Vehicle occupant restraint device

Abstract

The invention provides a vehicle occupant restraint device. The vehicle occupant restraint device includes: a seat belt configured to restrain an occupant to the vehicle seat; and a belt support airbag configured to inflate and deploy at least between a shoulder strap and a shoulder of the occupant by supplying gas from an inflator when a front collision of the vehicle occurs, so as to support the shoulder strap and the shoulder of the occupant as the occupant moving toward a front side of the vehicle moves toward the front side of the vehicle. And constraining at least the shoulder of the occupant; and a gas supply pipe having a first end connected to the inflator, a second end connected to the belt support airbag, and a predetermined region on the second end side, the predetermined region configured to extend as the belt support airbag moves toward the front side of the vehicle.

Description

Technical Field

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

[0002] A passenger protection device is known in the prior art that suppresses a sudden increase in the restraining force on the passenger's head when a frontal collision of a vehicle occurs (for example, refer to Japanese Unexamined Patent Application Publication No. 2017-124759 (JP 2017-124759 A)). The passenger protection device includes an airbag and a connecting fabric. The airbag is deployed in an area including the front side and left and right sides of the passenger's head to cover the head. The connecting fabric has an elongation that is equal to or less than the elongation of the airbag. A first end portion of the connecting fabric is connected to the front portion of the airbag, and a second end portion of the connecting fabric is connected to a force limiter mechanism provided in the headrest. Summary of the Invention

[0003] However, in the aforementioned occupant protection device, the momentum of the forward-deploying airbag is supported and controlled by a force limiter mechanism provided within the headrest, requiring a complex mechanism to be provided within the headrest. As described above, there is still room for improvement in effectively restraining an occupant in the event of a frontal vehicle collision without providing a complex mechanism.

[0004] The present invention provides a vehicle occupant restraint device that can effectively restrain a member when a frontal collision of the vehicle occurs even with a simple structure.

[0005] A first embodiment of the present invention relates to a vehicle occupant restraint device comprising a seat belt, a belt support airbag, and a gas supply pipe. The seat belt is configured to restrain an occupant seated on a vehicle seat to the vehicle seat. The belt support airbag is configured to inflate and deploy at least between a shoulder belt in the seat belt and the occupant's shoulder by supplying gas from an inflator in the event of a frontal collision of the vehicle, thereby moving toward the front of the vehicle as the occupant moves due to inertial force and restraining at least the occupant's shoulder. The gas supply pipe has a first end connected to the inflator and a second end connected to the belt support airbag. A predetermined region of the gas supply pipe on the second end side is configured to expand as the belt support airbag moves toward the front of the vehicle.

[0006] According to the first aspect of the present invention, in the event of a frontal vehicle collision, the belt-supported airbag inflates and deploys at least between the shoulder strap of the seatbelt and the shoulder of the occupant by supplying gas from the inflator. This airbag moves toward the front of the vehicle as the occupant moves due to inertial force, restraining at least the occupant's shoulder. In other words, the shoulder strap of the seatbelt serves as a member that receives the reaction force of the belt-supported airbag. In this case, a predetermined region of the gas supply tube, located near the second end of the gas supply tube, which has a first end connected to the inflator and a second end connected to the belt-supported airbag, expands toward the front of the vehicle as the belt-supported airbag moves.

[0007] Therefore, regardless of the occupant's physique, the belt-supported airbag can be continuously held between at least the shoulder belt and the occupant's shoulders, effectively restraining at least the occupant's shoulders from the front half to the rear half of the occupant restraint, while suppressing or preventing problems such as rupture of the gas supply tube. Furthermore, the inflated and deployed belt-supported airbag forms a predetermined gap between the shoulder belt and the occupant's chest.

[0008] As described above, according to the aspect of the present invention, even with a simple configuration in which a predetermined region of the gas supply pipe connected to the second end portion of the belt support airbag is extendable, an occupant can be effectively restrained in the event of a frontal collision of the vehicle. The phrase "in the event of a frontal collision" herein includes the case where a frontal collision of the vehicle is predicted (forecasted) to be unavoidable.

[0009] The vehicle occupant restraint device may further include a cover member. A bellows-shaped expandable portion is provided in the predetermined region of the gas supply pipe. The expandable portion of the gas supply pipe and the folded belt-supported airbag are accommodated in the cover member.

[0010] In this configuration, a predetermined area of ​​the gas supply tube connected to the second end of the belt-supported airbag serves as a bellows-shaped inflatable portion. The inflatable portion of the gas supply tube and the folded belt-supported airbag are housed within the cover member. In other words, the inflatable portion and the belt-supported airbag are positioned outside the vehicle seat. This eliminates the need for complex internal seat structures. Furthermore, since the inflatable portion and the belt-supported airbag are concealed by the cover member, deterioration of the vehicle seat's appearance is minimized.

[0011] The bellows-shaped inflatable portion may be configured to contract when housed in the cover member. The bellows-shaped inflatable portion may be configured to expand and to a predetermined outer diameter when the belt-supported airbag is inflated and deployed. The bellows-shaped inflatable portion may be configured to further expand and to contract to a predetermined inner diameter when the belt-supported airbag moves toward the front side of the vehicle.

[0012] With this construction, when the inflatable portion is accommodated in the cover member, the bellows-shaped inflatable portion is shortened. Therefore, the size of the accommodation space is reduced, and the accommodation performance is improved. In addition, when the belt-supported airbag is inflated and deployed, the bellows-shaped inflatable portion stretches and expands to a predetermined outer diameter. Therefore, gas is supplied to the belt-supported airbag quickly, sufficiently and stably. Furthermore, with respect to the bellows-shaped inflatable portion, when the belt-supported airbag moves toward the front side of the vehicle, the bellows-shaped inflatable portion further stretches and contracts to a predetermined inner diameter. Therefore, the gas supplied to the belt-supported airbag is less likely to return to the inflator side.

[0013] The expandable portion of the gas supply pipe may be provided with a stent member that restricts excessive expansion.

[0014] With this configuration, the expandable portion of the gas supply pipe is provided with a support member that restricts over-expansion. Therefore, it is possible to suppress a decrease in gas supply capacity (gas pressure) due to over-expansion of the expandable portion of the gas supply pipe.

[0015] In addition, when the inflatable portion is accommodated in the cover member, the inflatable portion of the gas supply tube may be formed in a flattened shape along the shoulder strap.

[0016] With this configuration, when the inflatable portion is accommodated in the cover member, the inflatable portion of the gas supply tube is formed into a flattened shape along the shoulder strap. Therefore, the inflatable portion of the gas supply tube can be used as a cushioning member, making it possible to improve the wearability of the shoulder strap portion when wearing the shoulder strap.

[0017] The shoulder belt may be movably inserted through a guide member accommodated in the cover member and may not come into contact with the inflatable portion of the gas supply pipe.

[0018] With this configuration, the shoulder belt is movably inserted through the guide member housed in the cover member without contacting the inflatable portion of the gas supply pipe. Therefore, when tightening or removing the seat belt, no external force, such as a tensile load, is applied to the inflatable portion of the gas supply pipe, and the seat belt can move smoothly.

[0019] A force limiter mechanism may be provided in a retractor that winds up the seat belt.The expandable portion of the gas supply pipe may be configured to expand under a load lower than a force limiter load of the force limiter mechanism.

[0020] With this configuration, the force limiter mechanism is incorporated into the retractor that winds the seat belt. The expandable portion of the gas supply pipe expands under a load lower than the force limiter load of the force limiter mechanism. This prevents or mitigates the possibility of the gas supply pipe interfering with the operation of the force limiter mechanism. As a result, occupant behavior can be easily controlled.

[0021] The inflator may be embedded in a seat back of the vehicle seat together with the retractor.

[0022] With this configuration, the inflator is embedded in the seat back of the vehicle seat together with the retractor. Therefore, the installation of the various components constituting the vehicle occupant restraint system, including the seat belt, etc., can be completed solely by the vehicle seat, thereby improving workability during vehicle assembly.

[0023] A bellows-shaped inflatable portion may be provided in the predetermined region of the gas supply pipe.The inflatable portion may be provided between a seat back and the belt-supported airbag.

[0024] As described above, according to the vehicle occupant restraint apparatus of the aspect of the present disclosure, even with a simple structure, it is possible to effectively restrain an occupant when a frontal collision of the vehicle occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described hereinafter with reference to the accompanying drawings, wherein like reference numerals represent like elements, and wherein:

[0026] Figure 1 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;

[0027] Figure 2 A schematic front view showing a state in which a belt-supported air bag of the vehicle occupant restraint apparatus according to the first embodiment is inflated and deployed;

[0028] Figure 3 A schematic side view showing a state in which a belt-supported air bag of the vehicle occupant restraint apparatus according to the first embodiment is inflated and deployed;

[0029] Figure 4 A schematic front view showing a normal state of a belt-supported airbag of a vehicle occupant restraint apparatus according to a first embodiment;

[0030] Figure 5 A schematic side view showing a normal state of a belt-supported airbag of a vehicle occupant restraint apparatus according to a first embodiment;

[0031] Figure 6 A schematic side sectional view showing the internal structure of the supported air bag of the vehicle occupant restraint apparatus according to the first embodiment when the supported air bag is inflated and deployed;

[0032] Figure 7 A schematic partially enlarged cross-sectional view showing the structure of a gas supply pipe of the vehicle occupant restraint apparatus according to the first embodiment;

[0033] Figure 8A A schematic cross-sectional view showing a state in which the gas supply pipe of the vehicle occupant restraint apparatus according to the first embodiment is expanded in diameter;

[0034] Figure 8B A schematic cross-sectional view showing a state in which the gas supply pipe of the vehicle occupant restraint apparatus according to the first embodiment is reduced in diameter;

[0035] Figure 9A A schematic side view showing a state before the gas supply pipe of the vehicle occupant restraint apparatus according to a modified example of the first embodiment is extended;

[0036] Figure 9B A schematic side view showing a state in which a gas supply pipe of a vehicle occupant restraint apparatus according to a modified example of the first embodiment is extended;

[0037] Figure 9C A schematic side view showing a state in which a gas supply pipe of a vehicle occupant restraint apparatus according to a modified example of the first embodiment is extended;

[0038] Figure 10 A schematic enlarged sectional view showing a normal state of a gas supply pipe of a vehicle occupant restraint apparatus according to a modified example of the first embodiment;

[0039] Figure 11A A schematic side view showing a state before a belt-supported air bag of the vehicle occupant restraint apparatus according to the first embodiment is inflated and deployed;

[0040] Figure 11B A schematic side view showing a state in which a belt-supported air bag of the vehicle occupant restraint apparatus according to the first embodiment is inflated and deployed;

[0041] Figure 12A A schematic side view showing a state immediately after completion of inflation and deployment of the belt-supported air bag of the vehicle occupant restraint apparatus according to the first embodiment;

[0042] Figure 12B A schematic side view showing a state in which the belt-supported air bag of the vehicle occupant restraint apparatus according to the first embodiment moves forward;

[0043] Figure 13 A schematic perspective 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;

[0044] Figure 14 is a schematic front view showing a state in which a belt-supported air bag of a vehicle occupant restraint apparatus according to a second embodiment is inflated and deployed; and

[0045] Figure 15 1 is a schematic side view showing a state in which a belt-supported air bag of a vehicle occupant restraint apparatus according to a second embodiment is inflated and deployed. DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. For ease of description, arrows are shown in each drawing as appropriate: the "UP" arrow indicates the upward direction of the vehicle and vehicle seat, the "FRONT" arrow indicates the forward direction of the vehicle and vehicle seat, and the "RIGHT" arrow indicates the rightward direction of the vehicle and vehicle seat. Therefore, in the following description, when the vertical, front-back, and left-right directions are described without specific reference, they represent the vertical, front-back, and left-right directions of the vehicle and vehicle seat. Furthermore, the left-right direction is the same as the vehicle width direction and the seat width direction.

[0047] First embodiment

[0048] First, the first embodiment will be described. Figures 1 to 5 As shown, the vehicle occupant restraint device 10 according to the first embodiment is provided on 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 is the vehicle seat 12. The vehicle seat 12 includes a seat cushion 14, a seat back 16 provided at a rear end portion of the seat cushion 14 so as to be rotatable about the seat width direction as an axial direction, and a headrest 18 provided at an upper end portion of the seat back 16 so as to be movable up and down.

[0049] exist Figure 1In the figures, a crash test dummy (human dummy) is shown sitting on the seat cushion 14 of the vehicle seat 12 as a model of the occupant to be protected. The dummy is, for example, an AM50 (American adult male 50th percentile) dummy (Hybrid III) used for frontal crash tests. The dummy is seated in a standard sitting posture determined by the crash test method, and the vehicle seat 12 is positioned in a reference set position corresponding to the sitting posture. The dummy is hereinafter referred to as "occupant P."

[0050] like Figures 1 to 5 As shown, an occupant P seated on a seat cushion 14 of a vehicle seat 12 is restrained to 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 and is a so-called seat-integrated seat belt device. In the following description, the portion of the seat belt 22 extending from the shoulder Ps to the abdomen Pt of the occupant P is referred to as a shoulder belt 22A.

[0051] A bezel 24 serving as an outlet for the seat belt 22 is provided on the vehicle width direction outer side (the first end side in the seat width direction) of the upper end surface of the seat back 16, and a buckle 26 for fixing a tongue 25 provided on the seat belt 22 is provided on the vehicle width direction inner side (the second end side in the seat width direction) of the seat cushion 14 (see FIG. Figure 2 The retractor 28 on the first end side around which the user winds up the seat belt 22 is attached to a lower portion of a side frame (not shown) provided on the vehicle width direction outer side inside the seat back 16 (see Figure 3 The retractor 28 is provided with a pre-tightening mechanism and a force limiter mechanism.

[0052] The vehicle seat 12 is provided with an airbag device 30. The airbag device 30 includes: an inflator 32 embedded in the side portion 16S of the seat back 16 on the vehicle width direction outer side; a belt support airbag 42, which is normally accommodated in a folded state in the cover member 40 (see FIG. Figure 4 、 Figure 5 as well as Figure 11A and a gas supply pipe 34 (described later), which connects the belt support airbag 42 and the inflator 32, and supplies gas from the inflator 32 to the belt support airbag 42.

[0053] like Figure 4 、 Figure 5 as well as Figure 11AAs shown, a cover member 40 is attached to a fabric retaining member (not shown) by sewing or the like, which retains the guide member 38 into which the shoulder belt 22A is movably inserted. The cover member 40 covers the retaining member, the folded belt-supporting airbag 42 arranged on the occupant P side relative to the guide member 38, and the inflatable portion 34A of the gas supply tube 34 (to be described later), surrounding the shoulder belt 22A facing the shoulder Ps of the occupant P. The cover member 40 is configured to rupture at least on the occupant P side when the belt-supporting airbag 42 is inflated and deployed.

[0054] The guide member 38 is formed into a rectangular flat tube shape and is made of, for example, a silicone-based resin material with high sliding properties so that the shoulder belt 22A can be easily moved (slid) (see Figure 10 ). The holding member is attached to the outer peripheral surface of the guide member 38 except for the passenger P side by any fixing member. Figure 6 and Figure 10 As shown, the guide member 38 is configured to prevent the shoulder belt 22A from contacting the expandable portion 34A of the gas supply tube 34. Furthermore, the guide member 38 is configured to prevent external force from being applied to the expandable portion 34A of the gas supply tube 34 when fastening or unfastening the seat belt 22.

[0055] The inflator 32 is, for example, an airtight (cold type) cylinder-type inflator having a substantially cylindrical shape. The inflator is configured to generate gas 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"), by being activated by a control device (not shown) provided in the vehicle.

[0056] 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 a frontal collision of the vehicle occurs. Types of frontal collisions of the vehicle in which the control device activates the inflator 32 include, in addition to full overlap frontal collisions, offset frontal collisions such as oblique collisions or small overlap collisions.

[0057] The inflator 32 is attached to a side frame on the vehicle width direction outer side of the seat back 16, for example, together with the retractor 28, with the vertical direction being the axial direction. A first end of a cylindrical gas supply pipe 34 is connected to a discharge port, which is the upper end of the inflator 32. A second end of the gas supply pipe 34 protrudes from the seat back 16 below the bezel 24 and is connected to the belt-supported air bag 42.

[0058] like Figure 6As shown, the gas supply pipe 34 for supplying gas from the inflation device 32 to the belt-supported airbag 42 is constructed so that a portion of the gas supply pipe 34 on the belt-supported airbag 42 side (the second end side), that is, a predetermined area portion protruding from the seat back 16, serves as an inflatable portion 34A, and the inflatable portion 34A is constructed to expand as the belt-supported airbag 42 moves forward.

[0059] Specifically, the gas supply pipe 34 is integrally constructed by connecting a first end portion of an expandable portion 34A made of, for example, a heat-resistant elastomer resin to an upper end portion of a main body pipe 34S made of resin or metal and embedded in the seat back 16. The first end portion of the expandable portion 34A is fixed to the upper end portion of the main body pipe 34S by a clamping member 35 or the like.

[0060] like Figures 6 to 8B As shown, the expandable portion 34A of the gas supply tube 34, which protrudes from the seat back 16, is formed into a bellows shape and has a three-layer structure capable of expanding under a predetermined tensile load. Specifically, the expandable portion 34A of the gas supply tube 34 includes an outer layer 34B formed into a bellows shape, an inner layer 34C embedded with a mesh-like metal bracket member 36 capable of limiting excessive expansion, and a silicone coating 34D disposed between the outer layer 34B and the inner layer 34C.

[0061] As a result, the expandable portion 34A of the gas supply pipe 34 is constructed so as to stretch and expand to a predetermined outer diameter when gas is supplied and the belt-supported airbag 42 is inflated and deployed. Specifically, the expandable portion 34A is constructed so that the trough portion of the bellows-shaped portion, which protrudes radially inward and has an inner diameter that decreases when shortened, expands due to the deformation of the bellows braided structure, thereby achieving rapid and sufficiently stable gas supply. The expandable portion 34A of the gas supply pipe 34 is constructed so as to further stretch and contract to a predetermined inner diameter (see FIG. 1 ) when the belt-supported airbag 42 moves forward as the occupant P moves forward. Figure 8B ).

[0062] That is, by contracting the diameter of the expandable portion 34A, the gas supply tube 34 also functions as a check valve, making it difficult for gas to return from the interior of the belt-supported airbag 42. The expandable portion 34A of the gas supply tube 34 is configured to expand under a load lower than the force limiter load of the force limiter mechanism provided in the retractor 28. The support member 36 is not limited to a metal material, as long as the support member 36 can withstand the tube expansion force during gas supply.

[0063] Furthermore, the expandable portion 34A of the gas supply pipe 34 is not limited to the configuration in which the support member 36 is provided in the inner layer 34C. The expandable portion 34A of the gas supply pipe 34 may be configured by being formed of an elastic body such as rubber as described above, for example, as shown in FIG. Figures 9A to 9CThat is, the expandable portion 34A of the gas supply pipe 34 is configured to elastically deform and thus expand only when a tensile load is applied, as shown in FIG. Figure 9B and Figure 9C , and is configured to return to its original state by elastic restoring force when no tensile load is applied, as shown Figure 9A shown.

[0064] With the inflatable portion 34A of the gas supply pipe 34 having such a configuration, as in the case where the support member 36 is provided, when gas is supplied and the belt-supporting airbag 42 is inflated and deployed, the inflatable portion 34A can expand and expand to a predetermined outer diameter. Furthermore, when the belt-supporting airbag 42 moves forward as the occupant P moves forward, the inflatable portion 34A can further expand and contract to a predetermined inner diameter.

[0065] like Figure 4 and Figure 5 As shown, when the expandable portion 34A of the gas supply pipe 34 is accommodated in the cover member 40, the bellows-shaped portion of the expandable portion 34A is in a shortened state. Figure 10 As shown, the inflatable portion 34A may be formed in a flattened shape along the inner surface of the shoulder belt 22A on the occupant P side. That is, both the inflatable portion 34A having the flattened gas supply tube 34 and the folded belt supporting airbag 42 may be accommodated in the cover member 40 .

[0066] The belt-supported airbag 42 is formed into a bag shape by overlapping two base fabrics in the front-rear direction, the two base fabrics having a substantially rectangular shape in a front view with the seat width direction being the longitudinal direction, and sewing the outer peripheral edges of the two base fabrics together. Figures 1 to 3 As shown, the belt-supported airbag 42 after inflating and deploying is constructed of a single chamber having a substantially cylindrical shape with the seat width direction being the longitudinal direction (axial direction), and its length in the axial direction is set to a length capable of facing the shoulder Ps of the occupant P in the front-rear direction. Each base fabric is formed of, for example, a polyamide-based fabric material or a polyester-based fabric material.

[0067] The belt-supported airbag 42 is configured to be supplied with gas from the inflator 32 via the gas supply tube 34 passing through the lower side of the bezel 24. Therefore, the belt-supported airbag 42 is inflated and deployed, thereby extending at least between the shoulder belt 22A and both shoulders Ps of the occupant P in the seat width direction, and moves forward in a manner pushed by the occupant P as the occupant P moves forward due to inertial force, thereby restraining at least both shoulders Ps of the occupant P, including the clavicle.

[0068] In the vehicle occupant restraint device 10 according to the first embodiment having the above-described configuration, the operation thereof will be described below. Figures 1 to 3 、 Figure 11B 、 Figure 12A as well as Figure 12B In FIG, the guide member 38 and the cover member 40 are not shown.

[0069] When a frontal collision of the vehicle occurs, the inflator 32 is activated by the control of the control device. That is, gas is ejected from the inflator 32. Then, the gas ejected from the inflator 32 is supplied to the belt support airbag 42 through the gas supply pipe 34. Figure 11B As shown, gas is supplied to the interior of the belt-supported air bag 42 in a folded state, which is housed in the cover member 40 and arranged on the occupant P side (back side) of the shoulder belt 22A.

[0070] Then, if Figures 1 to 3 as well as Figure 12A As shown, the belt-supported air bag 42 is inflated and deployed so as to extend 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-supported air bag 42 is arranged between the shoulder belt 22A and at least both shoulders Ps (including the clavicle) of the occupant P, in other words, behind the shoulder belt 22A and in front of both shoulders Ps of the occupant P.

[0071] like Figure 12B As shown, in the event of a frontal collision of the vehicle, the belt-supported air bag 42 moves forward along with the occupant P who moves forward due to the inertial force caused by the impact, and restrains at least both shoulders Ps, including the clavicle, of the occupant P. That is, the shoulder belt 22A serves as a member that receives the reaction force of the belt-supported air bag 42.

[0072] At this time, the expandable portion 34A of the gas supply tube 34 for supplying gas from the inflator 32 to the belt-supported airbag 42 expands as the belt-supported airbag 42 moves forward. Therefore, regardless of the physique of the occupant P, the belt-supported airbag 42 can be continuously held between the shoulder belt 22A and the shoulders Ps of the occupant P, and at least the shoulders Ps of the occupant P can be effectively restrained from the front half to the rear half of the occupant restraint, while problems such as rupture of the gas supply tube 34 (gas leakage) can be suppressed or prevented.

[0073] As described above, through the vehicle occupant restraint device 10 according to the first embodiment, even with a simple structure in which a predetermined area portion of the gas supply pipe 34 on the side supporting the air bag 42 is used as a bellows-shaped inflatable portion 34A and is able to stretch following the forward movement of the occupant P, the occupant P can be effectively restrained when a frontal collision of the vehicle occurs.

[0074] Furthermore, the belt-supporting airbag 42 can generate an appropriate restraining force at an early stage on the shoulder Ps on the opposite shoulder belt side from which the shoulder belt 22A is not suspended. In other words, the belt-supporting airbag 42 can distribute the localized load input from the shoulder belt 22A to the occupant P to both shoulders Ps at an early stage. Thus, even with a simple configuration, the input of the localized load from the shoulder belt 22A to the chest Pc of the occupant P can be reduced, and both shoulders Ps of the occupant P can be effectively restrained.

[0075] Furthermore, the thickness of the inflated and deployed belt-supported airbag 42 allows the shoulder belt 22A to be lifted from 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. Consequently, the localized load input from the shoulder belt 22A to the chest Pc of the occupant P can be reduced. Consequently, the magnitude of chest damage caused by the shoulder belt 22A hindering forward movement can be reduced, particularly for occupants with relatively low chest resistance, such as women or the elderly.

[0076] The expandable portion 34A of the gas supply pipe 34 is provided with a support member 36 that limits excessive expansion. This prevents a decrease in gas supply capacity (gas pressure) due to excessive expansion of the expandable portion 34A of the gas supply pipe 34, and prevents the expandable portion 34A from expanding and rupturing. Furthermore, excessive expansion of the expandable portion 34A of the gas supply pipe 34 near the head of the occupant P can be suppressed or prevented.

[0077] The retractor 28 is equipped with a force limiter mechanism. Here, the expandable portion 34A of the gas supply tube 34 expands under a load lower than the force limiter load of the force limiter mechanism. This can suppress or prevent the gas supply tube 34 from interfering with the operation of the force limiter mechanism. As a result, the behavior of the occupant P can be easily controlled.

[0078] In a normal state, the inflatable portion 34A of the gas supply pipe 34 and the folded belt-supported airbag 42 are housed in the cover member 40 in a state arranged on the occupant P side of the guide member 38. That is, the inflatable portion 34A of the gas supply pipe 34 and the folded belt-supported airbag 42 are provided outside the vehicle seat 12. Therefore, there is no need to provide a complex structure inside the vehicle seat 12.

[0079] Furthermore, the inflatable portion 34A of the gas supply tube 34 and the folded belt-supported airbag 42 are covered by the cover member 40 and are hidden from the outside, thereby suppressing or preventing deterioration of the appearance of the vehicle seat 12. This effect is particularly enhanced when the cover member 40 is a specially designed cover. Under normal conditions, unnecessary contact between the cover member 40 and the inflatable portion 34A of the gas supply tube 34 or the folded belt-supported airbag 42 is avoided, thereby ensuring durability.

[0080] Furthermore, when the expandable portion 34A of the gas supply pipe 34 is accommodated in the cover member 40, the bellows-shaped portion is shortened (see FIG. Figure 5 ). As a result, the size of the accommodation space is reduced to near the shoulder Ps of the occupant P, and the accommodation performance is improved. In addition, when the belt-supported airbag 42 inflates and deploys, the bellows-shaped portion of the inflatable portion 34A of the gas supply pipe 34 stretches and expands to a predetermined outer diameter. Therefore, gas can be supplied to the belt-supported airbag 42 quickly, sufficiently, and stably. Moreover, when the belt-supported airbag 42 moves forward, the bellows-shaped portion of the inflatable portion 34A of the gas supply pipe 34 further stretches and contracts to a predetermined inner diameter. Therefore, the gas supplied to the belt-supported airbag 42 is less likely to return to the inflator 32 side.

[0081] The inflatable portion 34A of the gas supply tube 34 can be housed in the cover member 40 in a collapsed shape along the inner surface of the shoulder belt 22A on the occupant P side (see FIG. Figure 10 ). Therefore, the expandable portion 34A of the gas supply tube 34 can function as a cushioning member, making it possible to improve the wearability of the shoulder strap 22A portion when the shoulder strap 22A is worn.

[0082] The shoulder belt 22A is movably inserted through the guide member 38 housed in the cover member 40, and does not come into contact with the inflatable portion 34A of the gas supply tube 34. Therefore, when tightening or removing the seat belt 22, no external force, such as a tensile load, is applied to the inflatable portion 34A of the gas supply tube 34, and the seat belt 22 can move smoothly. Furthermore, the guide member 38 prevents the seat belt 22 from being incorrectly worn in a twisted state.

[0083] The inflator 32 is embedded in the seat back 16 of the vehicle seat 12 together with the retractor 28. That is, the various components constituting the vehicle occupant restraint device 10, including the seat belt 22, are provided on the vehicle seat 12. Therefore, the various components constituting the vehicle occupant restraint device 10 can be installed solely on the vehicle seat 12. As a result, the vehicle occupant restraint device 10 can be easily installed in the vehicle by simply installing the vehicle seat 12, and assembly workability during vehicle assembly can be improved.

[0084] Second embodiment

[0085] Next, the second embodiment will be described. The same reference numerals are given to the same components as those of the first embodiment, and detailed descriptions (including common functions) will be omitted as appropriate.

[0086] like Figures 13 to 15As shown, in the second embodiment, only the shape of the belt-supported airbag differs from the first embodiment. Specifically, the belt-supported airbag 44 is formed into a bag shape by overlapping two base fabrics having a generally triangular shape in a front view in the front-back direction and sewing the peripheral edges of the two base fabrics together. After inflation and deployment, the belt-supported airbag 44 has a generally right-angled triangle shape in a front view, with the side of the buckle 26 forming the hypotenuse of the right-angled triangle. Each base fabric is formed, for example, from a polyamide-based fabric material or a polyester-based fabric material.

[0087] The belt-supported airbag 44 is secured by a plurality of (eg, two) tethers 46, 48 (see FIG. Figure 15 ) is divided into a plurality of chambers (e.g., three chambers) extending in the seat width direction. Specifically, two fabric-like tethers 46 and 48, longitudinally extending in the seat width direction, are attached to the interior of the belt-supported airbag 44 in the vertical direction with a gap therebetween. The tethers 46 and 48 are also formed, for example, of a polyamide-based fabric material or a polyester-based fabric material.

[0088] An opening (not shown) is formed on the outside of tether 46 in the vehicle width direction, and gas can be supplied from upper chamber 44U partitioned by tether 46 to middle chamber 44C. Similarly, an opening (not shown) is formed on the outside of tether 48 in the vehicle width direction, and gas can be supplied from middle chamber 44C partitioned by tether 48 to lower chamber 44D. Upper chamber 44U and middle chamber 44C are each provided with a check valve structure (not shown) for maintaining internal pressure.

[0089] With the belt-supported airbag 44 having such a configuration, when gas is supplied from the inflator 32 via the gas supply pipe 34, gas is first supplied to the upper chamber 44U, causing the upper chamber 44U to inflate and deploy. Subsequently, when the inflated and deployed upper chamber 44U is sealed by the check valve structure, gas is supplied to the middle chamber 44C through the opening of the upper tether 46, causing the middle chamber 44C to inflate and deploy. Thereafter, when the inflated and deployed middle chamber 44C is sealed by the check valve structure, gas is supplied to the lower chamber 44D through the opening of the lower tether 48, causing the lower chamber 44D to inflate and deploy.

[0090] As a result, the belt-supported airbag 44 is sequentially supplied with gas from the upper chamber 44U through the middle chamber 44C to the lower chamber 44D, and is arranged to inflate and deploy at least between the shoulder belt 22A and the chest Pc of the occupant P (in other words, behind the shoulder belt 22A and in front of the occupant P). In the event of a frontal collision of the vehicle, the inflated and deployed belt-supported airbag 44 moves forward with the occupant P, who moves forward due to the inertial force caused by the impact, and restrains at least the chest Pc of the occupant P. That is, in this case as well, the shoulder belt 22A serves as a member that receives the reaction force of the belt-supported airbag 44.

[0091] By supporting the air bag 44 with such a configuration, the local load applied by the shoulder belt 22A to the chest Pc of the occupant P is dispersed over a wide area of ​​the chest Pc of the occupant P and reduced. Therefore, the level of chest damage caused by the shoulder belt 22A hindering forward movement can be reduced, particularly for an occupant with relatively low chest resistance, such as a female or an elderly person.

[0092] Furthermore, by the belt-supported airbag 44 , for example, even if the occupant P seated in the vehicle seat 12 (e.g., the driver's seat or the passenger seat) during automatic driving adopts a seat position that is away from a steering wheel (not shown) or away from a front-impact airbag (not shown) that inflates and deploys toward the front of the occupant P, the occupant P can be effectively restrained. That is, by the belt-supported airbag 44 , the occupant P can be effectively restrained regardless of the seat position of the vehicle seat 12 at the time of a frontal collision of the vehicle.

[0093] In the belt-supported airbag 44, the upper chamber 44U is inflated and deployed first. This stabilizes the position of the shoulder belt 22A and effectively creates a predetermined gap between the shoulder belt 22A and the occupant P. Consequently, the inflation and deployment of each chamber, from the upper chamber 44U through the middle chamber 44C to the lower chamber 44D, can be performed smoothly.

[0094] Although the vehicle occupant restraint device 10 according to the present embodiment has been described based on the drawings, the vehicle occupant restraint device 10 according to the present embodiment is not limited to the illustrated examples, and the design can be appropriately modified within the scope that does not depart from the gist of the present invention. For example, the second end portion of the gas supply pipe 34 may be configured to protrude through the decorative ring 24.

[0095] The expandable portion 34A of the gas supply pipe 34 is not limited to being multi-layer (three-layer) and can be constructed as a single layer, for example. The expandable portion 34A of the gas supply pipe 34 is not limited to being formed into a bellows shape. For example, the outer layer 34B included in the expandable portion 34A of the gas supply pipe 34 can be formed of a knitted fiber as long as the outer layer 34B has sufficient stretchability or an effect of suppressing excessive expansion.

[0096] The cover member 40 can accommodate at least the inflatable portion 34A of the gas supply tube 34 and the folded belt supporting airbag 42, and, for example, the lower end portion of the guide member 38 can protrude from the cover member 40. In this embodiment, the guide member 38 is accommodated in the cover member 40 even in this case.

[0097] The belt-supported airbags 42 and 44 are not limited to a structure in which two base fabrics are overlapped and the peripheral edges are sewn together, and may have a structure in which three or more base fabrics are used and the peripheral edges are sewn together. 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 may also be used.

Claims

1. A vehicle occupant restraint device, characterized in that include: a seat belt configured to restrain an occupant seated in a vehicle seat to the vehicle seat; a belt-supported airbag configured to, in the event of a frontal collision of the vehicle, inflate and deploy at least between a shoulder belt in the seat belt and a shoulder of the occupant by supplying gas from an inflator, thereby moving toward the front of the vehicle as the occupant moves toward the front of the vehicle due to inertial force and restraining at least the shoulder of the occupant; as well as a gas supply tube having a first end connected to the inflator and a second end connected to the belt-supported airbag, wherein a predetermined region of the gas supply pipe on the second end side is configured to expand as the belt-supported airbag moves toward the front side of the vehicle.

2. The vehicle occupant restraint device according to claim 1, characterized in that Also included is a cover member, wherein: a bellows-shaped expandable portion is provided in the predetermined region of the gas supply pipe; and The inflatable portion of the gas supply pipe and the folded belt-supported airbag are accommodated in the cover member.

3. The vehicle occupant restraint device according to claim 2, characterized in that: the bellows-shaped expandable portion being configured to contract when the bellows-shaped expandable portion is accommodated in the cover member; the bellows-shaped inflatable portion is configured to stretch and expand to a predetermined outer diameter when the belt-supported airbag is inflated and deployed; and The bellows-shaped inflatable portion is configured to further expand and contract to a predetermined inner diameter when the belt-supported air bag moves toward the front side of the vehicle.

4. The vehicle occupant restraint device according to claim 3, characterized in that: The expandable portion of the gas supply pipe is provided with a support member that restricts excessive expansion.

5. The vehicle occupant restraint device according to claim 2, characterized in that: When the inflatable portion is accommodated in the cover member, the inflatable portion of the gas supply tube is formed into a flattened shape along the shoulder strap.

6. The vehicle occupant restraint device according to any one of claims 2 to 5, characterized in that: The shoulder belt is movably inserted through a guide member accommodated in the cover member and does not come into contact with the inflatable portion of the gas supply pipe.

7. The vehicle occupant restraint device according to any one of claims 2 to 5, characterized in that: a force limiter mechanism provided in a retractor that reels the seat belt; and The expandable portion of the gas supply tube is configured to expand under a load lower than a force limiter load of the force limiter mechanism.

8. The vehicle occupant restraint device according to claim 7, characterized in that: The inflator is embedded in a seat back of the vehicle seat together with the retractor.

9. The vehicle occupant restraint device according to claim 1, characterized in that: a bellows-shaped expandable portion is provided in the predetermined region of the gas supply pipe; and The inflatable portion is provided between a seat back and the belt-supported airbag.

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