Occupant protection device

Abstract

To provide an occupant protection device capable of accurately restraining the knees of an occupant seated on the seat and restricting the occupant's forward movement relative to the seat, regardless of the shape of members inside the cabin.SOLUTION: An occupant protection device S1 for protecting an occupant MP1 seated on a vehicle seat 1 comprises: a seat belt 7 which has a lap belt 10 capable of restraining a waist MW of the occupant; an inflator 17; and an air bag 25 which is folded and stored in a portion of the lap belt, and is inflatable so as to restrain a knees K1 of the occupant while getting protruding forward by allowing inflation gas discharged from the inflator to flow thereinto. The air bag includes a knee restraining portion 28 which is disposed so as to extend along a lateral direction in front of left and right knees of the occupant upon completion of inflation, and a connecting member which connects the knee restraining portion to the lap belt side.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an occupant protection device for protecting an occupant seated on a vehicle seat.

Background Art

[0002] Conventionally, as an occupant protection device, there has been a knee protection airbag device for protecting the knees of an occupant seated on a seat. The knee protection airbag device covers the front of the knees of an occupant seated on the seat with an inflated airbag, thereby restraining the knees and restricting the forward movement of the occupant with respect to the seat, and also protecting the knees from members on the vehicle body side disposed in front of the knees. Conventionally, as a knee protection airbag device, there has been a configuration in which it is mounted on a member on the vehicle body side (for example, inside the instrument panel in front of the driver's seat) that is in front of the knees of the occupant (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when mounting a knee protection airbag device as an occupant protection device on an instrument panel or the like on the vehicle body side as in the conventional case, especially when protecting an occupant seated in the passenger seat, depending on the design of the interior of the vehicle, etc., the seat (passenger seat) may be installed at a distance from the instrument panel, which is an interior material. When the mounting position of the knee protection airbag device is far from the seat, there is a risk that the knees cannot be quickly restrained by the inflated airbag and the forward movement of the occupant with respect to the seat cannot be restricted.

[0005] The present invention solves the above-described problems, and provides an occupant protection device that can accurately restrain the knees of an occupant sitting on a seat and can regulate the forward movement of the occupant with respect to the seat, regardless of the shape of the members inside the vehicle cabin.

Means for Solving the Problems

[0006] The occupant protection device according to the present invention is an occupant protection device for protecting an occupant sitting on a vehicle seat, a seat belt including a lap belt capable of restraining the waist of the occupant, an inflator, an airbag that is folded and stored in a portion of the lap belt, and when the inflator operates, allows the inflation gas discharged from the inflator to flow inside, and inflates so as to protrude forward and restrain the knees of the occupant, and is provided with The airbag when inflation is completed, is disposed so as to extend along the left-right direction in front of the left and right knees of the occupant, and has a knee restraint portion capable of restraining each knee, a connecting member that connects the knee restraint portion to the lap belt side, and is characterized by comprising.

[0007] The occupant protection device of the present invention is arranged on the seat side where the occupant is sitting. Specifically, when the occupant sits on the seat, an airbag that is folded and stored in the lap belt part of the seat belt worn by the occupant is inflated by inflowing inflation gas into it and projecting forward, and is configured to restrain the knees. That is, since the occupant protection device of the present invention is not mounted on a member on the vehicle body side like a conventional knee protection airbag device, regardless of the design of the interior space of the vehicle (the shape of the members in the vehicle interior), when the airbag inflates, the knee restraint part can be arranged close to the front of the occupant's knees, and the knee restraint part arranged close can stably restrain the occupant's knees. Also, in the occupant protection device of the present invention, the knee restraint part is configured to be connected to the lap belt side by a connecting member. Therefore, when the airbag deploys and inflates, while inflowing inflation gas into it, the knee restraint part that inflates and projects forward can be prevented from protruding excessively forward so as to be greatly separated from the lap belt. Therefore, it becomes possible to quickly restrain the occupant's knees by the knee restraint part, and in cooperation with the lap belt that restrains the waist, it is possible to accurately regulate the forward movement of the occupant relative to the seat.

[0008] Therefore, in the occupant protection device of the present invention, regardless of the shape of the members in the vehicle interior, the knees of the occupant sitting on the seat can be accurately restrained, and the forward movement of the occupant relative to the seat can be regulated.

[0009] Also, in the occupant protection device of the present invention, the airbag is provided with a gas flow path part through which the inflation gas discharged from the inflator can flow out to the knee restraint part side. The gas flow path part includes a horizontal flow path part arranged along the left - right direction on the rear end side of the airbag when inflation is completed, and two vertical flow path parts arranged on the left end side and the right end side of the airbag when inflation is completed, respectively, so as to connect the horizontal flow path part and the knee restraint part. It is configured to include The connecting member is composed of a flexible sheet body, and at least the front edge side and the rear edge side are respectively connected to the knee restraint part and the lateral flow path part. It is preferable that the lateral flow path part is configured to be attached to the lap belt in the region on the lower surface side when the airbag is fully inflated.

[0010] If the occupant protection device is configured in this way, the inflation gas discharged from the inflator flows into the knee restraint part through the lateral flow path part and the left and right longitudinal flow path parts. Therefore, even if the inflation gas is configured to flow into the interior only from one side (i.e., the left end side or the right end side) of the left and right on the rear end side of the airbag, the inflation gas flowing into the interior can quickly inflate the airbag evenly in the left and right directions. Further, in the occupant protection device having such a configuration, in the state where the airbag is viewed from the vertical direction in the fully inflated state, the parts (the lateral flow path part, the two longitudinal flow path parts, and the knee restraint part) where the inflation gas flows into the interior and inflates are arranged in a substantially square ring shape. Therefore, when the inflation gas flows into the interior and the airbag expands and protrudes forward from the lap belt, the airbag expands so as to quickly form a substantially square ring shape when viewed from above, and it is possible to suppress large fluctuations in the front, rear, left, and right directions. Therefore, the knee restraint part can be quickly arranged in front of the occupant's knees, and the forward movement of the occupant with respect to the seat can be quickly restricted.

[0011] Furthermore, in the occupant protection device having the above configuration, the knee restraint part is configured to include a front side part and a rear side part that are arranged in parallel in two in the front and rear so as to be able to protect the knees. It is preferable that the inflation of the airbag is controlled such that the rear side part is inflated when an occupant sitting with the knees close to the front end of the seat cushion in the seat is detected.

[0012] If the occupant protection device is configured in this way, for example, when detecting an occupant who is seated with their knees close to the front end of the seat, such as a relatively small-sized occupant, when the airbag deploys and inflates, in addition to the front side portion, the rear side portion is inflated, so that the rear side portion can restrain the knees of such a small-sized occupant. And when detecting an occupant who is seated with their knees separated from the front end of the seat, such as a relatively large-sized occupant, if the airbag is inflated without inflating the rear side portion, the inflated front side portion can restrain the knees of such a large-sized occupant. That is, in the occupant protection device with the above configuration, even when occupants of different builds with different knee positions relative to the seat at the time of seating are seated, the knees of each occupant can be accurately restrained by the knee restraint portion (front side portion or rear side portion).

[0013] Furthermore, in the occupant protection device with the above configuration, an auxiliary inflation portion configured to connect both end sides to the respective longitudinal flow path portions is disposed between the knee restraint portion and the lateral flow path portion. It is preferable that the auxiliary inflation portion is configured to be inflated so as to be interposed between the connecting member and the thigh portion of the occupant when the inflation of the airbag is completed.

[0014] If the occupant protection device is configured in this way, when the inflation of the airbag is completed, it becomes possible to bring the lower surface side of the auxiliary inflation portion disposed at the intermediate portion between the front and rear into contact with the upper surface of the thigh portion. In other words, since the lower surface side of the auxiliary inflation portion, which is in two locations separated front and rear, and the lower surface side of the lateral flow path portion can be supported by the occupant (thigh portion or waist around which the lap belt is wound) to inflate the airbag, the position of the knee restraint portion with respect to the knee (the position of the knee restraint portion in the vertical direction side with respect to the knee) can be stabilized. Therefore, the knee restraint portion can more stably restrain the knees of the occupant.

Brief Description of the Drawings

[0015]

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Mode for Carrying Out the Invention

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The occupant protection device S1 of the first embodiment is for protecting the occupant MP1 seated on the vehicle seat 1, and in the case of the embodiment, it is mounted on the vehicle seat 1. As shown in FIGS. 1 to 3, the occupant protection device S1 includes a seat belt 7, an airbag 25, an inflater 17 that supplies inflation gas to the airbag 25, and a cover portion 50 that covers the periphery of the folded complete body 55 formed by folding the airbag 25 (specifically, the bag body 26 described later). The airbag 25 is disposed at a portion of the lap belt 10 in the belt body 8 of the seat belt 7 described later. The seat 1 includes a backrest portion 2 and a seat portion 3. In the embodiment, the front-rear, up-down, and left-right directions will be described in accordance with the front-rear, up-down, and left-right directions with respect to the occupant MP1 seated on the seat 1 unless otherwise specified. In the first embodiment, a standard-built adult male (equivalent to an AM50 dummy) is assumed as the occupant MP1 to be protected.

[0017] In the case of the embodiment, the seat belt 7 is a three-point restraint type and is mounted on the seat 1. As shown in FIG. 2, it includes a belt body 8 for restraining the occupant MP1 seated on the seat 1, a tongue plate 12 attached to the belt body 8, and a buckle 13 for connecting the tongue plate 12. In the case of the embodiment, the buckle 13 is disposed on the rear right end side of the seat portion 3 in the seat 1 (on the right side near the boundary between the backrest portion 2 and the seat portion 3) (see FIG. 2). One end of the belt body 8 is locked to the winding shaft of a retractor (not shown) disposed in the backrest portion 2, and the other end is locked to the rear left end side of the seat portion 3 in the seat 1 by an anchor member 14 (see FIGS. 1 and 2), and is configured to be extendable from the retractor during mounting. Specifically, the belt body 8 is disposed so as to be exposed to the outside from the upper left edge side of the backrest portion 2. In the case of the embodiment, in the non-seated state of the occupant MP1, as shown in FIG. 2, the lap belt 10 for disposing the airbag 25 is configured to be exposed on the front surface of the backrest portion 2. Specifically, in the non-seated state of the occupant MP1, as shown in FIG. 2, the lap belt 10 is exposed on the front surface of the backrest portion 2 along the vertical direction on the left edge side of the backrest portion 2. The belt body 8 has a lap belt 10 and a shoulder belt 9 housed in the backrest portion 2. When the tongue plate 12 is fastened to the buckle 13 when the occupant is seated, the lower body (waist MW) of the occupant MP1 is restrained by the lap belt 10 disposed substantially along the left-right direction between the anchor member 14 and the buckle 13, and the upper body MU (from the shoulder to the chest) of the occupant MP1 is restrained by the shoulder belt 9 disposed obliquely from the upper left edge of the backrest portion 2 and extending to the buckle 13 (see FIGS. 1 and 3). That is, in the seat belt 7, the shoulder belt 9 is configured to restrain the upper body MU of the occupant MP1, and the lap belt 10 is configured to restrain the lower body MD (waist MW) of the occupant MP1. In the seat belt 7, a retractor (not shown) disposed in the backrest portion 2 has a pretensioner mechanism.

[0018] In the case of the embodiment, the inflator 17 is attached to the seat 1. Specifically, as shown in FIG. 1, it is disposed at a position near the lower end of the seat portion 3 on the back side of the seat 1. The inflator 17 includes a substantially cylindrical inflator body 18 (detailed illustration is omitted) arranged with its axial direction substantially along the left-right direction, and a pipe portion 19 extending from the inflator body 18 to supply inflation gas to the airbag 25 (see FIGS. 1 and 3). Although detailed illustration of the inflator body 18 is omitted, it is attached to the left region of the seat frame 4 using a predetermined bracket. The pipe portion 19 extends from the inflator body 18 and is arranged such that its tip is positioned near the boundary portion between the seat portion 3 and the backrest portion 2 on the left side of the seat 1. This tip is configured to be connected to a conduit portion 40 (described later) in the airbag 25 using a clamp 20 (see FIGS. 4 and 8). The inflator body 18 is electrically connected to a control device (not shown) and is configured to operate by receiving an operation signal from the control device. Also, in the case of the embodiment, the inflator body 18 is set to start operating later than the pretensioner mechanism of the seat belt 7 in order to restrict the withdrawal of the belt body 8 of the seat belt 7 accompanying the inflation of the airbag 25.

[0019] As described above, the airbag 25 is disposed at a portion of the lap belt 10 that restrains the lower body MD (waist MW) of the occupant MP1 sitting on the seat 1 and is formed from a flexible seat body. In the case of the embodiment, the airbag 25 is formed from a woven fabric made of polyester yarn, polyamide yarn, or the like. As shown in FIGS. 4 and 5, the airbag 25 includes a bag body 26 that inflates by allowing inflation gas to flow therein, a conduit portion 40 that connects the bag body 26 and the inflator 17, and a belt loop portion 45 through which the lap belt 10 (belt body 8) can be inserted.

[0020] In the case of the embodiment, the outer shape of the airbag body 26 at the completion of inflation when viewed from the vertical side is substantially rectangular as shown in FIG. 4. In the case of the embodiment, the airbag body 26 is arranged so as to cover substantially the entire upper part of the lower limbs (from the left and right thighs TL and TR to the knees KL1 and KR1) of the occupant MP1 at the completion of inflation (see FIG. 6). The airbag body 26 includes a knee restraint portion 28 that inflates to restrain the knees K1 (KL1, KR1) of the occupant MP1, a gas flow path portion 30, an auxiliary inflation portion 35, and a connecting member 37 that connects the knee restraint portion 28 to the lap belt 10 side.

[0021] The knee restraint portion 28 is arranged to extend along the left - right direction in front of the left and right knees K1 (KL1, KR1) of the occupant MP1 at the completion of inflation and is configured to be able to restrain each knee KL1, KR1. In the case of the embodiment, the outer shape at the completion of inflation is a long shape that extends along the left - right direction while aligning the width direction along the vertical direction (see the two - dot chain lines in FIGS. 5, 6, 8, and 9). In the case of the embodiment, the width dimensions in the left - right direction side and the vertical direction side of the knee restraint portion 28 are set to dimensions that can widely cover the left and right knees KL1, KR1 in the up - down, left - right directions. This knee restraint portion 28 is arranged close to the front of the knees KL1, KR1 of the occupant MP1 at the completion of inflation of the airbag 25 and is configured to be able to quickly restrain the knees KL1, KR1 of the forward - moving occupant MP1 (see FIGS. 8, 10). Specifically described, in the case of the embodiment, the knee restraint portion 28 is configured to be arranged close to the front of the knees KL1, KR1 of the occupant MP1 (equivalent to an adult male (AM50 dummy) with a standard build). Further, in the embodiment, the thickness dimension of the knee restraint portion 28 at the completion of inflation is set to a dimension that can accurately protect the knees KL1, KR1 while suppressing bottoming when contacting a body side member (not shown) arranged in front of the knees KL1, KR1.

[0022] The gas flow path portion 30 is connected to the inflator 17 via the conduit portion 40, and is configured such that the inflation gas discharged from the inflator 17 can flow out toward the knee restraint portion 28. It includes a cross flow path portion 31 and two longitudinal flow path portions 32L and 32R. As shown in FIG. 5, the cross flow path portion 31 and each of the longitudinal flow path portions 32L and 32R are set such that the width dimension in the vertical direction at the completion of inflation is smaller than the width dimension in the vertical direction of the knee restraint portion 28. In the case of the embodiment, it is set to about 2 / 5. The cross flow path portion 31 is disposed along the left-right direction at the rear end side of the bag body 26 at the completion of inflation. As will be described later, the cross flow path portion 31 is configured to have a belt loop portion 45 disposed on the lower surface 31c side of the left and right central portions at the completion of inflation, and is attached to the lap belt 10 in the region on the lower surface 31c side at the completion of inflation (see FIGS. 4 and 5). That is, the cross flow path portion 31 is disposed along the lap belt 10 above the waist MW at the completion of inflation of the bag body 26, and at least the lower surface 31c side near the left and right centers is supported by the waist MW via the lap belt 10 (see FIG. 10). Each of the longitudinal flow path portions 32L and 32R is disposed along the front-rear direction so as to connect the left ends 28a and 31a and the right ends 28b and 31b of the cross flow path portion 31 and the knee restraint portion 28 at the left end side and the right end side of the bag body 26 at the completion of inflation, respectively (see FIGS. 4 and 9). In the case of the embodiment, each of the longitudinal flow path portions 32L and 32R is disposed at a position outside the left and right thigh portions TL and TR of the occupant MP1 as shown in FIG. 9 at the completion of inflation of the bag body 26. And in the case of the embodiment, the gas flow path portion 30 communicates the conduit portion 40 near the intersection of the cross flow path portion 31 and the left longitudinal flow path portion 32L. Also, in the bag body 26 of the embodiment, in the state where the airbag 25 at the completion of inflation is viewed from the vertical direction side, the knee restraint portion 28, the cross flow path portion 31, and the two longitudinal flow path portions 32L and 32R are arranged in a substantially square annular shape (see FIGS. 4 and 7).

[0023] The auxiliary inflation part 35 is configured by connecting the left end 35a side and the right end 35b side to the respective vertical flow path parts 32L and 32R between the knee restraint part 28 and the lateral flow path part 31. In the case of the embodiment, it is formed in a rod shape along the left - right direction (along the lateral flow path part 31 and the knee restraint part 28), and is disposed in front of the lateral flow path part 31, which is behind the center in the front - rear direction of the bag body 26 (see FIGS. 4 and 5). In the case of the embodiment, the auxiliary inflation part 35 is set such that the width dimension in the up - down direction side and the width dimension in the front - rear direction side at the completion of inflation are substantially the same as those of the lateral flow path part 31. This auxiliary inflation part 35 expands so as to be interposed between the connecting member 37 and the thigh parts TL and TR of the occupant MP1 as shown in FIG. 10 when the inflation of the bag body 26 is completed. That is, the auxiliary inflation part 35 is supported by the thigh parts TL and TR on the lower surface 35c side when the inflation of the bag body 26 is completed.

[0024] In the case of the embodiment, the connecting member 37 for connecting the knee restraint part 28 to the lap belt 10 side is disposed so as to cover substantially the entire upper surface side of the bag body 26 as shown in FIGS. 4, 5, and 9. Specifically, the connecting member 37 connects the front edge 37a side to the upper end surface of the knee restraint part 28 over substantially the entire length, connects the rear edge 37b side to the upper end surface of the lateral flow path part 31 over substantially the entire length, and connects the left edge 37c side and the right edge 37d side to the upper end surfaces of the respective vertical flow path parts 32L and 32R over substantially the entire length. That is, the connecting member 37 connects (couples) its outer peripheral edge to the knee restraint part 28, the lateral flow path part 31, and the vertical flow path parts 32L and 32R over substantially the entire length. Also, the connecting member 37 is connected to the upper end surface of the auxiliary inflation part 35.

[0025] The conduit portion 40 is formed so as to extend leftward from the left end 31a of the horizontal flow path portion 31 so as to be continuous with the horizontal flow path portion 31 (see FIG. 4). The conduit portion 40 has an open tip 40a side and is to be connected to the inflator 17 (specifically, the pipe portion 19 of the inflator 17). This conduit portion 40 is configured to extend leftward from the bag body 26 and be disposed along the left-right direction so as to follow the lap belt 10 when the inflation of the airbag 25 is completed. The tip 40a side is connected to the pipe portion 19 of the inflator 17 using the clamp 20 as described above (see FIG. 8).

[0026] The belt loop portion 45 is disposed on the lower surface 31c side near the left and right centers of the horizontal flow path portion 31 in the bag body 26, and is configured as a substantially cylindrical shape disposed along the left-right direction so as to follow the lap belt 10, and is configured to allow the lap belt 10 to be inserted therethrough (see FIGS. 4 and 5). In the embodiment, by inserting the lap belt 10 through the belt loop portion 45, the bag body 26 (airbag 25) is held by the lap belt 10 (belt body 8).

[0027] In the embodiment, the airbag 25 is in a state of a folded completed body 55 in which the region of the bag body 26 is folded into a long shape along the lap belt 10 so that the width in the front-rear direction can be reduced. Together with the conduit portion 40, the periphery is covered by the cover portion 50 and is stored in the portion of the lap belt 10 (see FIG. 3). The cover portion 50 covers the periphery of the folded bag body 26 (folded completed body 55) and the conduit portion 40, including the lap belt 10. In the case of the embodiment, the folded completed body 55 is disposed on the back side (backrest portion 2 side) of the lap belt 10 that is exposed on the front surface of the backrest portion 2 in the non-mounted state as shown in FIG. 2.

[0028] The cover portion 50 is configured to cover the periphery of the folded bag body 26 (fully folded body 55) and the conduit portion 40, and is composed of a flexible sheet body. Specifically, in the case of the embodiment, the cover portion 50 is composed of a sheet body such as synthetic leather or fabric. Specifically, the cover portion 50 is configured to cover the outer peripheral side of the entire airbag 25 and the vicinity of the pipe portion 19 in the inflator 17. When the airbag 25 expands, a predetermined portion is broken over substantially the entire left and right areas so that the bag body 26 can protrude.

[0029] In the occupant protection device S1 of the first embodiment, when the occupant MP1 is seated while wearing the seat belt 7 on the seat 1 mounted on the vehicle and the inflator 17 operates in response to an operation signal from a control device (not shown), the inflation gas discharged from the inflator 17 flows into the bag body 26 through the conduit portion 40. The bag body 26 breaks the cover portion 50 and protrudes forward from the lap belt 10, and as shown in FIGS. 6 to 8, the inflation is completed.

[0030] In the passenger protection device S1 of the first embodiment, the passenger protection device S1 is mounted on the seat 1 on which the passenger MP1 is seated. Specifically, when the passenger MP1 sits on the seat 1, an airbag 25 folded and stored in the lap belt 10 of the seat belt 7 worn by the passenger MP1 is inflated by allowing inflation gas to flow into it and protrude forward, so as to restrain the knees KL1 and KR1. That is, since the passenger protection device S1 of the first embodiment is not mounted on a member on the vehicle body side like a conventional knee protection airbag device, regardless of the design of the interior space of the vehicle (the shape of the members in the vehicle interior), when the airbag 25 inflates, the knee restraint portion 28 can be arranged close to the front of the knees KL1 and KR1 of the passenger MP1. The knees KL1 and KR1 of the passenger MP1 can be stably restrained by the knee restraint portion 28 arranged close by. Also, in the passenger protection device S1 of the first embodiment, the knee restraint portion 28 is configured to be connected to the lap belt 10 side by a connecting member 37. Therefore, when the airbag 25 deploys and inflates, it is possible to suppress the knee restraint portion 28, which inflates while allowing inflation gas to flow into it and protrudes forward, from protruding excessively forward so as to be greatly separated from the lap belt 10. Therefore, it becomes possible to quickly restrain the knees KL1 and KR1 of the passenger MP1 by the knee restraint portion 28, and in cooperation with the lap belt 10 that restrains the waist MW, it is possible to accurately regulate the forward movement of the passenger MP1 (especially the lower body MD) with respect to the seat 1.

[0031] Therefore, in the passenger protection device S1 of the first embodiment, regardless of the shape of the members in the vehicle interior, the knees KL1 and KR1 of the passenger MP1 seated on the seat 1 can be accurately restrained, and the forward movement of the passenger MP1 with respect to the seat 1 can be regulated.

[0032] In addition, in the occupant protection device S1 of the first embodiment, in the airbag 25 (bag body 26), a gas flow path portion 30 through which the inflation gas discharged from the inflater 17 can flow out to the knee restraint portion 28 side is disposed on the rear end side of the bag body 26, and two vertical flow path portions 32L and 32R disposed on the left end side and the right end side of the bag body 26. Therefore, the inflation gas discharged from the inflater 17 flows into the knee restraint portion 28 through the horizontal flow path portion 31 and the left and right vertical flow path portions 32L and 32R. Therefore, even if the inflation gas is configured to flow into the interior only from one side (the left end side of the horizontal flow path portion 31 in the case of the embodiment) on the left or right side at the rear end side of the airbag 25 (bag body 26), the inflation gas that has flowed into the interior can quickly inflate the airbag 25 (bag body 26) in a well-balanced manner left and right. In addition, in the occupant protection device S1 of the first embodiment, in a state where the airbag 25 (bag body 26) is viewed from the vertical direction in the inflated state, a portion (the horizontal flow path portion 31, the two vertical flow path portions 32L and 32R, and the knee restraint portion 28) into which the inflation gas flows and inflates is configured to be arranged in a substantially square annular shape. Therefore, when the airbag 25 (bag body 26) expands and protrudes forward from the lap belt 10 by inflowing the inflation gas into the interior, the airbag 25 (bag body 26) inflates so as to quickly form a substantially square annular shape when viewed from above, and it is possible to suppress large fluctuations in the front, rear, left, and right directions. Therefore, the knee restraint portion 28 can be quickly arranged in front of the knees KL1 and KR1 of the occupant MP1, and it is possible to quickly restrict the occupant MP1 from moving forward with respect to the seat 1. In particular, in the occupant protection device S1 of the first embodiment, since the connecting member 37 is configured to be connected (coupled) to the knee restraint portion 28, the horizontal flow path portion 31, and the vertical flow path portions 32L and 32R over substantially the entire outer peripheral edge, the bag body 26 can easily form a square annular shape during deployment and inflation, and it is possible to accurately restrict large fluctuations in the front, rear, left, and right directions. Of course, the connecting member is not limited to the embodiment, and a configuration may be adopted in which only the front edge side and the rear edge side are connected to the knee restraint portion and the horizontal flow path portion, without connecting the left edge side and the right edge side to the vertical flow path portion.Furthermore, without considering the above points, as the gas flow path portion, a configuration in which the vertical flow path portions are not provided on both the left and right sides and are provided only on one of the left and right sides may be used.

[0033] Furthermore, in the occupant protection device S1 of the first embodiment, an auxiliary inflating portion 35 is disposed between the knee restraint portion 28 and the lateral flow path portion 31. This auxiliary inflating portion 35 inflates so as to be interposed between the connecting member 37 and the thighs TL, TR of the occupant MP1 when the inflation of the airbag 25 is completed. Therefore, when the inflation of the airbag 25 is completed, the lower surface 35c side of the auxiliary inflating portion 35 disposed at the intermediate portion in the front-rear direction can be brought into contact with the upper surfaces of the thighs TL, TR. In other words, in the airbag 25 of the occupant protection device S1 of the first embodiment, as shown in FIG. 10, the lower surface 35c side of the auxiliary inflating portion 35, which is in two locations separated in the front-rear direction, and the lower surface 31c side of the lateral flow path portion 31 are supported by the occupant MP1 (thighs TL, TR or the waist MW around which the lap belt 10 is wound), so that the airbag 25 can be inflated. Therefore, the position of the knee restraint portion 28 with respect to the knees KL1, KR1 (the position of the knee restraint portion 28 in the vertical direction with respect to the knees KL1, KR1) can be stabilized. Therefore, the knees KL1, KR1 of the occupant MP1 can be more stably restrained by the knee restraint portion 28. Without considering such points, as the airbag, a configuration in which the auxiliary inflating portion is not provided may be used.

[0034] Next, the occupant protection device S2 according to the second embodiment of the present invention will be described. In the case of the second embodiment, the occupant protection device S2 is for protecting the occupants MP (MP1, MP2) seated on the vehicle seat 1A (passenger seat). As shown in FIGS. 11 to 13, it is mounted on the vehicle seat 1A (passenger seat) and includes a seat belt 7, an airbag 70, an inflater 17 for supplying inflation gas to the airbag 70, a cover portion 50 that covers the periphery of the folded complete body formed by folding the airbag 70 (specifically, the bag body 71 described later), and a holding release means 60 as a shape control mechanism for controlling the inflation shape of the airbag 70 according to the physical differences of the occupants MP (MP1, MP2). In the occupant protection device S2 of the second embodiment, the members other than the airbag 70 and the holding release means 60 have the same configuration as the occupant protection device S1 of the first embodiment. Therefore, the same reference numerals are given to the same members, and detailed description thereof is omitted. In the occupant protection device S2 of the second embodiment, the inflater 17 and the holding release means 60 are configured to be controlled in operation by the control device 90 shown in FIG. 11.

[0035] As shown in FIG. 11, the control device 90 is electrically connected to an occupant detection sensor capable of detecting the physical build, seating position, etc. of the occupants MP1, MP2 seated on the seat 1A, for example, a position detection sensor 91 capable of detecting the distance between an instrument panel (hereinafter abbreviated as "IP") (not shown) disposed in front of the seat 1A and the occupants MP1, MP2, a weight detection sensor 92 capable of detecting the weight of the occupants MP1, MP2, and a collision detection sensor 93 capable of detecting the acceleration and direction of acceleration of the vehicle. The control device 90 inputs electrical signals from these position detection sensor 91, weight detection sensor 92, or collision detection sensor 93 to operate the inflater 17 and the holding release means 60. In the case of the embodiment, the holding release means 60 is controlled in operation by the control device 90 so as to regulate the inflation shape of the knee restraint portion 73 in the airbag 70 when the airbag 70 inflates during the operation of the inflater 17.

[0036] The release means 60 as the shape control mechanism connects a tether 80, which will be described later, extending from the airbag 70. In the occupant protection device S2 of the second embodiment, as shown in FIG. 12, it is attached to a region on the left end side of the seat frame 4A using a predetermined bracket (not shown) above the inflator 17. This release means 60 includes a locking pin 62 inserted into a connection hole 82a formed in the tip side portion 82 of the tether 80, and an actuator 61 attached to the rear surface side of the seat frame 4 and operable to retract the locking pin 62. When the actuator 61 operates to retract the locking pin 62, the locking pin 62 shifts from the state of locking the tip side portion 82 of the tether 80 to the state of releasing the locking, and the connection holding state of the tether 80 is released (see A and B in FIG. 14). This actuator 61 is electrically connected to the control device 90, and if the locking pin 62 can be moved by an electrical signal from the control device 90, a piston cylinder using fluid pressure including cases of generating hydraulic pressure, water pressure, air pressure, or the expanding gas pressure of an inflator or the like, a motor using those fluid pressures or electricity, an electromagnetic solenoid, a spring using the biasing force during restoration, etc. can be used. In the embodiment, the actuator 61 is arranged so as to project the locking pin 62 to the left, and on the left side of the actuator 61 (the tip side of the locking pin 62), a support base 63 that supports the tip side of the locking pin 62 and prevents the tip side portion 82 of the tether 80 from coming off the locking pin 62 during locking (maintains the connection holding state of the tether 80) is arranged so as to project from the seat frame 4A (see FIG. 14). Although detailed illustration is omitted, the release means 60 and the inflator 17 are covered by a predetermined cover.

[0037] Similar to the airbag 25 in the occupant protection device S1 of the first embodiment, the airbag 70 is disposed at a portion of the lap belt 10 that restrains the lower body MD (waist MW) of the occupant MP (MP1, MP2) sitting on the seat 1A, and is formed of a woven fabric made of polyester yarn, polyamide yarn, or the like. As shown in FIGS. 15 and 16, the airbag 70 includes a bag body 71 that inflates by allowing inflation gas to flow therein, a conduit portion 40 that connects the bag body 71 and the inflator 17, a tether 80 that regulates the inflated shape of a knee restraint portion 73 (to be described later) in the bag body 71, and a belt loop portion 45 through which the lap belt 10 (belt body 8) can be inserted. Since the conduit portion 40 and the belt loop portion 45 have the same configuration as the conduit portion 40 and the belt loop portion 45 in the airbag 25 of the aforementioned occupant protection device S1, the same reference numerals are given and detailed description thereof is omitted.

[0038] Similar to the bag body 26 in the aforementioned airbag 25, the bag body 71 has a substantially rectangular shape in the inflated completed state when viewed from the vertical side, and is disposed so as to cover substantially the entire upper side of the lower limbs (from the left and right thighs TL and TR to the knees K1 and K2) of the occupant MP (MP1, MP2) when inflation is completed (see FIG. 18). The bag body 71 includes a knee restraint portion 73 that inflates to restrain the knees K1 and K2 of the occupant MP (MP1, MP2), a gas flow path portion 30, an auxiliary inflation portion 35, and a connecting member 37A that connects the knee restraint portion 73 to the lap belt 10 side. Since the gas flow path portion 30 and the auxiliary inflation portion 35 have the same configuration as the gas flow path portion 30 and the auxiliary inflation portion 35 in the airbag 25 of the aforementioned occupant protection device S1, the same reference numerals are given and detailed description thereof is omitted.

[0039] The knee restraint portion 73 is arranged to extend along the left - right direction in front of the left and right knees K (K1, K2) of the occupant MP (MP1, MP2) when inflation is completed. In the airbag 70 of the occupant protection device S2 of the second embodiment, the knee restraint portion 73 is configured to include a front - side portion 74 and a rear - side portion 75 that are arranged in parallel in the front - rear direction so as to be able to restrain the knees K1 and K2 respectively. The front - side portion 74 is arranged to extend along the left - right direction on the front - end side of the bag body 71, and the left - end 73a side and the right - end 73b side are respectively connected to the front - end sides of the vertical flow path portions 32L and 32R in the gas flow path portion 30. The rear - side portion 75 is separated from the front - side portion 74 and is arranged to extend along the left - right direction along the front - side portion 74 while being close to the rear side of the front - side portion 74. The left - end 75a side and the right - end 75b side are respectively connected to the vertical flow path portions 32L and 32R. That is, the front - side portion 74 and the rear - side portion 75 that constitute the knee restraint portion 73 do not communicate with each other, and are configured to inflate by allowing inflation gas to flow into the interior through the vertical flow path portions 32L and 32R respectively. In the case of the embodiment, the vertical width dimension and thickness at the time of inflation completion of the front - side portion 74 and the rear - side portion 75 are made substantially the same (see FIGS. 16 and 22). Similar to the knee restraint portion 28 in the airbag 25 described above, the outer shape at the time of inflation completion is in the shape of a long strip that extends along the left - right direction while the width direction is along the up - down direction. The width dimensions of the left - right direction side and the up - down direction side of these front - side portion 74 and rear - side portion 75 at the time of inflation completion are set to dimensions that can widely cover the left and right knees K1 and K2 of the occupant MP (MP1, MP2) in the up - down, left - right directions. In the occupant protection device S2 of the second embodiment, as will be described later, the inflation shape of the rear - side portion 75 is controlled by the tether 80. The front - side portion 74 is configured to be arranged close to the front of the knee K1 of a relatively large - framed occupant MP1 (equivalent to an adult male of standard build (AM50 dummy) or an occupant MP who is seated so as to separate the knee K1 from the front - end 3b of the seat portion 3) when inflation is completed (see FIG. 19).The rear portion 75 is configured to be disposed in proximity to the front of the knee K2 of a relatively small-sized occupant MP2 (an adult female of standard build (equivalent to the AF05 dummy) or an occupant MP seated with the knee K2 close to the front end 3b of the seat part 3A) when inflation is completed (see Fig. 22). As shown by the two-dot chain line in Fig. 16 and Fig. 22, the inner peripheral surface side of the lower end 75d of the rear portion 75 when inflation is completed is connected to the tether 80.

[0040] The connecting member 37A that connects the knee restraint part 73 to the lap belt 10 side is connected (joined) to the knee restraint part 73, the lateral flow path part 31, and the longitudinal flow path parts 32L and 32R over substantially the entire outer peripheral edge, in the same manner as the connecting member 37 in the airbag 25 described above. Specifically described, the front edge side of the connecting member 37A is connected to the upper end surface of the front portion 74 in the knee restraint part 73 over substantially the entire length, and the rear edge side is connected to the upper end surface of the lateral flow path part 31 over substantially the entire length. Also, the left edge side and the right edge side of the connecting member 37A are each connected to the upper end surfaces of the respective longitudinal flow path parts 32L and 32R over substantially the entire length. Further, the connecting member 37A is also connected to the upper end surface of the rear portion 75 in the knee restraint part 73 and the upper end surface of the auxiliary inflation part 35.

[0041] Also, in the airbag 70 of the second embodiment, an insertion slit 77 for inserting the tether 80 is formed linearly along the left-right direction in the region of the connection part between the upper end 75c of the rear portion 75 and the connecting member 37A (see Figs. 15 and 16).

[0042] The tether 80 that restricts the inflated shape of the knee restraint portion 73 is formed as a belt-like body made of a flexible sheet, and is disposed so as to connect the lower end 75d side of the rear side portion 75 in the knee restraint portion 73 and the holding release means 60. Specifically, the tether 80 has its base portion side 81 connected to the inner peripheral surface side of the lower end 75d of the rear side portion 75 in the knee restraint portion 73, passes through the insertion slit 77 formed on the upper end 75c side of the rear side portion 75, and is disposed so as to be exposed on the outer peripheral surface side of the bag body 71, and the tip side portion 82 is configured to be connected to the holding release means 60 disposed above the inflator 17 (see FIGS. 14 to 16). Specifically, the tether 80 is disposed at a position substantially in the center of the left and right of the bag body 71. As shown in FIGS. 14, 17, and 18, when the inflation of the airbag 70 is completed, it passes through the insertion slit 77 and extends rearward along the front-rear direction on the upper surface side of the bag body 71 to the region of the transverse flow path portion 31 which is the rear end side of the bag body 71, and is bent in the region on the upper surface side of the transverse flow path portion 31 so as to extend leftward, and is disposed so as to pass through the outer surface (left side surface in the case of the embodiment) of the conduit portion 40 from the upper surface of the transverse flow path portion 31. And the tether 80 has the locking pin 62 of the holding release means 60 inserted through the connection hole 82a provided in the tip side portion 82, thereby connecting the tip side portion 82 to the holding release means 60 (see A in FIGS. 13 and 14). The length dimension of this tether 80 is set to a dimension such that, when the airbag 70 is inflated while maintaining the connection with the holding release means 60, as shown in FIG. 19, the base portion side 81 connected to the lower end 75d side of the rear side portion 75 can pull the region on the lower end 75d side of the rear side portion 75 upward (the downward deployment of the rear side portion 75 can be suppressed). Also, in the tether 80 of the embodiment, the base portion side 81 is configured as a belt-like shape (wide on the left and right) that can be connected to the region on the lower end 75d side of the rear side portion 75 in a wide range in the left and right directions, and the region excluding the base portion side 81 in the tether 80 is made narrower than the base portion side 81 and is formed as a belt-like shape with a substantially constant width dimension including the tip side portion 82 (see FIG. 17).Then, in the case of the embodiment, when the inflation of the airbag 70 is completed while maintaining the connection between the tip-side portion 82 and the release means 60, the base-side portion 81 is disposed in the rear-side portion 75 close to the upper-end 75c side of the rear-side portion 75, and restricts the downward deployment of the rear-side portion 75 in a wide range left and right (see FIGS. 16, 20, and 21).

[0043] Further, on the upper surface side of the airbag 70 of the embodiment (specifically, on the upper surface side of the bag body 71 and the left side surface side of the conduit portion 40), a position-regulating member 85 capable of regulating the arrangement position of the tether 80 is disposed. The position-regulating member 85 is disposed at a plurality of locations along the length direction of the tether 80, and is formed in a strip shape along the width direction of the tether 80 with both ends connected to the bag body 71 side, and is configured such that the arrangement position of the tether 80 can be regulated by inserting the tether 80 therethrough. Specifically, in the case of the embodiment, the position-regulating member 85 is disposed at six locations along the length direction of the tether 80 (see FIGS. 15, 18, and 19).

[0044] Also in the occupant protection device S2 of the second embodiment, with the occupant MP (MP1, MP2) seated while wearing the seat belt 7 on the seat 1A mounted in the vehicle, when the inflator 17 is actuated in response to an actuation signal from the control device 90, the inflation gas discharged from the inflator 17 flows into the bag body 71 through the conduit portion 40, and the bag body 71 breaks the cover portion 50 and protrudes forward from the lap belt 10, and as shown in FIGS. 18 and 19, the inflation is completed.

[0045] And in the occupant protection device S2 of the second embodiment, the airbag 70 is configured to have different inflation shapes according to the physiques of the occupants MP1 and MP2 seated on the seat 1A. Specifically, in the occupant protection device S2 of the second embodiment, the airbag 70 is configured to inflate with different inflation shapes according to the difference in the positions of the knees K1 and K2 with respect to the seat portion 3A of the occupants MP1 and MP2 seated on the seat 1A.

[0046] Specifically, in the occupant protection device S2 of the second embodiment, a control device 90 that receives signals from predetermined sensors 91, 92, 93 outputs an activation signal to an actuator 61 of the release means 60 substantially simultaneously with the activation of the inflator 17 when it detects an occupant MP, such as a relatively petite occupant MP2 (equivalent to an adult female (AF05 dummy) of standard build), or an occupant MP seated on the seat 1A in a state of approaching the front instrument panel. The actuator 61 is activated to retract the locking pin 62, and as shown in B of FIG. 14, the connection state of the tip-side portion 82 of the tether 80 is released. Then, since the rear-side portion 75 of the knee restraint portion 73 in the airbag 70 is released from the state of being pulled upward on the lower-end 75d side, when the airbag 70 is fully inflated, the knee restraint portion 73 inflates both the front-side portion 74 and the rear-side portion 75 as shown in FIG. 22 and is disposed in front of the knee K2 of the occupant MP (MP2). Such an occupant MP (MP2) is assumed to be seated with the knee K2 close to the front end 3b of the seat portion 3A, and the inflated rear-side portion 75 is disposed close to the front of the knee K2, and the rear-side portion 75 can smoothly restrain the knee K2 of such an occupant MP (petite occupant MP2).

[0047] Conversely, when the control device 90 detects, for example, a relatively large-sized occupant MP1 (equivalent to an adult male with a standard build (AM50 dummy) or an occupant MP sitting on the seat 1A in a state separated from the front instrument panel), no actuation signal is output from the control device 90 to the actuator 61, and the airbag 70 will inflate while maintaining the held state by the holding release means 60 of the tip-side portion 82 of the tether 80. When the inflation of the airbag 70 is completed, as shown in FIG. 20, the knee restraint portion 73 suppresses the downward protrusion of the rear-side portion 75 (in a state where the rear-side portion 75 is not inflated) and inflates only the front-side portion 74, and thus will be disposed in front of the knee K2 of the occupant MP (MP1). Such an occupant MP (MP1) is assumed to be sitting in such a manner that the knee K1 is separated from the front end 3b of the seat portion 3A, and the inflated front-side portion 74 will be disposed in the vicinity of the front of the knee K1, and the front-side portion 74 can smoothly restrain the knee K1 of such an occupant MP (large-sized occupant MP1). Incidentally, during the traction maintenance by such a tether 80, the rear-side portion 75 will be tractioned upward in a wide range on the left and right by the base-side portion 81 of the tether 80 in the left and right central regions on the lower end 75d side, and the contact between the left and right central regions and the knee K1 can be suppressed (see FIG. 21). Also, when the inflation of the airbag 70 is completed, since a certain amount of space is generated between the upper end 75c side of the rear-side portion 75, that is, between the connecting member 37A and the knee K1, the left and right edge-side regions of the rear-side portion can also suppress the rear-side portion 75 from pressing the knee K1 of the occupant MP1 downward. Therefore, it is possible to regulate the rear-side portion 75 from unnecessarily pressing the knee K1, and the front-side portion 74 can stably restrain the knee K1. Note that the shape of the tether is not limited to the embodiment, and a belt-shaped one with a constant width dimension over the entire length including the base-side portion may be used.

[0048] That is, in the occupant protection device S2 of the second embodiment, even when occupants MP (MP1, MP2) with different physiques, whose positions of knees K1 and K2 relative to the seat portion 3 at the time of seating are different front and rear, are seated, the knees K1 and K2 of each occupant MP (MP1, MP2) can be accurately restrained by the knee restraint portion 73 (front side portion 74 or rear side portion 75) (see FIGS. 20 and 22). In the airbag 70 of the second embodiment, the front side portion 74 and the rear side portion 75 are configured such that the thickness and the vertical width dimension at the time of complete inflation are substantially the same. However, the rear side portion may be configured to inflate thinner than the front side portion. This is because in the normal case, when the rear side portion inflates, the front side portion is already inflated. However, considering the occurrence of a delay in the operation of the actuator, etc., it is desirable that the front side portion and the rear side portion inflate with substantially the same thickness.

[0049] In the occupant protection devices S1 and S2 of the first and second embodiments, the seat belt 7 and the inflator 17 are configured to be mounted on the seats 1 and 1A. Therefore, even when the seats 1 and 1A are slid or rotated significantly back and forth and used in a state of being moved relative to the vehicle, the occupants MP (MP1, MP2) seated on the seats 1 and 1A can be accurately protected by the airbags 25 and 70. Of course, the occupant protection device of the present invention is not limited to seats having such a configuration, and can also be mounted on a seat of a type that restrains an occupant with a seat belt having a retractor provided on the vehicle body side. Also, the inflator may be configured to be attached to the vehicle body side. In the occupant protection devices S1 and S2 of the first and second embodiments, although the airbags 25 and 70 are held by the lap belt 10 of the seat belt 7, since the inflator 17 operates with a delay (about 5 ms) compared to the operation of the pretensioner mechanism of the seat belt 7, the airbags 25 and 70 can be inflated in a state where the seating state of the occupants MP (MP1, MP2) relative to the seats 1 and 1A is stably maintained by the seat belt 7, and the occupants MP (MP1, MP2) can be stably protected by the airbags 25 and 70 and the seat belt 7.

Description of Reference Numerals

[0050] 1,1A... seat, 3,3A... seat part, 3b... front end, 7... seat belt, 10... lap belt, 17... inflator, 25... airbag, 26... bag body, 28... knee restraint part, 30... gas flow path part, 31... cross flow path part, 32L, 32R... longitudinal flow path parts, 35... auxiliary inflation part, 37, 37A... connecting member, 40... conduit part, 45... belt loop part, 60... holding release means, 70... airbag, 71... bag body, 73... knee restraint part, 74... front side part, 75... rear side part, 80... tether, 90... control device, MP, MP1, MP2... occupant, TL, TR... thigh, K1, K2... knee, MW... waist, S1, S2... occupant protection device.

Claims

1. An occupant protection device for protecting an occupant seated on a vehicle seat, comprising: a seat belt having a lap belt capable of restraining the occupant's waist; an inflator; an airbag that is folded and stored in a portion of the lap belt and that, when the inflator operates, allows inflation gas discharged from the inflator to flow therein, projects forward, and inflates so as to restrain the occupant's knees; and comprising: the airbag being: when inflation is complete, disposed so as to extend along the left-right direction in front of the left and right knees of the occupant, and having a knee restraint portion capable of restraining each knee; a connecting member that connects the knee restraint portion to the lap belt side; An occupant protection device, characterized by comprising the above.

2. The airbag includes a gas flow path portion through which inflation gas discharged from the inflator can flow out to the knee restraint portion side, the gas flow path portion being: a horizontal flow path portion disposed along the left-right direction on the rear end side of the airbag when inflation is complete; two vertical flow path portions disposed on the left end side and the right end side of the airbag when inflation is complete, respectively, so as to connect the horizontal flow path portion and the knee restraint portion; and being configured to include the above. The connecting member is composed of a flexible seat body, and at least the front edge side and the rear edge side are connected to the knee restraint portion and the horizontal flow path portion, respectively. The occupant protection device according to claim 1, characterized in that the horizontal flow path portion is attached to the lap belt in a region on the lower surface side of the airbag when inflation is complete.

3. The knee restraint portion is configured to include a front side portion and a rear side portion that are arranged in parallel in two rows in the front-rear direction so as to be able to restrain the knees. The occupant protection device according to claim 2, characterized in that the inflation of the airbag is controlled such that the rear side portion is inflated when an occupant sitting so as to bring the knees close to the front end of the seat portion of the seat is detected.

4. An auxiliary inflation portion configured by connecting both end sides to the respective vertical flow path portions is disposed between the knee restraint portion and the horizontal flow path portion. The occupant protection device according to claim 2 or 3, characterized in that the auxiliary inflation portion inflates so as to be interposed between the connecting member and the thigh portion of the occupant when inflation of the airbag is complete.

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