Vehicular occupant restraint device

Abstract

To provide a vehicular occupant restraint device that can suppress a belt support airbag from interfering with a front-collision airbag, at the time of front collision of a vehicle, reduce input of local loads from a shoulder belt to the chest of an occupant and secure a function of restraining both shoulders of the occupant.SOLUTION: A vehicular occupant restraint device 10 is provided with: a three-point type seatbelt device 20 that restrains an occupant P seated on a vehicular seat 12 on the vehicular seat 12; a front-collision airbag 46 that is supplied with gas from an inflator 32 at the time of front collision of a vehicle to inflate and expand from a front side of the vehicle toward the occupant P; and a belt supporting airbag 42 that is supplied with gas from the inflator at the time of front collision of the vehicle to inflate and expand to extend in a seat width direction between a shoulder belt 22A in a seat belt 22 of the seat belt device 20 and both shoulders Ps of the occupant P, so as to restrain both shoulders Ps including clavicles of the occupant P.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a vehicle occupant restraint device. [Background technology]

[0002] A vehicle occupant restraint device has been known for some time (see, for example, Patent Document 1), in which an auxiliary airbag device is provided on the shoulder belt that inflates and deploys an auxiliary bag body on the front side of the vehicle of the occupant's shoulder on the side opposite the shoulder belt (inner side in the vehicle width direction) in the event of a frontal collision of the vehicle, so that the occupant's shoulder on the side opposite the shoulder belt is restrained to the seat via the auxiliary bag body, and both sides of the occupant's upper body in the vehicle width direction are stably restrained.

[0003] In addition, a vehicle occupant restraint device has also been known that includes an airbag that inflates in the thickness direction of the shoulder belt in the area from the belt guide located at the top of the seat back along the shoulder belt to the occupant's shoulders in the event of a frontal collision of the vehicle, thereby restraining the occupant's shoulders and separating the shoulder belt from the chest, thereby reducing the input load acting on the occupant's chest from the shoulder belt side (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-217740 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-047790 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in a vehicle front collision, an airbag deployed toward the front side of the shoulder belt cannot reduce the local load applied to the occupant's chest from the shoulder belt. This means that the occupant's chest deflection cannot be suppressed. Furthermore, the airbag may interfere with a frontal airbag that deploys toward the occupant from the front of the vehicle, potentially preventing the airbag from deploying at the intended location. Furthermore, because the airbag inflates in the thickness direction of the shoulder belt during a vehicle front collision and is positioned along the shoulder belt, it does not provide sufficient restraint for the occupant's shoulders on the inner side of the vehicle width direction, where the shoulder belt is not fastened. This leaves room for improvement in terms of enhancing restraint.

[0006] Therefore, an object of the present invention is to provide a vehicle occupant restraint device that can suppress interference of a belt-supported airbag with a frontal collision airbag during a frontal collision of the vehicle, reduce the input of local load from the shoulder belt to the occupant's chest, and ensure restraint of both occupant's shoulders. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a first aspect of the vehicle occupant restraint device according to the present invention comprises a three-point seat belt device that restrains an occupant seated in a vehicle seat to the vehicle seat, a frontal impact airbag that is supplied with gas from an inflator in the event of a frontal collision of the vehicle and inflates and deploys from the front of the vehicle toward the occupant, and a belt-supported airbag that is supplied with gas from an inflator in the event of a frontal collision of the vehicle and inflates and deploys so as to extend in the seat width direction between the shoulder belt of the seat belt of the seat belt device and the shoulders of the occupant, restraining both shoulders including the collarbone of the occupant.

[0008] According to the first aspect of the invention, when gas is supplied from the inflator during a frontal collision of the vehicle, the belt-supported airbag inflates and deploys so as to extend in the seat width direction between the shoulder belt of the seatbelt of the seatbelt device and the occupant's shoulders, restraining both shoulders including the collarbone. In other words, the shoulder belt of the seatbelt serves as a member that receives the reaction force of the belt-supported airbag. Therefore, interference of the belt-supported airbag with the frontal collision airbag is suppressed.

[0009] Furthermore, the local load input from the shoulder belt to the occupant is distributed to both shoulders via the belt-supported airbag, reducing the local load input from the shoulder belt to the occupant's chest and ensuring restraint of both shoulders. Furthermore, the thickness of the belt-supported airbag allows the shoulder belt to be raised above the occupant's chest, reducing the local load input from the shoulder belt to the occupant's chest. This reduces chest injury levels caused by the shoulder belt impeding forward movement of occupants with relatively low chest resistance, particularly women and elderly people.

[0010] In addition, when the vehicle has a frontal collision, the belt support airbag inflates and deploys, making it possible to take up slack in the shoulder belt at the beginning of the collision, making it possible to eliminate the pretensioner mechanism of the seatbelt device. Note that the "frontal collision" of the vehicle mentioned here also includes when it is predicted (foreseen) that a frontal collision of the vehicle is unavoidable.

[0011] In addition, a second aspect of the vehicle occupant restraint device according to the present invention is a vehicle occupant restraint device of the first aspect, wherein the belt-supported airbag has an upward extension portion at least at the end on the shoulder belt side that faces the upper surface of the occupant's shoulder on the shoulder belt side.

[0012] According to the second aspect of the invention, an upward extension portion is formed at least on the shoulder belt side end of the belt-supported airbag, facing the upper surface of the occupant's shoulder on the shoulder belt side. Therefore, compared to a case where the belt-supported airbag does not have an upward extension portion, the amount of interference by the belt-supported airbag with the occupant's shoulder, including the collarbone, which moves forward due to inertial force during a frontal collision of the vehicle, is increased. This makes it easier for the belt-supported airbag to stay on the occupant's shoulder, including the collarbone, as its target, regardless of differences in physique among occupants.

[0013] Furthermore, a third aspect of the vehicle occupant restraint device according to the present invention is a vehicle occupant restraint device of the first or second aspect, wherein the belt-supported airbag begins restraining the occupant using the shoulder belt as a reaction member, and then, as the occupant moves toward the front of the vehicle due to inertial force, continues restraining the occupant using the frontal impact airbag as a further reaction member.

[0014] According to the third aspect of the invention, the belt-supported airbag begins restraining the occupant using the shoulder belt as a reaction member, and then as the occupant moves forward due to inertial force, the frontal airbag continues restraining the occupant using the frontal airbag as a further reaction member. This effectively generates restraining force on the shoulders, including the collarbone, on the non-shoulder belt side where the shoulder belt is not engaged, enabling efficient occupant restraint.

[0015] Furthermore, a fourth aspect of the vehicle occupant restraint device according to the present invention is the vehicle occupant restraint device of the third aspect, wherein the belt-supported airbag is configured to inflate and deploy to a predetermined shape before the frontal impact airbag.

[0016] According to the fourth aspect of the invention, the belt-supported airbag inflates and deploys to a predetermined shape before the frontal-impact airbag, and therefore the belt-supported airbag inflates and deploys to the targeted shoulder area including the collarbone of the occupant without being affected by the frontal-impact airbag.

[0017] Furthermore, a fifth aspect of the vehicle occupant restraint device according to the present invention is a vehicle occupant restraint device of the third or fourth aspect, wherein the internal pressure of the inflated and deployed belt support airbag is higher than the internal pressure of the inflated and deployed front impact airbag.

[0018] According to the fifth aspect of the invention, the internal pressure of the inflated and deployed belt support airbag is set higher than the internal pressure of the inflated and deployed front impact airbag. Therefore, in the latter half of the occupant restraint period, the inflated and deployed belt support airbag is not significantly crushed by the inflated and deployed front impact airbag, and the shoulder belt can be kept lifted off the occupant's chest. This more effectively reduces the local load input to the occupant's chest.

[0019] In addition, a sixth aspect of the vehicle occupant restraint device according to the present invention is a vehicle occupant restraint device of any one of the first to fifth aspects, in which the pretensioner mechanism of the seat belt device is activated after the belt support airbag has completed inflation and deployment.

[0020] According to the sixth aspect of the invention, the pretensioner mechanism of the seatbelt device is activated after the belt support airbag has been fully inflated and deployed, so that the belt support airbag is inflated and deployed over the shoulders, including the collarbone, of the occupant, without being affected by the pretensioner mechanism.

[0021] In addition, a seventh aspect of the vehicle occupant restraint device according to the present invention is a vehicle occupant restraint device of any one of the first to fifth aspects, in which operation of the pretensioner mechanism of the seat belt device is prohibited while the belt support airbag is inflating and deploying.

[0022] According to the seventh aspect of the invention, the operation of the pretensioner mechanism of the seatbelt device is prohibited while the belt-supported airbag is inflating and deploying, so that the belt-supported airbag is inflated and deployed over the shoulders, including the collarbone, of the occupant, without being affected by the pretensioner mechanism. [Effects of the Invention]

[0023] As described above, according to the present invention, interference of the belt-supported airbag with the frontal collision airbag can be suppressed during a frontal collision of the vehicle, the input of local load from the shoulder belt to the occupant's chest can be reduced, and restraint of both shoulders of the occupant can be ensured. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic perspective view showing a state in which a belt-supported airbag of a vehicle occupant restraint device according to a first embodiment is inflated and deployed. [Figure 2] 1 is a schematic front view showing a state in which a belt-supported airbag of a vehicle occupant restraint device according to a first embodiment is inflated and deployed. FIG. [Figure 3] 1 is a schematic side view showing a state in which a belt-supported airbag of a vehicle occupant restraint device according to a first embodiment is inflated and deployed. [Figure 4] 1 is a schematic front view showing a normal state of a belt-supported airbag of a vehicle occupant restraint device according to a first embodiment. [Figure 5] 1 is a schematic side view showing a normal state of a belt-supported airbag of a vehicle occupant restraint device according to a first embodiment. [Figure 6] 1 is a schematic side view showing a vehicle occupant restraint device according to a first embodiment when an occupant is restrained. [Figure 7] 1 is a schematic plan view showing a state in which a vehicle occupant restraint device according to a first embodiment is mounted on a vehicle. [Figure 8] FIG. 10 is a schematic front view showing a state in which a belt-supported airbag of a vehicle occupant restraint device according to a second embodiment is inflated and deployed. [Figure 9] FIG. 10 is a schematic side view showing a state in which a belt-supported airbag of a vehicle occupant restraint device according to a second embodiment is inflated and deployed. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. For convenience of explanation, the arrow UP shown in each drawing indicates the upward direction of the vehicle and the vehicle seat, the arrow FR indicates the forward direction of the vehicle and the vehicle seat, and the arrow RH indicates the rightward direction of the vehicle and the vehicle seat. Therefore, in the following description, unless otherwise specified, when the directions of up / down, front / rear, and left / right are mentioned, they refer to up / down, front / rear, left / right, and right / left of the vehicle and the vehicle seat. Furthermore, the left / right direction is synonymous with the vehicle width direction and the seat width direction.

[0026] First Embodiment First, a first embodiment will be described. As shown in Figures 1 to 5, a vehicle occupant restraint device 10 according to the first embodiment is mainly provided in a vehicle seat 12. The vehicle seat 12 is a front seat or a rear seat of a vehicle (automobile), and here, the front seat on the driver's seat side is taken as the vehicle seat 12. The vehicle seat 12 has a seat cushion 14, a seat back 16 provided at the rear end of the seat cushion 14 so as to be rotatable about an axial direction that is the width direction of the seat, and a headrest 18 provided at the upper end of the seat back 16 so as to be movable up and down.

[0027] In addition, in Figure 1 and other figures, a crash test dummy (human dummy) is shown seated on the seat cushion 14 of the vehicle seat 12 as a model of the occupant (seat occupant) to be protected. The dummy is, for example, a frontal crash test dummy (Hybrid III) AM50 (50th percentile of American adult males). The dummy is seated in a standard seating position defined by the crash test method, and the vehicle seat 12 is positioned in a reference setting position corresponding to the seating position. Hereinafter, this dummy will be referred to as "occupant P."

[0028] 1 to 5, an occupant P seated on a seat cushion 14 of a vehicle seat 12 is restrained in the vehicle seat 12 by a seat belt (webbing) 22 provided in a seat belt device 20. The seat belt device 20 is a three-point seat belt device, or a so-called seat-attached seat belt device. In the following, a portion of the seat belt 22 that is stretched from the shoulders Ps to the abdomen Pt of the occupant P is referred to as a shoulder belt 22A.

[0029] A bezel 24, which is an outlet for the seat belt 22, is provided on the outer side in the vehicle width direction (one end side in the seat width direction) of the upper end surface of the seat back 16, and a buckle 26, to which a tongue 25 provided on the seat belt 22 is attached, is provided on the inner side in the vehicle width direction of the seat cushion 14 (the other end side in the seat width direction) (see FIG. 2). A retractor 28, which retracts one end side of the seat belt 22, is attached to a lower part of a side frame (not shown) provided inside the seat back 16 on the outer side in the vehicle width direction (see FIG. 3). The retractor 28 is provided with a pretensioner mechanism and a force limiter mechanism.

[0030] The vehicle seat 12 is provided with an airbag device 30. The airbag device 30 includes an inflator 32 embedded in a side portion 16S on the outer side in the vehicle width direction of the seat back 16, a belt support airbag 42 that is normally stored in a folded state inside a cover member 40 (see FIGS. 4 and 5), and a gas supply pipe 34 (described later) that connects the belt support airbag 42 and the inflator 32 and supplies gas from the inflator 32 to the belt support airbag 42.

[0031] 4 and 5, the cover member 40 is attached by sewing or the like to a cloth holder member (not shown) that holds the guide member 38 through which the shoulder belt 22A is movably inserted. The cover member 40 covers the holder member, the belt support airbag 42 that is disposed closer to the occupant P than the guide member 38, and an expandable portion 34A (described later) of the gas supply pipe 34, around the shoulder belt 22A that faces the shoulders Ps of the occupant P. The cover member 40 is configured so that at least the portion on the occupant P side breaks as the belt support airbag 42 inflates and deploys.

[0032] The guide member 38 is formed in a rectangular flat tube shape from, for example, a silicone-based resin material with high sliding properties so that the shoulder belt 22A can move (slide) easily. The holder member is attached by any fixing means to the peripheral surface of the guide member 38 except for the side facing the occupant P. Furthermore, the guide member 38 is configured so that the shoulder belt 22A does not come into contact with the expansion / contraction portion 34A of the gas supply pipe 34, and no external force is applied to the expansion / contraction portion 34A of the gas supply pipe 34 when the seat belt 22 is fastened or detached.

[0033] The inflator 32 is, for example, a gas-filled (cold type) approximately cylindrical inflator, and is configured to generate gas by being activated by a control device (not shown) installed in the vehicle when a collision sensor (not shown) including a camera or the like detects a frontal collision of the vehicle or predicts (forecasts) that a frontal collision is unavoidable (hereinafter referred to as "when a frontal collision of the vehicle occurs").

[0034] That is, the control device is electrically connected to the inflator 32 and the collision sensor, and activates the inflator 32 based on information from the collision sensor when the vehicle has a frontal collision. Note that the types of vehicle frontal collisions for which the control device activates the inflator 32 include not only full-overlap frontal collisions, but also offset frontal collisions such as oblique collisions and small-overlap collisions.

[0035] The inflator 32 is attached, for example, together with the retractor 28, to a side frame on the outer side of the seat back 16 in the vehicle width direction, with its axis extending substantially vertically, and one end of a gas supply pipe 34 formed, for example, by a flexible tube, is connected in communication with the upper end of the inflator 32, which is an outlet. The other end of the gas supply pipe 34 protrudes from the seat back 16 below the bezel 24, and is connected in communication with the belt-supported airbag 42.

[0036] As shown in FIG. 6, the gas supply pipe 34 for supplying gas from the inflator 32 to the belt support airbag 42 has a part on the belt support airbag 42 side, i.e., a predetermined area protruding from the seat back 16, which is an expandable part 34A configured to be expandable in response to the forward movement of the belt support airbag 42.

[0037] Specifically, the expandable portion 34A of the gas supply pipe 34 protruding from the seat back 16 is formed in a bellows shape and is expandable under a predetermined tensile load. As a result, when gas is supplied and the belt support airbag 42 is inflated and deployed, the expandable portion 34A of the gas supply pipe 34 expands to a predetermined outer diameter to achieve a fast and stable gas supply. When the belt support airbag 42 moves forward as the occupant P moves forward, the expandable portion 34A of the gas supply pipe 34 expands and contracts to a predetermined inner diameter.

[0038] In other words, the gas supply pipe 34 also functions as a check valve by contracting its expandable portion 34A, making it difficult for gas to return from the inside of the belt-supported airbag 42. The expandable portion 34A of the gas supply pipe 34 is configured to extend under a load lower than the force limiter load of the force limiter mechanism provided in the retractor 28.

[0039] 4 and 5, the accordion-shaped portion of the expandable portion 34A of the gas supply pipe 34 is shortened when the expandable portion 34A is housed inside the cover member 40, but the expandable portion 34A may be collapsed along the shoulder belt 22A. In other words, the collapsed expandable portion 34A of the gas supply pipe 34 and the folded belt support airbag 42 may both be housed inside the cover member 40.

[0040] The belt support airbag 42 is formed into a bag shape by overlapping two front and rear base fabrics, each of which has a generally rectangular shape in a front view and whose longitudinal direction is the seat width direction, and sewing together the peripheral edges. That is, as shown in Figures 1 to 3, after inflation and deployment, the belt support airbag 42 is composed of a generally cylindrical single chamber whose longitudinal direction (axial direction) is the seat width direction, and its axial length is set to be a length that allows it to face both shoulders Ps of the occupant P in the front-rear direction. Each base fabric is made of, for example, a polyamide-based or polyester-based fabric material.

[0041] Gas is supplied to the belt-supported airbag 42 from the inflator 32 via a gas supply pipe 34 that passes below the bezel 24. As a result, the belt-supported airbag 42 inflates and deploys so as to extend only in the seat width direction between at least the shoulder belt 22A and both shoulders Ps of the occupant P, and moves forward as it is pushed by the occupant P who is moving forward due to inertial force, thereby being able to restrain at least both shoulders Ps of the occupant P, including the collarbones.

[0042] 7, on the front seat side, a frontal collision airbag device 44F (44) is built into the vehicle's steering wheel 48 and the rear side of the passenger-side instrument panel 47. On the rear seat side, a frontal collision airbag device 44R (44) is built into the rear side of the seatback 16 of the front seat. These frontal collision airbag devices 44 include inflators (not shown) disposed in the center of the steering wheel 48, behind the instrument panel 47, and behind the seatback 16, and frontal collision airbags 46F, 46R (46) that are normally stored in a folded state in the center of the steering wheel 48, behind the instrument panel 47, and behind the seatback 16.

[0043] The inflator is, for example, a gas-filled (cold type) substantially cylindrical inflator similar to inflator 32, and is configured to generate gas by being activated by a control device provided in the vehicle in the event of a frontal collision of the vehicle. That is, the control device is also electrically connected to this inflator, and is configured to activate this inflator, for example, at a timing that is delayed by a predetermined time from inflator 32, based on information from a collision sensor in the event of a frontal collision of the vehicle. As a result, the belt-supported airbag 42 is configured to inflate and deploy to a predetermined shape before the frontal collision airbags 46F, 46R (46).

[0044] The frontal collision airbag 46 is a well-known airbag that is configured to inflate and deploy from the front toward the occupant P when gas is supplied from an inflator, as shown in Figures 6 and 7. This makes it possible to restrain and protect the occupant P who is moving forward due to inertial force. The frontal collision airbag 46 is also formed into a bag shape by overlapping two pieces of base fabric made of, for example, a polyamide or polyester fabric material and sewing the peripheral edges together.

[0045] Furthermore, after the belt-supported airbag 42 starts restraining the occupant P using the shoulder belt 22A as a reaction member, as the occupant P moves forward due to inertial force, the belt-supported airbag 42 continues to restrain the occupant P using the frontal collision airbag 46 as a further reaction member. Therefore, as described above, the frontal collision airbag 46 is configured to inflate and deploy at a timing that is delayed by a predetermined time from the belt-supported airbag 42. In other words, the belt-supported airbag 42 is configured to inflate and deploy to a predetermined shape before the frontal collision airbag 46.

[0046] The output of the inflator 32 for the belt support airbag 42 and the output of the inflator for the front collision airbag 46 are set so that the internal pressure of the inflated and deployed belt support airbag 42 is higher than the internal pressure of the inflated and deployed front collision airbag 46. Also, under the control of the control device, the pretensioner mechanism provided in the retractor 28 is activated after the belt support airbag 42 has been completely inflated and deployed. In other words, the activation of the pretensioner mechanism is prohibited while the belt support airbag 42 is inflating and deploying.

[0047] Next, the operation of the vehicle occupant restraint device 10 according to the first embodiment configured as described above will be described. Note that the guide member 38 and the cover member 40 are not shown in Figures 1 to 3.

[0048] In the event of a frontal collision of the vehicle, the inflator 32 is activated under the control of the control device. That is, gas is ejected from the inflator 32. The gas ejected from the inflator 32 is then supplied to the inside of the belt support airbag 42 through the gas supply pipe 34. That is, gas is supplied to the inside of the folded belt support airbag 42, which is housed inside the cover member 40 and arranged on the occupant P side (back side) of the shoulder belt 22A.

[0049] 1 to 3, the belt support airbag 42 inflates and deploys so as to extend only in the seat width direction between the shoulder belt 22A and the shoulders Ps of the occupant P. As a result, the inflated and deployed belt support airbag 42 is positioned between the shoulder belt 22A and both shoulders Ps of the occupant P, including at least the collarbone, in other words, behind the shoulder belt 22A and in front of both shoulders Ps of the occupant P.

[0050] 6, the belt support airbag 42 moves forward following the occupant P who moves forward due to the inertial force associated with the impact of a frontal collision of the vehicle, and restrains at least both shoulders Ps including the collarbone of the occupant P. In other words, the shoulder belt 22A serves as a member that receives the reaction force of the belt support airbag 42. Therefore, interference of the belt support airbag 42 with the frontal collision airbag 46 can be suppressed or prevented.

[0051] Then, the occupant P, who has been moved forward by inertial force, has his / her upper body, including his / her head, restrained and protected by the frontal collision airbag 46. The frontal collision airbag 46 inflates and deploys at a timing that is delayed by a predetermined time from the belt-supported airbag 42. In other words, the belt-supported airbag 42 inflates and deploys to a predetermined shape before the frontal collision airbag 46. Therefore, the belt-supported airbag 42 can be inflated and deployed at the target position, i.e., at the shoulders Ps including the collarbone of the occupant P, without being affected by the frontal collision airbag 46.

[0052] At this time, the expandable portion 34A of the gas supply pipe 34, which supplies gas from the inflator 32 to the belt-supported airbag 42, expands in response to the forward movement of the belt-supported airbag 42. Therefore, regardless of the physique of the occupant P, the belt-supported airbag 42 can be continuously held between the shoulder belt 22A and both shoulders Ps of the occupant P, and at least both shoulders Ps of the occupant P can be effectively restrained from the first half to the second half of the occupant restraint.

[0053] Furthermore, the belt support airbag 42 can quickly generate an appropriate restraining force on the shoulder Ps on the anti-shoulder belt side (inner side in the vehicle width direction) where the shoulder belt 22A is not applied. In other words, the local load input from the shoulder belt 22A to the occupant P can be quickly distributed to both shoulders Ps (mainly supported by the collarbone) via the belt support airbag 42. Therefore, despite the simple configuration, it is possible to reduce the input of the local load from the shoulder belt 22A to the chest Pc of the occupant P, and both shoulders Ps of the occupant P can be efficiently restrained.

[0054] Moreover, after the belt support airbag 42 starts restraining the occupant P using the shoulder belt 22A as a reaction member, as the occupant P moves forward due to inertial force, the frontal collision airbag 46 continues to restrain the occupant P using the frontal collision airbag 46 as a further reaction member. Therefore, compared to a configuration that does not use the frontal collision airbag 46 as a reaction member, a restraining force can be more effectively generated on the shoulder Ps on the anti-shoulder belt side where the shoulder belt 22A is not engaged, and the upper body of the occupant P can be restrained efficiently and stably in a well-balanced manner.

[0055] Furthermore, the thickness of the inflated and deployed belt support airbag 42 can raise the shoulder belt 22A above the chest Pc of the occupant P, and a predetermined gap can be formed between the shoulder belt 22A and the chest Pc of the occupant P. This reduces the local load input from the shoulder belt 22A to the chest Pc of the occupant P. This reduces the chest injury value caused by the shoulder belt 22A hindering forward movement, particularly for occupants with relatively low chest resistance, such as women and elderly people.

[0056] Furthermore, the internal pressure of the inflated and deployed belt support airbag 42 is set higher than the internal pressure of the inflated and deployed frontal collision airbag 46. Therefore, in the latter half of the occupant restraint, the inflated and deployed belt support airbag 42 is not significantly crushed by the inflated and deployed frontal collision airbag 46, and the shoulder belt 22A can be kept lifted off the chest Pc of the occupant P. This makes it possible to more effectively reduce the input of local load to the chest Pc of the occupant P.

[0057] Furthermore, the pretensioner mechanism of the seatbelt device 20 is activated after the belt support airbag 42 has been completely inflated and deployed. In other words, the pretensioner mechanism of the seatbelt device 20 is prohibited from activation while the belt support airbag 42 is inflating and deploying. Therefore, the belt support airbag 42 can be inflated and deployed onto the shoulders Ps, including the collarbone, of the occupant P, as its target, without being affected by the pretensioner mechanism.

[0058] Thus, the vehicle occupant restraint device 10 according to the first embodiment can improve the restraint performance of the occupant P, enabling more efficient occupant restraint. Furthermore, with this vehicle occupant restraint device 10, the belt support airbag 42 inflates and deploys during a frontal collision of the vehicle, thereby making it possible to remove slack in the shoulder belt 22A at the initial stage of the collision. Therefore, it is not necessary to provide a pretensioner mechanism in the retractor 28 of the seatbelt device 20. In other words, the pretensioner mechanism can be eliminated.

[0059] Furthermore, the belt-supported airbag 42 is disposed in a folded state on the occupant P side (back side) of the shoulder belt 22A, and the inflator 32 that supplies gas to the belt-supported airbag 42 and the seat belt 22 are provided in the vehicle seat 12. In other words, all of the components that make up the vehicle occupant restraint device 10, except for the front-impact airbag 46 and its inflator, are provided in the vehicle seat 12. Therefore, the vehicle occupant restraint device 10 can be easily installed in a vehicle by simply mounting the vehicle seat 12. As shown in FIG. 7 , the vehicle occupant restraint device 10 can be installed not only in the driver's seat side of the vehicle seat 12, but also in the front seat on the passenger side and in a rear seat of a minivan, SUV, or the like that is configured to slide significantly in the fore-and-aft direction.

[0060] Second Embodiment Next, a second embodiment will be described. Note that the same reference numerals are used to designate parts equivalent to those in the first embodiment, and detailed descriptions (including common functions) will be omitted as appropriate.

[0061] As shown in Figures 8 and 9, the vehicle occupant restraint device 10 according to the second embodiment differs from the first embodiment only in that upward extensions 42A that face the upper surfaces of both shoulders Ps of the occupant P are formed at both ends (left and right sides) of the inflated and deployed belt support airbag 42 in the seat width direction.

[0062] This configuration increases the amount of interference (contact area) of the belt support airbag 42 with the shoulders Ps, including the collarbone, of the occupant P, which moves forward due to inertial force during a frontal collision of the vehicle, compared to a configuration in which the belt support airbag 42 does not have the upward extension portion 42A. Therefore, even if there are differences in the physiques of occupants P, the belt support airbag 42 can more easily be retained on the shoulders Ps, including the collarbone, of the occupant P as the target.

[0063] The upward extension 42A may be formed only on at least the outer end in the vehicle width direction, i.e., only on the end on the shoulder belt 22A side. However, if the upward extension 42A is formed on both the left and right sides of the belt support airbag 42, the belt support airbag 42 can be installed in the front seat on the passenger side, for example, without any design changes, which is advantageous in terms of manufacturing costs.

[0064] While the vehicle occupant restraint device 10 according to this embodiment has been described above with reference to the drawings, the vehicle occupant restraint device 10 according to this embodiment is not limited to the one shown in the drawings, and the design can be modified as appropriate within the scope of the gist of the present invention. For example, the other end of the gas supply pipe 34 may be configured to protrude through the bezel 24.

[0065] Furthermore, the belt support airbag 42 and the front impact airbag 46 may be configured to inflate and deploy approximately simultaneously, as long as the belt support airbag 42 can be inflated and deployed toward the shoulder region Ps, including the collarbone, of the occupant P, as its target, without being affected by the front impact airbag 46. Furthermore, in the latter half of occupant restraint, as long as the inflated and deployed belt support airbag 42 is not crushed by the inflated and deployed front impact airbag 46, the internal pressure of the belt support airbag 42 and the internal pressure of the front impact airbag 46 may be equal.

[0066] Furthermore, since the seatbelt device 20 is installed in the vehicle seat 12, the shoulder belt 22A does not necessarily need to be placed around the shoulder on the outer side in the vehicle width direction. That is, the vehicle occupant restraint device 10 according to this embodiment can also be applied to a configuration in which the shoulder belt 22A is placed around the shoulder on the inner side in the vehicle width direction. Furthermore, the belt support airbag 42 is not limited to a configuration in which two layers of base fabric are overlapped and their peripheral edges are sewn together, but may be a configuration in which three or more layers of base fabric are used and their peripheral edges are sewn together. Furthermore, the material of the guide member 38 is not limited to a silicone-based resin material with high sliding properties, and other materials with excellent sliding properties can be used. [Explanation of symbols]

[0067] 10. Vehicle occupant restraint system 12 Vehicle seats 20 Seatbelt device 22 Seatbelt 22A Shoulder Belt 32 Inflator 42 Belt-supported airbag 42A Upper extension 46 Frontal airbags P crew Ps Shoulder

Claims

1. a three-point seat belt device that restrains an occupant seated in a vehicle seat to the vehicle seat; a frontal collision airbag that is inflated and deployed from the front of the vehicle toward the occupant by gas being supplied from an inflator in the event of a frontal collision of the vehicle; a belt-supported airbag that is inflated and deployed in a seat width direction between a shoulder belt of a seat belt of the seat belt device and the shoulders of the occupant by gas being supplied from an inflator in the event of a frontal collision of the vehicle, and that restrains both shoulders including the collarbone of the occupant; A vehicle occupant restraint device comprising:

2. 2. The vehicle occupant restraint device according to claim 1, wherein the belt-supported airbag has an upward extension at least at a shoulder-belt-side end thereof that faces an upper surface of the occupant's shoulder on the shoulder-belt side.

3. 3. A vehicle occupant restraint device as described in claim 1 or claim 2, wherein the belt-supported airbag starts restraining the occupant using the shoulder belt as a reaction member, and then continues restraining the occupant using the frontal collision airbag as a further reaction member as the occupant moves forward of the vehicle due to inertial force.

4. 4. The vehicle occupant restraint device according to claim 3, wherein the belt support airbag is configured to inflate and deploy to a predetermined shape before the frontal collision airbag.

5. 4. The vehicle occupant restraint device according to claim 3, wherein the internal pressure of the inflated and deployed belt support airbag is higher than the internal pressure of the inflated and deployed frontal collision airbag.

6. 3. The vehicle occupant restraint device according to claim 1, wherein the pretensioner mechanism of the seatbelt device is activated after the belt support airbag has been completely inflated and deployed.

7. 3. The vehicle occupant restraint device according to claim 1, wherein operation of the pretensioner mechanism of the seatbelt device is prohibited while the belt support airbag is inflated and deployed.

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