Occupant protection device

An occupant protection device is such that an airbag is housed in a housing region of a lap belt portion that can be disposed on a front side of a waist portion of an occupant seated in a seat. The airbag can receive and protect an upper body of the occupant using a rear face side occupant restraining face when inflation is completed. The airbag includes an exhaust port that can discharge an inflating gas and a regulating valve mechanism that restricts a discharge of the inflating gas from the exhaust port. The regulating valve mechanism permits a discharge of the inflating gas from the exhaust port when a protrusion upward of the airbag from the housing portion is restricted, and restricts a discharge of the inflating gas from the exhaust port when a protrusion upward of the airbag from the housing portion is not restricted.

The present application claims priority from Japanese Patent Application No. 2021-159078 of Matsuzaki et al, filed on Sep. 29, 2021 the disclosures of which are hereby incorporated into the present application by reference.

BACKGROUND

1. Field of the Invention

The present invention relates to an occupant protection device for protecting an occupant seated in a seat.

2. Description of Related Art

As an existing occupant protection device, there is an occupant protection device such that an airbag that inflates owing to an inflating gas being caused to flow in is disposed in a lap belt portion of a seat belt, thereby protecting an occupant seated in a seat (refer to JP-A-2015-5174). The lap belt portion is a belt region disposed on a front side of a waist portion of an occupant seated in a seat, in a state wherein left and right ends are coupled to a left and a right of the seat. The occupant protection device is such that an airbag is housed folded in a housing region provided in the lap belt portion, and when operating, the airbag inflates owing to an inflating gas being caused to flow in, and the completely inflated airbag protects an upper body of an occupant moving forward by receiving the upper body with a rear face side occupant restraining face, in a state wherein a lower face side supported face is supported by a thigh portion of the occupant.

The existing occupant protection device is such that when fixing a child seat to a seat using the seat belt, the lap belt portion is passed through a through hole portion penetrating to the left and right on a bottom face side of a sitting portion of the child seat, after which the child seat can be fixed to the seat, disposed from a backrest portion to the sitting portion of the seat, by coupling the left and right ends of the lap belt portion to the left and right of the seat. However, the occupant protection device is such that an inflating airbag is housed in the lap belt portion of the seat belt. This means that when a vehicle crashes, and the airbag housed in the lap belt portion inflates in such a way as to protrude, in a state wherein the child seat is fixed to a seat, the child seat is pushed up, which is undesirable.

Consequently, an occupant protection device is such that when protrusion of an airbag housed in a lap belt portion is restricted, it is preferable that protrusion of the airbag can be restricted by discharging the inflating gas.

SUMMARY

An occupant protection device according to an embodiment is formed to include a lap belt portion disposed, in a state wherein left and right ends are coupled to a left and right of a seat, on a front side of a waist portion of an occupant seated in the seat, and an airbag that is housed folded up in a housing region of the lap belt portion and, when inflation is completed by an inflating gas being caused to flow in, has a lower face side as a supported face that is supported by a thigh portion of the occupant, and a rear face side as an occupant restraining face that receives an upper body of the occupant who moves forward. The airbag includes an exhaust port that can discharge the inflating gas flowing in, and a regulating valve mechanism that opens and closes the exhaust port. The regulating valve mechanism permits a discharge of the inflating gas from the exhaust port when a protrusion upward from the housing portion when the airbag inflates is restricted, and restricts a discharge of the inflating gas from the exhaust port when a protrusion upward from the housing portion when the airbag inflates is not restricted.

DETAILED DESCRIPTION

Preferred embodiments of the present invention are described below with reference to accompanying drawings. However, the invention is not limited to the embodiments disclosed herein. All modifications within the appended claims and equivalents relative thereto are intended to be encompassed in the scope of the claims.

An occupant protection device10of an embodiment is mounted on a seat1of a vehicle, as shown inFIGS.1to6. The occupant protection device10of the embodiment includes a seat belt11, an airbag30, an inflator24that supplies an inflating gas to the airbag30, and a regulating valve mechanism45. The regulating valve mechanism45discharges the inflating gas from the airbag30when the inflated airbag30interferes with an obstacle (for example, a child seat90(refer toFIGS.12and13)). The seat1includes a backrest portion2and a sitting portion5.

The seat belt11restrains an occupant MP seated in the seat1. The seat belt11is such that an upper end11aside is disposed on one left-right direction side (the left side in the embodiment) of the seat1, and can be fed out from a retractor15. The retractor15is disposed in an interior on a left edge3aside of an upper end3of the backrest portion2. Also, the seat belt11is such that a lower end11bside is fixed as a fixed end to an anchoring member17disposed on a left side portion6side of the sitting portion5.

A member with a reference sign18shown inFIGS.1and2is a retaining member, and the retaining member18retains the seat belt11in such a way that the seat belt11does not become detached from the left side portion6of the sitting portion5by enabling the seat belt11to pass through.

A tongue20is disposed in an intermediate region of the seat belt11. The tongue20is fastened to a buckle19. The buckle19is disposed on a right side portion7side of the sitting portion5on another left-right direction side (the right side in the embodiment) of the seat1. Further, the seat belt11is such that, in a state wherein the tongue20is fastened to the buckle19, a region extending to the retractor15side from the tongue20is a shoulder belt portion12disposed on a front face side of an upper body (chest portion) MB of the occupant MP, and a region extending from the tongue20to the fixed end11bside is a lap belt portion13disposed on a front face side of a waist portion MW of the occupant MP. An unshown release button is disposed in the buckle19. This means that by carrying out an operation of pressing the release button when unfastening the tongue20fastened to the buckle19, the tongue20can be removed from the buckle19. Also, when there is an abrupt withdrawal of the seat belt11, the retractor15causes the withdrawal to stop. Furthermore, the retractor15incorporates an unshown pretensioner. Because of this, the seat belt11is wound in by the pretensioner when there is a vehicle collision or the like.

The inflator24is attached to and fixed to a rear face side of the sitting portion5of the seat1(refer toFIGS.1and2). The inflator24includes an inflator main body25of an approximately cylindrical form, which emits an inflating gas, and a pipe portion26, which protrudes from the inflator main body25and bends in an approximate L-form. A leading end portion38bside of a conduit portion38connected to the airbag30is mounted externally, and coupled to the pipe portion26using a clamp27.

The conduit portion38is such that a base portion38aside is coupled to an inlet portion37for causing an inflating gas of the airbag30to flow in.

The airbag30is housed as a folded up folded body77in a housing region22of the lap belt portion13in the seat belt11. The housing region22is a vicinity of a left-right direction center on an upper face13aside of the lap belt portion13. The folded body77is disposed in the housing region22of the lap belt portion13wrapped in a cover82that breaks when the airbag30inflates. The conduit portion38is connected to the folded body77when housed. Specifically, the conduit portion38extends from the inflator24, and is for causing an inflating gas from the inflator24to flow into the airbag30. Further, the conduit portion38is connected to the inlet portion37of the airbag30that is the folded body77.

The airbag30is formed from a woven fabric having flexibility, such as polyester. In the same way as the airbag30, the conduit portion38is also formed from a woven fabric having flexibility, such as polyester. Also, a valve body46and a strap50, to be described hereafter, configuring the regulating valve mechanism45are also formed from a woven fabric having flexibility, such as polyester.

The airbag30is of a configuration such that, when completely inflated, a peripheral wall31inflates into an approximately triangular prismatic form as seen from a side. The peripheral wall31includes a bottom face side bottom wall portion32, a rear face side rear wall portion33, a front face side front wall portion34, and left and right side wall portions35(L and R). Further, the airbag30when completely inflated is such that a lower face side of the bottom wall portion32is a supported face32athat is supported by a thigh portion MF of the occupant MP, and a rear face side of the rear wall portion33is an occupant restraining face33a. Further, the airbag30protects the upper body MB of the occupant MP who moves forward by receiving the upper body MB with the occupant restraining face33a.

The inlet portion37is disposed in a vicinity of a rear edge of the bottom wall portion32(refer toFIGS.6to8). The inlet portion37includes a multiple of inlets37afor causing an inflating gas from the conduit portion38to flow in. Also, a venthole40through which excess inflating gas flowing into the airbag30is discharged is disposed in front sides of the left and right side wall portions35L and35R.

Furthermore, an exhaust port41through which inflating gas is discharged is disposed in the right side wall portion35R of the airbag30. Inflating gas is discharged through the exhaust port41in such a way as to restrict inflation when the airbag30interferes with an obstacle while inflating. The valve body46and the strap50are disposed on a peripheral edge of the exhaust port41. The valve body46and the strap50configure the regulating valve mechanism45. The regulating valve mechanism45enables the exhaust port41to open and close, and permits a discharge of inflating gas from the exhaust port41when a protrusion upward of the airbag30from the housing region22when operating (when inflating) is restricted. Also, the regulating valve mechanism45restricts a discharge of inflating gas from the exhaust port41when a protrusion upward of the airbag30from the housing region22when operating is not restricted.

Further, the valve body46is a tubular body47having flexibility. The valve body46is such that a base portion46ais joined to the peripheral edge of the exhaust port41. Specifically, the tubular body47acting as the valve body46is formed of two valve body base fabrics70and70of the same trapezoidal form, as shown inFIGS.7,10A,10B,10C,11A,11B, and11C. Further, the valve body46is formed by a base side edge70aon a bottom side side of the valve body base fabric70being sewn to an inner peripheral edge of the exhaust port41, and by leading side edges70bof the valve body base fabrics70and70, and side edges70cand70c, being sewn to each other.

One end side of the strap50is coupled as a valve body side end portion51to a leading end portion46bof the valve body46. When the leading side edges70bof the valve body base fabrics70and70are sewn to each other, the valve body side end portion51is sewn together with the leading side edges70b(sewn coinciding with the leading side edges70b). Because of this, the valve body side end portion51is coupled to the leading end portion46bside of the valve body46. Also, another end side of the strap50is coupled as a peripheral wall side end portion52to the left side wall portion35L on a side opposite to that of the exhaust port41. When outer peripheral edges61and65aof a front side base fabric60and a rear side base fabric63, to be described hereafter, configuring the peripheral wall31of the airbag30are sewn together, the peripheral wall side end portion52is sewn together with the outer peripheral edges61and65a, thereby being coupled to the left side wall portion35L side.

Further, the valve body46of the regulating valve mechanism45is such that a multiple (two in the embodiment) of vents40are formed opening in a circular form penetrating inner and outer peripheries in a vicinity of the leading end portion46b. The vents48are disposed in vicinities of the leading side edges70bof the two valve body base fabrics70and70. As shown inFIG.10CandFIG.11C, a state wherein the exhaust port41closed by the valve body46is such that when the leading end portion46bof the valve body46is pulled strongly into the airbag30due to being pulled by the strap50, peripheral walls of peripheral edges on the base portion46aside, that is, inner peripheral face47asides of the tubular body47, are pressed together in such a way as to come into close contact with each other by pressure of an inflating gas G (in the embodiment, the valve body base fabrics70and70are brought into close contact superimposed one on the other). As a result of this, an inner peripheral side of the exhaust port41of the airbag30is closed. Meanwhile, as shown inFIG.10BandFIG.11B, an opened state of the exhaust port41is such that when a state wherein the valve body46is not subjected to pulling by the strap50exists, the valve body46is pushed out from the exhaust port41by the pressure of the inflating gas G. That is, the tubular body47is pushed outside the airbag30in such a way as to cause a vicinity of the vents48to be disposed farther to an outer side of the airbag30than the exhaust port41. As a result of this, the inflating gas G inside the airbag30is discharged to the outside of the airbag30from the exhaust port41, while passing through the vents48, and the exhaust port41attains an opened state.

A length dimension of the regulating valve mechanism45from the valve body side end portion51to the peripheral wall side end portion52of the strap50is as follows. Firstly, when inflation of the airbag30is completed, the length dimension is a length dimension such that the valve body46can be pulled strongly into the airbag30(a length dimension such that the exhaust port41can be closed), within a range such that restraining of the occupant MP by the occupant restraining face33ais not impeded. Also, when inflation of the airbag30is restricted, that is, when swelling of the side wall portion35R to which the peripheral wall side end portion52is coupled is restricted, and an amount of movement of the peripheral wall side end portion52is slight, the length dimension is a length dimension such that the valve body46is not pulled (a length dimension such that the exhaust port41can be opened).

As shown inFIG.7, the peripheral wall31of the airbag30is formed of the rear side base fabric63and the front side base fabric60. The rear side base fabric63configures the rear wall portion33, the bottom wall portion32, and, a rear portion side of the left and right side wall portions35(L and R) of the peripheral wall31(refer toFIGS.4to6). The front side base fabric60configures the front wall portion34, and, a front portion side of the left and right side wall portions35(L and R) (refer toFIGS.4to6). The rear side base fabric63is provided with slits63aand63aon the left and right, and includes an upper side portion64of an approximately hexagonal plate form on an upper side of the slit63a, and a lower side portion65of an approximately hexagonal plate form on a lower side of the slit63a. The front side base fabric60is of a large hexagonal plate form. Further, the peripheral wall31is formed by firstly providing the venthole40and the inlet37ain the rear side base fabric63, then sewing opposing edges64band65b, which are opposed in a region of the slit63aof the rear side base fabric63, to each other. Next, the upper side portion64, excepting the region of the slit63a, and the lower side portion65are flattened, and the front side base fabric60is placed thereon. Then, the peripheral wall31can be formed by coinciding outer peripheral edges61,64a, and65abeing sewn to each other. An upper side outer peripheral edge61aof the front side base fabric60is of the same form as the outer peripheral edge64aof the upper side portion64of the rear side base fabric63, and in the same way, a lower side outer peripheral edge61bof the front side base fabric60is of the same form as the outer peripheral edge65aof the lower side portion65of the rear side base fabric63. Because of this, sewing together of the front side base fabric60and the rear side base fabric63can be carried out easily by superimposing the front side base fabric60and the rear side base fabric63one on the other. Also, the conduit portion38, to which a belt attachment portion80that is not of tubular form is attached, is attached in advance to the inlet portion37provided with the inlet37aof the rear side basic fabric63. The conduit portion38is formed by outer peripheral edges of an outer side material38cand a bag side material38d, whose external forms are the same, being sewn to each other. The bag side material38dis sewn to an outer peripheral face side of the inlet portion37, and includes a communication port38dathat communicates with the inlets37aand37a.

Also, in the case of the embodiment, the base side edge70aof the valve body base fabric70is sewn to each of regions61baand65aa(refer toFIG.7) of the lower side outer peripheral edge61bof the front side base fabric60of a region in which the exhaust port41is formed and the outer peripheral edge65aof the lower side portion65of the rear side base fabric63, in a vicinity of the exhaust port41. At this time, the region of the exhaust port41is not closed. Further, the lower side outer peripheral edge61bof the front side base fabric60on a peripheral edge of the exhaust port41and the outer peripheral edge65aof the lower side portion65of the rear side base fabric63are sewn together. Also, the valve body base fabrics70and70are such that the side edges70cand70care sewn to each other, and the leading side edges70band70bare sewn to each other together with the valve body side end portion51of the strap50. The peripheral wall side end portion52of the strap50is sewn together with strap coupling regions61bband65ab(refer toFIG.7) when the lower side outer peripheral edge61bof the front side base fabric60and the outer peripheral edge65aof the lower side portion65of the rear side base fabric63are sewn together. Further, the peripheral wall31of the airbag30provided with the conduit portion38can be formed by the lower side outer peripheral edge61bof the front side base fabric60and the outer peripheral edge65aof the lower side portion65of the rear side base fabric63being sewn together, and the upper side outer peripheral edge61aof the front side base fabric60and the outer peripheral edge64aof the upper side portion64of the rear side base fabric63being sewn together.

The folded body77of the airbag30housed in the housing region22is formed as shown inFIGS.8,9A,9B,9C and9D. Firstly, as shown inFIG.8, the front wall portion34and the rear wall portion33opposed in a front-rear direction of the airbag30when inflation is completed are superimposed one on the other, and furthermore, in the case of the embodiment, a crease73in the left-right direction is formed, and a folding in two is carried out on the front wall portion34side, whereby a flattened initial stage airbag72is formed. In other words, the initial stage airbag72is formed by folding the front wall portion34in two while flattening a vicinity of the inlet portion37that causes the inflating gas G to flow into the airbag30, superimposing the rear wall portion33, which is a peripheral wall region of the airbag30, above the vicinity of the inlet portion37, and flattening. Further, when forming the initial stage airbag72, the strap50is disposed in the left-right direction. Also, while disposing the vents46in a vicinity of the exhaust port41, the base portion46aside of the valve body46is put into a state pushed to the outside of the airbag30from the exhaust port41. Furthermore, the peripheral wall side end portion52of the strap50is put into a state placed inside the airbag30in such a way as to approach the valve body46side. Next, as shown inFIG.9A, a width direction reduced body75is formed by both edges72aand72bin the left-right direction, which is a width direction of the initial stage airbag72, being folded to a central side using a width direction reduction fold. The width direction reduction fold may be omitted when a left-right direction width dimension of the folded body77or the housing region22can be increased.

Subsequently, as shown inFIGS.9A,9B, and9C, the folded body77is formed by end edges75aand75bbeing folded in a direction perpendicular to the left-right direction of the width direction reduced body75using a longitudinal direction reduction fold that causes the end edges75aand75bsuperimposed one on the other, to approach the inflating gas G inlet portion37side disposed on the supported face32aside of the airbag30, then wrapped in a breakable tape material78that prevents unraveling. The folded body77is a columnar body having an axial center X in the left-right direction.

The folded body77formed in this way is such that the belt attachment portion80is disposed in the housing region22of the lap belt portion13of the seat belt11, then the belt attachment portion80is sewn in such a way as to enclose the housing region22, whereby a circular insertion hole80ais formed. Next, by enclosing the folded body77, together with the belt attachment portion80and the lap belt portion13, with the cover82, the folded body77can be installed in the lap belt portion13of the seat belt11(refer toFIG.3). Furthermore, the leading end portion38bof the conduit portion38extending from the folded body77is connected to the pipe portion26extending from the inflator main body25of the inflator24. As a result of this, the occupant protection device10can be mounted on the seat1.

The occupant protection device10of the embodiment is activated when a vehicle crashes, or the like, in a state wherein the occupant MP seated in the seat1has fastened the seat belt11. At this time, the lap belt portion13is disposed on the front side of the waist portion MW of the occupant MP seated in the seat1. Further, inflating gas from the inflator24flows into the airbag30from the inlet37aof the inlet portion37via the conduit portion38.

At this time, as shown inFIGS.3to6, a protrusion upward of the airbag30is not restricted provided that there is no obstacle disposed above the housing region22. Because of this, the airbag30inflates in such a way as to protrude upward smoothly from the housing region22, eliminating the folds, while breaking the tape material78and the cover82. That is, when the airbag30inflates, the peripheral wall31swells, the peripheral wall side end portion52of the strap50in the regulating valve mechanism45moves in accompaniment to the inflation of the left side wall portion35L, and the strap50pulls the valve body46in the regulating valve mechanism45into the airbag30, as shown inFIG.10AandFIG.11AtoFIG.10CandFIG.11C. Because of this, the pressure of the inflating gas G is caused to act, and the tubular body47of the valve body46is crushed to an inner peripheral side, because of which the regulating valve mechanism45closes the exhaust port41, thereby restricting a discharge of the inflating gas G from the exhaust port41. Further, the airbag30completes inflation swiftly, without inflating gas being discharged from the exhaust port41. As a result of this, the airbag30can protect the occupant MP by receiving the upper body MB of the occupant MP who moves forward with the rear face side occupant restraining face33a, in a state wherein the lower face side supported face32ais supported by the thigh portion MF of the occupant MP.

Meanwhile, the occupant protection device10of the embodiment is such that there is a case wherein a child seat90is disposed on the seat1utilizing the seat belt11, as shown inFIG.12. In this case, the lap belt portion13is passed through a through hole portion94penetrating to the left and right on a bottom face side of a sitting portion92of the child seat90, and the tongue20is fastened to the buckle19, whereby the left and right ends of the lap belt portion13are coupled to the left and right of the seat1. Owing to this kind of operation, the child seat90is disposed from the backrest portion2of the seat1to the sitting portion5, and is fixed to the seat1. The shoulder belt portion12of the seat belt11is such that the retractor15side distanced from the tongue20is sandwiched in a holding tool95. The holding tool95is disposed on an upper portion94aside of the left side face side through hole portion94of the child seat90.

When the child seat90is fixed to the seat1utilizing the seat belt11in this way, the housing region22of the airbag30in the lap belt portion13is in a condition blocked from above by a rear face93aof a frame93of the child seat90in a vicinity of a central portion94cbetween the upper end portion94aand a front end portion94bof the through hole94. This means that when the occupant protection device10attempts to operate in this condition, that is, when the airbag30attempts to protrude upward from the housing region22, the airbag30comes into contact with the rear face93aof the frame93of the child seat90, and protrusion upward from the housing region22is restricted. Thereupon, the regulating valve mechanism45permits a discharge of the inflating gas G from the exhaust port41, the inflating gas G is discharged from the exhaust port41, and inflation of the airbag30is restricted. That is, the regulating valve mechanism45enables the exhaust port41to open and close, permits a discharge of the inflating gas G from the exhaust port41when a protrusion upward of the airbag30from the housing region22when operating is restricted, and restricts a discharge of the inflating gas G from the exhaust port41when a protrusion upward of the airbag30from the housing region22when operating is not restricted. This means that when the lap belt portion13is disposed on a lower portion side of the child seat90in such a way as to attach the child seat90to the seat1, and a protrusion upward of the airbag30is restricted, the regulating valve mechanism45permits a discharge of the inflating gas G from the exhaust port41. Because of this, the inflating gas G is discharged from the exhaust port41(refer toFIG.14), and inflation of the airbag30is restricted. As a result of this, a pushing up of the child seat90by the airbag30is prevented, and a problem such as the child seat90being thrown around is prevented.

Consequently, the occupant protection device10of the embodiment is such that when a protrusion of the airbag30housed in the lap belt portion13is restricted, protrusion of the airbag30can be restricted by the inflating gas G being discharged. Further, when a protrusion of the airbag30is not restricted, the airbag30completes inflation smoothly, and can protect the occupant MP.

Further, the occupant protection device10of the embodiment is such that the regulating valve mechanism45is configured of the tubular valve body46, which has flexibility, and the strap50, which has flexibility. The valve body46is disposed on the peripheral edge of the exhaust port41on an inner peripheral face side of the airbag30. The strap50is such that the valve body side end portion51on one end side is coupled to the leading end portion46bside of the valve body46distanced from the base portion46aon the peripheral edge of the exhaust port41, and the peripheral wall side end portion52on the other end side is coupled to the peripheral wall31of the airbag30. Further, the regulating valve mechanism45is such that when a tensile force of the peripheral wall31of the airbag30acts on the strap50when the airbag30inflates, the valve body46is pulled into the airbag30by the strap50, and the peripheral wall (tubular body)47of the valve body46, which receives the pressure of the inflating gas G, closes the exhaust port41in such a way that the inner peripheral faces47aare brought into close contact with each other. Also, the regulating valve mechanism45is such that when the tensile force of the peripheral wall31of the airbag30does not act on the strap50when the airbag30inflates, the opened state of the exhaust port41is maintained, without the valve body46being pulled into the airbag30.

Because of this, the embodiment is such that when the airbag30inflates without inflation being restricted, the peripheral wall31of the airbag30swells, and the peripheral wall side end portion52of the strap50of the regulating valve mechanism45is pulled, as shown inFIG.10AandFIG.11AtoFIG.10CandFIG.11C. Further, the valve body46coupled to the valve body side end portion51of the strap50is pulled into the airbag30, and the valve body46closes the exhaust port41. Because of this, a discharge of the inflating gas C from the exhaust port41is restricted, and the airbag30completes inflation smoothly. Meanwhile, when the airbag30attempts to inflate in a restricted state, no tensile force acts on the strap50, and at least one portion of the valve body46is in a state pushed to the outside of the airbag30from the exhaust port41, as shown inFIG.10AandFIG.11AtoFIG.10BandFIG.11B. Because of this, the valve body46does not close the exhaust port41, the inflating gas C is discharged from the exhaust port41, and inflation of the airbag30is restricted. That is, the regulating valve mechanism45is configured of two members, those being the tubular valve body46, which is joined the peripheral edge of the exhaust port41and has flexibility, and the strap50, which is coupled to the valve body46and the peripheral wall31of the airbag30and has flexibility, meaning that the regulating valve mechanism45can be configured simply.

In this case, in the embodiment, the valve body46is such that the multiple of vents48are opened penetrating the inner and outer peripheries in the peripheral wall in a vicinity of a region coupled to the strap50.

Because of this, the embodiment is such that when inflation of the airbag30is restricted, that is, when the strap50swells and at least one portion of the valve body46is pushed to the outside of the airbag30from the exhaust port41, the inflating gas G flows into the tubular region (tubular body)47of the valve body46extended from the peripheral edge of the exhaust port41(refer toFIG.10B), then the inflating gas G that has flowed in is discharged smoothly to the outside of the airbag30via the multiple of vents48. This means that provided that the valve body46includes the multiple of vents48, restricting inflation of the airbag30can be carried out stably.

Further, the occupant protection device10of the embodiment is such that the exhaust port41is opened in one of the left and right side wall portions35(L and R) (in the embodiment, the right side wall portion35R) of the airbag30when inflation is completed. Also, the direction in which the exhaust port41of the airbag30and the peripheral wall side end portion52of the strap50are disposed when inflation is completed is the left-right direction of the seat1. Furthermore, the folded body77of the airbag30when housed in the housing region22is formed as follows. Firstly, the initial stage airbag72is formed. The initial stage airbag72is formed by, while flattening a vicinity of the inlet portion37that causes the inflating gas G to flow into the airbag30, superimposing the peripheral wall region (rear wall portion)33of the airbag30above the vicinity of the inlet portion37, and flattening. Furthermore, at this time, the initial stage airbag72is formed by disposing the strap50in the left-right direction, putting the base portion46aside of the valve body46into a state pushed to the outside of the airbag30from the exhaust port41, and putting the peripheral wall side end portion52of the strap50into a state placed inside the airbag30in such a way as to approach the valve body46side (refer toFIG.8. Next, the end edge75aand75bsides in a direction perpendicular to the left-right direction of the initial stage airbag72are folded in such a way as to approach the inlet portion37side, and folded into a columnar body form whose axial center X is in the left-right direction, whereby the folded body77is formed (refer toFIGS.9A,9B,9C, and9D).

Because of this, the embodiment is such that when the airbag30inflates without a protrusion upward being restricted, the inflating gas G is caused to flow in from the inlet portion37, and the airbag30inflates by eliminating the crease on the end edge75aand75bsides in the direction perpendicular to the left-right direction of the initial stage airbag72, while pushing up the opposing region (the rear wall portion)33of the peripheral wall31of the airbag30in the vicinity of the inlet portion37of the initial stage airbag72. However, when the airbag30inflates in a state wherein a protrusion upward is restricted, elimination of the crease on the end edge75aand75bsides in the direction perpendicular to the left-right direction of the initial stage airbag72is regulated. That is, the columnar body form of the folded body77of the airbag30, wherein the axial center X is in the left-right direction, is such that swelling in a direction perpendicular to the axial center X is regulated, and the inflating gas G flowing in from the inlet portion37flows in the left-right direction along the axial center X. At this time, the initial stage airbag72is such that the strap50is disposed in the least-right direction in such a way as to follow the axial center X of the columnar body form of the folded body77of the airbag30. Also, the base portion46aside of the valve body46is in a state pushed to the outside of the airbag30from the exhaust port41. Furthermore, the peripheral wall side end portion52of the strap50is in a state placed inside the airbag30in such a way as to approach the valve body46side. Further still, the position of the exhaust port41is in the right side wall portion35R, which is one of the left and right side wall portions35(L and R) of the airbag30, rather than in the upper side of the airbag30, and is not positioned on a side wherein protrusion is restricted. This means that provided that a protrusion upward of the airbag30is regulated when the airbag30starts inflating, the peripheral wall31of the airbag30in the vicinity of the peripheral wall side end portion52of the strap50is unlikely to swell upward, and a state wherein tensile force does not act on the strap50exists. As a result of this, as shown inFIG.10BandFIG.11B, the state wherein the base portion46aside of the valve body46is pushed out from the exhaust port41is maintained, the opened state of the exhaust port41is maintained, the inflating gas G is discharged from the exhaust port41, and inflation of the airbag30is restricted. Of course, when a protrusion upward of the airbag30is not restricted, the airbag30is such that the inflating gas G is caused to flow in from the inlet portion37, and the airbag30inflates by eliminating the crease on the end edge75aand75bsides in the direction perpendicular to the left-right direction of the initial stage airbag72, while pushing up the opposing region (the rear wall portion)33of the peripheral wall31of the airbag30in the vicinity of the inlet portion37of the initial stage airbag72. Because of this, as shown inFIG.10C, andFIG.11C, the peripheral wall31of the airbag30in the vicinity of the peripheral wall side end portion52of the strap50swells, and tensile force acts on the strap50. As a result of this, the strap50pulls the valve body46into the airbag30, the peripheral wall (tubular body)47of the valve body46, which receives the pressure of the inflating gas G, closes the exhaust port41, and the airbag30completes inflation smoothly. In addition, a discharge from the exhaust port41of the inflating gas G when inflation of the airbag30is restricted is a discharge from the exhaust port41opened in the one side (the right side wall portion)35R of the left and right side wall portions of the airbag30when inflation is completed. That is, the discharge is a discharge from the exhaust port41disposed in one left-right side (the left side) of the lap belt portion13disposed in the left-right direction (refer toFIG.14). This means that even when the rear face93aof the frame93of the child seat90acting as an obstacle restricting inflation of the airbag30is disposed on a side above the folded body77disposed in the lap belt portion13(refer toFIGS.13and14), the exhaust port41disposed on the right side among the left and right sides of the lap belt portion13is not blocked by the child seat90acting as an obstacle. Further, the exhaust port41can cause the inflating gas G to be discharged smoothly, as a result of which inflation of the airbag30is restricted smoothly.

In the embodiment, the child seat90is fixed to the seat1facing forward. However, the child seat90may also be fixed to the seat1facing backward, as in a modification shown inFIG.15.

Also, in the embodiment, the seat belt11wherein the retractor15is provided inside the seat1is shown as an example. However, a seat belt extending from a retractor15A provided on a vehicle body side ma y be used as a seat belt11A, as shown inFIG.16. Further, the folded body77wherein the airbag30is folded up is housed in a region of a lap belt portion13A of the seat belt11A, and the conduit portion38extending from the inflator24is coupled to the airbag30.

Furthermore, as a seat belt is not limited to the cases of three-point types shown inFIGS.1and16, the folded body77wherein the airbag30is folded up may be housed in a lap belt portion of a two-point seat belt that has no shoulder belt portion. Of course, the conduit portion38extending from the inflator24is coupled to the airbag30.

Further still, in the embodiment, a valve body such that the leading end portion46bis closed, and the vent48is opened in a vicinity of the leading end portion46b, is shown as the valve body46of the regulating valve mechanism45. However, it is sufficient as a regulating valve mechanism formed of a valve body and a strap that when tensile force of a peripheral wall of an airbag acts on the strap when the airbag inflates, the valve body is pulled into the airbag by the strap, and a peripheral wall of the valve body, which has received pressure of an inflating gas, closes an exhaust port, and when tensile force of the peripheral wall of the airbag does not act on the strap, an opened state of the exhaust port is maintained, without the valve body being pulled into the airbag. Because of this, a valve body46A may be configured simply of a tubular body47A of which the leading end portion46bis opened, as in a regulating valve mechanism45A shown inFIGS.17A,17B and17C. The valve body46A is such that the base portion46aside is joined to the peripheral edge of the exhaust port41, and the leading end portion46bside is a simple opened end of the tubular form. Further, the valve body46A is such that one aperture (vent)48A is opened on a terminal side of the leading end portion46b, and a valve body side end portion51A of a string-form strap50A branched into a forked form is coupled to the leading end portion46bside.

The regulating valve mechanism45A is also such that when the airbag30inflates without the inflation being restricted, the peripheral wall31of the airbag30inflates, and the peripheral wall side end portion52of the strap50A of the regulating valve mechanism45A is pulled, as shown inFIG.17AtoFIG.17C. Further, the valve body46A coupled to the valve body side end portion51A of the strap50A is pulled into the airbag30, the inner peripheral faces47aof the tubular body47A are brought into close contact with each other by the pressure of the inflating gas G, and the valve body46A closes the exhaust port41. Because of this, a discharge of the inflating gas G from the exhaust port41is restricted, and the airbag30completes inflation smoothly. Meanwhile, when the airbag30attempts to inflate in a restricted state, no tensile force acts on the strap50A. Because of this, the valve body46A is in a state pushed to the outside of the airbag30from the exhaust port41, as shown inFIG.17AtoFIG.17B. That is, the vent46A formed of the opened end of the leading end portion46bis disposed outside the airbag30in an opened state. Because of this, the inflating gas G is discharged to the outside of the airbag30from the exhaust port41, while passing through the vent48A, and inflation of the airbag30is restricted. As the strap50A is of a string form, the inflating gas G when being discharged to the outside of the airbag30is discharged to the outside of the airbag30from the vent48A through a gap in a periphery of the strap50A. Further, the regulating valve mechanism45A can also be configured of two members, those being the tubular valve body46A, which is joined to the peripheral edge of the exhaust port41and has flexibility, and the strap50A, which is coupled to the valve body46A and the peripheral wall31of the airbag30and has flexibility, meaning that opening and closing of the exhaust port41can be carried out simply.

An occupant protection device of the embodiment is formed to include a lap belt portion disposed, in a state wherein left and right ends are coupled to a left and right of a seat, on a front side of a waist portion of an occupant seated in the seat, and an airbag that is housed folded up in a housing region of the lap belt portion and, when inflation is completed by an inflating gas being caused to flow in, has a lower face side as a supported face that is supported by a thigh portion of the occupant, and a rear face side as an occupant restraining face that receives an upper body of the occupant who moves forward. The airbag includes an exhaust port that can discharge the inflating gas flowing in, and a regulating valve mechanism that opens and closes the exhaust port. The regulating valve mechanism permits a discharge of the inflating gas from the exhaust port when a protrusion upward from the housing portion when the airbag inflates is restricted, and restricts a discharge of the inflating gas from the exhaust port when a protrusion upward from the housing portion when the airbag inflates is not restricted.

The occupant protection device of the embodiment is such that when operating, the inflating gas is caused to flow into the airbag housed in the housing region of the lap belt portion, and the airbag attempts to inflate. At this time, when a protrusion upward of the airbag from the housing region is restricted, the regulating valve mechanism permits a discharge of the inflating gas from the exhaust port, because of which the inflating gas is discharged from the exhaust port, and inflation of the airbag is restricted. This means that even when the lap belt portion is disposed on a lower side of a child seat in such a way as to attach the child seat to the seat, a pushing up of the child seat by the airbag can be prevented. Of course, when the lap belt portion is disposed on the front side of the waist portion of an occupant seated in the seat, without being used for attaching a child seat to the seat, a protrusion upward of the airbag from the housing region is not restricted. Because of this, the regulating valve mechanism restricts a discharge of the inflating gas from the exhaust port, and the inflating gas is not discharged from the exhaust port. As a result of this, the airbag completes inflation smoothly and, in a state wherein the lower face side supported face is supported by the thigh portion of the occupant, the upper body of the occupant who moves forward is received by the rear face side occupant restraining face, and can be protected.

Consequently, the occupant protection device of the embodiment is such that when a protrusion of the airbag housed in the lap belt portion is restricted, the inflating gas is discharged, and protrusion of the airbag can be restricted, and when a protrusion of the airbag is not restricted, the airbag completes inflation smoothly, and the occupant can be protected.

Further, the occupant protection device of the embodiment is such that the regulating valve mechanism is configured to include a tubular valve body having flexibility that is disposed in a peripheral edge of the exhaust port of the airbag, and a strap, which is a strap having flexibility including one end side and another end side, wherein the one end side is a valve body side end portion coupled to a leading end portion side of the valve body distanced from a base portion in the peripheral edge of the exhaust port, and the other end side is a peripheral wall side end portion coupled to a peripheral wall of the airbag via an interior of the airbag. Further, when a tensile force of the peripheral wall of the airbag is applied when the airbag inflates, the strap pulls the valve body into the airbag, and the exhaust port is closed by a peripheral wall of the valve body, which has received pressure of the inflating gas. Also, the strap is of a configuration such that when no tensile force of the peripheral wall of the airbag is applied, an opened state of the exhaust port is maintained, without the valve body being bulled into the airbag.

This kind of configuration is such that when the airbag inflates without inflation being restricted, the peripheral wall of the airbag swells, and the peripheral wall side end portion of the strap of the regulating valve mechanism is pulled. Further, the valve body coupled to the valve body side end portion of the strap is pulled into the airbag, and closes the exhaust port. Because of this, a discharge of the inflating gas from the exhaust port is restricted, and the airbag completes inflation smoothly. Meanwhile, when the airbag attempts to inflate in a restricted state, no tensile force acts on the strap. Therefore, at least one portion of the valve body is in a state pushed to the outside of the airbag from the exhaust port, the valve body does not close the exhaust port, and the inflating gas is discharged from the exhaust port. Because of this, inflation of the airbag is restricted. That is, this kind of occupant protection device is such that the regulating valve mechanism can be configured of two members, those being the tubular valve body, which is joined to the peripheral edge of the exhaust port and has flexibility, and the strap, which is coupled to the valve body and the peripheral wall of the airbag and has flexibility, meaning that the regulating valve mechanism can be configured simply.

In this case, the valve body is such that a multiple of vents may be provided penetrating inner and outer peripheries in the peripheral wall in a vicinity of a region coupled to the strap. This kind of configuration is such that when inflation of the airbag is restricted, that is, when the strap swells and at least one portion of the valve body is pushed to the outside of the airbag from the exhaust port, the inflating gas flows into a tubular region of the valve body extended from the peripheral edge of the exhaust port. Then, the inflating gas that has flowed in is discharged smoothly to the outside of the airbag via the multiple of vents of the valve body. Because of this, restricting inflation of the airbag can be carried out stably with this valve body.

Further, the occupant protection of the embodiment is such that the exhaust port is provided in one of left and right side wall portions of the airbag when inflation is completed. The direction in which the exhaust port of the airbag and the peripheral wall side end portion of the strap are disposed when inflation is completed is the left-right direction of the seat. A folded body of the airbag when housed in the housing region is formed by forming an initial stage airbag wherein, while flattening a vicinity of the inlet portion that causes the inflating gas to flow into the airbag, the peripheral wall region of the airbag is superimposed above the vicinity of the inlet portion, and flattened, then folding end edge sides in a direction perpendicular to the left-right direction of the initial stage airbag in such a way as to approach the inlet portion side, thereby folding into a columnar body form whose axial center is in the left-right direction. Also, the initial stage airbag is formed by disposing the strap in the left-right direction, putting the base portion side of the valve body into a state pushed to the outside of the airbag from the exhaust port, and putting the peripheral wall side end portion of the strap into a state placed inside the airbag in such a way as to approach the valve body side.

This kind of configuration is such that when the airbag inflates without a protrusion upward being restricted, the inflating gas is caused to flow in from the inlet portion, and the airbag inflates by eliminating a crease on the end edge sides in the direction perpendicular to the left-right direction of the initial stage airbag, while pushing up the opposing region of the peripheral wall of the airbag in the vicinity of the inlet portion of the initial stage airbag. However, when the airbag inflates in a state wherein a protrusion upward is restricted, elimination of the crease on the end edge sides in the direction perpendicular to the left-right direction of the initial stage airbag is regulated. Because of this, the columnar body form of the folded body of the airbag, wherein the axial center is in the left-right direction, is such that swelling in a direction perpendicular to the axial center is regulated. Further, the inflating gas flowing in from the inlet portion flows in the left-right direction along the axial center. At this time, the initial stage airbag is such that the strap is disposed in the left-right direction in such a way as to follow the axial center of the columnar body form of the folded body of the airbag, in addition to which the base portion side of the valve body is in a state pushed to the outside of the airbag from the exhaust port, and furthermore, the peripheral wall side end portion of the strap is in a state placed inside the airbag in such a way as to approach the valve body side. Furthermore, the position in which the exhaust port is disposed is in one of the left and right side wall portions of the airbag, rather than in the upper side of the airbag, and the exhaust port is not positioned on a side wherein protrusion is restricted. This means that provided that a protrusion upward of the airbag is regulated when the airbag starts inflating, the peripheral wall of the airbag in the vicinity of the peripheral wall side end portion of the strap is unlikely to swell outward, and a state wherein tensile force does not act on the strap exists. Because of this, the base portion side of the value body maintains, a state pushed to the outside from the exhaust port. As a result of this, the opened state of the exhaust port is maintained, the inflating gas is discharged from the exhaust port, and inflation of the airbag restricted. Of course, when a protrusion upward of the airbag is not restricted, the airbag is such that the inflating gas is caused to flow in from the inlet portion, and the airbag inflates by eliminating the crease on the end edge sides in the direction perpendicular to the left-right direction of the initial stage airbag, while pushing up the opposing region of the peripheral wall of the airbag in the vicinity of the inlet portion of the initial stage airbag. Further, the peripheral wall of the airbag in the vicinity of the peripheral wall side end portion of the strap swells, and tensile force acts on the strap. Because of this, the strap pulls the valve body into the airbag, and the peripheral wall of the valve body, which has received the pressure of the inflating gas, closes the exhaust port. Because of this, the airbag completes inflation smoothly. In addition, a discharge from the exhaust port of the inflating gas when inflation of the airbag is restricted is a discharge from the exhaust port opened in one side of the left and right side wall portions of the airbag when inflation is completed, that is, a discharge from the exhaust port disposed in one left-right side of the lap belt portion disposed in the left-right direction. This means that even when an obstacle restricting inflation of the airbag is disposed on a side above the folded body disposed is the lap belt portion, the exhaust port disposed on one of the left and right sides of the lap belt portion is not blocked by the obstacle, the inflating gas can be discharged smoothly, and inflation of the airbag can be restricted smoothly.