Vehicle occupant restraint device

Abstract

[Problem] To provide a vehicle occupant restraint device enabling an air bag cushion to be retained with an efficient storage configuration and to be smoothly inflated and deployed. [Solution] A side airbag device 100 includes a side frame 110 and an airbag module 112. The airbag module 112 includes: an airbag cushion 114; and a cover member 120 that covers a part of an outer periphery of the airbag cushion 114 in an orthogonal direction L2 of the side frame 110. The side frame 110 has a frame vertical wall portion 130 along the side surface of a seat back 104, and a frame projection portion 132 projecting outward in the width direction of the seat back 104. The cover member 120 is disposed in a state spanning between the frame vertical wall portion 130 and an end portion 142 on the outer side in the vehicle width direction of the frame projection portion 132 in an A-A cross section in the orthogonal direction L2 of the side frame 110.

Description

Vehicle occupant restraint device

[0001] The present invention relates to a vehicle occupant restraint device for restraining a vehicle occupant in an emergency.

[0002] Airbag systems for restraining occupants have become standard equipment in most modern vehicles. Airbag systems are safety devices that activate in emergencies such as vehicle collisions, and protect occupants by using airbag cushions that inflate and deploy using gas pressure.

[0003] There are various types of airbag devices depending on the installation location and application. For example, Fig. 1 of Patent Document 1 discloses a side airbag device installed on the side of a seat 1. In the technology of Patent Document 1, an airbag module 11 is housed in a resin module case 12 and attached to the outside of a side frame 2F.

[0004] JP 2015-58884 A

[0005] In recent years, there has been a trend toward an increase in the number of performance requirements and items required for automobile collision safety performance evaluations. To meet these requirements, it has become inevitable for airbag cushions to become larger. Furthermore, with the trend toward autonomous driving, seat frames are also becoming more and more innovative in shape. These larger airbag cushions and new seat frame shapes are making it increasingly difficult to secure storage space for side airbag devices.

[0006] In particular, the new seat frame shape described above may be detrimental to the smooth inflation and deployment of the airbag cushion. To further improve the performance of the side airbag device, it is necessary to ensure both efficient storage and smooth inflation and deployment.

[0007] SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a vehicle occupant restraint device that can efficiently maintain the stored configuration of an airbag cushion and smoothly inflate and deploy it.

[0008] In order to solve the above problems, a typical configuration of a vehicle occupant restraint device according to the present invention is a vehicle occupant restraint device comprising a side frame that is built into the seat back of a vehicle seat and extends along the side of the seat back, and an airbag module that is attached to the side frame on the widthwise outer side of the seat back, wherein the airbag module has an airbag cushion that is rolled or folded into a predetermined storage configuration, and a cover member that wraps around at least a portion of the outer periphery of the airbag cushion in the stored configuration in a direction perpendicular to the longitudinal direction of the side frame, and the side frame has a frame vertical wall portion that runs along the side of the seat back, and a frame protrusion portion that is provided on the front side of the seat back of the frame vertical wall portion and protrudes outward in the widthwise direction of the seat back beyond the frame vertical wall portion, and the cover member is arranged in a state that spans between the frame vertical wall portion and the widthwise outer end of the frame protrusion portion in a cross section of the side frame in the perpendicular direction.

[0009] The above-described cover member allows the airbag cushion to be stored more efficiently in the limited space within the seatback than with a resin case, etc. Furthermore, with the above-described configuration, the cover member covers the space in the inner angle between the frame vertical wall portion of the side frame and the frame protrusion portion, thereby preventing the airbag cushion from entering the inner angle during deployment and allowing the airbag cushion to inflate and deploy smoothly and quickly toward the front of the seatback.

[0010] The cover member may extend linearly from the frame vertical wall portion toward the outer end of the frame protrusion in the width direction.

[0011] The cover member having the above configuration also prevents the airbag cushion from getting caught in the inner corner of the side frame during deployment, allowing the airbag cushion to inflate and deploy smoothly.

[0012] The cover member may have a rear grounding portion that contacts the frame vertical wall portion along the frame vertical wall portion, an inclined portion that extends from the rear grounding portion toward the widthwise outer end of the frame protrusion, and a front grounding portion that contacts the end of the frame protrusion and extends to the front of the seat back.

[0013] The cover member having the above configuration also makes it possible to efficiently store the airbag cushion in the limited space within the seat back, while preventing the airbag cushion from getting caught in the inner corner of the side frame during deployment.

[0014] The cover member may cover the side frame so as to form a predetermined space in the interior angle formed by the frame vertical wall portion and the frame protrusion portion in a cross section of the side frame in the orthogonal direction.

[0015] The cover member having the above configuration also prevents the airbag cushion from getting caught in the inner corner of the side frame during deployment, allowing the airbag cushion to inflate and deploy smoothly.

[0016] The cover member may have at least a hard portion formed by compressing a plurality of polymer fibers.

[0017] For example, by using the hard portion of the above configuration to cover the inner corner of the side frame, it is possible to efficiently prevent the airbag cushion from getting into the inner corner of the side frame during deployment, and to allow the airbag cushion to inflate and deploy smoothly.

[0018] The airbag module may be for a side airbag. With the above configuration, it is possible to realize a side airbag device that can efficiently store an airbag cushion.

[0019] According to the present invention, it is possible to provide a vehicle occupant restraint device that can efficiently maintain the stored configuration of an airbag cushion and smoothly inflate and deploy it.

[0020] 2(a) and 2(b) are diagrams illustrating an outline of a vehicle side airbag device according to an embodiment of the present invention; FIG. 2(a) is a diagram illustrating the side airbag device of FIG. 1 as viewed from the inside in the width direction of a seat back; FIG. 2(b) is a diagram illustrating the airbag module of FIG. 2(a) alone; FIG. 2(b) is a diagram illustrating a process in which the side airbag device of FIG. 2(a) moves; and FIG. 2(b) is a diagram illustrating a modified example of the cover member of FIG.

[0021] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0022] 1A and 1B are diagrams illustrating an example of an outline of a vehicle occupant restraint device (hereinafter referred to as a side airbag device 100) according to an embodiment of the present invention. Fig. 1A is a diagram illustrating the side airbag device 100 before it is deployed.

[0023] In this embodiment, when an occupant is seated in the seat 102 in a normal posture, the direction the occupant faces is referred to as "forward," and the opposite direction is referred to as "rear." When an occupant is seated in the seat 102 in a normal posture, the right side of the occupant is referred to as the right direction, and the left side of the occupant is referred to as the left direction. When an occupant is seated in a normal posture, the direction of the occupant's head is referred to as "up," and the direction of the occupant's waist is referred to as "down." In the drawings used in the following description, the front, back, left, right, up, and down directions relative to the occupant are illustrated as arrows F (Forward), B (Back), L (Left), R (Right), U (Up), and D (Down), respectively, as necessary.

[0024] Generally, vehicle seats can be rotated in any direction. Therefore, the direction relative to the occupant seated in the seat 102 may differ from the direction relative to the vehicle. The side airbag device 100 can be installed in any seat in the front row, rear row, or even on either the left or right side of the vehicle.

[0025] The seat 102 has a seat back 104 that supports the back of the occupant and a seat cushion 106 that supports the buttocks of the occupant. In Fig. 1(a), the seat back 104 is illustrated with an internal seat frame 108 and the like being transparent, and the outer surface is illustrated by a dashed line.

[0026] The seat frame 108 is a skeletal member built into the seat back 104. A seat pad made of urethane material or the like is filled around the seat frame 108. The side frame 110 is a portion of the seat frame 108 that extends along the side of the seat back 104. The side airbag device 100 is attached to the side frame 110 and is used while built into the seat back 104.

[0027] Fig. 1(b) illustrates an example of the state of the side airbag device 100 of Fig. 1(a) after it has been activated. In an emergency, such as when a vehicle is impacted, the side airbag device 100 inflates and deploys an airbag cushion 114 to restrain an occupant seated in the seat 102 from the side.

[0028] The airbag cushion 114 is a bag-shaped member that receives the occupant, and is formed by layering and sewing or gluing multiple base fabrics that make up its surface, or by weaving using OPW (One-Piece Woven).

[0029] The inflator 116 is a gas generating device that is activated upon receiving an activation signal transmitted from the vehicle when an impact occurs, and supplies gas to the inside of the airbag cushion 114. In this embodiment, a cylindrical inflator 116 is used.

[0030] The inflator 116 is housed inside the rear side of the airbag cushion 114. The inflator 116 has a plurality of stud bolts 118, and is fixed to the side frame 110 by fastening the stud bolts 118.

[0031] Currently popular inflators include types that are filled with gas generating agent and burn it to generate gas, types that are filled with compressed gas and supply gas without generating heat, and hybrid types that use both combustion gas and compressed gas. Any of these types can be used as the inflator 116.

[0032] Figure 2 is a diagram illustrating the side airbag device 100 of Figure 1 as viewed from the inside in the width direction of the seat back 104. Figure 2(a) is a diagram illustrating the side airbag device 100 of Figure 1(a) as viewed from the inside in the width direction of the seat back 104.

[0033] Before activation, the airbag cushion 114, with the inflator 116 inserted, is rolled up, folded, or otherwise stored, and its outer periphery is wrapped in a cover member 120 to form a unit as an airbag module 112. The airbag module 112 is attached to the side frame 110 on the outer side of the seat back 104 in the width direction.

[0034] In this embodiment, the airbag module 112 is mounted to the side frame 110 on the right side in the width direction of the seat back 104, but it can also be mounted to the side frame on the left side in the width direction. In other words, the airbag module 112 can be installed either on the side of the seat 102 on the door side (near side) that is closer to the collision point, or on the side on the interior side of the vehicle that is farther from the collision point (far side).

[0035] 2(b) is a diagram illustrating the side airbag device 100 of FIG. 1(b) as viewed from the widthwise inner side of the seat back 104. When the airbag cushion 114 receives gas from the inflator 116, the inflation pressure of the gas tears open the cover member 120, causing the airbag cushion 114 to inflate and deploy forward from the side frame 110.

[0036] Fig. 3 is a diagram illustrating the airbag module 112 of Fig. 2(a) in isolation, and Fig. 3(a) is a diagram illustrating the airbag module 112 of Fig. 2(a) before activation.

[0037] As described above, the airbag module 112 has the airbag cushion 114 in the stored configuration wrapped in the cover member 120. The cover member 120 is made of a ductile fabric material containing a plurality of polymer fibers, wraps around the periphery of the airbag cushion 114 in the stored configuration, and breaks under the inflation pressure of the airbag cushion 114 to release the airbag cushion 114.

[0038] The cover member 120 may be configured to enclose the entire outer periphery of the airbag cushion 114 in the stored configuration, or may be configured to enclose only a portion of the outer periphery of the airbag cushion 114 in the stored configuration. In other words, the cover member 120 may be configured in any manner as long as it can maintain the rolled or folded state of the airbag cushion 114.

[0039] The stud bolts 118 of the inflator 116 penetrate the cover member 120 from the inside toward the outside. In order to keep the airbag cushion 114 wrapped around the cover member 120, the cover member 120 may be fastened by hooking onto the stud bolts 118 or by using a breakable tape or the like.

[0040] Fig. 3(b) is a diagram showing the cover member 120 of Fig. 3(a) in an open state. Fig. 3(b) illustrates the cover member 120 in a state where it is spread out flat. The cover member 120 has bolt holes 122 at various positions to pass the stud bolts 118 of the inflator 116 through.

[0041] As described above, the cover member 120 is made of a ductile fabric material containing a plurality of polymer fibers, and in this embodiment is embodied as a felt-like nonwoven fabric. Examples of the polymer fibers include polyester fibers.

[0042] The polymeric fibers may be monocomponent fibers or bicomponent fibers in which the core and the coating have different properties. In the case of bicomponent fibers, a lower melting point of the coating than that of the core is advantageous for fusing the fibers together. The ductile fabric material may also be formed from a plurality of different types of polymeric fibers.

[0043] In this embodiment, the cover member 120 is formed with a hard portion 124 in part or all of it so that it can maintain its shape while encasing the airbag cushion 114. The hard portion 124 is made by compressing multiple polymer fibers by pressing with a specific device, making it hard and difficult to bend.

[0044] The hard portion 124 is formed by compressing and fusing the multiple polymer fibers of the cover member 120 through a press process. The press process is performed, for example, on the bicomponent composite fibers contained in the cover member 120, at a temperature higher than the melting point of the coating and lower than the melting point of the core. This operation causes the bicomponent composite fibers to fuse with other fibers.

[0045] The hard portion 124 has a higher bending rigidity (second moment of area × Young's modulus) than the other regions. On the other hand, the region not subjected to press processing can be used as a flexible soft portion that maintains its original softness. In the soft portion, the multiple polymer fibers are not fused together, or at least the fusion ratio is lower than in the hard portion 124.

[0046] The cover member 120 is provided with a weakened portion 128. The weakened portion 128 is a portion that becomes the starting point for tearing when the airbag cushion 114 is inflated and deployed. The weakened portion 128 can be implemented as, for example, a broken-line slit formed vertically through the cover member 120.

[0047] By providing the fragile portions 128, the cover member 120 can be smoothly torn open by the inflation pressure of the airbag cushion 114, thereby releasing the airbag cushion 114. Note that the fragile portions 128 can be realized as not only dashed slits, but also as a configuration in which a series of notched cuts or a series of small notches (through holes) are arranged.

[0048] Figure 4 is a diagram illustrating an example of a process in which the side airbag device 100 of Figure 2(a) moves. Figure 4(a) is a cross-sectional view taken along line A-A of the side airbag device 100 of Figure 2(a). The cross-section A-A is a cross-section taken along line L2 perpendicular to the longitudinal direction L1 of the side frame 110 illustrated in Figure 2(a).

[0049] The airbag module 112 is attached to the side frame 110 on the outer side of the seat back 104 in the width direction using stud bolts 118. The airbag cushion 114 in the stored configuration has a cushion rear portion 114a that houses an inflator 116 and a cushion front portion 114b that is folded or otherwise configured.

[0050] The side frame 110 has a cross section that is curved in the orthogonal direction L2 (see FIG. 2A). More specifically, the side frame 110 is formed with a frame vertical wall portion 130 and a frame protrusion portion 132.

[0051] The frame vertical wall portion 130 is a flat portion that extends along the side surface of the seat back 104 (see FIG. 1A). Behind the frame vertical wall portion 130, a frame rear wall portion 134 is bent and extends toward the inside of the seat back 104 in the width direction.

[0052] The frame protrusion 132 is a portion of the frame vertical wall portion 130 provided on the front side of the seat back 104 , and protrudes outward in the width direction of the seat back 104 beyond the frame vertical wall portion 130 .

[0053] The cover member 120 is in a state in which it covers at least a part of the outer periphery of the airbag cushion 114 in the stored form in the orthogonal direction L2 illustrated in FIG. 2(a).

[0054] The cover member 120 is entirely provided with the above-described hard portion 124. In particular, the hard portion 124 is formed with a rear ground contact portion 136, an inclined portion 138, and a front ground contact portion 140 in accordance with the cross-sectional shape of the side frame 110.

[0055] The rear grounding portion 136 is a portion that contacts the frame vertical wall portion 130 along the vertical frame wall portion 130, and is formed on the cushion rear portion 114a on the side frame 110 side. The rear grounding portion 136 is formed flat so that it can easily contact the frame vertical wall portion 130.

[0056] The inclined portion 138 is a portion that extends obliquely from the front side of the rear ground contact portion 136, and is formed on the side frame 110 side from the cushion rear portion 114a to the cushion front portion 114b. The inclined portion 138 extends obliquely and linearly from the rear ground contact portion 136 toward the outer end 142 of the frame protrusion 132 in the width direction.

[0057] The front ground contact portion 140 is a portion that contacts the end portion 142 of the frame protrusion 132, and is formed on the side frame 110 side of the cushion front portion 114b. The front ground contact portion 140 extends from the inclined portion 138 to the front side of the seat back 104 so as to contact the end portion 142.

[0058] FIG. 4B is a diagram illustrating a state when the side airbag device 100 of FIG. 4A starts to move.

[0059] When a vehicle sensor detects an impact, gas is supplied from the inflator 116. At this time, the cover member 120 is provided with a weakened portion 128 that is positioned, for example, in front of the seat back 104 or on the outer side in the vehicle width direction. The weakened portion 128 is then torn by the inflation pressure of the airbag cushion 114, and the cover member 120 releases the airbag cushion 114.

[0060] When the airbag cushion 114 begins to inflate and deploy, it inflates and deploys forward from the seat back 104. However, the side frame 110 of the seat back 104 may have unevenness formed thereon due to the frame protrusion 132 or the like. Therefore, in this embodiment, the cover member 120 is provided with an inclined portion 138 as the hard portion 124, and the inclined portion 138 covers the unevenness of the side frame 110.

[0061] The inclined portion 138 is disposed so as to cover the interior angle 144 between the frame vertical wall portion 130 and the frame protruding portion 132 in the A-A cross section of the side frame 110 in the orthogonal direction L2 (see FIG. 2(a)), forming a space E1. Therefore, when viewed from the cushion rear portion 114a, the inclined portion 138 forms a guide from the frame vertical wall portion 130 toward the end portion 142 of the frame protruding portion 132.

[0062] The inclined portion 138 is disposed in a straight line spanning the frame vertical wall portion 130 and the end portion 142 of the frame protrusion portion 132. The inclined portion 138 separates the area near the interior angle 144 into a triangular space E1, and the airbag cushion 114 does not enter the space E1 during deployment.

[0063] According to this embodiment, the hard portion 124 of the cover member 120 forms the inclined portion 138, and this inclined portion 138 covers the space E1 at the inner angle 144 between the frame vertical wall portion 130 of the side frame 110 and the frame protruding portion 132, thereby preventing the airbag cushion 114 from entering the inner angle 144 during deployment. In other words, the inclined portion 138 prevents the airbag cushion 114 from getting caught on the frame protruding portion 132. This configuration prevents the airbag cushion 114 from interfering with the frame protruding portion 132 during deployment, and enables the airbag cushion 114 to be inflated and deployed smoothly and quickly toward the front of the seat back 104.

[0064] In this embodiment, the cover member 120 having the hard portion 124 allows the airbag cushion 114 to be kept smaller in size when stored. In particular, the cover member 120 made of polymer fiber can change its shape to a certain extent compared to a resin case or the like, and therefore the airbag cushion 114 can be stored to fit the surrounding structure. Therefore, the cover member 120 allows the airbag cushion 114 to be efficiently stored in the limited space within the seat back 104 (see FIG. 1( a)).

[0065] The cover member 120 of the airbag module 112 can prevent the airbag cushion 114 from becoming unwound, which facilitates, for example, the assembly of the airbag cushion 114 to a vehicle, etc. Furthermore, the cover member 120 of the airbag module 112 can prevent interference of other structures with the airbag cushion 114 after assembly to the vehicle, and the airbag cushion 114 can be kept properly wound or folded even when subjected to vibrations, etc. while driving.

[0066] In this embodiment, the hard portion 124 is formed in advance on the cover member 120 before it wraps the airbag cushion 114. Therefore, compared to when some processing is performed on the cover member 120 after the airbag cushion 114 has been wrapped, there is no risk of disturbing the winding of the airbag cushion 114, and there is little effect on devices such as the inflator 116, which is preferable.

[0067] The fragile portion 128 can be provided not only on the front side of the airbag cushion 114 but also in various locations on the cover member 120 as appropriate. Furthermore, there is no limit to the number of sheets of ductile fabric material that form the cover member 120, and it is possible, for example, to form a hard portion with higher bending rigidity by stacking and pressing multiple layers of cloth-like ductile fabric material. This makes it possible to increase the bending rigidity of the cover member 120 and improve the retention performance of the airbag cushion 114, or to increase the bending rigidity of the inclined portion 138 and more completely prevent interference of the airbag cushion 114 with the frame protrusion 132.

[0068] The cover member 120 can also be formed by heat welding the edges of multiple scraps of polymeric fibers together. In this case, the inflation pressure of the airbag cushion 114 causes the edges of the scraps to peel away from each other, allowing the edges to be used as the fragile portions 128. The cover member 120 is not limited to being made of a nonwoven fabric material, but can also be made of a woven fabric material. In other words, the cover member 120 can be made of any fabric having a material composition or fiber structure that imparts mobility or elastic behavior to the fibers.

[0069] 5 is a diagram illustrating a modified example (cover member 204) of cover member 120 in FIG. 4. In the following description, components that have already been described are assigned the same reference numerals, and their description will be omitted. Furthermore, components with the same names as components already described have the same configuration and function even if assigned different reference numerals.

[0070] Fig. 5A is a diagram illustrating a cover member 204 corresponding to Fig. 4A. In this cover member 204, the inclined portion 206 is formed in a stepped shape rather than a straight line.

[0071] Similar to the inclined portion 138 (see FIG. 4A), the inclined portion 206 also extends diagonally in a stepped manner from the rear grounding portion 136 toward the widthwise outer end 142 of the frame protruding portion 132. The inclined portion 206 is also disposed so as to cover the interior angle 144 between the frame vertical wall portion 130 and the frame protruding portion 132 in the A-A cross section of the side frame 110 in the orthogonal direction L2 (see FIG. 2A), forming a space E2.

[0072] Fig. 5(b) is a diagram illustrating an example of the cover member 204 corresponding to Fig. 4(b). The inclined portion 206 forms a guide from the frame vertical wall portion 130 toward the end portion 142 of the frame protrusion portion 132 when viewed from the cushion rear portion 114a.

[0073] The inclined portion 206 is disposed in a stepped manner spanning the frame vertical wall portion 130 and the end portion 142 of the frame protrusion portion 132. The inclined portion 206 also partitions the area near the interior angle 144 into a state in which a space E2 is formed, and the airbag cushion 114 is prevented from entering the space E2 during deployment.

[0074] As described above, even if the inclined portion 206 is not linear but has unevenness such as a stepped shape, it can cover the space E2 at the interior angle 144 between the frame vertical wall portion 130 and the frame protrusion 132, thereby preventing the airbag cushion 114 from entering the interior angle 144 during deployment. The cover member 204 also prevents the airbag cushion 114 from interfering with the frame protrusion 132 during deployment, allowing the airbag cushion 114 to be smoothly and quickly inflated and deployed toward the front of the seat back 104.

[0075] In this embodiment, the occupant restraint device has been described as being implemented as a side airbag device 100 that restrains an occupant from the side. However, the occupant restraint device according to the present invention can also be implemented as a device other than the side airbag device 100. For example, the occupant restraint device can also be implemented as a center airbag that is disposed in the center of the rear seat.

[0076] A center airbag is a device that uses an airbag cushion to prevent rear-row seat occupants from colliding with each other. In this case, the side frame 110 and airbag module 112 shown in FIG. 4A are mounted in the center portion of the rear seat. This example also allows the side frame 110 and airbag module 112 to efficiently store the airbag cushion 114 in the limited space within the rear seat, while allowing the airbag cushion 114 to inflate and deploy smoothly and quickly toward the front of the seatback of the rear seat.

[0077] Although preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the above-described embodiments are merely preferred examples of the present invention, and other embodiments may be implemented or performed in various ways. Unless otherwise specified in the present specification, the present invention is not limited to the detailed shapes, sizes, and configurations of parts shown in the accompanying drawings. Furthermore, the expressions and terms used in the present specification are for the purpose of explanation and are not intended to be limiting unless otherwise specified.

[0078] Therefore, it is clear that a person skilled in the art can think of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0079] The present invention can be used in a vehicle occupant restraint device that restrains a vehicle occupant in an emergency.

[0080] 100...side airbag device, 102...seat, 104...seat back, 106...seat cushion, 108...seat frame, 110...side frame, 112...airbag module, 114...airbag cushion, 114a...rear portion of cushion, 114b...front portion of cushion, 116...inflator, 118...stud bolt, 120...cover member, 122...bolt hole, 124...hard portion, 128...weak portion, 130...frame vertical wall portion, 132...frame protrusion, 134...frame rear wall portion, 136...rear side ground contact portion, 138...inclined portion, 140...front side ground contact portion, 142...end portion, 144...inner angle, E1...space, L1...longitudinal direction, L2...orthogonal direction, 200...side airbag device, 202...airbag module, 204...cover member, 206...inclined portion, E2...space

Claims

1. A vehicle occupant restraint device comprising: a side frame built into a seat back of a vehicle seat and extending along a side of the seat back; and an airbag module attached to the side frame on the widthwise outer side of the seat back, wherein the airbag module has: an airbag cushion in a predetermined storage configuration that is rolled or folded; and a cover member that covers at least a part of the outer periphery of the airbag cushion in the stored configuration in a direction perpendicular to the longitudinal direction of the side frame, wherein the side frame has a frame vertical wall portion along the side surface of the seat back, and a frame protruding portion of the frame vertical wall portion that is provided on the front side of the seat back and protrudes further outward in the widthwise direction of the seat back than the frame vertical wall portion, and wherein the cover member is arranged in a state in which it is stretched between the frame vertical wall portion and the widthwise outer end of the frame protruding portion in a cross section of the side frame in the perpendicular direction.

2. A vehicle occupant restraint device according to claim 1, characterized in that the cover member extends linearly from the frame vertical wall portion toward the widthwise outer end of the frame protrusion portion.

3. A vehicle occupant restraint device as described in claim 1, characterized in that the cover member has a rear grounding portion that contacts the frame vertical wall portion along the frame vertical wall portion, an inclined portion that extends from the rear grounding portion toward the widthwise outer end of the frame protrusion, and a front grounding portion that extends to the front of the seat back while contacting the end of the frame protrusion.

4. A vehicle occupant restraint device as described in claim 1, characterized in that the cover member covers the side frame so as to form a predetermined space in the interior angle formed by the frame vertical wall portion and the frame protrusion portion in the cross section of the side frame in the perpendicular direction.

5. A vehicle occupant restraint device according to any one of claims 1 to 4, characterized in that the cover member has at least a hard portion in which the plurality of polymeric fibers are compressed.

6. A vehicle occupant restraint device according to any one of claims 1 to 4, characterized in that the airbag module is for a side airbag.

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