Occupant restraint device

Abstract

Provided is an occupant restraint device capable of softly restraining an occupant at the time of a vehicle collision.　This occupant restraint device is provided with: a webbing; an airbag that is provided to the webbing and that inflates and deploys on the front surface of an occupant on a vehicle seat at the time of the vehicle collision; and a delivery mechanism that causes the webbing to be delivered at the time of the vehicle collision.

Description

occupant restraint system

[0001] The present invention relates to an occupant restraint device.

[0002] 2. Description of the Related Art Vehicles are equipped with seat belt devices that restrain occupants in vehicle seats, and airbags that are deployed in the event of a vehicle emergency to restrict movement of occupants.

[0003] A seat belt device has a retractor that retracts and unwinds the webbing by rotating a spool. In a motorized retractor, when the vehicle suddenly decelerates (for example, when there is a possibility of a collision), the motor rotates the spool in the retraction direction to retract a certain amount of webbing, thereby lightly restraining the occupant. In a retractor with a pretensioner, in the event of a frontal collision of the vehicle, the pretensioner rotates the spool in the retraction direction to forcibly and instantly retract the webbing, thereby restricting forward movement of the occupant's upper body and quickly and reliably restraining the occupant (see, for example, Patent Document 1).

[0004] JP 2011-162157 A

[0005] In recent years, there has been a growing demand for reducing the load from webbing to an occupant in the event of a frontal collision of a vehicle.

[0006] An object of the present invention is to provide an occupant restraint device that can softly restrain an occupant in the event of a vehicle collision.

[0007] An occupant restraint device according to one aspect of the present invention is an occupant restraint device that includes a webbing and an airbag that is attached to the webbing and inflates and deploys in front of an occupant sitting on a vehicle seat in the event of a vehicle collision, and further includes a payout mechanism that pays out the webbing in the event of a vehicle collision.

[0008] According to this aspect, contrary to conventional retractors with pretensioners, the webbing is unwound during a vehicle collision. This provides slack or slack in the webbing relative to the occupant during a vehicle collision. Furthermore, during a vehicle collision, an airbag attached to the webbing inflates and deploys in front of the occupant. Therefore, during a frontal collision, for example, the unwound webbing reduces the load that the occupant receives from the webbing, and the inflated and deployed airbag absorbs the impact and suppresses forward movement of the occupant due to inertia. In this way, during a vehicle collision, the unwound webbing and the inflated and deployed airbag work together to softly restrain the occupant.

[0009] 7A and 7B are perspective views of a vehicle seat having an occupant restraint device according to an embodiment; a perspective view of a seat belt device; a view of a vehicle seat having an occupant restraint device according to an embodiment, viewed from the front, with an occupant seated; a schematic cross-sectional view taken along line A-A in FIG. 3; a schematic cross-sectional view of a method of attaching an airbag to a webbing, according to another embodiment different from that of FIG. 3A, showing a state in which the airbag is housed in an inflation tube in the webbing; a schematic view of a method of attaching an airbag to a webbing, according to yet another embodiment, where (a) is a front view of a shoulder belt portion of the webbing in front of the occupant, and (b) is a cross-sectional view taken along line B-B in (a); a view showing the airbag in FIG. 5 after inflation and deployment, and a schematic view of a configuration similar to that of FIG. 5; a view showing several examples of attachment of the airbag and webbing in FIG. 5; a view showing an example of how the airbag is deployed in the example of FIG. 7A; a top view of the interior of a vehicle when the airbag is inflated and deployed; a side view of the interior of a vehicle when the airbag is inflated and deployed; a view showing a payout mechanism according to an example; a view showing a payout mechanism according to another example. 16 is a schematic cross-sectional view of the payout mechanism of FIG. 16, where (A) shows the load transmission path before switching, and (B) shows the load transmission path after switching. FIG. 17 is a diagram showing the relationship between the rotation speed of the spool in the payout direction and the energy absorption load during a vehicle collision, for the payout mechanism of FIG. 16. FIG. 18 is a block diagram showing the control configuration of an occupant restraint device having the payout mechanism of FIG. 11 or 12. FIG. 19 is a flowchart showing a control method for the occupant restraint device of FIG. 13. FIG. 20 is a diagram showing a payout mechanism according to yet another example. FIG. 21 is a diagram showing a payout mechanism according to yet another example. FIG. 22 is a diagram showing a payout mechanism according to the payout mechanism of FIG. 21.

[0010] A preferred embodiment of the present invention will be described with reference to the accompanying drawings.

[0011] In this document, up / down, left / right, and front / rear are defined as follows: When an occupant is seated in a seat (vehicle seat) in a normal posture, the direction the occupant is facing is referred to as the forward direction, and the opposite direction is referred to as the rearward direction, and when indicating the axes of coordinates, these are referred to as the front / rear direction. Also, when an occupant is seated in a vehicle seat in a normal posture, the right side of the occupant is referred to as the right direction, and the left side of the occupant is referred to as the left direction, and when indicating the axes of coordinates, these are referred to as the left / right direction. Similarly, when an occupant is seated in a normal posture, the direction of the occupant's head is referred to as the upward direction, and the direction of the occupant's waist is referred to as the downward direction, and when indicating the axes of coordinates, these are referred to as the up / down direction.

[0012] In this document, "occupant" refers to a person with a physique equivalent to that of an average American male, conforming to the frontal crash test dummy (Hybrid III AM50 / frontal crash test dummy established by the NHTSA [National Highway Traffic Safety Administration] standard [49CFR Part 572 Subparts E and O]), with approximate dimensions of 175 cm in height, 88 cm in seated height, and 78 kg in weight.

[0013] In this document, the term "vehicle collision" primarily refers to a frontal collision of a vehicle, but is not limited to this and may also include a side collision or an oblique collision.

[0014] 1, a vehicle seat 100 includes a seat back 110 that supports the back of an occupant, a seat cushion 112 on which the occupant sits, and a headrest 114 that supports the head of the occupant. The vehicle seat 100 may be a front seat (i.e., a driver's seat or a passenger seat) or a rear seat.

[0015] [Occupant Restraint Device] The occupant restraint device 200 includes a seat belt device 12 and an airbag module 50 , and is provided in association with the vehicle seat 100 .

[0016] Seat Belt Apparatus The seat belt apparatus 12 includes a webbing 14, which is a seat belt that restrains an occupant. The webbing 14 includes a shoulder belt portion 16 that extends from an upper guide loop or anchorage 18 to a tongue 20 and a lap belt portion 22 that extends from the tongue 20 to an anchorage 24. The tongue 20 may include a loop portion 26 through which the webbing 14 extends. The tongue 20 is configured to be insertable into a buckle 28 to lock and unlock the seat belt apparatus 12. A cable 30 of the buckle 28 secures the buckle 28 to a portion 31 of the vehicle structure (e.g., the vehicle frame), either directly or in cooperation with other components. When the tongue 20 is inserted into the buckle 28 and fastened, the seat belt apparatus 12 defines a three-point restraint between the anchorage 18, the tongue 20, and the anchorage 24.

[0017] 2, the seat belt device 12 has a retractor 32. The retractor 32 is configured to be able to retract the webbing 14, thereby making it possible to adjust the effective length of the webbing 14. The retractor 32 is positioned within the vehicle seat 100 or structurally coupled to the vehicle body.

[0018] The retractor 32 has a spool 36 rotatably housed in a frame 34. The spool 36 engages with the shoulder belt portion 16 of the webbing 14 and rotates to wind or unwind the webbing 14. The spool 36 biases the webbing 14 in the winding direction by a power spring, an electric motor, or the like. Meanwhile, the end of the lap belt portion 22 of the webbing 14 is fixed to an anchorage 24 (e.g., the frame 34, the vehicle seat 100, or another part of the vehicle such as a floor pan).

[0019] The retractor 32 may also include a torsion bar and a locking mechanism. Known configurations can also be employed for the torsion bar and the locking mechanism. An example of these will be described. For example, the torsion bar constitutes a force limiter and is disposed inside the spool 36, with one end connected to the spool 36 and the other end connected to a locking member of the locking mechanism. For example, when the vehicle decelerates at a predetermined rate or the brakes are applied with a predetermined force, the locking mechanism locks the rotation of the spool 36 by limiting the rotation of the locking member (locking the locking member), thereby stopping the unwinding of the webbing 14. During normal vehicle operation, the retractor 32 allows the webbing 14 to be unwound, providing the occupant with a certain degree of freedom of movement, and the webbing 14 may become slack during normal use.

[0020] 3 and 3A, an airbag module 50 is provided in association with the seat belt device 12. Here, the airbag module 50 is provided below the shoulder belt portion 16. The airbag module 50 includes an inflator 51 and an airbag 52.

[0021] The inflator 51 and the airbag 52 may be provided at different locations. For example, the airbag 52 may be provided in the shoulder belt portion 16, while the inflator 51 may be provided at a location away from the shoulder belt portion 16, such as on the anchorage 24 side or the buckle 28 side. In this case, the inflator 51 may be provided at the end of the lap belt portion 22, for example.

[0022] The inflator 51 supplies gas for inflation and deployment to the inside of the airbag 52 during a vehicle collision. The inflator 51 is electrically connected to an electronic control unit (ECU: for example, the controller 700 in FIG. 13 ). For example, the inflator 51 receives a signal from the ECU that detects the situation during a vehicle collision, and is activated to instantly supply gas to the airbag 52. Various inflators can be used as the inflator 51, such as those filled with a gas generating agent, compressed gas, or both. As an example, a micro gas generator can be used as the inflator 51. The inflator 51 is built into the airbag 52. However, in other embodiments, the inflator 51 may be built into the webbing 14 or the vehicle seat 100.

[0023] The airbag 52 inflates and deploys in front of an occupant in the vehicle seat 100 during a vehicle collision. The outline of the airbag 52 when inflated and deployed is shown by a two-dot chain line in FIG. 3 . The airbag 52 is formed into a bag shape, for example, by sewing or bonding one or more pieces of base fabric or the like at appropriate positions, or by weaving using OPW (One-Piece Woven). The airbag 52 receives gas from the inflator 51 and inflates and deploys from a stored state to a deployed state. In the stored state, the airbag 52 may be folded, and the folding method may be a roll shape, an accordion shape, or a combination thereof. In the stored state, the airbag 52 is attached to the webbing 14.

[0024] Here, various structures and attachment methods can be used for the airbag 52 and the webbing 14 as long as the airbag 52 can be attached to the webbing 14. For example, the airbag 52 and the webbing 14 can be integral or separate. The airbag 52 can be attached within the webbing 14 (e.g., between two webbing sections), or the airbag 52 can be attached to the outer surface of the webbing 14 (e.g., the surface facing the occupant). The airbag 52 can be attached directly to the webbing 14 (e.g., by sewing the two together) or indirectly (e.g., by attaching a container containing the airbag 52 to the webbing 14). The airbag 52 is attached to the webbing 14 so that at least a portion of the webbing 14 is located forward of the airbag 52 as viewed from the occupant. Some examples are described below.

[0025] 3A , the airbag 52 is provided on the occupant-facing surface of the webbing 14. For example, the airbag 52 is folded and attached to the rear surface of the shoulder belt portion 16. The airbag 52 is formed as a separate body from the shoulder belt portion 16 and is attached by being sewn to the rear surface of the shoulder belt portion 16 at an appropriate position. In another embodiment, the airbag 52 is integral with the shoulder belt portion 16 and woven together with the shoulder belt portion 16. In this case, part of the rear surface of the shoulder belt portion 16 forms part of the outer periphery of the airbag 52.

[0026] In FIG. 4 , the airbag 52 is stored in an inflation tube 61 in the webbing 14. For example, the airbag 52 is folded and placed in the inflation tube 61 together with the inflator 51. The inflation tube 61 is provided in the shoulder belt portion 16 of the webbing 14. The airbag 52 is sewn to the webbing 14. When inflated and deployed, the airbag 52 deploys from inside the inflation tube 61 to outside, and then inflates outside the inflation tube 61.

[0027] 5, there are at least two webbings 14 in the front-to-rear direction as seen from the occupant. For example, the webbing 14 has a front webbing portion 14A and a rear webbing portion 14B. The airbag 52 is provided so as to be sandwiched between the front webbing portion 14A and the rear webbing portion 14B, and is woven together with or sewn to the front webbing portion 14A and / or the rear webbing portion 14B.

[0028] Fig. 6 shows the state in which the airbag 52 in Fig. 5 is inflated and deployed. As shown in Fig. 6, the airbag 52 is sandwiched between the front webbing portion 14A and the rear webbing portion 14B, and inflates and deploys beyond the front webbing portion 14A and the rear webbing portion 14B on both sides in the vehicle width direction.

[0029] 7 shows several examples of attachment of the airbag 52 and webbing 14 in FIG. 5. As shown in FIG. 7( a), the airbag 52 and the webbing 14 may be woven together as an OPW, and both may be tack-sewn together at both widthwise ends of the webbing 14 with tacking 71, 71. Also, as shown in FIG. 7( b), the front webbing portion 14A and the rear webbing portion 14B may each be sewn to the airbag 52. Sewn points 72a, 72a between the front webbing portion 14A and the airbag 52 may be located outward in the widthwise direction of the webbing 14 than sewn points 72b, 72b between the rear webbing portion 14B and the airbag 52. Furthermore, as shown in FIG. 7( c), one of the front webbing portion 14A and the rear webbing portion 14B may be woven together with the airbag 52 as an OPW and then temporarily sewn at 73, and the other of the front webbing portion 14A and the rear webbing portion 14B may be sewn to the airbag 52 at sewing points 74, 74.

[0030] Figure 8 shows an example of how the airbag 52 in the example of Figure 7(a) deploys. A tear line 81 is formed in the webbing 14. The tear line 81 is formed, for example, on one side, both sides, the center, or a combination of these in the width direction of the rear webbing portion 14B. Because the rear webbing portion 14B is an OPW, the tear line 81 is formed in a location where the thickness of the base fabric in the rear webbing portion 14B is thinner than in other locations. When the airbag 52 inflates and deploys, the tacking stitches 71, 71 are torn by the inflating and deploying airbag 52.

[0031] Here, due to the positional relationship between the airbag 52 and the webbing 14, when the airbag 52 inflates and deploys, a portion of the webbing 14 serves as a reaction surface. This applies whether the airbag 52 is inflated or deployed using a single webbing 14 or multiple webbings. Specifically, during normal use when a single webbing 14 is used, the airbag 52 is located forward of the occupant, and the webbing 14 is located further forward of the airbag 52 (see FIG. 3A ). Furthermore, when there are at least two webbings 14 in the front-to-rear direction as viewed from the occupant (as in FIG. 5 ), during normal use, the order of positions is as follows: front webbing portion 14A of the webbing 14, airbag 52, rear webbing portion 14B of the webbing 14, and the occupant. Due to this positional relationship, when the airbag 52 inflates and deploys, the airbag 52 inflates and deploys using a portion of the webbing 14 that is forward of the airbag 52 as viewed from the occupant as a reaction surface. Therefore, the reaction force characteristics of the airbag 52 can be easily obtained by the tension of the webbing 14.

[0032] 9 and 10 , an overview of the inflation and deployment of the airbag 52 will be described. The airbag 52 has an outer shape of a substantially rectangular parallelepiped 90 in a deployed state (see FIG. 3 ). The left and right ends of the substantially rectangular parallelepiped 90 reach the left and right shoulders of the occupant. The substantially rectangular parallelepiped 90 also extends vertically from near the head to near the thighs of the occupant. For example, the upper part of the substantially rectangular parallelepiped 90 is located above the center of gravity of the occupant's head, and the lower part of the substantially rectangular parallelepiped 90 reaches the upper thighs of the occupant. Since the airbag 52 receives a reaction force from the upper thighs when inflated and deployed, its deployment behavior can be stabilized. In this way, the airbag 52 inflates and deploys from the occupant's head through the neck, chest, and waist, so that the lower part of the airbag 52 reaches the upper thighs of the occupant in front of these areas.

[0033] Furthermore, when the airbag 52 is inflated and deployed, the amount of inflation varies depending on the position in the front-to-rear direction as seen from the occupant. Specifically, the airbag 52 has a maximum inflation portion 92. The maximum inflation portion 92 is the portion of the substantially rectangular parallelepiped shape 90 that has the greatest length in the front-to-rear direction as seen from the occupant. With respect to the occupant, the maximum inflation portion 92 is positioned so as to face the vicinity of the occupant's collarbone.

[0034] In relation to the vehicle seat 100, when viewed from the side of the vehicle seat 100, the maximum inflation portion 92 is located near the boundary between the seat back 110 and the headrest 114 in the up-down direction. Here, "near the boundary" refers to a range from the boundary 115 between the seat back 110 and the headrest 114 to ±10% of the seat back height. "Seat back height" refers to the distance from the upper end 110a of the seat back 110 to the surface height position of the seat cushion 112 (or the position where the surface of the seat cushion 112 contacts the seat back 110). "Within ±10% of the seat back height" refers to a range from the boundary 115 between the seat back 110 and the headrest 114 to a length that is 10% of the seat back height in at least one of the upward and downward directions.

[0035] From another perspective, when viewed from the side of the vehicle seat 100, the maximum inflation portion 92 is located near the upper end of the seat back 110 in the up-down direction. Here, "near the upper end" refers to a range from the upper end 110a of the seat back 110 to ±10% of the seat back height. The vicinity of the upper end can also be considered as the vicinity of the upper end of the seat back portion of the vehicle seat 100 that is wider in width than the upper portion.

[0036] By providing the airbag 52 with the maximum inflation portion 92, which takes into consideration the positional relationship with the occupant or the vehicle seat 100, the inflated and deployed airbag 52 is less likely to come off the occupant's shoulder. Also, the webbing 14 is easily pulled forward when the airbag 52 is inflated and deployed. This has the effect of pulling out the wound-up webbing 14, and also makes it easier for the airbag 52 to deploy forward of the head.

[0037] In another embodiment, the airbag 52 may be configured to include a sub-chamber in addition to the main chamber having a substantially rectangular parallelepiped shape 90. The main chamber and the sub-chamber can be connected to each other via a communication hole, and gas from the inflator 51 can be supplied to the sub-chamber via the communication hole. The sub-chamber can protrude from the substantially rectangular parallelepiped shape 90 to be able to respond to oblique collisions and side collisions. For example, the sub-chamber inflates and deploys on both sides or one side of the main chamber having a substantially rectangular parallelepiped shape 90 in the vehicle width direction (left-right direction of the vehicle), thereby restraining the head / thorax of the occupant that moves obliquely or laterally during a vehicle collision.

[0038] As described above, the airbag 52 is provided in the lower part of the shoulder belt portion 16. The airbag 52 may also be provided in a position closer to the buckle in the lower part of the shoulder belt portion 16. Because the airbag 52 inflates and deploys from the lower part of the shoulder belt portion 16, it can be shaped to inflate to a position that can protect the occupant regardless of the physique of the occupant. In other embodiments, the airbag 52 may be provided in the upper or central part of the shoulder belt portion 16.

[0039] The airbag 52 inflates and deploys between the webbing 14 and the occupant. The inflated and deployed airbag 52 is positioned between the webbing 14 and the occupant. Specifically, the front surface of the approximately rectangular parallelepiped shape 90 of the airbag 52 contacts the shoulder belt portion 16 of the webbing 14, and the rear surface of the approximately rectangular parallelepiped shape 90 contacts the front of the occupant's upper body (the front of the head, chest, and waist). The inflated and deployed airbag 52 restrains the occupant from moving forward while absorbing impact. At this time, the shoulder belt portion 16 of the webbing 14 restrains the inflated and deployed airbag 52 from moving forward, while restraining the occupant to the seat back 110 of the vehicle seat 100 via the airbag 52.

[0040] [Payout Mechanism] Here, in the occupant restraint device 200 of this embodiment, the webbing 14 is configured to be paid out when the airbag 52 is inflated and deployed between the webbing 14 and the occupant. That is, the occupant restraint device 200 further includes payout mechanisms 300, 400, 500, 600 (see FIGS. 11, 12, 15, and 16, respectively) that pay out the webbing 14 during a vehicle collision. The payout mechanisms 300, 400, 500, 600 pay out a predetermined amount of the webbing 14 from the spool 36 of the retractor 32, creating slack in the webbing 14. The slack in the webbing 14 is mainly the slack in the shoulder belt portion 16. The slack creates a gap (space) between the shoulder belt portion 16 and the occupant, and the airbag 52 is inflated and deployed in this space. The payout mechanisms 300, 400, 500, 600 are set to operate when the airbag 52 is inflated or deployed or immediately before the airbag 52 is inflated and deployed.

[0041] The unwinding mechanisms 300, 400, 500, 600 can be provided in the retractor 32. The unwinding mechanisms may be those that rotate the spool 36 in the unwinding direction by electrical / electronic control, like unwinding mechanisms 300, 400 described below, or those that rotate the spool 36 in the unwinding direction by a mechanical configuration that utilizes the tensile force acting on the webbing 14, like unwinding mechanisms 500, 600 described below. The former will be described first below with reference to Figures 11 to 14, and then the latter will be described below with reference to Figures 15 to 17.

[0042] 11 shows an example in which a motor is used as the unwinding mechanism 300. The unwinding mechanism 300 has a motor 310 as a drive source and a power transmission mechanism 320 that transmits power from the motor 310 to the spool 36. The motor 310 is configured to be able to selectively rotate in either a forward rotation direction or a reverse rotation direction, and the drive of the motor 310 is controlled by an ECU (for example, the controller 700 in FIG. 13 ). Here, the forward rotation corresponds to the rotation in the webbing winding direction, and the reverse rotation corresponds to the rotation in the webbing unwinding direction.

[0043] The power transmission mechanism 320 has a gear assembly made up of multiple (here, three) gears 321, 322, and 323. Specifically, the output gear 321 is fixed to the output shaft 310a of the motor 310, the output gear 321 meshes with a worm gear 322, and the worm gear 322 meshes with a worm wheel 323. A center portion of the worm wheel 323 is coupled to one end of the spool 36. When the motor 310 rotates forward, the spool 36 rotates in the winding direction via the power transmission mechanism 320. When the motor 310 rotates reversely, the spool 36 rotates in the unwinding direction via the power transmission mechanism 320, and the webbing 14 is unwound.

[0044] In the event of a vehicle collision, the motor 310 receives an activation signal from the ECU and rotates in reverse, causing the unwinding mechanism 300 to unwind a predetermined amount of the webbing 14 from the spool 36 via the power transmission mechanism 320 .

[0045] Note that after the webbing 14 has been paid out in the event of a vehicle collision and after the inflation and deployment of the airbag 52 has progressed, the motor 310 may be rotated in the forward direction to wind a predetermined amount of the webbing 14 onto the spool 36. This allows the webbing 14 to be paid out by a predetermined amount when the airbag 52 is inflated and deployed, and by winding up the webbing 14 by a predetermined amount after the inflation and deployment of the airbag 52 has progressed, the occupant can be lightly restrained by the webbing 14 via the airbag 52.

[0046] Furthermore, the winding rotation by the motor 310 of the power transmission mechanism 320 can be utilized for pre-crash operation and comfort operation, similar to existing motorized retractors. For example, when a sensor detects a sudden vehicle deceleration state (e.g., when there is a possibility of a collision), the motor 310 may rotate the spool 36 in the winding direction to wind up a predetermined amount of the webbing 14, thereby lightly restraining the occupant with the webbing 14 (pre-crash operation). Furthermore, the motor 310 may assist in winding up the webbing 14 to eliminate slack when the webbing 14 is worn and to improve storability when the webbing 14 is released (comfort operation).

[0047] 12 shows another example of a payout mechanism 400. This example utilizes a pretensioner of an existing pretensioner-equipped retractor with an inverted configuration. For example, the payout mechanism 400 includes a gas generator 410 as a drive source and a power transmission mechanism 420 that transmits power from the gas generator 410 to the spool 36. The gas generator 410 is electrically connected to an ECU (e.g., the controller 700 in FIG. 13 ) and instantaneously generates gas upon receiving an activation signal from the ECU in the event of a vehicle collision.

[0048] The power transmission mechanism 420 includes, for example, a tube 422, a plurality of balls 424 housed in the tube 422, and a grooved pinion 426 rotated by the balls 424. The balls 424 are pushed out of the tube 422 by the gas generated by the gas generator 410 and enter the grooves of the pinion 426, causing the pinion 426 to rotate. The rotation of the pinion 426 is input to the spool 36, causing the spool 36 to rotate in the reeling direction. As a result, a predetermined amount of webbing 14 is reeled out from the spool 36. The pinion 426 may be journaled on an end of the spool 36 so that the rotation of the pinion 426 is input directly to the spool 36, or the rotation of the pinion 426 may be input to the spool 36 via a torsion bar or the like.

[0049] In another embodiment, a rod may be used instead of the ball 424. In this case, the rod is pushed out of the tube 422 by the gas generated by the gas generator 410, and the tip portion of the rod engages with a pinion or a wheel to rotate the pinion or wheel, thereby rotating the spool 36 in the reeling direction. It will be understood that in either embodiment of the ball 424 or the rod, the power transmission mechanism 420 has at least one movable member (e.g., the ball 424, the rod, the pinion 426, etc.) that is driven by gas pressure from the gas generator 410 and inputs power to the spool 36 in the direction to reel out the webbing 14.

[0050] 13 shows the control configuration of the occupant restraint device 200 including the payout mechanisms 300, 400. The controller 700 in the occupant restraint device 200 is an electronic control unit (ECU) equipped with a CPU 710, a memory 720, and an input / output interface 730, and is configured as, for example, a microcomputer. The CPU 710 executes desired calculations according to a control program and performs various processes and controls. The memory 720 includes, for example, a ROM and a RAM. The ROM stores the control program and control data processed by the CPU 710, and the RAM is primarily used as a work area for various control processes. The input / output interface 730 is electrically connected to an external sensor 750, the inflator 51 of the airbag module 50, and the drive sources (motor 310 and gas generator 410) of the payout mechanisms 300, 400.

[0051] The sensor 750 is for detecting a vehicle collision, and may be any of various known types, such as an acceleration sensor or a pressure sensor. With this configuration, the controller 700 receives an input signal from the sensor 750 and outputs an activation signal to the drive sources (motor 310 and gas generator 410) of the inflator 51 and the payout mechanisms 300, 400 upon a vehicle collision.

[0052] The controller 700 may be configured as an airbag ECU capable of communicating with the vehicle-side ECU, and may control the activation of not only the inflator 51 of the occupant restraint device 200, but also inflators in other airbag devices (for example, a side airbag device, a curtain airbag device, etc.). In another embodiment, the vehicle-side ECU may determine whether or not the vehicle has experienced a frontal collision, and the controller 700 may receive collision information from the vehicle-side ECU and output an activation signal to the drive sources (motor 310, gas generator 410) of the inflator 51 and the payout mechanisms 300, 400.

[0053] 14 is a flowchart showing a control method for the occupant restraint device 200. This control method is executed by the controller 700 when the vehicle crashes (S11).

[0054] In this control method, the payout mechanisms 300, 400 start paying out the webbing 14 before the airbag 52 starts to inflate and deploy. Therefore, the payout mechanisms 300, 400 are set to operate immediately before the airbag 52 starts to inflate and deploy. For example, first, the controller 700 outputs an activation signal to the motor 310 of the payout mechanism 300 or the gas generator 410 of the payout mechanism 400 to pay out a predetermined amount of the webbing 14 from the spool 36 (S12). Next, the controller 700 outputs an activation signal to the inflator 51 to inflate and deploy the airbag 52 (S13). By performing such control, it is possible to reliably create a gap (space) between the shoulder belt portion 16 and the occupant, and then to inflate and deploy the airbag 52 between the webbing 14 and the occupant.

[0055] 15 shows another example of a reeling mechanism 500. Unlike the reeling mechanisms 300 and 400 described above, the reeling mechanism 500 rotates the spool 36 in the reeling direction by a mechanical configuration that utilizes the tension acting on the webbing 14.

[0056] The unwinding mechanism 500 has a torsion bar 510. The torsion bar 510 is disposed within the spool 36, with one end connected to the spool 36 and the other end connected to a locking member 520 of the locking mechanism. The locking member 520 is normally rotatable in the winding direction and the unwinding direction together with the spool 36 via the torsion bar 510, but is locked against rotation in the event of a vehicle collision. Therefore, the other end of the torsion bar 510 becomes a fixed end in the event of a vehicle collision due to the locking of the locking member 520.

[0057] In the event of a vehicle collision, the unwinding mechanism 500 is set to operate immediately before the airbag 52 is inflated and deployed. During a vehicle collision, after the locking member 520 is locked, the tensile load acting on the webbing 14 increases. When this tensile load exceeds a threshold, the spool 36 rotates in the unwinding direction in response to the pulling of the webbing 14. As a result, a predetermined amount of the webbing 14 is unwound from the spool 36. Immediately thereafter, the airbag 52 is inflated and deployed. The rotation of the spool 36 generates a twist in the torsion bar 510, which absorbs energy. Note that the tensile load acting on the webbing 14 increases as the occupant is displaced forward in the vehicle cabin due to inertia. The threshold for rotating the spool 36 in the unwinding direction can be adjusted by the shaft diameter of the torsion bar 510.

[0058] 16 shows yet another example of a reeling mechanism 600. Similar to the reeling mechanism 500 described above, the reeling mechanism 600 rotates the spool 36 in the reeling direction by a mechanical configuration that utilizes the tension acting on the webbing 14. However, the reeling mechanism 600 employs a configuration that can switch the load to an increasing direction when energy is absorbed.

[0059] For example, the unwinding mechanism 600 has two torsion bars 610, 620 with different shaft diameters. The thick torsion bar 610 and the thin torsion bar 620 are connected in series inside a torque tube 630. The end of the thick torsion bar 610 opposite the thin torsion bar 620 is connected to a tread head 640. The end of the thin torsion bar 620 opposite the thick torsion bar 610 is connected to the spool 36. A portion of the thick torsion bar 610 and the torque tube 630 are connected so that torque can be transmitted. Similar to the locking member 520 described above, the tread head 640 is normally rotatable in the winding direction and the unwinding direction together with the spool 36 via the two torsion bars 610, 620, but is locked from rotation in the event of a vehicle collision.

[0060] A switching slider 650 is provided on the outer surface of the torque tube 630 so as to be axially movable and lockable. The switching slider 650 is provided inside the spool 36 and is configured to be rotatable integrally with the spool 36. In the initial position, the switching slider 650 is not locked to the outer surface of the torque tube 630. In the event of a vehicle collision, the tensile force acting on the webbing 14 causes the switching slider 650 to move and lock to the torque tube 630, thereby switching the transmission path of the tensile load acting from the webbing 14 to the spool 36 from the thin torsion bar 620 to the thick torsion bar 610.

[0061] Specifically, as shown in FIG. 17A , during a vehicle collision, the tensile load acting on the webbing 14 is transmitted in this order to the spool 36, the thin torsion bar 620, the thick torsion bar 610, and the tread head 640. At this time, the thin torsion bar 620 twists due to the tensile load acting on the webbing 14, absorbing energy. The spool 36 also rotates in the unwinding direction, causing the switching slider 650 to move axially on the outer surface of the torque tube 630. When the spool 36 rotates a predetermined amount in the unwinding direction (e.g., 0.5 rotations), the switching slider 650 is locked on the outer surface of the torque tube 630. This results in the transmission path shown in FIG. 17B . That is, the tensile load acting on the webbing 14 is transmitted in this order to the spool 36, the switching slider 650, the torque tube 630, the thick torsion bar 610, and the tread head 640. At this time, the thick torsion bar 610 is twisted by the tensile load acting on the webbing 14, and energy is absorbed.

[0062] Here, in the event of a vehicle collision, the unwinding mechanism 600 is set to operate immediately before the airbag 52 is inflated and deployed. For example, in the event of a vehicle collision, after the tread head 640 is locked, the tensile load acting on the webbing 14 increases. When this tensile load exceeds a threshold, the spool 36 rotates in the unwinding direction in response to the pulling of the webbing 14. As a result, a predetermined amount of the webbing 14 is unwound from the spool 36. Immediately thereafter, the airbag 52 is inflated and deployed. That is, when the spool 36 rotates a predetermined amount (e.g., 0.5 rotations) in the unwinding direction (see FIG. 18 ), the airbag 52 is inflated and deployed. When the airbag 52 is activated (inflated and deployed), it is preferable to set the tensile load (unwinding load) of the webbing 14 to, for example, 2000 N or less and to be able to unwind the webbing 14 by 50 mm or more, as this improves the balance between the load applied to the occupant and the force restraining the occupant. That is, the load of the webbing 14 on the occupant is not too large, and the occupant can be restrained so as to appropriately suppress forward movement during a collision.

[0063] Thereafter, as the rotation of the spool 36 progresses, the transmission path switches from Fig. 17(A) to Fig. 17(B), and the payout mechanism 600 switches to a high load limiter load (energy absorption load). That is, as shown in Fig. 18, after the inflation and deployment of the airbag 52 progresses, the load is switched to an increasing direction during energy absorption.

[0064] As described above, the occupant restraint device 200 according to this embodiment includes the webbing 14, the airbag 52 that is attached to the webbing 14 and inflates and deploys in front of the occupant on the vehicle seat 100 in the event of a vehicle collision, and the payout mechanisms 300, 400, 500 that pay out the webbing 14 in the event of a vehicle collision.

[0065] According to this aspect, contrary to conventional retractors with pretensioners, the webbing 14 is unwound during a vehicle collision. As a result, slack or slack is created in the webbing 14 relative to the occupant during a vehicle collision. Furthermore, during a vehicle collision, the airbag 52 attached to the webbing 14 inflates and deploys in front of the occupant. Therefore, during a frontal vehicle collision, for example, the unwound webbing 14 reduces the load that the occupant receives from the webbing 14, and the inflated and deployed airbag 52 suppresses forward movement of the occupant due to inertia while absorbing the impact. In this way, during a vehicle collision, the unwound webbing 14 and the inflated and deployed airbag 52 cooperate to softly restrain the occupant.

[0066] Furthermore, by providing slack or slack in the webbing 14 during a vehicle collision, the inflating and deploying airbag 52 can be easily positioned between the webbing 14 and the occupant, and the inflating and deploying airbag 52 can fill in the slack created by the slack or slack at the same time as or immediately after slack or slack occurs in the webbing 14. A significant ride-down effect can be expected as occupant restraint, and thereafter, gradual upper torso restraint and head restraint are possible while maintaining the reaction force surface of the webbing 14.

[0067] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, sizes, etc., are not limited to those exemplified and can be modified as appropriate.

[0068] <Additional Considerations Regarding Various Embodiments> [Embodiment 1] An occupant restraint device comprising: a webbing; and an airbag attached to the webbing, which inflates and deploys in front of an occupant sitting on a vehicle seat in the event of a vehicle collision, the occupant restraint device further comprising a payout mechanism that pays out the webbing in the event of the vehicle collision.

[0069] [Embodiment 2] The occupant restraint device of embodiment 1, wherein the unwinding mechanism starts unwinding the webbing before the airbag starts to inflate and deploy during the vehicle collision.

[0070] [Embodiment 3] An occupant restraint device according to embodiment 1 or 2, wherein, in the event of a vehicle collision, the unwinding mechanism unwinds the webbing so that the airbag inflates and deploys using a portion of the webbing in front of the occupant as a reaction surface.

[0071] [Embodiment 4] The occupant restraint device of embodiment 3, wherein the airbag is attached to the webbing so that a portion of the webbing is positioned forward of the airbag as viewed from the occupant.

[0072] [Embodiment 5] The occupant restraint device of embodiment 3, wherein the airbag is attached to the webbing so as to be sandwiched between the webbing in the front-rear direction as viewed from the occupant.

[0073] [Embodiment 6] The occupant restraint device of any one of embodiments 1 to 5, wherein the airbag is woven together with the webbing or sewn to the webbing.

[0074] [Embodiment 7] An occupant restraint device according to any one of embodiments 1 to 6, wherein the webbing is wound around a spool so as to be able to be unwound and retracted, and the unwinding mechanism comprises: a drive source that generates power to rotate the spool in the direction of unwinding the webbing upon receiving an activation signal during the vehicle collision; and a power transmission mechanism that transmits power from the drive source to the spool.

[0075] [Embodiment 8] The occupant restraint device of embodiment 7, wherein the drive source is configured by a motor that can selectively rotate in a direction to pay out the webbing and a direction to retract the webbing.

[0076] [Embodiment 9] An occupant restraint device according to embodiment 7, wherein the drive source is a gas generator that generates gas when the vehicle collides, and the power transmission mechanism has at least one movable member that is driven by gas pressure from the gas generator and inputs power to the spool in the direction of unwinding the webbing.

[0077] [Embodiment 10] An occupant restraint device according to any one of embodiments 1 to 9, wherein the webbing is wound around a spool so as to be able to be reeled in and out, the reeling mechanism has a torsion bar disposed within the spool, one end of which is connected to the spool and the other end of which becomes a fixed end in the event of the vehicle collision, and after the torsion bar becomes the fixed end in the event of the vehicle collision, the spool rotates in the direction of reeling out the webbing in response to an increase in the tensile load acting on the webbing.

[0078] [Embodiment 11] An occupant restraint device according to any one of embodiments 1 to 10, wherein the webbing has a shoulder belt portion and a lap belt portion, and the airbag inflates and deploys from below the shoulder belt portion during a vehicle collision.

[0079] [Embodiment 12] An occupant restraint device according to any one of embodiments 1 to 11, wherein the airbag inflates and deploys in front of the occupant's head during a vehicle collision.

[0080] [Embodiment 13] An occupant restraint device according to any one of embodiments 1 to 12, wherein the airbag inflates and deploys in front of the occupant's chest and waist during a vehicle collision so that the lower part of the airbag reaches the occupant's upper thighs.

[0081] [Embodiment 14] An occupant restraint device according to any one of embodiments 1 to 13, wherein the airbag inflates and deploys during a vehicle collision so that the maximum inflation portion in the fore-and-aft direction as seen from the occupant is located in the vicinity of the occupant's collarbone in the up-and-down direction, near the boundary between the seatback and headrest of the vehicle seat, or near the upper end of the seatback.

[0082] [Embodiment 15] An occupant restraint device according to any one of embodiments 1 to 14, wherein the airbag has a main chamber and at least one sub-chamber that inflates and deploys on at least one side of the main chamber in the left-right direction of the vehicle.

[0083] [Embodiment 16] An occupant restraint device according to any one of embodiments 1 to 15, wherein the extension mechanism is set to operate when the airbag is inflated or immediately before it is inflated and deployed.

[0084] [Embodiment 17] An occupant restraint device according to any one of embodiments 1 to 16, wherein the airbag is configured to inflate and deploy between the webbing and the occupant.

[0085] 12...seat belt device, 14...webbing, 14A...front webbing portion, 14B...rear webbing portion, 16...shoulder belt portion, 18...anchorage, 20...tongue, 22...lap belt portion, 24...anchorage, 26...loop portion, 28...buckle, 30...cable, 31...vehicle structural portion, 32...retractor, 34...frame, 36...spool, 50...airbag module, 51...inflator, 52...airbag, 61...inflation tube, 71...temporary stitching, 72a, 72b...sewing points, 73...temporary stitching, 74...sewing points, 81...tear line, 90...substantially rectangular parallelepiped shape, 92...maximum inflation portion, 100...vehicle seat, 110...seat back, 110a...upper end, 112...seat cushion ion, 114...headrest, 115...boundary, 200...occupant restraint device, 300...extension mechanism, 310...motor, 310a...output shaft, 320...power transmission mechanism, 321...output gear, 322...worm gear, 323...worm wheel, 400...extension mechanism, 410...gas generator, 420...power transmission mechanism, 422...tube, 424...ball, 426...pinion, 500...extension mechanism, 510...torsion bar, 520...locking member, 600...extension mechanism, 610, 620...torsion bar, 630...torque tube, 640...tread head, 650...switching slider, 700...controller, 710...CPU, 720...memory, 730...input / output interface, 750...sensor

Claims

1. An occupant restraint device comprising: a webbing; and an airbag attached to the webbing that inflates and deploys in front of an occupant sitting on a vehicle seat in the event of a vehicle collision, the occupant restraint device further comprising a payout mechanism that pays out the webbing in the event of a vehicle collision.

2. The occupant restraint device according to claim 1, wherein, in the event of a vehicle collision, the unwinding mechanism starts unwinding the webbing before the airbag starts to inflate and deploy.

3. An occupant restraint device as described in claim 1, wherein the payout mechanism pays out the webbing so that, in the event of a vehicle collision, the airbag inflates and deploys using a portion of the webbing in front of the occupant as a reaction surface.

4. An occupant restraint device according to claim 3, wherein the airbag is attached to the webbing so that a portion of the webbing is positioned forward of the airbag as viewed from the occupant.

5. An occupant restraint device according to claim 3, wherein the airbag is attached to the webbing so as to be sandwiched between the webbing in the front-to-rear direction as viewed from the occupant.

6. An occupant restraint device according to any one of claims 3 to 5, wherein the airbag is woven together with the webbing or stitched to the webbing.

7. The occupant restraint device according to claim 1, wherein the airbag is configured to inflate and deploy between the webbing and the occupant.

8. An occupant restraint device according to claim 1, wherein the extension mechanism is set to operate when the airbag is inflated or immediately before it is inflated and deployed.

9. An occupant restraint device as described in any one of claims 1 to 5, wherein the webbing is wound around a spool so as to be able to be unwound and retracted, and the unwinding mechanism comprises: a drive source that generates power to rotate the spool in the direction of unwinding the webbing upon receiving an activation signal in the event of a vehicle collision; and a power transmission mechanism that transmits power from the drive source to the spool.

10. An occupant restraint device as claimed in any one of claims 1 to 5, wherein the webbing is wound around a spool so as to be able to be reeled in and out, the reeling mechanism has a torsion bar disposed within the spool, one end of which is connected to the spool and the other end of which becomes a fixed end in the event of a vehicle collision, and wherein after the torsion bar becomes the fixed end in the event of a vehicle collision, the spool rotates in the direction of reeling out the webbing in response to an increase in the tensile load acting on the webbing.

11. An occupant restraint device as claimed in any one of claims 1 to 5, wherein the webbing has a shoulder belt portion and a lap belt portion, and the airbag inflates and deploys from below the shoulder belt portion in the event of a vehicle collision.

12. An occupant restraint device according to any one of claims 1 to 5, wherein the airbag inflates and deploys in front of the occupant's head in the event of a vehicle collision.

13. An occupant restraint device as described in any one of claims 1 to 5, wherein the airbag inflates and deploys in front of the occupant's chest and waist during a vehicle collision so that the lower part of the airbag reaches the occupant's upper thighs.

14. An occupant restraint device as described in any one of claims 1 to 5, wherein the airbag inflates and deploys during a vehicle collision so that the maximum inflation portion in the fore-and-aft direction as seen from the occupant is located in the vicinity of the occupant's collarbone in the up-down direction, in the vicinity of the boundary between the seat back and headrest of the vehicle seat, or in the vicinity of the upper end of the seat back.

15. An occupant restraint device as described in any one of claims 1 to 5, wherein the airbag has a main chamber and at least one sub-chamber that inflates and deploys on at least one side of the main chamber in the left-right direction of the vehicle.

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