Patent ID: 12194942

DESCRIPTION OF THE PREFERRED EMBODIMENTS

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.

Hereafter, an occupant protection device10according to one embodiment of the invention will be described, based on the drawings.FIG.1is a perspective view of a seat1in which the occupant protection device10is mounted.FIG.2is a left side view of the seat1in which the occupant protection device is mounted.FIG.3is a front view of the seat1in a state wherein a seatbelt11is worn by an occupant MP, and a sectional schematic view of an airbag29, and shows the airbag29when inflated as two-dotted chain lines.FIG.4is a left side view of the seat1in a state wherein the seatbelt11is worn by the occupant MP.FIG.5is a sectional schematic view of a periphery of a waist portion of the occupant MP in a state wherein the seatbelt11is worn.

As shown inFIGS.1to5, the occupant protection device10is mounted in the seat1of a vehicle. The occupant protection device10includes the seatbelt11, the airbag29, a bag cover65that covers the airbag29in a folded state, and an inflator24acting as a gas supply device that supplies an inflating gas to the airbag29. The seat1includes a backrest portion2and a seat portion5.

The seatbelt11is a member for restraining the occupant MP seated on the seat1. An upper end11aside of the seatbelt11can be fed out from a retractor15provided in an interior on one left-right direction side (a left edge3aside in the present embodiment) of an upper end3of the backrest portion2of the seat1. A lower end11bside (a leading end side) of the seatbelt11forms a fixed end fixed to an anchor member16disposed on a left side portion6side of the seat portion5.

Also, a tongue18is disposed in an intermediate region of the seatbelt11. The tongue18is fastened to a buckle17provided on another left-right direction side (a right side portion7side in the present embodiment) of the seat portion5of the seat1. A state wherein the tongue18is fastened to the buckle17is a state wherein the occupant MP is wearing the seatbelt11. The seatbelt11in a state wherein the tongue18is fastened to the buckle17is such that a region that extends from the tongue18to the retractor15side is a shoulder belt portion12disposed on a front face side of an upper body MU of the occupant MP, and a region that extends from the tongue18to the fixed end11bside is a lap belt portion13that is disposed on a front face side of a waist portion MW of the occupant MP, and restrains the waist portion MW. An unshown release button is disposed on the buckle17, and the tongue18can be removed from the buckle17by carrying out a pressing operation of the release button when releasing the fastening of the tongue18.

The retractor15has a pretensioner mechanism15a(a take-up unit) that causes the drawing out to stop when there is an abrupt drawing out of the seatbelt11, and furthermore, can take up the drawn out seatbelt11when there is a collision or the like of the vehicle. When the pretensioner mechanism15aoperates, the lap belt portion13is taken up approximately 30 mm by the pretensioner mechanism15a.

The inflator24acting as the gas supply device is attached and fixed to the left side portion6on a back side of the seat portion5(refer toFIGS.1and2). The inflator24includes an approximately cylindrical inflator main body25, which discharges an inflating gas, and a pipe portion26disposed bent into an approximate L-shape protruding from the inflator main body25. A leading end portion48side of a conduit portion45of the airbag29, to be described hereafter, is connected to the pipe portion26. Specifically, the conduit portion45is mounted on an exterior of the pipe portion26, a leading end72aof an extended tube portion72of the bag cover65, to be described hereafter, is mounted on an exterior of the conduit portion45from above, and a clamp27is fastened onto the bag cover65from above, whereby the conduit portion45is connected (coupled) to the pipe portion26.

As shown inFIGS.6,8, and9, the airbag29includes a bag main body portion30, which inflates significantly owing to an inflating gas being caused to flow in, and receives the occupant MP, and the conduit portion45, which communicates with a lower end30aside of the bag main body portion30, guides the inflating gas discharged from the inflator24to the bag main body portion30, and causes the inflating gas to flow into the bag main body portion30. The bag main body portion30and the conduit portion45are formed of a woven fabric having flexibility, such as polyester.

A peripheral wall31of the bag main body portion30when inflation is completed is of an approximate triangular prism form when seen from a side. The bag main body portion30when inflation is completed includes a bottom wall portion32on a bottom face side, a back wall portion33on a back face side, a front wall portion34on a front face side, a left side wall portion35L on a left face side, and a right side wall portion35R on a right face side. The left side wall portion35L and the right side wall portion35R oppose each other in the left-right direction. A lower face32aof the bottom wall portion32is a supported face37supported by a thigh portion MF of the occupant MP, and a back face33aof the back wall portion33is an occupant restraining face38that receives the upper body MU of the occupant MP who moves forward.

Two inflow ports40, which are aperture portions for causing inflating gas inside the conduit portion45to flow in, are provided in a vicinity of a back edge32bof the bottom wall portion32. Also, a venthole43, which is an aperture portion for discharging excess inflating gas flowing into the bag main body portion30, is provided in a front portion side of the left side wall portion35L and a front portion side of the right side wall portion35R. A tuck portion33bis formed in the back wall portion33in such a way as to reduce an up-down direction dimension, whereby an upper end33cside of the back wall portion33comes into proximity with a head portion MH of the occupant MP when inflation of the bag main body portion30is completed.

As shown inFIGS.6and7, the peripheral wall31of the bag main body portion30is formed by two sheet members, those being a front side region31aand a back side region31b, being sewn together. The front side region31aincludes a region forming the front wall portion34, the front portion side of the left side wall portion35L, and the front portion side of the right side wall portion35R, and the back side region31bincludes a region forming the back wall portion33, the bottom wall portion32, a back portion side of the left side wall portion35L, and a back portion side of the right side wall portion35R.

A base portion46(one end portion) of the conduit portion45is linked (joined) to the inflow port40of the bag main body portion30of the airbag29. A leading end portion48(another end portion) of the conduit portion45is linked (joined) to the pipe portion26of the inflator24. The base portion46is wide, and a region between the leading end portion48and the base portion46forms a tubular intermediate portion49of a width dimension equivalent to a width dimension of the leading end portion48. The conduit portion45is formed by sewing together outer peripheral edges of an outer side member50and a bag side member51whose external forms are the same as each other (refer toFIGS.6and7). A communication port47that communicates with the inflow port40of the bag main body portion30is provided in the base portion46of the conduit portion45. A peripheral edge of the communication port47is sewn to a peripheral edge of the inflow port40, whereby the conduit portion45is linked to the back edge32bside of the bottom wall portion32forming the lower end30aof the bag main body portion30. The conduit portion45guides an inflating gas discharged from the inflator main body25to the bag main body portion30, thereby supplying the inflating gas to the bag main body portion30.

Also, the conduit portion45is such that a region of the outer side member50in the base portion46separated from the bag main body portion30is joined as a joining region53to a bag disposition region22of the lap belt portion13by sewing using a thread54. That is, the airbag29is joined to the lap belt portion13such that the conduit portion45joined to the bag main body portion30is joined by sewing to the lap belt portion13.

A length dimension L1of the joining region53along the lap belt portion13is set to be shorter than a length dimension L0of a bag assembly60, to be described hereafter, along the lap belt portion13. In the present embodiment, the length dimension L1is approximately 100 mm, and the length dimension L0is approximately 260 mm (refer toFIG.5). Herein, in the present embodiment, the conduit portion45is joined by sewing to the lap belt portion13, meaning that the length dimension L1of the joining region53along the lap belt portion13is a length dimension along the lap belt portion13in a portion in which the conduit portion45and the lap belt portion13are sewn together.

When forming the conduit portion45, the peripheral edge of the communication port47of the bag side member51is sewn to the peripheral edge of the inflow port40of the bag main body portion30before the outer peripheral edges of the outer side member50and the bag side member51are sewn together, and the joining portion53of the outer side member50is sewn to the bag disposition region22of the lap belt portion13.

The bag main body portion30is folded and joined as a folded body56to the bag disposition region22together with the base portion46of the conduit portion45, forming the bag assembly60. The folded body56is formed by, while flattening a whole region of the front wall portion34in the peripheral wall31of the bag main body portion30, overlaying the front wall portion34on the back wall portion33in a state wherein a vicinity of the inflow port40is flattened and on a region of the flattened bottom wall portion32, folding both the left and right peripheral edges in the overlaid state to the inflow port40side of the front wall portion34side, and furthermore, folding both end sides perpendicular to the left-right direction in such a way as to come into proximity on the inflow port40on the front wall portion34side.

Also, the bag assembly60is installed covered by the bag cover65in the lap belt portion13. The bag cover65is formed of a cover material75formed of a sheet member of artificial leather or the like having decorative properties (refer toFIG.6). The bag cover65includes a main body cover portion66, which covers the bag assembly60together with the joining region53, tubular belt cover portions70(L and R), which cover vicinity regions13aand13bof the lap belt portion13extending left and right from the joining region53, and which protrude from the main body cover portion66, and the tubular extended tube portion72, which extends from the main body cover portion66and covers the intermediate portion49of the conduit portion45. The main body cover portion66includes a front side portion67, which separates from the occupant MP when the lap belt portion13is worn, and a back side portion68on the occupant MP side. Communication apertures68aand68b, through which the vicinity regions13aand13bof the lap belt portion13are caused to protrude, are opened in the back side portion68. Although outer peripheral edges of the front side portion67and the back side portion68are sewn together, an edge on an upper side when the lap belt portion13is worn forms a protrusion edge66athat can open in such a way as to cause the bag main body portion30when inflating to protrude.

The belt cover portions70L and70R are tubular (of an approximately rectangular tube form) regions that protrude from peripheral edges of the communication apertures68aand68b, and a lead-out hole70athrough which the lap belt portion13is inserted is formed in a leading end of each.

The cover material75includes a front side material76, which extends from the front side portion67of the main body cover portion66to a front side region of the extended tube portion72, a back side material77, which extends from the back side portion68of the main body cover portion66to a back side region of the extended tube portion72, and four belt cover materials81, which form the belt cover portions70(L and R) (refer toFIG.7). The back side material77is formed of an end side portion78, an intermediate portion79, and an extended side portion80. A region between the end side portion78and the intermediate portion79forms a region in which the communication aperture68bis formed, a peripheral edge thereof forms a region linked to the belt cover portion70R, a region between the intermediate portion79and the extended side portion80forms a region in which the communication aperture68ais formed, and a peripheral edge thereof forms a region linked to the belt cover portion70L.

The bag cover65is such that the belt cover material81is sewn to each of the region of the back side material77of the cover material75between the end side portion78and the intermediate portion79and the region between the intermediate portion79and the extended side portion80, and corresponding outer peripheral edges of the belt cover material81are sewn together, forming the belt cover portions70(L and R). At this time, the back side material77is formed by the end side portion78, the intermediate portion79, and the extended side portion80being linked to each other. Further, the bag cover65is formed by the front side material76being sewn to the back side material77.

Note that the bag cover65is formed by forming the main body cover portion66and the belt cover portions70(L and R) leaving an assembly aperture66bin a leading end side of the main body cover portion66. The assembly aperture66bis utilized when causing the bag assembly60to join the bag disposition region22of the lap belt portion13.

Assembly of the occupant protection device10will be described. Firstly, the folded body56is formed by folding the bag main body portion30in a state wherein a region of the bag side member51on the peripheral edge of the communication port47of the base portion46of the conduit portion45is sewn to the peripheral edge of the inflow port40in the bottom wall portion32of the bag main body portion30. Also, the fixed end11bside before fixing to the seat1of the seatbelt11fed out from the retractor15is inserted into the bag cover65from the lead-out hole70aof the belt cover portion70R of the bag cover65, this is extracted from the assembly aperture66b, and the joining region53of the outer side member50of the conduit portion45is sewn to the bag disposition region22of the extracted lap belt portion13utilizing the thread54. Next, the outer peripheral edges of the outer side member50and the bag side member51are sewn together, forming the conduit portion45. Further, the fixed end11bside of the seatbelt11is inserted into the main body cover portion66of the bag cover65, and furthermore, caused to protrude from the lead-out hole70aof the bag cover portion70L via the belt cover portion70R. Also, the leading end portion48side of the conduit portion45is inserted into the main body cover portion66, and furthermore, caused to protrude from the leading end72avia the extended tube portion72of the bag cover65, together with which the bag assembly60formed of the folded body56and the base portion46of the conduit portion45is housed in the main body cover portion66of the bag cover65, and the assembly aperture66bof the bag cover65is closed off by sewing. Next, the fixed end11bof the seatbelt11is linked and fixed to the anchor member16of the left side portion6of the seat portion5of the seat1, together with which the leading end portion48of the conduit portion45is linked together with the leading end72aof the extended tube portion72of the bag cover65to the pipe portion26of the inflator24already installed in the seat1, utilizing the clamp27. By so doing, the occupant protection device10can be mounted in the seat1.

The occupant MP seated on the seat1puts on the seatbelt11by feeding out the seatbelt11and fastening the tongue18to the buckle17, thereby wearing the lap belt portion13to which the bag assembly60is attached around the waist portion MW. In other words, the occupant MP seated on the seat1puts on the seatbelt11by feeding out the seatbelt11and fastening the tongue18to the buckle17, thereby wearing the lap belt portion13to which the airbag29is joined around the waist portion MW. When doing so, a gap h is formed between left and right edge60aand60bsides of the bag assembly60in front of left and right edge MWL and MWR sides of the waist portion MW of the occupant MP, as shown inFIG.5. Meanwhile, the lap belt portion13itself is worn tightly on the waist portion MW of the occupant MP. That is, as the length dimension L1of the joining region53to which the bag assembly60is to be attached in the bag disposition region22of the lap belt portion13is shorter than the length dimension L0of the bag assembly60, the lap belt portion13is worn tightly on the waist portion MW of the occupant MP in a region equivalent to the shorter dimension. Seen from another perspective, the length dimension L1of the joining region53along the lap belt portion13is shorter than a length dimension of the bag main body portion30in a folded state along the lap belt portion13, because of which a region in which a force maintaining the form of the bag main body portion30acts on the lap belt portion13becomes smaller, as a result of which the lap belt portion13is worn tightly on the waist portion MW of the occupant MP. This means that on the pretensioner mechanism15aoperating, the lap belt portion13worn tightly on the waist portion MW of the occupant MP is taken up, and the waist portion MW of the occupant MP is appropriately secured. Consequently, according to the occupant protection device10of the present embodiment, a configuration wherein the airbag29is joined to the lap belt portion13is such that a worsening of a performance of the lap belt portion13in restraining the waist portion MW of the occupant MP when the pretensioner mechanism15aoperates can be restricted, and the waist portion MW of the occupant MP can be appropriately secured.

Also, on the inflator24operating after the operation of the pretensioner mechanism15a, an inflating gas flows into the bag main body portion30via the leading end portion48, the intermediate portion49, the base portion46, the communication port47, and the inflow port40of the conduit portion45. On the bag main body portion30starting to inflate owing to the inflating gas, the bag cover65is subjected to pressure from the bag main body portion30and ruptures, and the bag main body portion30is fed out from the bag disposition region22of the lap belt portion13. Subsequently, the bag main body portion30completes inflation in front of the upper body MU of the occupant MP, attaining the state shown inFIGS.8and9. Because of this, the bag main body portion30supported by the thigh portion MF at the supported face37receives the upper body MU of the occupant MP who moves forward with the occupant restraining face38, whereby the occupant MP is protected.

Also, the length dimension L1of the joining region53along the lap belt portion13is set to be 100 mm, which is within the range of 50 to 120 mm. Because of this, the following advantage is obtained. That is, when the length dimension L1of the joining region53is less than 50 mm, joining strength of the bag assembly60attached to the lap belt portion13is difficult to ensure. Also, when the length dimension L1of the joining region53exceeds 120 mm, a state wherein the lap belt portion13is in close contact with the waist portion MW of the occupant MP is difficult to ensure. Specifically, in a case wherein the occupant MP wearing the lap belt portion13is a small-bodied occupant MPS, as shown inFIG.10, a position of a joining region53A when the lap belt portion13is worn deviates to the left or right with respect to a left-right direction center MC of the occupant MPS, and the possibility arises of the joining region53A being disposed in a position of large curvature in the periphery of the waist portion MW. In this case, when the length dimension L1of the joining region53A exceeds 120 mm, a gap hl is liable to appear between vicinities of edges53aand53aof the joining region53A and the edge MWR and MWL sides of the waist portion MW of the occupant MPS, leading to a decrease in a securing force. Because of this, the length dimension L1of the joining region53is preferably within the range of 50 to 120 mm, and more preferably within the range of 70 to 100 mm.

Also, the bag assembly60is such that the regions13aand13bof the lap belt portion13extending left and right from the joining region53are caused to protrude, and is disposed covered by the bag cover65in such a way as to be able to open when the bag main body portion30inflates. This means that as the bag assembly60is covered by the bag cover65, a foreign body entering the folded body56, wherein the bag main body portion30is folded, can be prevented, and an unraveling of the bag main body portion30can be prevented.

Also, the bag cover65includes the main body cover portion66, which covers the bag assembly60together with the joining region53, and the tubular belt cover portions70(L and R), which cover the regions13aand13bof the lap belt portion13protruding from the main body cover portion66and extending left and right from the joining region53. This means that the bag cover65covers not only the bag assembly60but also the lap belt portion13in a vicinity of the joining region53, because of which a foreign body entering the folded body56of the bag main body portion30is easily prevented.

When the aforementioned point is not taken into consideration, a configuration including a main body cover portion66A that covers the bag assembly60including the joining region53, without providing the belt cover portions70(L and R), wherein the apertures68aand68bthrough which the regions13aand13bof the lap belt portion13in the vicinity of the joining region53are caused to protrude are provided in the main body cover portion66A, may be adopted, as in the case of a bag cover65A shown inFIGS.11and12.

Also, in the present embodiment, a configuration wherein the bag assembly60is joined by sewing to the bag disposition region22of the lap belt portion13has been described, but the invention is not limited to this. That is, provided that the bag assembly60is in a state of being joined to the bag disposition region22with deviation restricted, the bag assembly60may be joined to the bag disposition region22by utilizing a joining member85that encloses the bag disposition region22of the lap belt portion13, as shown inFIGS.13and14. The joining member85is such that the lap belt portion13is inserted therethrough in the left-right direction, and is a strip-form member wherein both upper and lower edges85aare sewn to a region of the outer side member50in the base portion46of the conduit portion45, and the length dimension L1thereof is configured to be 100 mm, which is shorter than the length dimension L0(approximately 260 mm) of the bag assembly60. That is, the joining member85is an insertion portion, provided in the conduit portion45, that causes the lap belt portion13and the conduit portion45to join by the lap belt portion13being inserted therethrough, and the length dimension L1of the joining region53along the lap belt portion13is a length dimension of the joining member85along the lap belt portion13.