Seat belt load adjustment for vehicle frontal tilt collision

Abstract

A system includes a sensor, a controller, and a seat belt retractor. The controller is programmed to receive a signal from the sensor indicating detection of a tilt-frontal collision of a vehicle. The seat belt retractor includes a load limiting mechanism that is selectively releasable from a high-load mode to a low-load mode. The controller is programmed to release the load limiting mechanism from the high-load mode to the low-load mode at a predetermined time in response to the signal from the sensor indicating a tilt-frontal collision of the vehicle.

Description

Technical Field

[0001] The present invention relates to the field of vehicle seat belts, and in particular to a vehicle seat belt retractor comprising a load limiting mechanism. Background Art

[0002] Seat belts in vehicles may be equipped with a "load-limiting" feature. During a collision, the seat belt's retractor can lock the seat belt webbing from further extension from the retractor and allow some additional, limited extension of the webbing when the force applied to the webbing exceeds a load-limiting threshold. This additional extension of the webbing from the retractor limits the load applied by the webbing to the occupant's chest, reducing chest deflection.

[0003] Load limiting can be achieved by using a torsion bar. As an example, in U.S. Patent No. 7,240,924, a retractor can include a first torsion bar and a second torsion bar that are coaxially aligned. During a collision, a spool can selectively engage with the first torsion bar or the second torsion bar. The second torsion bar absorbs greater forces than the first torsion bar, i.e., a greater force is required to twist the second torsion bar than the first torsion bar. Thus, when the occupant is relatively heavy, the spool engages with the second torsion bar (i.e., in high load mode), and when the occupant is relatively light, the spool engages with the first torsion bar (i.e., low load mode). The retractor includes a pyrotechnic device that engages the spool with the first torsion bar or the second torsion bar.

[0004] As another example, in U.S. Patent No. 8,814,074, a retractor includes a torsion bar secured to a spool. The torsion bar is selectively engageable with a deforming member, which is more easily deformable than the torsion bar. Thus, the torsion bar and the deforming member can be connected in parallel (i.e., in a high-load mode) when the seat occupant is relatively heavy, and can be connected in series (i.e., in a low-load mode) when the seat occupant is relatively light.

[0005] As another example, in U.S. Patent No. 8,220,735, a retractor includes a torsion bar having two segments and a pretensioner that can be activated to switch between a high load mode and a low load mode. The first segment of the torsion bar can be engaged by default, and the pretensioner can ignite a charge to engage the second segment of the torsion bar.

[0006] As another example, in U.S. Patent No. 7,370,822, a retractor includes a braking system that can engage two torsion bars. In this case, the braking system can engage each torsion bar individually to prevent rotation of the torsion bar, i.e., to set a load limit level. In other words, the braking system can engage both torsion bars, one of the torsion bars, or none of the torsion bars to meet the load limit requirement. Summary of the Invention

[0007] A system includes: a sensor; a controller programmed to receive a signal from the sensor indicating detection of a tilt-frontal collision of a vehicle; and a seatbelt retractor including a load limiting mechanism selectively releasable from a high-load mode to a low-load mode. The controller is programmed to release the load limiting mechanism from the high-load mode to the low-load mode at a predetermined time in response to the signal from the sensor indicating a tilt-frontal collision of the vehicle.

[0008] The system may include a webbing retractable from the seat belt retractor.The webbing may be engaged with a load limiting mechanism.

[0009] A seatbelt retractor can exert a force on the webbing that resists webbing withdrawal during a frontal angled collision. A load limiting mechanism can prevent the seatbelt retractor force on the webbing from exceeding a high load limit. The predetermined time can be based on the seatbelt retractor force reaching the high load limit.

[0010] The load limiting mechanism may be locked in a high load mode during a frontal collision.

[0011] The predetermined time may be based on a sensor detecting a frontal tilt collision of the vehicle.

[0012] When the load limiting mechanism is released from the high load mode to the low load mode, the load limiting mechanism may prevent the seat belt retractor's force on the webbing from exceeding a low load limit. The low load limit may be less than the high load limit.

[0013] The load limiting mechanism may be released from the high load mode to the low load mode during a step time. The step time may include a start time and an end time. The start time of the step time may be at a predetermined time. The end time of the step time may be at a predetermined time. The end time of the step time may be after the predetermined time.

[0014] The load limiting mechanism may include a pyrotechnic device. The pyrotechnic device may release the load limiting mechanism from the high load mode to the low load mode in response to a signal from the sensor indicative of a frontal tilt collision of the vehicle.

[0015] The system may include an airbag that is inflatable to an inflated position. The predetermined time may be based on initiation of inflation of the airbag. The predetermined time may occur when an occupant impacts the airbag in the inflated position.

[0016] The system may include a component sensor. The controller may be programmed to receive a signal from the component sensor indicating a crash condition. The predetermined time may be determined based on receiving the signal from the component sensor.

[0017] The system may include a seat movable along a seat track to a plurality of positions. The component sensor may be a seat position sensor. The signal may be a position of the seat.

[0018] The component sensor may be an occupant classification sensor. The signal may be a physical characteristic of an occupant in the seat.

[0019] The component sensor may be a seat belt extension sensor. The signal may be the amount of webbing extended from the seat belt retractor.

[0020] The component sensor may be an accelerometer and the signal may be the acceleration of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a perspective view of a vehicle including a vehicle seat and a system with a seat belt retractor and webbing.

[0022] Figure 2 is a perspective view of the system's seat belt retractor.

[0023] Figure 3 is an exploded view of the system's seat belt retractor.

[0024] Figure 4A is a top view of a system including a load limiting mechanism that engages a high load mode before an occupant impacts the airbag.

[0025] Figure 4B is a top view of a system including a load limiting mechanism that engages a low load mode when an occupant impacts the air bag.

[0026] Figure 5A is a graph of step times when the load limiting mechanism releases the high load mode and substantially simultaneously engages the low load mode.

[0027] Figure 5B is a graph of step times as the load limiting mechanism releases the high load mode and gradually engages the low load mode.

[0028] Figure 5C is a graph of step times when the load limiting mechanism releases the high load mode before the force from the webbing reaches the high load limit.

[0029] Figure 6 is a block diagram of the control system used for the system.

[0030] Figure 7 is a flow chart illustrating the steps of a method of selectively releasing a load limiting mechanism from a high load mode to a low load mode. DETAILED DESCRIPTION

[0031] Referring to the accompanying drawings, in which like reference numerals indicate like parts throughout the several views, a vehicle 10 is generally illustrated. Vehicle 10 includes a seat 12 and a system 14 having a seatbelt retractor 16 and a webbing 18 retractable from the seatbelt retractor 16. During a vehicle collision, the occupant's momentum can cause the occupant to be biased relative to seat 12. For example, in a frontal oblique vehicle collision, the occupant's momentum can cause the occupant to be tilted away from seat 12 in the vehicle fore-aft direction D, i.e., bias the occupant in both the vehicle fore-aft direction D and the vehicle lateral direction. In other words, a "frontal oblique vehicle collision" is a frontal collision in which vehicle 10 is at an angle relative to the longitudinal axis of vehicle 10.

[0032] When the occupant moves away from the seat 12 during a frontal angled vehicle collision, the system 14 (e.g., the webbing 18) can apply force to the occupant to retain the occupant in the seat 12. During a frontal angled vehicle collision, the seatbelt retractor 16 can be releasable to achieve load limitation while the system 14 retains the occupant in the seat 12. Specifically, the seatbelt retractor 16 can be released to allow the webbing 18 of the system 14 to be additionally pulled out to reduce the rotational velocity of the occupant, and in particular, the rotational velocity of the occupant's head, during a frontal angled vehicle collision. During this release, the system 14 can reduce the force applied by the webbing 18 to the occupant, which can reduce the occupant's rotational velocity.

[0033] The system 14 includes at least one sensor 20 and a controller 22 programmed to receive a signal from the sensor 20 indicating a frontal tilt collision of the vehicle. The seatbelt retractor 16 includes a load limiting mechanism 24 that is selectively releasable from a high load mode to a low load mode. In the high load mode, the load limiting mechanism 24 allows the webbing 18 to be pulled out of the seatbelt retractor 16 under relatively high loads applied to the webbing 18 by the occupant during a frontal tilt collision of the vehicle, and prevents the webbing from being pulled out under relatively low loads. In the low load mode, the load limiting mechanism 24 allows the webbing 18 to be pulled out of the seatbelt retractor 16 under relatively low loads applied to the webbing 18 by the occupant during a frontal tilt collision of the vehicle.

[0034] The controller 22 is programmed to respond to a signal from the sensor 20 indicating a frontal tilt collision of the vehicle at a predetermined time T pThe load limiting mechanism 24 is released from the high load mode to the low load mode. During a frontal angled vehicle collision, upon receiving a signal from the controller 22, the load limiting mechanism 24 may be released from the high load mode to the low load mode to allow additional extension of the webbing 18. The additional extension of the webbing 18 may allow the system 14 (e.g., the webbing 18) to reduce the forces applied to the occupant and may reduce the rotation of the occupant, and specifically the occupant's head, during a frontal angled vehicle collision. By reducing the occupant's rotation, the system 14 may reduce the rotational velocity of the occupant's head, which may reduce the brain injury criteria (BrIC).

[0035] Additionally, when the load limiting mechanism 24 is in the high load mode, the load limiting mechanism 24 limits the occupant's movement relative to the seat 12 more than when the load limiting mechanism 24 is in the low load mode. In other words, when the load limiting mechanism 24 is in the high load mode, the occupant is held to the seat 12 more than when the load limiting mechanism 24 is in the low load mode. When the load limiting mechanism 24 is in the high load mode, the webbing 18 can, for example, apply a greater force to the occupant than when the load limiting mechanism 24 is in the low load mode, which can reduce the occupant's movement relative to the seat 12 (e.g., toward vehicle components). By reducing the occupant's movement away from the seat 12, the system 14 can reduce the likelihood that the occupant will impact vehicle components (e.g., the instrument panel, steering wheel, A-pillars, etc.), which can reduce head injury criteria (HIC). The criteria for HIC and BrIC are standardized by the National Highway Traffic Safety Administration (NHTSA).

[0036] refer to Figure 1 The vehicle 10 may be, for example, any suitable type of automobile. The vehicle 10 may include a body 26 that defines a passenger compartment 28 for accommodating occupants of the vehicle 10 (if any). The body 26 may include a floor 30 and a plurality of pillars 32, 34 extending upward from the floor 30. For example, the pillars 32, 34 may include an A-pillar 32 and a B-pillar 34 spaced apart from the A-pillar 32. The pillars 32, 34 may include additional pillars, such as a C-pillar (not shown).

[0037] One or more seats may be disposed in the front portion of the passenger compartment 28, for example, between the A-pillar 32 and the B-pillar 34. In this case, the seat 12 may be a front seat. The passenger compartment 28 may include one or more rear seats (not shown) disposed rearward of the front seats. The passenger compartment 28 may also include a third row of seats (not shown) at the rear portion (unnumbered) of the passenger compartment 28, in which case the seats may be second row seats (unnumbered) instead of or in addition to the front seats. The passenger compartment 28 may include any suitable number of rows of seats, such as one or more rows of seats. Figure 1As shown, the seat 12 is a bucket seat, but the seat 12 may be another suitable type of seat, such as a bench seat.

[0038] The seats 12 may each include a seat back 36 and a seat bottom 38, as shown. Figure 1 As shown, the seat back 36 can be supported by the seat bottom 38 and can extend upward from the seat bottom 38. The seat back 36 can be stationary or movable relative to the seat bottom 38. The seat back 36 and / or the seat bottom 38 can be adjustable in multiple degrees of freedom. Specifically, the seat back 36 and / or the seat bottom 38 can themselves be adjustable, in other words, can have adjustable components within them, and / or can be adjustable relative to each other.

[0039] refer to Figure 1 The seats 12 can be supported on the floor 30, either directly or through an intermediate component. Each of the seats 12 can, for example, move along a seat track 40 secured to the floor 30. For example, the seat bottom 38 can be slidably engaged with the seat track 40. The seat track 40 can extend in the vehicle fore-aft direction D. The seat track 40 can include two end portions 42, 44 spaced apart from each other in the vehicle fore-aft direction D, and a center position 46 centered between the two end portions 42, 44. In other words, the center position 46 can be equidistant from the two end portions 42, 44 along the seat track 40 in the vehicle fore-aft direction D. The seat 12 can move along the seat track 40 to a plurality of positions, for example, to the center position 46. In other words, the seat 12 can be positioned in any suitable position along the seat track 40 in the vehicle fore-aft direction D. The seat 12 can be releasably secured in position relative to the seat track 40 at a selected one of the plurality of positions in any suitable manner. As another example, the seat 12 can be secured to the floor 30 of the vehicle 10. In other words, the seat bottom 38 may be fixed to the floor 30. Additionally or alternatively, the seat 12 may be movable to a plurality of positions transverse to the vehicle fore-aft direction D, ie, vertically relative to the floor 30 of the vehicle 10.

[0040] The system 14 may include an air bag 48 spaced apart from the seat 12 in the vehicle fore-aft direction D. The air bag 48 may be positioned such as Figure 1 Inflate to the uninflated position shown. Figure 4A and Figure 4BThe airbag 48 is shown in the inflated position. During inflation, the airbag 48 can extend along the vehicle fore-aft direction D toward the seat 12 (i.e., toward the occupant). In other words, the airbag 48 can inflate toward the seat 12 from an uninflated position to an inflated position. The airbag 48 can be supported by any suitable vehicle component, such as the instrument panel, steering wheel, etc. As another example, if the seat 12 is a rear seat, the airbag 48 can be supported on the seatback 36 of the front seat.

[0041] The airbag 48 can be unitary, for example, a single piece of fabric. As another example, the airbag 48 can include multiple segments, that is, two or more segments that are formed separately and then attached together. The segments can be attached to each other in any suitable manner (e.g., sewing, ultrasonic welding, etc.).

[0042] Airbag 48 can be formed from any suitable type of material. Airbag 48 can be formed from any suitable airbag material (e.g., a braided polymer). For example, airbag 48 can be formed from braided nylon yarn (e.g., nylon 6-6). Other suitable examples include polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyester, or any other suitable polymer. The braided polymer can include a coating such as silicone, neoprene, polyurethane, etc. For example, the coating can be a polyorganosiloxane.

[0043] refer to Figure 1 The inflator 50 can be in fluid communication with the airbag 48 so that the inflator 50 inflates the airbag 48 from an uninflated position to an inflated position. The inflator 50 inflates the airbag 48 with an inflation medium (such as a gas) to move the airbag 48 from the uninflated position to the inflated position. The inflator 50 can be disposed in any suitable location in the vehicle 10, for example, in the dashboard, the steering wheel, etc.

[0044] The system 14 may include a seat belt assembly 52 having a seat belt retractor 16 and a webbing 18 that is retractably extendable from the seat belt retractor 16, such as Figure 2 Additionally, the seat belt assembly 52 may include an anchor 54 coupled to the webbing 18, and a clip 56 engaging a buckle 58, as shown. Figure 1 As shown. The seat belt assembly 52 can be disposed adjacent to the seat 12. For example, the seat belt assembly 52 is adjacent to the front seat, such as Figure 1 The seat belt assembly 52 holds the occupant in the seat 12 when fastened, for example, during a sudden deceleration of the vehicle 10 .

[0045] Anchor 54 attaches one end of the webbing 18 to the seat 12. The other end of the webbing 18 enters the seat belt retractor 16. A clip 56 slides freely along the webbing 18 and, when engaged with the buckle 58, separates the webbing 18 into a lap belt and a shoulder belt.

[0046] like Figure 1 As shown, the seat belt assembly 52 may be a three-point harness, meaning that the webbing 18 is attached to the occupant at three points when fastened: the anchor 54, the seat belt retractor 16, and the buckle 58. Alternatively, the seat belt assembly 52 may include another arrangement of attachment points.

[0047] The seat belt retractor 16 may include a housing 60 having a housing body 62 and a housing cover 64 attached to the housing body 62, as shown in FIG. Figure 2 As shown. The housing 60 can be formed of metal or plastic. The webbing guide 66 can be attached to the housing 60. The housing 60 can be mounted to the vehicle body 26. For example, the housing 60 can be connected to the B-pillar 34, as shown. Figure 1 As another example, when the seat belt assembly 52 is adjacent to the rear seat, the housing 60 can be attached to the C-pillar. Alternatively, the housing 60 can be attached to the front seat, for example, the frame of the front seat (not shown). The housing 60 can be attached to the vehicle body 26 in any suitable manner, for example, with fasteners.

[0048] The seatbelt retractor 16 can be engaged from an unlocked position to a locked position. By default (i.e., in the absence of sudden deceleration), the seatbelt retractor 16 is in the unlocked position. In the unlocked position, the spool 68 can rotate within the housing 60 to allow the webbing 18 to be extended from and retracted into the seatbelt retractor 16. During sudden deceleration of the vehicle 10, the seatbelt retractor 16 can be moved from the unlocked position to the locked position, i.e., the deceleration triggers a component of the seatbelt retractor 16 to change from the unlocked position to the locked position. For example, the seatbelt retractor 16 can be moved from the unlocked position to the locked position in response to a vehicle collision. In the locked position, the seatbelt retractor 16 exerts a force (not shown) on the webbing 18 that resists the webbing 18 from being pulled out during a frontal angled collision of the vehicle. In this condition, one end of the spool 68 is rotationally locked relative to the housing 60 , which stops extension of the webbing 18 from the seat belt retractor 16 to limit forward movement of the occupant.

[0049] refer to Figure 3The spool 68 of the seat belt retractor 16 is rotatably coupled to the housing 60. The spool 68 is freely rotatable relative to the housing 60. The spool 68 can be cylindrical. The spool 68 can define an axis of rotation A about which the spool 68 rotates. The spool 68 can be adapted to receive the webbing 18, for example, by including a webbing attachment slot (not shown) and allowing the webbing 18 to be wound around the spool 68.

[0050] Continue to refer Figure 3 , a reel spring 70 can be coupled to the reel 68 and the housing 60. When the webbing 18 is fully retracted, the reel spring 70 can be loaded in tension or compression, and when the webbing 18 is extended from the reel 68, the reel spring 70 can be further loaded in tension or compression. Thus, the reel spring 70 can apply a retraction force (not shown) tending to retract the webbing 18. The reel spring 70 can be a helical torsion spring or any other suitable type of spring.

[0051] The webbing 18 is attached to the spool 68. Specifically, as described above, one end of the webbing 18 may be attached to the anchor 54, and the other end of the webbing 18 may be attached to the spool 68, where the webbing 18 begins to wind around the spool 68. The webbing 18 may be formed from a fabric (e.g., nylon).

[0052] The webbing 18 is engaged with the load limiting mechanism 24. For example, when the seat belt retractor 16 is in the locked position, the webbing 18 may exert a force on the load limiting mechanism 24 in response to a vehicle collision. In this case, the load limiting mechanism 24 may prevent the webbing 18 from extending from the seat belt retractor 16, i.e., being pulled out from the seat belt retractor 16, as further described below. When the load limiting mechanism 24 is in the high load mode, the load limiting mechanism 24 allows additional extension of the webbing 18 when the load from the occupant on the webbing 18 is relatively high (i.e., exceeds a high threshold). As described above, at the predetermined time T p Thereafter, the load limiting mechanism 24 is released to the low load mode, which allows additional pulling of the webbing 18 from the seat belt retractor 16 .

[0053] The load limiting mechanism 24 may be of any suitable type for selectively operating in a high load mode or a low load mode. As an example, refer to Figure 3 The load limiting mechanism 24 may, for example, include a first torsion bar 72, a second torsion bar 74 extending coaxially with the first torsion bar 72, a torque tube 80 supporting both the first torsion bar 72 and the second torsion bar 74, and a transition collar 118 engageable with the first torsion bar 72. As further explained below, the load limiting mechanism 24 may be operated from a high load mode to a low load mode by selectively loading the second torsion bar 74 or the first torsion bar 72, respectively.

[0054] An example of a load limiting mechanism 24 is Figure 3 Alternatively, the seat belt retractor 16 may include any suitable type of load limiting mechanism 24 that is releasable from the high load mode to the low load mode.

[0055] refer to Figure 3 The seat belt retractor 16 includes a pawl 86 that is selectively engageable with one end of the second torsion bar 74, and specifically, in the locked position, the pawl 86 is engaged with one end of the second torsion bar 74. In the high load mode, the spool 68 is engageable with the other end of the second torsion bar 74, and in the low load mode, it is alternatively engageable with the first torsion bar 72. The second torsion bar 74 absorbs greater forces than the first torsion bar 72, which causes the load limiting mechanism 24 to be in the high load mode when the spool 68 is engaged with the second torsion bar 74, and to be in the low load mode when the spool 68 is engaged with the first torsion bar 72.

[0056] Specifically, continue to refer to Figure 3 . The pawl 86 is rotatable relative to the housing 60 and the weighted rocker 84, which is fixed relative to the pawl 86. When the vehicle 10 is moving at a constant speed, gradually accelerating, or gradually decelerating, the weight of the weighted rocker 84 disengages the pawl 86 from the second torsion bar 74 to allow the spool 68 to rotate relative to the housing 60, i.e., the seat belt retractor 16 is in an unlocked position. In this case, in the high load mode, the spool 68 engages with the other end of the second torsion bar 74. When the vehicle 10 suddenly decelerates, the momentum of the weighted rocker 84 engages the pawl 86 with one end of the second torsion bar 74, i.e., the seat belt retractor 16 is in a locked position, wherein the pawl 86 prevents one end of the second torsion bar 74 from rotating about the rotation axis A. In this case, the load limiting mechanism 24 prevents the webbing 18 from rotating the spool 68 unless the webbing 18 exerts a load on the spool 68 that exceeds the high load limit F h In this case, the second torsion bar 74 twists, i.e., deforms, to allow the webbing 18 to be pulled out. In other words, the load limiting mechanism 24 prevents the force of the seat belt retractor 16 on the webbing 18 (i.e., the force of the webbing 18 on the occupant when the load limiting mechanism 24 is in the high load mode) from exceeding the high load limit F h ,like Figure 4A During a type of frontal collision other than a frontal vehicle tilt collision, the load limiting mechanism 24 may lock in the high load mode.

[0057] During a frontal tilt collision of the vehicle, the components of the load limiting mechanism 24 move to engage the spool 68 with the first torsion bar 72 to release the load at a predetermined time T. p The load limiting mechanism 24 is moved to the low load mode. Figure 3In the example shown in FIG. 1 , the conversion collar 118 moves to engage the first torsion bar 72 to transfer force to the first torsion bar 72. In this case, the load limiting mechanism 24 prevents the webbing 18 from rotating the spool 68 unless the webbing 18 exerts a load on the spool 68 that exceeds the low load limit F. l When the force exceeds the low load limit F l The first torsion bar 72 twists, i.e., deforms, to allow additional extension of the webbing 18. In other words, when the load limiting mechanism 24 is in the low load mode, the load limiting mechanism 24 prevents the force of the seat belt retractor 16 on the webbing 18 (i.e., the force of the webbing 18 on the occupant) from exceeding the low load limit F l ,like Figure 4B As shown. Low load limit F l Less than high load limit F h .

[0058] The load limiting mechanism 24 may include a pyrotechnic device 120 in communication with the controller 22. In response to a signal from the sensor 20 indicating a frontal tilt collision of the vehicle, the pyrotechnic device 120 may release the load limiting mechanism 24 from the high load mode to the low load mode. After the sensor 20 detects a frontal tilt collision of the vehicle, the controller 22 may, for example, send a signal to the pyrotechnic device 120 to ignite a pyrotechnic charge, which causes the reel 68 to engage the first torsion bar 72. The pyrotechnic device 120 may, for example, release the load limiting mechanism 24 from the high load mode to the low load mode. p The pyrotechnic charge is then ignited to release the load limiting mechanism 24 from the high load mode to the low load mode. The pyrotechnic device 120 may be any suitable type of pyrotechnic device 120.

[0059] The system 14 may include component sensors 92 in communication with the controller 22, such as Figure 6As shown. Component sensor 92 is adapted to detect a crash condition. The crash condition may be the position and movement of an occupant and / or the vehicle (e.g., seat 12, webbing 18, etc.) during a frontal tilt collision of the vehicle. Component sensor 92 may be any suitable type of sensor, such as a camera, LIDAR, pressure sensor, etc. For example, component sensor 92 may be a seat position sensor attached to any suitable vehicle component (e.g., seat 12, seat track 40, instrument panel, B-pillar 34, etc.). The seat position sensor may be adapted to detect the position of seat 12 on seat track 40, for example, relative to the position of airbag 48. As another example, component sensor 92 may be an occupant classification sensor attached to any suitable vehicle component (e.g., seat 12, seat track 40, instrument panel, B-pillar 34, etc.). The occupant classification sensor may be adapted to detect physical characteristics of an occupant in seat 12, such as height, weight, etc. In this case, the occupant classification sensor may be adapted to detect the presence or absence of an occupant in seat 12. As another example, the component sensor 92 can be a webbing pull-out sensor attached to one of the seatbelt retractor 16 and the webbing 18. The webbing pull-out sensor can be adapted to determine the amount of webbing 18 pulled out of the seatbelt retractor 16 (i.e., the occupant's movement away from the seat 12). As yet another example, the component sensor 92 can be an accelerometer. The accelerometer can be adapted to detect the acceleration of the vehicle. The accelerometer can be attached to any suitable vehicle component, such as the seat 12, the instrument panel, the B-pillar 34, etc. The system 14 can include any suitable number of component sensors 92.

[0060] refer to Figures 5A to 5C , the load limiting mechanism 24 may be released from the high load mode to the low load mode during the step time T. The step time T may include the start time T s and end time T f Start time T s You can p In other words, the load limiting mechanism 24 can be operated at a predetermined time T p Start releasing to low load.

[0061] Figures 5A to 5C is a graph of curve 82 that depicts the step time T versus the force applied by the seat belt retractor 16 to the webbing 18 (ie, the high load limit F h and low load limit F l The relationship between one of the end time T f Can occur at a predetermined time T p For example, the load limiting mechanism 24 may be p substantially simultaneously (i.e., at the same time) releasing from the high load mode and engaging the low load mode, such as Figure 5A and Figure 5C As shown. Or, the end time T f You can p In other words, the load limiting mechanism 24 can release from the high load mode and engage the low load mode at different times. For example, the load limiting mechanism 24 can gradually release from the high load mode to the low load mode, such as Figure 5B In other words, the start time T when engaging the high load mode s To the end time T when the low load mode is engaged f In between, the load limiting mechanism 24 may be partially engaged in both the high load mode and the low load mode.

[0062] As explained above, the load limiting mechanism 24 may be p The load is released from high load mode to low load mode. p may be selected to release the load limiting mechanism 24 from the high load mode to the low load mode during a frontal angled impact of the vehicle when an occupant impacts the air bag 48 in the inflated position, such as Figure 4A and Figure 4B In other words, the predetermined time T p Occurs when the occupant impacts the airbag 48 in the inflated position. p This can occur, for example, when the force of the seat belt retractor 16 on the webbing 18 reaches a high load limit F h Then appears, such as Figure 5A and Figure 5B Alternatively, the scheduled time T p It may occur that the force of the seat belt retractor 16 on the webbing 18 reaches the high load limit F h Before, if Figure 5C shown.

[0063] Scheduled time T p It may be a fixed time after the vehicle front tilt collision (ie, after the controller 22 receives a signal from the sensor 20 that detects the vehicle front tilt collision). For example, the predetermined time T p It can be based on the sensor 20 that detects the front tilt collision of the vehicle. In other words, the predetermined time T p It may be a fixed time after the controller 22 receives a signal from the sensor 20 indicating a frontal tilt collision of the vehicle. As another example, the predetermined time T p It may be based on the initiation of inflation of the airbag 48, ie, a fixed time after the initiation of inflation of the airbag 48. In this case, the predetermined time T pThe predetermined time T may occur after the airbag activation time (i.e., the time between the vehicle frontal tilt collision and the initiation of inflation of the airbag 48) and the time when the airbag 48 is fully deployed (i.e., in the inflated position). As another example, the predetermined time T p A high load limit F may be achieved based on the force of the seat belt retractor 16 h ,like Figure 5A and Figure 5B In this case, the predetermined time T p It may be that the force of the seat belt retractor 16 reaches the high load limit F h A fixed time later.

[0064] Additionally or alternatively, the predetermined time T p The predetermined time T may be based on the collision condition detected by the component sensor 92 during a frontal tilt collision of the vehicle. p The predetermined time T may be based on a signal received from the component sensor 92. In this case, the controller 22 may determine the predetermined time T based on the signal from the component sensor 92 (eg, from a lookup table). p The signal may be, for example, a position of the seat 12, a physical characteristic of an occupant in the seat 12, an acceleration of the vehicle 10, and / or an amount of extension of the webbing 18. For example, when the seat 12 is forward of the center position 46 (i.e., between one end 42 and the center position 46 on the seat track 40), the predetermined time T may be greater than when the seat 12 is rearward of the center position 46 (i.e., between the center position 46 and the other end 44 on the seat track 40). p As another example, the predetermined time T p For example, it may occur after a predetermined extension of the webbing 18. As another example, when the body features of the occupant are relatively large, the predetermined time T p As another example, when the acceleration of the vehicle 10 is relatively large, the predetermined time T p It occurs earlier than when the acceleration of the vehicle 10 is relatively small. p The crash conditions may be based on any suitable number of signals from one or more component sensors 92 .

[0065] The controller 22 may be a microprocessor-based controller. The controller 22 may include a processor, memory, and the like. The memory of the controller 22 may include memory for storing instructions executable by the processor and for electronically storing data and / or databases. The controller 22 may be a restraint control module (RCM), in other words, a module that, among other things, can communicate with and control airbags, pretensioners, and the like in the vehicle 10.

[0066] The sensor 20 may communicate with the controller 22, such as Figure 6 As shown. Sensor 20 is suitable for detecting a collision with vehicle 10. Specifically, sensor 20 is suitable for detecting a frontal tilt collision with the vehicle. Sensor 20 can be of any suitable type, for example, post-contact sensors such as linear or angular accelerometers, gyroscopes, pressure sensors, and contact switches; and pre-collision sensors such as radar, lidar, and vision sensing systems. The vision system can include one or more cameras, charge coupled device (CCD) image sensors, complementary metal oxide semiconductor (CMOS) image sensors, etc. Sensor 20 can be located at multiple points in or on vehicle 10.

[0067] The controller 22 may transmit and receive signals via a communication network 94, such as a controller area network (CAN) bus, Ethernet, a local interconnect network (LIN), and / or any other wired or wireless communication network. The controller 22 may communicate with the sensors 20 and component sensors 92 via the communication network 94, such as Figure 6 shown.

[0068] refer to Figure 7 , a method 96 for selectively releasing the load limiting mechanism 24 from the high-load mode to the low-load mode is shown. As shown in block 98, the method 96 includes identifying the onset of a collision event. For example, the method 96 may detect a vehicle collision, such as a head-on collision, a frontal vehicle tilt collision, etc. The sensor 20 may detect the collision and transmit a signal to the controller 22 via the communication network 94. Substantially simultaneously, the occupant of the seat 12 experiences momentum relative to the seat 12 and exerts tension on the webbing 18. In this case, i.e., in the low-load mode, the seatbelt retractor 16 is engaged in the locked position, and the spool 68 engages the other end of the second torsion bar 74. The load limiting mechanism 24 in the high-load mode can prevent the occupant's momentum from freely pulling the webbing 18 out. In this case, the second torsion bar 74 can resist the torque on the spool 68.

[0069] As shown in block 100, method 96 includes determining the position of seat 12. Specifically, method 96 includes determining the position of seat 12 on seat track 40. Seat sensors, i.e., component sensors 92, can detect the position of seat 12 and transmit signals to computer 22 via communication bus 94. For example, seat 12 can be positioned at and / or forward of center position 46, i.e., between center position 46 and one end 42 of seat track 40. Alternatively, seat 12 can be positioned rearward of center position 46, i.e., between center position 46 and another end 44 of seat track 40.

[0070] As shown in block 102, the method 96 may include determining whether the seat 12 is positioned behind the neutral position 46 on the seat track 40 or forward of the neutral position 46. When the seat 12 is positioned behind the neutral position 46, the method 96 continues to block 104. When the seat 12 is positioned forward of the neutral position 46, the method 96 continues to block 106.

[0071] As shown in block 104 , the method 96 includes determining a lateral acceleration of the vehicle collision. The vehicle collision may, for example, include a lateral acceleration, i.e., a lateral acceleration oriented transverse to the vehicle's fore-aft direction D. The sensor 20 may detect the lateral acceleration of the vehicle collision and transmit a signal to the controller 22 .

[0072] As indicated at decision block 108, method 96 may include determining whether the lateral acceleration is above or below a threshold. In other words, sensor 20 may detect a frontal tilt collision of the vehicle. The threshold may be any suitable acceleration. For example, the threshold may be the acceleration required to activate a side impact restraint system in vehicle 10. When the lateral acceleration is below the threshold, method 96 proceeds to block 106. When the lateral acceleration is above the threshold, method 96 proceeds to block 110.

[0073] As shown in block 106, the method 96 includes preventing the load-limiting mechanism 24 from switching, for example, from the high-load mode to the low-load mode. In other words, the method 96 locks the load-limiting mechanism 24 in the high-load mode. For example, the controller 22 may send a signal to the load-limiting mechanism 24 to remain in the high-load mode, for example, to prevent the pyrotechnic device 120 from igniting. In this case, the load-limiting mechanism 24 remains in the high-load mode until the vehicle collision is complete, as shown in block 116.

[0074] As shown in block 110, the method 96 includes calculating an airbag activation time for the inflator 50. The inflator 50 can communicate with the controller 22 such that the inflator 50 initiates inflation of the airbag 48 after the controller 22 transmits a signal to the inflator 50 indicating a vehicle collision. After a vehicle collision, the controller 22 can initiate inflation of the airbag 48 by the inflator 50 at the airbag activation time. The activation time can be fixed or depend on the conditions of the vehicle collision, such as force, direction, etc.

[0075] As shown in block 112 , the method 96 includes determining a predetermined time T p Scheduled time T p It can be based on the airbag activation time. In other words, the predetermined time T p It may occur after the initiation of inflation of the airbag 48. Specifically, the predetermined time T p The predetermined time T may be after the time at which the air bag 48 is fully deployed, as described above.p occurs when the occupant impacts the air bag 48 in the inflated position. In this case, when the occupant impacts the air bag 48, the load limiting mechanism 24 is released from the high load mode to the low load mode, such as Figure 4A and Figure 4B shown.

[0076] Additionally or alternatively, the predetermined time T may be determined based on the crash conditions detected by one or more component sensors 92 (eg, occupant classification sensor, webbing pull-out sensor, accelerometer, etc.). p , as explained above. For example, the controller 22 may select the predetermined time T based on the signal received from the component sensor 92 (ie, the collision condition). p In other words, based on the possible combinations of collision conditions, the controller 22 may store a plurality of predetermined times T in a lookup table, for example. p In this case, the controller 22 determines the predetermined time T based on the impact condition of the vehicle collision. p .

[0077] As shown in block 114, the method includes switching the load limiting mechanism 24 to the low-load mode. In other words, the load limiting mechanism 24 is released from the high-load mode to the low-load mode. The load limiting mechanism 24 may be released from the high-load mode and engaged in the low-load mode in any suitable step time T, substantially simultaneously, gradually, etc. In the high-load mode, the seat belt assembly 52 may retain the occupant to the seat 12, i.e., limit the occupant's movement relative to the seat 12 to prevent the occupant from impacting components of the vehicle 10 between inflations of the air bag 48.

[0078] During a frontal tilt collision of the vehicle, an occupant may rotate based on the forces applied to the occupant to restrain the occupant. For example, the force applied to the occupant by webbing 18 limits the occupant's movement relative to vehicle 10 (e.g., seat 12) and, because the force of webbing 18 deviates from the occupant's lateral centerline, causes rotation of the occupant (particularly the upper body). As another example, when an occupant (e.g., the occupant's head) impacts airbag 48, the force applied to the occupant by airbag 48 may cause the occupant to rotate. In this case, the occupant rotation may increase based on the lateral acceleration of the frontal tilt collision of the vehicle, that is, as the lateral acceleration of the frontal tilt collision of the vehicle increases, the occupant may impact airbag 48 at a sharper angle, which may increase the rotation of the occupant's head.

[0079] When the load limiting mechanism 24 is engaged in the high load mode, the movement of the occupant (particularly the movement of the head and chest) is reduced compared to when the load limiting mechanism 24 is engaged in the low load mode. When the load limiting mechanism 24 is released from the high load mode to the low load mode, the force required to rotate the spool 68 from the webbing 18 is reduced to allow the spool 68 to rotate and the webbing 18 to be pulled out. In this case, the rotation speed of the occupant can be reduced compared to when the load limiting mechanism 24 is maintained in the high load mode in the event of a full collision. Therefore, in the event of a frontal tilt collision of the vehicle, the system 14 can allow the occupant to rotate for a predetermined time T. p The webbing 18 is additionally pulled out to reduce the rotational speed of the occupant (especially the upper body). After being released into the low load mode, the load limiting mechanism 24 may remain in the low load mode until the crash event is complete, as shown in block 116.

[0080] exist Figure 3 In the example shown in FIG, when the controller 22 sends a signal to the load-limiting mechanism 24 to release to the low-load mode, the pyrotechnic device 120 initiates the release from the high-load mode to the low-load mode. In other words, the pyrotechnic device 120 causes the load-limiting mechanism 24 to disengage the high-load mode and engage the low-load mode. For example, the pyrotechnic device 120 causes the transition collar 118 to engage the first torsion bar 72. In this case, as explained above, the force of the webbing 18 on the load-limiting mechanism 24 is transferred to the first torsion bar 72.

[0081] As shown in block 116, the method includes identifying the end of the crash event. The end of the crash event can be, for example, when the momentum of the vehicle 10 and the occupant has ceased following the vehicle impact. In other words, the crash event can terminate when the vehicle 10 and the occupant are stationary. In this case, the system 14 can be reset, i.e., the load limiting mechanism 24 can be engaged in the high-load mode, so that the sensor 20 can detect a subsequent vehicle impact and send a signal to the controller 22 to release the load limiting mechanism 24 to the low-load mode.

[0082] The present disclosure has been described in an illustrative manner, and it will be understood that the terminology used is intended to be in the nature of words of description rather than of limitation. In light of the above teachings, many modifications and variations of the present disclosure are possible, and the present disclosure may be practiced in ways other than those specifically described.

[0083] According to the present invention, a system is provided, comprising: a sensor; a controller programmed to receive a signal from the sensor indicating detection of a tilt-frontal collision of a vehicle; and a seat belt retractor including a load limiting mechanism selectively releasable from a high load mode to a low load mode; the controller programmed to release the load limiting mechanism from the high load mode to the low load mode at a predetermined time in response to the signal from the sensor indicating a tilt-frontal collision of the vehicle.

[0084] According to an embodiment, the invention also features webbing retractable from the seat belt retractor, the webbing engaging the load limiting mechanism.

[0085] According to an embodiment, the invention is further characterized in that the seat belt retractor exerts a force on the webbing that resists webbing pullout during a frontal angled vehicle collision, and wherein the load limiting mechanism prevents the force of the seat belt retractor on the webbing from exceeding a high load limit.

[0086] According to an embodiment, the present invention is further characterized in that when the load limiting mechanism is released from the high load mode to the low load mode, the load limiting mechanism prevents the force of the seat belt retractor on the webbing from exceeding a low load limit, the low load limit being less than the high load limit.

[0087] According to an embodiment, the invention is further characterized in that said predetermined time is based on said force of said seat belt retractor reaching said high load limit.

[0088] According to an embodiment, the invention is further characterized in that the predetermined time occurs before the force of the seat belt retractor reaches the high load limit.

[0089] According to an embodiment, the present invention is further characterized in that the predetermined time is based on the sensor detecting a frontal tilt collision of the vehicle.

[0090] According to an embodiment, the invention is further characterized in that the load limiting mechanism is locked in the high load mode during a frontal collision.

[0091] According to an embodiment, the invention further features an airbag inflatable to an inflated position, and wherein the predetermined time is based on initiation of inflation of the airbag.

[0092] According to an embodiment, the invention is further characterized by an airbag inflatable to an inflated position, and wherein the predetermined time occurs when an occupant impacts the airbag in the inflated position.

[0093] According to an embodiment, the invention further features a component sensor, the controller being programmed to receive a signal indicative of a crash condition from the component sensor.

[0094] According to an embodiment, the invention is further characterized in that the predetermined time is based on receiving a signal from the component sensor.

[0095] According to an embodiment, the invention also features a seat that is movable along a seat track to a plurality of positions, and wherein the component sensor is a seat position sensor and the signal is a position of the seat.

[0096] According to an embodiment, the invention also features a seat, and wherein the component sensor is an occupant classification sensor, and wherein the signal is a physical characteristic of an occupant in the seat.

[0097] According to an embodiment, the invention is further characterized by webbing being retractable from the seat belt retractor, and wherein the component sensor is a webbing pull-out sensor, the signal being the amount the webbing is pulled out from the seat belt retractor.

[0098] According to an embodiment, the invention is also characterized in that the component sensor is an accelerometer and the signal is the acceleration of the vehicle.

[0099] According to an embodiment, the present invention is further characterized in that the load limiting mechanism is released from the high load mode to the low load mode during a step time, the step time including a start time and an end time.

[0100] According to an embodiment, the present invention is further characterized in that the start time of the step time is on the predetermined time, and the end time of the step time is on the predetermined time.

[0101] According to an embodiment, the present invention is further characterized in that the start time of the step time is at the predetermined time, and the end time of the step time is after the predetermined time.

[0102] According to an embodiment, the invention is further characterized in that the load limiting mechanism includes a pyrotechnic device that releases the load limiting mechanism from the high load mode to the low load mode in response to a signal from the controller indicating a frontal tilt collision of the vehicle.

Claims

1. A system for a vehicle, comprising: sensor; a controller programmed to receive a signal from the sensor indicating a detected lateral acceleration of the vehicle collision; as well as a seat belt retractor including a load limiting mechanism that is selectively releasable from a high load mode to a low load mode; The controller is programmed to release the load limiting mechanism from the high load mode to the low load mode at a predetermined time in response to a signal from the sensor indicating that the lateral acceleration of the vehicle collision is above a threshold value, and to prevent the load limiting mechanism from being released from the high load mode to the low load mode at a predetermined time in response to a signal from the sensor indicating that the lateral acceleration of the vehicle collision is below the threshold value.

2. The system of claim 1 further comprising a webbing retractable from the seat belt retractor, the webbing engaging the load limiting mechanism.

3. The system of claim 2 , wherein the seat belt retractor exerts a force on the webbing that resists webbing pullout during a frontal angled vehicle collision, and wherein the load limiting mechanism prevents the force of the seat belt retractor on the webbing from exceeding a high load limit.

4. The system of claim 3 , wherein when the load limiting mechanism is released from the high load mode to the low load mode, the load limiting mechanism prevents the force of the seat belt retractor on the webbing from exceeding a low load limit, the low load limit being less than the high load limit. 5 . The system of claim 3 , wherein the predetermined time is based on the force of the seat belt retractor reaching the high load limit.

6. The system of claim 3, wherein the predetermined time occurs before the force of the seat belt retractor reaches the high load limit.

7. The system of any one of claims 1 to 6, wherein the predetermined time is based on the sensor detecting a frontal tilt collision of the vehicle.

8. The system of any one of claims 1 to 6, wherein the load limiting mechanism is locked in the high load mode during a frontal collision.

9. The system of any one of claims 1 to 6, further comprising an airbag inflatable to an inflated position, and wherein the predetermined time occurs when an occupant impacts the airbag in the inflated position.

10. The system of any one of claims 1 to 6, further comprising a component sensor, the controller being programmed to receive a signal indicative of an occupant condition from the component sensor, and wherein the predetermined time is based on receiving the signal from the component sensor.

11. The system of claim 10, further comprising a seat movable along a seat track to a plurality of positions, and wherein the component sensor is a seat position sensor and the signal is a position of the seat.

12. The system of claim 10, further comprising a seat, and wherein the component sensor is an occupant classification sensor, the signal being a physical characteristic of an occupant in the seat.

13. The system of claim 10, further comprising webbing retractable from the seat belt retractor, and wherein the component sensor is a webbing pull-out sensor, the signal being the amount the webbing is pulled out from the seat belt retractor.

14. The system of claim 10, wherein the component sensor is an accelerometer and the signal is an acceleration of the occupant.

15. The system of any one of claims 1 to 6, wherein the load limiting mechanism is released from the high load mode to the low load mode during a step time, the step time comprising a start time and an end time.

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