates, these rear straps, together with the pair of front and rear extensions of the front and rear chambers, extend forward toward the seat. Because of this structure, a pair of rear straps can be provided even when the vehicle seat is a long seat.

[0026] The eleventh type of airbag device includes, in any one of the first to tenth types, a pair of left and right front upper straps, which respectively connect the upper part of the airbag body that expands towards the seat above the front and rear cavities to the pair of front and rear extensions of the front and rear cavities.

[0027] According to the eleventh embodiment of the airbag device, the upper part of the airbag body that expands towards the upper side of the seat relative to the front and rear chambers, and a pair of front and rear extensions of the front and rear chambers, are connected by a pair of front upper straps. This prevents the airbag body from accidentally shifting towards the upper side of the seat relative to the front and rear chambers after expansion.

[0028] The twelfth type of airbag device includes a pair of left and right lower front straps in any one of the first to eleventh types. The pair of left and right lower front straps connect the lower part of the airbag body that expands and deploys towards the underside of the seat compared to the front and rear cavities to the pair of front and rear extensions of the front and rear cavities.

[0029] According to the twelfth type of airbag device, the lower part of the airbag body that expands towards the underside of the seat relative to the front and rear chambers, and a pair of front and rear extensions of the front and rear chambers, are connected by a pair of front lower straps. This prevents the airbag body from accidentally shifting towards the underside of the seat relative to the front and rear chambers after expansion.

[0030] The thirteenth type of airbag device is that, in any one of the first to twelfth types, in the airbag body in the inflated state, a slit is formed along the vertical direction of the seat at the center of the rear side of the seat, allowing the occupant's head to enter when restrained.

[0031] According to the thirteenth type of airbag device, when the occupant is restrained by the airbag, the occupant's head enters a slit formed along the vertical direction of the seat in the center of the seat's left-right direction on the rear side of the airbag body. Therefore, since the occupant's head can easily move forward, it becomes difficult for the occupant's neck to buckle.

[0032] The occupant protection device of the fourteenth embodiment includes: a vehicle seat for occupants to sit on; and an airbag device as described in any one of the first to thirteenth embodiments, which is mounted on the rear side of the upper part of the vehicle seat.

[0033] In the fourteenth type of occupant protection device, an airbag is installed on the rear side of the upper part of the vehicle seat where the occupant sits. Since this airbag is any one of the airbag devices in the first to thirteenth types, it achieves the same effect as any one of the first to thirteenth types.

[0034] As explained above, the airbag device and occupant protection device disclosed herein can improve the energy absorption performance of an airbag that expands and deploys from the rear side of the upper part of the vehicle seat to the front side of the seat. Attached Figure Description

[0035] Figure 1 This is a perspective view showing the state of the airbag after it has inflated and deployed in the occupant protection device according to the first embodiment.

[0036] Figure 2 To be Figure 1 The structure shown is a side view taken from the left side of the vehicle;

[0037] Figure 3 To be Figure 1 The structure shown is a top view taken from above the vehicle;

[0038] Figure 4 To be Figure 1 The structure shown is presented in a front view as seen from the front of the vehicle;

[0039] Figure 5 In order to be in Figure 4 The front view of the airbag is shown with a perspective view.

[0040] Figure 6 A diagram showing the deployment of the front and rear cavities of an airbag;

[0041] Figure 7 A diagram showing the deployment of the main body of an airbag;

[0042] Figure 8 A side view showing the state immediately following the completion of airbag inflation;

[0043] Figure 9 A side view showing the initial state of occupant restraint achieved by the airbag;

[0044] Figure 10 A side view showing the state of occupant restraint achieved by the airbag during the middle stage;

[0045] Figure 11 A side view showing the state of occupant restraint achieved by the airbag in the later stages;

[0046] Figure 12 A side view illustrating the sway-suppressing effect of the airbag achieved by the rear seatbelt;

[0047] Figure 13 A side view illustrating the contact between the anterior and posterior chambers and the occupant's shoulder;

[0048] Figure 14 A side view illustrating the sway-suppressing effect of the airbag achieved by the front upper seatbelt;

[0049] Figure 15 This is a side view used to illustrate the sway-suppressing effect of the airbag achieved by the front lower seatbelt;

[0050] Figure 16 A side view showing an example of an improperly installed front upper seatbelt, and a diagram showing the state of occupant restraint that is about to be implemented by an airbag;

[0051] Figure 17 A side view showing an example of improper installation of the front upper seatbelt, and a diagram showing the state of occupant restraint after being achieved by the airbag;

[0052] Figure 18 A cross-sectional view shown in an enlarged form of an example where a portion of the multiple base fabrics constituting the front and rear cavities is a base fabric that is difficult to stretch;

[0053] Figure 19 A line graph showing the relationship between the load acting on the occupant's chest and the chest displacement;

[0054] Figure 20 This is a side sectional view showing the main part of the occupant protection device according to the second embodiment before the airbag inflates and deploys.

[0055] Figure 21 This is a side sectional view showing the main part of the occupant protection device according to the second embodiment, in the state just after the airbag has finished inflating and deploying.

[0056] Figure 22 This is a side sectional view showing the state of occupant restraint achieved by the airbag in the occupant protection device according to the second embodiment.

[0057] Figure 23 This is a front view showing a portion of the vehicle seat included in the occupant protection device according to the second embodiment;

[0058] Figure 24A side sectional view showing the state of the airbag before it inflates and deploys in the occupant protection device according to the third embodiment.

[0059] Figure 25 A side sectional view showing the main part of the occupant protection device according to the third embodiment, just after the airbag has finished inflating and deploying.

[0060] Figure 26 A side sectional view showing the state of occupant restraint achieved by the airbag in the occupant protection device according to the third embodiment.

[0061] Figure 27 A side sectional view showing the main part of the occupant protection device according to the fourth embodiment before the airbag inflates and deploys.

[0062] Figure 28 A side sectional view showing the main part of the occupant protection device according to the fourth embodiment, just after the airbag has finished inflating and deploying.

[0063] Figure 29 A side sectional view showing the state of occupant restraint achieved by the airbag in the occupant protection device according to the fourth embodiment.

[0064] Figure 30 This is a front view showing a portion of the vehicle seat included in the occupant protection device according to the fourth embodiment;

[0065] Figure 31 A side sectional view showing the main part of the occupant protection device according to the fifth embodiment before the airbag inflates and deploys.

[0066] Figure 32 A side sectional view showing the main part of the occupant protection device according to the fifth embodiment, just after the airbag has finished inflating and deploying.

[0067] Figure 33 A side sectional view showing the state of occupant restraint achieved by the airbag in the occupant protection device according to the fifth embodiment;

[0068] Figure 34 This is a front view showing a portion of the vehicle seat included in the occupant protection device according to the fifth embodiment;

[0069] Figure 35 An unfolded diagram illustrating the first alteration of the anterior and posterior cavities;

[0070] Figure 36 To be Figure 35 An enlarged view of a portion of the structure shown;

[0071] Figure 37 A side view showing the airbag during its initial inflating phase, passing through the gap between the occupant's head and the vehicle's roof.

[0072] Figure 38 To represent the state of the airbag during its mid-expansion phase. Figure 37 Corresponding side view;

[0073] Figure 39 To indicate the state at which the airbag has finished inflating and deploying. Figure 37 Corresponding side view;

[0074] Figure 40 An unfolded diagram illustrating a second alteration of the anterior and posterior cavities;

[0075] Figure 41 An unfolded diagram illustrating a third alteration example of the anterior and posterior cavities;

[0076] Figure 42 An unfolded view showing an example of a connecting hole with a small diameter formed on the airbag body;

[0077] Figure 43 This is a top view illustrating an example of a slit formed in the airbag body that allows an occupant's head to enter. Detailed Implementation

[0078] First Implementation Method

[0079] The following is for reference Figures 1 to 19 The occupant protection device 10 according to the first embodiment of this disclosure will be described. Additionally, some symbols are sometimes omitted in the accompanying drawings for ease of observation. Furthermore, the arrows FR, UP, LH, and RH, appropriately marked in the drawings, respectively indicate the front (direction of travel), top, left, and right of the vehicle. Hereinafter, only the directions of front-back, left-right, and up-down will be used in the description; unless otherwise specified, these directions refer to front-back in the front-back direction, left-right in the left-right direction, and up-down in the up-down direction.

[0080] like Figures 1 to 5 As shown, the occupant protection device 10 consists of a vehicle seat 12 and an airbag device 30. The vehicle seat 12 is either a front seat or a rear seat of a vehicle (automobile). The vehicle seat 12 has a seat cushion 14, a seat back 16 erected on the upper side of the rear end of the seat cushion 14, and a headrest 18 connected to the upper end of the seat back 16. The front-back, left-right, up-down, and right-up directions of the vehicle seat 12 are consistent with the front-back, left-right, up-down, and right-up directions of the vehicle.

[0081] In addition, Figures 1 to 5 The illustration shows a crash test dummy D seated on the seat cushion 14 of a vehicle seat 12, representing a model of an occupant (seat-taker) to be protected. The dummy D is, for example, an AM50 (50% of an adult male in the United States) frontal crash test dummy (Hybrid III). The dummy D is seated in a standard seating posture prescribed by crash test law, and the vehicle seat 12 is located at a reference setting position corresponding to this seating posture. Hereinafter, for ease of understanding, the dummy D will be referred to as "occupant D".

[0082] The occupant D, seated on the seat cushion 14 of the vehicle seat 12, is connected to the seat belt 22 (see reference) by the seat belt device 20. Figures 1 to 3 ;exist Figure 4 as well as Figure 5 (Illustrations omitted) are restrained to the vehicle seat 12. The seat belt device 20 is a three-point seat belt device, and is a so-called seat belt device attached to the seat, consisting of a retractor (not shown), an anchor, and a buckle (omitted symbols) provided on the vehicle seat 12.

[0083] The airbag device 30 includes: an airbag 32 and a pair of inflators 44 (see reference). Figure 6 ), and module box 46 (in Figures 8 to 17 (Illustrations omitted). The airbag 32 is normally folded and housed in a module box 46 along with a pair of inflators 44. The module box 46 is formed into a hollow cuboid shape. The module box 46 is located behind the upper part of the vehicle seat 12 (specifically, behind the upper end of the seat back 16 and the headrest 18) and is fixed to the upper end of the seat back 16 or the vehicle body (not shown).

[0084] The airbag 32 receives gas from a pair of inflators 44 and expands forward from the rear side of the upper part of the vehicle seat 12. The airbag 32 has front and rear chambers 34 and an airbag body 40. The front and rear chambers 34 have a pair of left and right front and rear extensions 34A that pass through the left and right sides of the head H of the occupant D and expand forward, and a connecting portion 34B that connects the front ends of the pair of front and rear extensions 34A in the left-right direction. The airbag body 40 expands and deploys towards the occupant D (rear side) at the rear side of the connecting portion 34B, following the front and rear chambers 34.

[0085] Anterior and posterior cavities 34 Figure 6 The two strips of base fabric 36 and 38 shown are overlapped, and their perimeters are sewn together at the seam S1, thus forming a long, bag-like shape. The airbag body 40 is constructed by... Figure 7A base fabric 42, as shown, is bent along four fold lines L1, L2, L3, and L4 and sewn together at the seam S2 to form a bag shape. In this seam S2, sewing threads SL21 and SL22 are sewn together, SL23 and SL24 are sewn together, SL25 and SL26 are sewn together, and SL27 and SL28 are sewn together. The aforementioned base fabrics 36, 38, and 42 are, for example, made of nylon or polyester fabric. One or both of the two base fabrics 36 and 38 constituting the front and rear cavities 34 are designed to be less stretchable than the base fabric 42 constituting the airbag body 40.

[0086] The two ends of the long side of the front and rear chambers 34 are provided with a pair of left and right inflator housings 34C for housing a pair of inflator devices 44. The central part of the long side of the front and rear chambers 34 is provided with a connecting part 34B, and the connecting part 34B and the pair of inflator housings 34C are respectively provided with front and rear extensions 34A. The pair of inflator devices 44 are combustion-type or cold-air-type cylinder-type inflator devices, and generate gas by operating. These inflator devices 44 are controlled to operate by a control device (not shown), thereby generating gas in the event of a vehicle collision.

[0087] A pair of inflatable device storage sections 34C are separately arranged on the left and right sides within the module box 46. Each inflatable device 44, stored within its respective storage section 34C, is positioned axially along the vertical direction of the seat back 16. For example, a pair of double-ended bolts are provided on each inflatable device 44. These double-ended bolts pass through the inflatable device storage section 34C, the module box 46, and a frame (not shown) of the seat back 16, and a nut is screwed onto each bolt. Thus, the inflatable device storage section 34C, the inflatable device 44, and the module box 46 are fixed to the frame of the seat back 16.

[0088] A pair of front and rear extensions 34A are each formed into a long, tubular shape. A connecting portion 34B is a roughly T-shaped bag that communicates with each of the front and rear extensions 34A. The connecting portion 34B has a sewn section S3 (see reference) located at its center. Figure 6 as well as Figure 7 The connecting part S3 is sewn together with the airbag body 40 at the connecting part S3. As an example, the sewn part S3 is generally inverted trapezoidal in shape. A connecting hole 48 is formed on the inner side of the sewn part S3, allowing communication between the connecting part 34B and the airbag body 40. The connecting hole 48 is also generally inverted trapezoidal in shape. This connecting hole 48 is formed by a through hole 50 formed on the base fabric 36 of the front and rear cavities 34 and a through hole 52 formed on the base fabric 42 of the airbag body 40.

[0089] The pair of front and rear extensions 34A, the connecting portion 34B, and the airbag body 40 are normally folded in a predetermined folding manner, such as roll folding or corrugated folding, and stored in the module box 46. When the pair of inflation devices 44 are in operation, gas is generated in the pair of inflation device storage portions 34C. The gas generated in the pair of inflation device storage portions 34C flows through the pair of front and rear extensions 34A to the connecting portion 34B side, and is supplied to the airbag body 40 through the connecting hole 48. As a result, the airbag 32 inflates and deploys in the order of the pair of front and rear extensions 34A, the connecting portion 34B, and the airbag body 40. The tear line (not shown) formed in the module box 46 is configured to rupture under the inflation pressure of the airbag 32 during its inflation and deployment. As a result, the airbag 32 can inflate and deploy to the outside of the module box 46.

[0090] After expansion, a pair of front and rear extensions 34A extend in the front-rear direction on the left and right sides of the head H of the occupant D, and are positioned opposite each other with a gap between them relative to the head H. The pair of front and rear extensions 34A are pulled rearward and diagonally downward by a pair of left and right rear straps 54 (described later), thus achieving a tilted posture that descends forward. The front ends of the pair of front and rear extensions 34A after expansion are connected in the left-right direction by the expanded connecting portion 34B. Figure 3 As shown, the front and rear cavities 34, including a pair of front and rear extensions 34A and a connecting portion 34B, expand into a U-shape with a rearward opening when viewed from above.

[0091] like Figure 1 , Figure 2 , Figure 4 as well as Figure 5As shown, an enlarged portion 34B1 is provided at the center of the connecting portion 34B in the left-right direction after expansion. The enlarged portion 34B1 is larger in the vertical direction than the left and right ends of the connecting portion 34B. The enlarged portion 34B1 protrudes downward compared to the left and right ends of the connecting portion 34B. The aforementioned connecting hole 48 is formed on the enlarged portion 34B1. The connecting hole 48 is located on the rear side of the center of the connecting portion 34B in the left-right direction after expansion. Gas from the inflation device 44 is supplied to the airbag body 40 through the connecting hole 48 in a rearward manner. As a result, the airbag body 40 expands and deploys towards the occupant D (rear side) at the rear of the connecting portion 34B, after the front and rear chambers 34 have expanded and deployed. After the airbag body 40 expands and deploys from the rear side to the front side through the gap between the head H of the occupant D and the roof of the vehicle (not shown), it expands and deploys towards the rear side. The inflated airbag body 40 is positioned in a way that it is separated from the occupant D’s head H, chest C and abdomen B by a gap from the front.

[0092] like Figures 8 to 11 As shown, the inflated airbag body 40 restrains the occupant D, who is moving forward due to inertia caused by the impact of a vehicle collision, from the front side. During this restraint, the front and rear chambers 34 extend in the front-rear direction, while the airbag body 40 is compressed in the front-rear direction. Figures 9 to 11 As shown, the airbag body 40 is shaped to be sandwiched between the thigh F and chest C of the occupant D from the middle to the later stages of occupant restraint.

[0093] The airbag 32 with the above-described structure is equipped with a pair of rear straps 54, a pair of upper front straps 56, and a pair of lower front straps 58. The rear straps 54, upper front straps 56, and lower front straps 58 are formed into long strips, for example, using nylon or polyester fabric. The fabric constituting the rear straps 54, upper front straps 56, and lower front straps 58 is configured to be less stretchable than the base fabrics 36 and 38 constituting the front and rear cavities 34 and the base fabric 42 constituting the airbag body 40. This degree of stretchability can be adjusted by utilizing the fabric material and thickness.

[0094] One end of each of the pair of rear straps 54 is secured (sewn) to the middle of the long side of the pair of front and rear extensions 34A (specifically, the front of each front and rear extension 34A after expansion). The other end of each of the pair of rear straps 54 is secured to the seat back 16 or a vehicle body (not shown) on the rearward side relative to the occupant D. In the expanded state of the airbag 32, the pair of rear straps 54 extend in the front-rear direction below the pair of front and rear extensions 34A. In this state, the pair of rear straps 54 are tilted in a rearward and downward manner. Thus, the pair of front and rear extensions 34A are configured to be pulled rearward and diagonally downward by the pair of rear straps 54 (see reference). Figure 12 (See arrow marker P1). This suppresses the airbag 32 from swinging vertically and horizontally at the end of its inflated deployment (see...). Figure 12 The airbag 32 is shown in the middle with double dots and dashes.

[0095] As described above, by pulling the pair of front and rear extensions 34A, the lower surfaces of the pair of front and rear extensions 34A will abut against the left and right shoulders K of the occupant D during occupant restraint achieved by the airbag 32 (see reference). Figure 13 When occupant restraint is achieved by the airbag 32, the airbag body 40 is supported by the tensile loads of a pair of front and rear extensions 34A and a pair of rear straps 54 (see reference). Figure 13 (Arrow markings P1 and P2). In addition, in this embodiment, although the occupant D is AM50, even if the occupant D is AM95 (95% of adult males in the United States) or the occupant D is AF05 (5% of adult females in the United States), the length of the pair of rear straps 54 is set such that the lower surfaces of the pair of front and rear extensions 34A abut against the left and right shoulder parts K of the occupant D.

[0096] A pair of upper front straps 56 connect to the left and right sides of the front portion of the upper part of the airbag body 40, which expands upwards relative to the front and rear cavities 34, and to the front portion of a pair of front and rear extensions 34A. One end of each pair of upper front straps 56 is sewn to the left and right sides of the front portion of the upper part of the airbag body 40, which expands upwards relative to the front and rear cavities 34. The other end of each pair of upper front straps 56 is sewn to the front portion of a pair of front and rear extensions 34A. The pair of upper front straps 56 prevent the airbag body 40 from rotating upwards around the connecting portion 34B when the airbag 32 has finished expanding (see reference). Figure 14 The airbag body 40 is shown in the double-dotted line.

[0097] A pair of front lower straps 58 connect to the left and right sides of the lower portion of the airbag body 40 that expands downwards relative to the front and rear cavities 34, respectively, and to the front portion of a pair of front and rear extensions 34A. One end of each pair of front lower straps 58 is sewn to the left and right sides of the lower portion of the airbag body 40 that expands downwards relative to the front and rear cavities 34. The other end of each pair of front lower straps 58 is sewn to the front portion of a pair of front and rear extensions 34A. The pair of front lower straps 58 prevent the airbag body 40 from rotating downwards around the connecting portion 34B when the airbag 321 has finished expanding (see reference). Figure 15 The airbag body 40 is shown in the double-dotted line.

[0098] In addition, such as Figure 16 As shown, when one end of each of the pair of upper front tether straps 56 is sewn to the left and right sides of the upper rear portion of the airbag body 40, which expands and deploys above the front and rear cavities 34, the following problem arises. That is, as... Figure 17 As shown, when occupant restraint is achieved by the airbag 32, the pair of upper front straps 56 protrude, thus hindering the compression deformation of the airbag body 40. Therefore, one end of each of the pair of upper front straps 56 needs to be sewn to the left and right sides of the upper front portion of the airbag body 40, which expands and deploys above the front and rear cavities 34.

[0099] The aforementioned airbag device 30 includes an ECU (not shown) that controls the operation of a pair of inflators 44. The ECU is electrically connected to the pair of inflators 44 and a collision sensor (not shown). Based on information from the collision sensor, the ECU can detect or predict the occurrence (or unavoidable frontal collision) of various types of frontal collisions applied to the vehicle, according to each collision mode described later.

[0100] When the control device detects or predicts a frontal collision based on information from the collision sensors, it activates a pair of inflation devices 44. Furthermore, among the frontal collisions in which the control device activates the inflation devices 44, in addition to a fully overlapping frontal collision, there are also eccentric frontal collisions such as oblique collisions and minor overlapping collisions.

[0101] (Functions and effects)

[0102] Next, the function and effects of the first embodiment will be explained.

[0103] The occupant protection device 10 according to this embodiment includes a vehicle seat 12 for an occupant D of the vehicle to sit on, and an airbag device 30 for protecting the occupant D in the event of a vehicle collision. In this airbag device 30, gas generated from a pair of inflation devices 44 is supplied to the airbag 32 in the event of a vehicle collision, thereby causing the airbag 32 to inflate and deploy from the rear side of the upper part of the vehicle seat 12 to the front side.

[0104] The airbag 32 has a front and rear cavity 34 and an airbag body 40. The front and rear cavity 34 has a pair of left and right front and rear extensions 34A that expand forward from the left and right sides of the head H of the occupant D, and a connecting portion 34B that connects the front ends of the pair of front and rear extensions 34A in the left and right direction. The airbag body 40 expands towards the occupant D later than the front and rear cavity 34 at the rear side of the connecting portion 34B, and when the occupant D is restrained, the airbag body 40 is compressed in the front and rear direction while the front and rear cavity 34 extends in the front and rear direction. The energy absorption performance can be improved by the compression deformation of the airbag body 40. That is, although the load applied to the occupant D from the airbag body 40 will continuously increase when both the front and rear cavity 34 and the airbag body 40 are subjected to tensile loads, in this embodiment, the load applied to the occupant D is reduced by the compression deformation of the airbag body 40.

[0105] Furthermore, in this embodiment, after the airbag body 40 expands and deploys in the front and rear cavities 34, it expands and deploys towards the occupant D (i.e., the rearward side) at the rear side of the connecting portion 34B. As a result, the gap between the airbag body 40 and the occupant D decreases. Consequently, since the occupant D is restrained by the airbag body 40 earlier, the initial restraint performance of the occupant D achieved by the airbag body 40 is improved.

[0106] Furthermore, in this embodiment, the airbag body 40, in its inflated and deployed state of the front and rear chambers 34, is supplied with gas from the inflation device 44 via a connecting hole 48 located at the rear side of the center portion of the connecting portion 34B in the left-right direction. That is, gas passing through the pair of front and rear extensions 34A and the connecting portion 34B of the front and rear chambers 34 is supplied to the airbag body 40 from the aforementioned connecting hole 48 toward the rear. This allows the airbag body 40 to inflate and deploy sufficiently later than the front and rear chambers 34. As a result, for example, the airbag 32 can easily inflate and deploy through the narrow gap between the occupant D's head H and the vehicle's roof (not shown).

[0107] In other words, in this embodiment, after the airbag body 40 expands and unfolds through the front and rear chambers 34, passing through the gap between the occupant D's head H and the vehicle's roof from the rear to the front, it expands and unfolds towards the rear. Therefore, since it is easy to prevent the airbag body 40 from getting stuck in the aforementioned gap, it is easy to prevent malfunctions in airbag deployment.

[0108] Furthermore, in this embodiment, the base fabrics 36 and 38 constituting the front and rear cavities 34 include base fabrics that are less prone to stretching compared to the base fabric 42 constituting the airbag body 40. Specifically, the front and rear cavities 34 are structures in which two base fabrics 36 and 38 overlap and their peripheries are sewn together, and one or both of the two base fabrics 36 and 38 are the aforementioned less prone to stretching base fabrics. Additionally, as... Figure 18 As shown, it can also be configured with a base fabric 37, which is less prone to stretching compared to the base fabric of the airbag body 40, placed between the two base fabrics 36 and 38. In such a configuration... Figure 18 In the structure shown, the two base fabrics 36 and 38 are set to have the same degree of stretching difficulty as the base fabric 42 that constitutes the airbag body 40.

[0109] By constructing the anterior and posterior cavities 34 in the manner described above, thereby enabling... Figure 19 As shown in the graph with the solid line, the energy absorption achieved by the extension of the front and rear cavities 34 in the front-rear direction can be increased. Furthermore, in Figure 19 In the diagram, the vertical axis F represents the load applied from the airbag body 40 to the chest C of occupant D, and the horizontal axis S represents the displacement of the chest C of occupant D. Figure 19 The diagram, illustrated with double-dotted lines, shows a situation where the base fabric constituting the front and rear cavities 34 has the same degree of stretching difficulty as the base fabric constituting the airbag body 40. By constructing it as in this embodiment, thus... Figure 19 The energy absorption is particularly improved in the range of (2) to (3). Furthermore, when the front and rear cavities 34 are structured without the base fabric 37, the number of base fabric pieces and the volume of the folded airbag 32 can be increased. Figure 18 The structure shown is reduced compared to the previous one. In this embodiment, since the front and rear cavities 34 and the airbag body 40 are manufactured from separate base fabrics, the stretching difficulty of the base fabric of the front and rear cavities 34 can be changed to the stretching difficulty of the base fabric of the airbag body 40.

[0110] Furthermore, in this embodiment, the airbag body 40 is shaped such that it is sandwiched between the thigh F and chest C of the occupant D from the middle to the later stages of occupant restraint achieved by the airbag 32. As a result, since the upper body of the occupant D can contact the airbag body 40 with a wider area, the load exerted on the occupant D from the airbag body 40 can be effectively reduced.

[0111] Furthermore, according to this embodiment, when occupant D is restrained by the airbag 32, one end of each of the rear extensions 34A of the front and rear chambers 34 is sewn onto a pair of rear extensions 34A, and the other end of each is secured to a pair of rear straps 54 on the seat back 16 or the vehicle body at a position relative to the rear of the seat compared to occupant D. These rear straps 54, when restrained by the airbag body 40, extend in the front-rear direction together with the front and rear chambers 34. These rear straps 54, together with the front and rear chambers 34, bear the load applied from occupant D to the airbag body 40, thus acting as support members.

[0112] Furthermore, the pulling action achieved by the pair of rear straps 54 suppresses the vertical and horizontal swaying of the airbag 32 at the end of its deployment. Also, the pulling action by the pair of rear straps 54 causes the lower surfaces of the pair of front and rear extensions 34A to abut against the left and right shoulders K of the occupant D. Thus, regardless of the occupant D's physique, the vertical position of the airbag body 40 relative to the occupant D's head H is stabilized.

[0113] Furthermore, in this embodiment, the front portion of the upper part of the airbag body 40, which expands upward relative to the front and rear cavities 34, and a pair of front and rear extensions 34A of the front and rear cavities 34 are respectively connected by a pair of front upper straps 56. As a result, it is possible to prevent the airbag body 40 from accidentally shifting (rotating) upward relative to the front and rear cavities 34 around the connecting portion 34B after expansion.

[0114] Furthermore, in this embodiment, the lower portion of the airbag body 40 that expands downward relative to the front and rear cavities 34 and the pair of front and rear extensions 34A of the front and rear cavities 34 are respectively connected by a pair of front lower straps 58. As a result, it is possible to prevent the airbag body 40 from accidentally shifting (rotating) downward relative to the front and rear cavities 34 around the connecting portion 34B after expansion.

[0115] Next, other embodiments of this disclosure will be described. Furthermore, for structures and functions substantially the same as those in the described embodiments, the same symbols will be used, and their descriptions will be omitted.

[0116] Second Implementation Method

[0117] exist Figure 20 The main portion of the occupant protection device 60 according to the second embodiment of this disclosure before the airbag 32 inflates and deploys is shown in a side view. Figure 21The image shows, via a side view, the state immediately following the completion of the inflatation and deployment of the airbag 32 in the occupant protection device 60 according to the second embodiment. Figure 22 The image shows, via a side view, the state of occupant restraint implemented by the airbag 32 in the occupant protection device 60 according to the second embodiment during the later stages of occupant restraint. Figure 23 In the front view, part of the long seat 62, which is a vehicle seat, is shown in the occupant protection device 60 according to the second embodiment.

[0118] The aforementioned long seat 62 is, for example, the rear seat of a vehicle. Figure 23 The image shows the right side of the long seat 62. Figure 22 In the diagram, symbol 13 represents the front seats of the vehicle. The long seat 62 includes a seat cushion 64, a seat back 66, and a headrest 68. A pair of narrow slits 70 extending vertically along the seat back 66 are formed on the left and right sides of the seat for the occupant seated on the right side of the long seat 62. Figure 20 As shown, in the state before the airbag 32 inflates and deploys, a pair of slits 70 are each pierced by a portion (middle of the long side) of each of a pair of rear straps 54. Additionally, in Figure 23 The illustration of a pair of rear lacing straps 54 is omitted in the text.

[0119] One end of each of the pair of rear straps 54 is sewn onto the middle portion of the long side of a pair of front and rear extensions 34A. The other end of each of the pair of rear straps 54 is secured behind a pair of slits 70 to a pair of left and right fixing portions 74 provided on the frame or body of the seat back 66. Inside each pair of slits 70, a winding portion 72 is provided, around which the middle portion of the long side of the pair of rear straps 54 is wound from the front side. These winding portions 72 are fixed to a frame (not shown) of the seat back 66. In this embodiment, compared to the first embodiment, the module box 46 extends upward and forward. The module box 46 is covered by the surface of the seat back 66. In this embodiment, the structure other than that described above is the same as in the first embodiment.

[0120] In this embodiment, when the airbag 32 inflates and deploys, as the front and rear chambers 34 expand forward, a pair of rear straps 54, each with one end sewn onto a pair of front and rear extensions 34A, are pulled out from a pair of slits 70 (see reference). Figure 21 The arrow marked E1) expands forward (see the arrow marker E1). Figure 21(arrow E2). Because of this structure, even when the vehicle seat is a long seat 62, a pair of rear straps 54 can be provided, thereby achieving essentially the same effect as the first embodiment. Furthermore, the unfolding direction of the pair of rear straps 54 can be restricted by a pair of slits 70.

[0121] Third Implementation Method

[0122] exist Figure 24 The main portion of the occupant protection device 80 according to the third embodiment of this disclosure is shown in a side view, depicting the state of the airbag 32 before inflating and deploying. Figure 25 The image shows, via a side view, the main portion of the occupant protection device 80 according to the third embodiment, in the state immediately following the completion of airbag 32 inflation. Figure 26 The image shows the state of occupant restraint implemented by the airbag 32 in the occupant protection device 80 according to the third embodiment, as shown by a side view.

[0123] This embodiment is configured with a structure similar to the second embodiment. In this embodiment, the other ends of each of the pair of rear straps 54 are respectively secured to a pair of left and right fixing parts 74 provided on the vehicle body on the rear side of the seat back 16 and above the inflation device 44. In this embodiment, as Figure 25 as well as Figure 26 As shown, in the inflated state of the airbag 32, the pair of rear straps 54 are bent at the winding portion that is wound around the pair of winding portions 72. In this embodiment, the same effect as in the second embodiment can be obtained.

[0124] Fourth Implementation Method

[0125] exist Figure 27 The main portion of the occupant protection device 90 according to the fourth embodiment of this disclosure before the airbag 32 inflates and deploys is shown in a side view. Figure 28 The image shows, via a side view, the main portion of the occupant protection device 90 according to the fourth embodiment, in the state immediately following the completion of airbag 32 inflation. Figure 29 The image shows, via a side view, the state of occupant restraint implemented by the airbag 32 in the occupant protection device 90 according to the fourth embodiment, in the later stage of occupant restraint. Figure 30 In the front view, part of the long seat 62, which is a vehicle seat, is shown in the occupant protection device 90 according to the fourth embodiment.

[0126] This embodiment is configured with a structure similar to the second embodiment. In this embodiment, the pair of winding portions 72 are omitted; instead, widening portions 70A (see reference 70A) are provided at the upper ends of each pair of slits 70. Figure 30 ;exist Figures 27 to 29 (The symbols are omitted). At each widening portion 70A, the width of each slit 70 in the left-right direction increases as it approaches the upper side. Furthermore, it is configured such that, during the inflating and deployment of the airbag 32, a portion of each rear strap 54 passes through each widening portion 70A and is inserted into each slit 70. In this embodiment, essentially the same effect as in the second embodiment can be obtained.

[0127] Fifth Implementation Method

[0128] exist Figure 31 The main portion of the occupant protection device 100 according to the fifth embodiment of this disclosure is shown in a side view, depicting the state of the airbag 32 before its inflation and deployment. Figure 32 The image shows, via a side view, the main portion of the occupant protection device 100 according to the fifth embodiment, in the state immediately following the completion of airbag 32 inflation. Figure 33 The image shows, via a side view, the state of occupant restraint implemented by the airbag 32 in the occupant protection device 100 according to the fifth embodiment, in the later stage. Figure 34 In the front view, part of the long seat 62, which is a vehicle seat, is shown in the occupant protection device 100 according to the fifth embodiment.

[0129] This embodiment is configured with a structure similar to the second embodiment. In this embodiment, the pair of winding portions 72 are omitted; instead, fixing portions 74 are provided inside each of the pair of slits 70. Each fixing portion 74 is part of the frame of the seat back 66, and the other ends of each of the pair of rear straps 54 are respectively secured to the fixing portion 74. In this embodiment, substantially the same effects as the second embodiment can be achieved.

[0130] Various changes

[0131] Next, various modifications to the embodiments of this disclosure will be described. Figure 35 The diagram shows a first modified example of the front and rear cavities 34 through an unfolded view. In this first modified example, a pair of narrow sections 35 are provided on the connecting portion 34B. The pair of narrow sections 35 are positioned upstream of the flow of gas flowing within the front and rear cavities 34, relative to the connecting hole 48. Each narrow section 35 is constructed by sewing two base fabrics 36 and 38 constituting the front and rear cavities 34 together. Figure 36At any one of the U-shaped seams S4, S5, and S6 shown, the internal cross-sectional area of ​​the connecting portion 34B (i.e., the flow channel cross-sectional area of ​​the connecting portion 34B) is narrowed in a pair of narrow portions 35. Therefore, when the airbag 32 inflates and deploys, gas becomes difficult to flow from the front and rear cavities 34 to the airbag body 40, thus allowing the airbag body 40 to inflate and deploy later. As a result, as... Figures 37 to 39 As shown in the schematic diagram, the airbag body 40 more easily passes through the narrow gap G between the occupant D's head H and the vehicle's roof R, and the airbag body 40 easily inflates after passing through the gap G. Alternatively, it can be provided as an alternative to the sewing part S4. Figure 36 The structure of the sewing part S5 or the sewing part S6 shown. This allows for adjustment of the method by which the internal cross-sectional area of ​​the pair of narrow parts 35 is narrowed.

[0132] exist Figure 40 The image shows a second modified example of the front and rear cavities 34. In this second modified example, the two base fabrics 36 and 38 constituting the front and rear cavities 34 are sewn together... Figure 40 At the seam of the elongated strip S7, a pair of narrow sections 35 are formed. Figure 41 The diagram shows a third modification of the front and rear cavities 34. In this third modification, the two base fabrics 36 and 38 constituting the front and rear cavities 34 are sewn together... Figure 41 At the two island-shaped seam portions S8 shown, a pair of narrow portions 35 are formed. The second and third modified examples also achieve the same effect as the first modified example.

[0133] exist Figure 42 The diagram shows an example of a small-diameter connecting hole 49 formed on the airbag body 40. The opening area of ​​this connecting hole 49 is set to be smaller than the opening area of ​​the connecting hole 48 in the first embodiment. Therefore, by making the connecting hole 49 smaller, gas becomes less likely to flow from the front and rear cavities 34 to the airbag body 40 during the inflation and deployment of the airbag 32, thereby allowing the airbag body 40 to inflate and deploy later. As a result, the airbag body 40 becomes easier to pass through the aforementioned gap G (see reference). Figures 37 to 39 Furthermore, since it is not necessary to add sewing parts to the front and rear cavities 34 as in the first to third modified examples described above, the increase in manufacturing costs can be suppressed.

[0134] exist Figure 43The diagram shows an example of an airbag body 40 with a slit 41 formed therein, allowing the head H of occupant D to enter. This slit 41 is formed such that, in the deployed state, it extends vertically from the center of the rear side surface in the left-right direction. When the airbag 32 restrains the occupant, by allowing the head H of occupant D to enter the slit 41, the head H becomes easier to move forward, thus reducing the likelihood of neck retraction. Furthermore, the slit 41 may or may not be formed at the point of contact between the chest C and occupant D in the airbag body 40.

[0135] While several embodiments and modifications have been described above, this disclosure can be implemented with various changes without departing from its spirit. Of course, the scope of this disclosure is not limited to the aforementioned embodiments and modifications.

Claims

1. An airbag device, comprising: An inflation device that generates gas upon vehicle collision; The airbag is supplied with gas and inflates and deploys from the upper rear side of the vehicle seat towards the front side. The airbag has front and rear cavities and an airbag body. The front and rear cavities have a pair of left and right front and rear extensions that expand and extend towards the front of the seat from the left and right sides of the head of the occupant sitting on the vehicle seat, and a connecting portion that connects the front ends of the pair of front and rear extensions in the left and right direction of the seat. The airbag body expands and deploys towards the occupant side at the rear side of the connecting part of the seat, following the front and rear chambers. When the occupant is restrained, the airbag body is compressed in the front and rear direction of the seat while the front and rear chambers extend in the front-to-back direction. The airbag body, in its inflated and deployed state, is supplied with gas from the inflation device via a connecting hole located at the rear side of the seat in the left-right direction center of the connecting part. The connecting part is sewn together with the airbag body at the sewn part located in the center of the connecting part. The inner side of the sewn part has a connecting hole that allows the connecting part to communicate with the airbag body.

2. The airbag device as described in claim 1, wherein, The base fabric constituting the front and rear cavities includes a base fabric that is less stretchable compared to the base fabric constituting the airbag body.

3. The airbag device as described in claim 2, wherein, The front and rear cavities are structures formed by overlapping and sewing multiple base fabrics, a portion of which is the difficult-to-stretch base fabric.

4. The airbag device according to any one of claims 1 to 3, wherein, The airbag body is shaped so that it is clamped between the occupant's thigh and chest when restrained.

5. The airbag device according to any one of claims 1 to 3, wherein, It has a pair of left and right rear straps, one end of each of the left and right rear straps is respectively secured to the pair of front and rear extensions, and the other end of each is respectively secured to the seat back or body of the vehicle seat at the rear side relative to the occupant. When restrained, the left and right rear straps pull the pair of front and rear extensions backward and diagonally downward toward the seat.

6. The airbag device as described in claim 5, wherein, The airbag device is configured such that, when restrained, the lower surfaces of the pair of front and rear extensions abut against the left and right shoulders of the occupant.

7. The airbag device as described in claim 5, wherein, The vehicle seats are long seats. A pair of narrow slits are formed on the back of the long seat, extending from the left and right sides of the occupant's seat in the vertical direction. Before the airbag inflates and deploys, a portion of each of the rear straps is inserted into each of the slits.

8. The airbag device as claimed in claim 5, wherein, The vehicle seats are long seats. A pair of narrow slits are formed on the back of the long seat, extending from the left and right sides of the occupant's seat in the vertical direction. The upper end of each of the slits is provided as a widening portion that increases the width of each slit towards the upper side of the seat. When the airbag inflates, a portion of each of the rear straps passes through each of the widened portions and is inserted into each of the slits.

9. The airbag device as claimed in claim 5, wherein, The vehicle seats are long seats. A pair of narrow slits are formed on the back of the long seat, extending from the left and right sides of the occupant's seat in the vertical direction. The other end of each of the rear straps is secured to the frame of the seat back within each of the slits.

10. The airbag device according to any one of claims 1 to 3, wherein, It has a pair of left and right front upper straps, which respectively connect the upper part of the airbag body that expands and unfolds towards the seat above the front and rear cavities and the pair of front and rear extensions of the front and rear cavities.

11. The airbag device according to any one of claims 1 to 3, wherein, It has a pair of left and right front lower straps, which respectively connect the lower part of the airbag body that expands and unfolds towards the underside of the seat compared to the front and rear chambers, and the pair of front and rear extensions of the front and rear chambers.

12. The airbag device according to any one of claims 1 to 3, wherein, In the inflated and deployed state, a slit is formed at the center of the seat in the left-right direction on the rear side of the seat body of the airbag body, along the vertical direction of the seat, allowing the occupant's head to enter when restrained.

13. An occupant protection device, comprising: Vehicle seats, for passengers to sit on; The airbag device according to any one of claims 1 to 12 is mounted on the rear side of the upper part of the vehicle seat.

Images