Vehicle knee airbag

Abstract

A knee airbag comprises a front panel, a rear panel coupled to the front panel to define an inflation chamber, and an intermediate panel located within the inflation chamber between the front panel and the rear panel. The intermediate panel is connected to the front panel and the rear panel at various locations between the proximal and distal ends of the intermediate panel to control the inflation shape of the knee airbag. The knee airbag has a two-layer structure comprising only the front panel and the rear panel in the thickness direction, a three-layer structure comprising the front panel, the rear panel, and the intermediate panel in the thickness direction, and a transitional structure comprising the front panel, the rear panel, and an air-permeable portion in the thickness direction. The knee airbag comprises the two-layer structure in at least first and second two-layer regions that extend at least substantially along the first and second sides of the knee airbag. The knee airbag comprises the three-layer structure in a transverse central region between the first and second sides.

Description

Technology Field

[0001] Cross-reference to related applications:

[0002] This application claims priority to U.S. Patent Application No. 18 / 372,728, filed September 26, 2023. The entire contents of the disclosure of said application are incorporated herein by reference as part of this specification.

[0003] The present invention generally relates to an inflatable occupant protection system for a vehicle. More specifically, and according to one particular application, the present invention relates to a knee airbag device for a vehicle. Background Technology

[0004] This section provides background information related to the present invention and does not necessarily imply prior art.

[0005] Inflatable occupant restraints, or airbags, are typically included in vehicles for passive occupant protection. Airbags used for frontal collision protection are generally installed inside the steering wheel for the driver and behind the instrument panel for other front-seat occupants. In addition to frontal collision protection, inflatable restraints are used to protect occupants from side collisions. For example, side curtain airbags are typically mounted along the vehicle's roof rails and deploy downward to provide an energy-absorbing structure between the occupant's head and upper body and the vehicle's interior components.

[0006] In the event of an accident or an impending accident, if in-vehicle sensors detect abnormal deceleration, the airbag is triggered to inflate within a few milliseconds (ms) by gas generated, for example, by a device commonly referred to as an "inflator." The inflated airbag acts as a cushion, protecting the vehicle occupants from the impact force.

[0007] An inflatable occupant protection system may include a knee airbag device to protect the occupant's knees and / or lower body in the event of a collision. Such a knee airbag device generally includes an inflatable knee airbag to absorb at least a portion of the impact energy directed toward the occupant's knees and lower body during a collision, and restrains the occupant, in particular, by restricting the forward movement of the knees and lower body.

[0008] One suitable knee airbag device is illustrated and described in U.S. Patent No. 9,592,787 (hereinafter the '787 Patent'), which was assigned to the same person as the present application. The '787 Patent discloses a knee airbag device having an inflatable cushion configured and positioned to deploy rapidly between a passenger's knee and the vehicle's instrument panel. The inflatable cushion of the knee airbag device comprises a front panel, a rear panel coupled to the front panel, and a hinge portion having a thin inflatable section at a position corresponding to a housing connection. When inflated, the inflatable cushion connects at the hinge portion to the housing connection. The '787 Patent is incorporated by reference as described in detail herein.

[0009] Another suitable knee airbag device is illustrated and described in U.S. Patent Application No. 18 / 107,332 (hereinafter the “332 application”) filed on February 8, 2023, by the same person as the present application. The “332 application” discloses a knee airbag device having a front panel, a rear panel coupled to the front panel to define an inflation chamber, and an intermediate panel within the inflation chamber between the front panel and the rear panel. The intermediate panel is connected to the front panel and the rear panel at various positions between the proximal end and the distal end of the intermediate panel to control the inflation shape of the knee airbag. First and second suspension portions suspend the proximal end of the intermediate panel between the front panel and the rear panel and allow inflation gas to pass through. The first suspension portion extends between the front panel and the proximal end of the intermediate panel. The second suspension portion extends between the rear panel and the proximal end of the intermediate panel. An inflator for inflating the knee airbag is positioned within the inflation chamber at the proximal end of the knee airbag. An inflation gas diffusion device is positioned within the inflation chamber between the inflator and the proximal end of the intermediate panel. Application '332 is incorporated by reference as described in detail herein.

[0010] Although known occupant protection systems including knee airbag devices, such as the knee airbag device shown and described in the '787 patent and '332 application, have proven to be suitable for their intended use, there remains a need for continued improvement in the relevant technical field. Brief explanation of the drawing

[0011] The drawings described herein are provided for the purpose of illustrating selected embodiments only and do not represent all possible embodiments and are not intended to limit the scope of the invention. FIG. 1 is a side view of a knee airbag for a vehicle according to the present invention, showing a state in which the knee airbag is inflated and operably positioned between a passenger's knee and the vehicle's instrument panel. FIG. 2 is a longitudinal cross-sectional view of the knee airbag of FIG. 1, showing the knee airbag in a state before deployment within the airbag housing and operably coupled with an inflator. FIG. 3 is a front view of a knee airbag according to the present invention. FIG. 4 is a cross-sectional view of a knee airbag according to the present invention. Figure 5 is another cross-sectional view passing through the lateral portion of the knee airbag. Specific details for implementing the invention

[0012] This specification provides a general overview of the invention and does not comprehensively disclose the full scope or all features of the invention.

[0013] A general objective of the present invention is to provide a knee airbag capable of more easily guiding inflation gas to the distal end of the knee airbag.

[0014] According to one embodiment, the present invention provides a knee airbag for a vehicle. The knee airbag comprises a front panel, a rear panel coupled to the front panel to define an inflation chamber, and an intermediate panel located within the inflation chamber between the front panel and the rear panel. The intermediate panel is connected to the front panel and the rear panel at various positions between the proximal end and the distal end of the intermediate panel to control the inflation shape of the knee airbag. The knee airbag has a two-layer structure comprising only the front panel and the rear panel in the depth direction, a three-layer structure comprising the front panel, the rear panel, and the intermediate panel in the depth direction, and a transitional structure comprising the front panel, the rear panel, and an air-permeable portion in the depth direction. The knee airbag comprises the two-layer structure in at least first and second two-layer regions that extend at least substantially along the first and second lateral sides of the knee airbag. The knee airbag comprises the three-layer structure in a lateral central region between the first and second sides.

[0015] Additional areas of application will become clear from the descriptions provided herein. The descriptions and specific examples provided herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0016] One or more exemplary embodiments will be described in more detail with reference to the accompanying drawings. One or more exemplary embodiments are provided to ensure that the invention is fully realized and that the scope of the invention is sufficiently conveyed to those skilled in the art. Numerous specific details, such as examples of specific components, devices, and methods, are described to provide a thorough understanding of the embodiments of the invention. It will be apparent to those skilled in the art that specific details do not need to be adopted and that the exemplary embodiments should not be interpreted as limiting the scope of the invention. Well-known processes, well-known device structures, and well-known technologies are not described in detail herein.

[0017] The phrases “connected to,” “coupled to,” and “in communication with” refer to any form of interaction between two or more entities, including mechanical, electrical, magnetic, electromagnetic, fluid, and thermal interactions. Two components may be coupled to each other without direct contact. The term “adjacent” refers to a state in which items are physically close to each other, although they do not necessarily have to be in direct contact. The phrase “fluid communication” refers to two features connected so that fluid within one feature can pass into the other. As used herein, “exemplary” means serving as a typical or representative example or case, and does not necessarily mean special or preferred.

[0018] In the following description, directional terms such as upward, downward, forward, and rearward are defined based on the knee airbag with its associated airbag housing attached to the lower part of the instrument panel. That is, the direction toward the vehicle's roof is defined as the upward direction (U), the direction toward the vehicle's floor as the downward direction (L), the direction toward the passenger as the rearward direction (R), and the direction toward the front of the vehicle as the forward direction (F). The terms distal and proximal, used to describe the knee airbag or its elements, should be understood based on the direction in which the knee airbag is deployed. More specifically, the term distal refers to the end of the knee airbag within the housing or its direction, while the term proximal refers to the end of the knee airbag opposite the housing or its direction.

[0019] With particular reference to the environmental views of FIGS. 1 and 2, a knee airbag for a vehicle according to the present invention is illustrated and is generally identified by reference numeral 10. The knee airbag (10) is illustrated as being integrated into a knee airbag device (12), said device (12) further comprises an inflator (14) for supplying inflation gas to the knee airbag (10) upon detection of a predetermined collision, and an airbag housing (16) that accommodates the knee airbag (10) and the inflator (14). The airbag housing (16) includes a door (18) that normally covers an opening (20) of the airbag housing (16). The knee airbag device (12) is installed at the bottom of an instrument panel (22) inside the vehicle. When deployed, the knee airbag (10) is positioned so as to be operable in a longitudinal direction (e.g., from F to R) between the knee (24) of the passenger (26) and the instrument panel (22) of the vehicle.

[0020] With continued reference to the peripheral drawings of FIGS. 1 and 2 and further reference to the remaining drawings, details of the knee airbag (10) according to the present invention will be described in more detail. The knee airbag (10) is generally illustrated as comprising a first panel (28A), a second panel (28B), and a third panel (28C). In the illustrated embodiment, the first panel is the front panel (28A), the second panel is the rear panel (28B), and the third panel is the middle panel (28C). As will become clearer below, the middle panel (28C) works in conjunction with the front and rear panels (28A, 28B) to define the desired deployment shape of the knee airbag (10). As illustrated in the simplified cross-sectional view of FIG. 4, the intermediate panel (28C) is positioned within the inflation chamber (30) and extends at least substantially across the inflation chamber (30) in the airbag transverse direction (L1), and is attached to both the front panel (28A) and the rear panel (28B) at various positions between the proximal end (32) and the distal end (34) of the intermediate panel (28C).

[0021] When the front and rear panels (28A, 28B) are internally connected to the middle panel (28C), a predetermined deployment profile or shape is defined. It should be understood that the specific deployment profile and the corresponding attachment location between the middle panel (28C) and the upper panel (28A), and the corresponding attachment location between the middle panel (28C) and the lower panel (28B) shown in the drawing are merely exemplary with respect to the present invention. The specific attachment locations between the panels (28A-28C), that is, between the upper panel (28A) and the lower panel (28B), work together to define an airbag shape that is deployed and unfolded between the passenger's (26) knee (24) and the vehicle's instrument panel (22) to protect the passenger (26).

[0022] As illustrated in the drawing, the attachment positions between the panels (28A-28C) include a first attachment position (35A) connecting the front panel (28A) and the middle panel (28C), and a second attachment position (35B) connecting the rear panel (28B) and the middle panel (28C). The first attachment position (35A, indicated by a solid line in FIG. 3) and the second attachment position (35B, indicated by a dotted line in FIG. 3) are arranged in rows extending in the transverse direction (L1) across the airbag (10). The rows of the first attachment position (35A) or the second attachment position (35B) are spaced apart from each other in the vertical direction (L2).

[0023] The knee airbag (10) has a two-layer structure comprising only a front panel (28A) and a rear panel (28B) in the thickness direction (i.e., a direction perpendicular to the transverse direction L1 and the longitudinal direction L2) in different regions, a three-layer structure comprising a front panel (28A), a rear panel (28B), and a middle panel (28C) in the thickness direction, and a transition structure comprising a front panel (28A), a rear panel (28B), and an air-permeable portion in the thickness direction. As will be discussed below, the air-permeable portion may include both weft threads and warp threads that are not woven together. In the illustrated embodiment, the airbag (10) comprises the two-layer structure in at least first and second two-layer regions (36A, 36B) that extend at least substantially along the first and second sides (38A, 38B) of the knee airbag (10). As illustrated, the first and second two-layer regions (36A, 36B) can be fully extended to the distal end (10B) of the airbag (10).

[0024] The knee airbag (10) includes the three-layer structure in the transverse central region (40) between the first and second sides (38A, 38B).

[0025] The knee airbag (10) includes the aforementioned transition structure in first and second transition regions (42A, 42B) located laterally between the first two-layer region (36A) and the transverse central region (40), and between the second two-layer region (38B) and the transverse central region (40), respectively. As will become clearer below, the transition regions (42A, 42B) function to suspend the intermediate panel (28C) laterally within the expansion cavity (30) and are air permeable to allow the expansion gas to pass through. Between the front and rear panels (28A, 28B) in the thickness direction, the first and second transition regions (42A, 42B) include both warp and weft that define the inner OPW (One Piece Woven) layer. However, the important point is that these warp and weft threads are not woven together in the first and second transition regions (42A, 42B). The weft threads continue transversely through the first and second transition regions (42A, 42B) to support the intermediate panel (28C), and cross-weave with the warp threads in the intermediate panel (28C) to form the intermediate panel (28C). Because the warp and weft threads in the first and second transition regions (42A, 42B) are not woven together, the first and second transition regions (42A, 42B) are permeable to the passage of expansion gas.

[0026] The weft is arranged into a first weft group (43A) extending from the front panel (28A) to the middle panel (28C) and a second weft group (43B) extending from the rear panel (28B) to the middle panel (28C). Accordingly, the transition structure of the first and second transition regions (42A, 42B) allows the passage of expansion gas while holding the middle panel (28C) suspended between the front panel (28A) and the rear panel (28B). Additional warp threads (45) are shown extending perpendicularly to the weft threads (43A, 43B). These additional warp threads (45) are spaced apart from the weft threads (43A, 43B) and are not woven together with the weft threads (43A, 43B).

[0027] The knee airbag (10) may further include an additional two-layer area (36C) in the proximal end (10A) and may further include an additional transition area (42C) in the longitudinal direction between the additional two-layer area (36C) and the transverse central area (40). The additional transition area (42C) may include first and second suspension members (44A, 44B) that suspend and maintain the proximal end of the intermediate panel (28C) between the front panel (28A) and the rear panel (28B). The first and second suspension sections (44A, 44B) are permeable to the passage of inflation gas to inflate the knee airbag (10) from the proximal end (10A) to the distal end (10B) of the airbag (10), and cooperate to keep the proximal end (32) of the middle panel (28C) suspended within the inflation cavity (30) so that the proximal end (32) of the middle panel (28C) "floats" between the front panel (28A) and the rear panel (28B). The first suspension section (44A) extends between the front panel (28A) and the proximal end (32) of the middle panel (28A). The second suspension section (44B) extends between the rear panel (28B) and the proximal end (32) of the middle panel (28C).

[0028] In one specific application, the knee airbag (10) of the present invention may be a one-piece woven (OPW) airbag (10). In this example, the front panel (28A), the rear panel (28B), and the middle panel (28C) may be formed by weaving using OPW technology. Additionally, the first and second transition regions (42A, 42B) may be formed together with the front panel (28A), the rear panel (28B), and the middle panel (28C) using OPW technology. The front and rear panels (28A, 28B) may be formed by general OPW technology to include weft and warp threads. The weft threads extend transversely (L1) across the knee airbag (10), and the warp threads extend longitudinally (L2) perpendicular to the weft threads and extend from the proximal end (10A) to the distal end (10B) of the airbag (10). According to the disclosed method, the warp and weft threads of the front panel (28A) are woven together with the warp and weft threads of the rear panel (28B) around the perimeter of the knee airbag (10) to seal or close the inflation chamber (30). The warp threads extend in the machine direction, and the weft threads extend in a direction perpendicular to the machine direction. In the illustrated embodiment, each fabric layer (28A, 28B, 28C) is created by weaving at least two sets of warp threads and one set of weft threads. Thus, the 3-layer OPW uses at least six sets of warp threads and three sets of weft threads. The warp threads extend along the entire length of the airbag (10), but the weft threads may be excluded from some parts of the airbag (10).

[0029] The first and second transition regions (42A, 42B) may be formed integrally with the front panel (28A), rear panel (28B), and middle panel (28C) using OPW technology. In one particular embodiment, the first and second transition regions (42A, 42B) may each be formed by a first and second plurality of additional weft threads of the OPW knee airbag (10). As shown in FIG. 5, the first plurality of additional weft threads may be woven together with the warp and weft threads of the front panel (28A) in the first and second two-layer regions (42A, 42B) and may extend laterally from the front panel (28A) to the middle panel (28C). Likewise, the second plurality of additional weft threads can be woven together with the warp and weft threads of the rear panel (28B) in the first and second two-layer areas (42A, 42B) and can be extended laterally to the middle panel (28C).

[0030] The first and second suspension sections (44A, 44B) can also be formed together with the front panel (28A), rear panel (28B) and middle panel (28C) using OPW technology. The first and second suspension sections (44A, 44B) can be formed using only warp threads without weft threads. Among these warp threads, a first plurality of warp threads can be extended vertically from the front panel (28A) to the middle panel (28C). Likewise, a second plurality of warp threads can be extended vertically from the rear panel (28B) to the middle panel (28C).

[0031] The deployment of the knee airbag (10) occurs in response to the activation of the inflator (14). The inflator (14) is activated in response to a detected condition indicating a predetermined vehicle collision or event. The inflator (14), its activation, and the detection of the vehicle collision or event will be understood as conventional insofar as the present invention relates to this invention. The inflator (14) delivers inflation gas through a hole in the diffuser panel to inflate the knee airbag (10).

[0032] While specific embodiments and applications of the present invention have been illustrated and described, it should be understood that the present invention is not limited to the exact configurations and components disclosed herein. Various modifications, changes, and variations that will be apparent to those skilled in the art may be made to the arrangement, operation, and details of the methods and systems of the present invention without departing from the essence and scope of the invention.

Claims

Claim 1 A knee airbag (10) for a vehicle comprises: a front panel (28A); a rear panel (28B) coupled to the front panel (28A) to define an inflation chamber (30); an intermediate panel (28C) located within the inflation chamber (30) between the front panel (28A) and the rear panel (28B), and connected to the front panel (28A) and the rear panel (28B) at various positions between the proximal end (32) and the distal end (34) of the intermediate panel (28C) to control the inflation shape of the knee airbag (10); and the knee airbag (10) comprises a two-layer structure including only the front panel (28A) and the rear panel (28B) in the thickness direction, a three-layer structure including the front panel (28A), the rear panel (28B), and the intermediate panel (28C) in the thickness direction, and the front panel (28A), the rear panel (28B), and an air permeable portion (42A) in the thickness direction A knee airbag (10) characterized by having a transition structure including 42B), wherein the knee airbag (10) includes the two-layer structure in at least first and second two-layer regions that each extend substantially along the first and second sides (38A, 38B) of the knee airbag, and the knee airbag (10) includes the three-layer structure in a transverse central region between the first and second sides (38A, 38B). Claim 2 A knee airbag according to claim 1, characterized by a transition structure of first and second transition regions located in the respective lateral directions between the first two-story region and the lateral central region, and between the second two-story region and the lateral central region. Claim 3 A knee airbag according to claim 1, characterized in that the first and second two-layer regions extend at least substantially over the entire length along the first and second sides (38A, 38B) of the knee airbag (10). Claim 4 A knee airbag according to claim 1, characterized in that the three-layer structure of the lateral central region extends distally to the distal end (10B) of the knee airbag (10). Claim 5 A knee airbag according to claim 2, wherein, between the front and rear panels (28A, 28B), the transition structure of the first and second transition regions comprises warp threads and weft threads that are not woven together, and the weft threads of the first and second transition regions allow the passage of expansion gas while suspending an intermediate panel (28C) laterally between the front panel (28A) and the rear panel (28B). Claim 6 A knee airbag according to claim 2, wherein the transition structure of the first and second transition regions (42A, 42B) includes a weft thread and a warp thread between the front and rear panels (28A, 28B), and the weft thread and the warp thread are not woven together. Claim 7 A knee airbag according to claim 1, characterized by an inflator (14) disposed within an inflation chamber located at the proximal end of the knee airbag to inflate the knee airbag (10). Claim 8 A knee airbag according to paragraph 2, wherein the airbag is an OPW (One Piece Woven) airbag, and the first and second transition areas are characterized by transitioning the knee airbag (10) from a three-layer structure to a two-layer structure in the first and second side (38A, 38B) directions, respectively, from the lateral central area (40). Claim 9 A knee airbag according to claim 8, wherein the knee airbag (10) comprises weft and warp threads woven together in first and second two-layer regions along the transverse central region (40) and first and second sides (38A, 38B), and comprises weft and warp threads not woven together in the transverse section between the transverse central region (40) and the first and second two-layer regions. Claim 10 A knee airbag according to claim 1, characterized in that it comprises an additional two-layer region located at the proximal end (10A) of the knee airbag (10), and an additional transition region located longitudinally between the additional two-layer region and the transverse central region (40), wherein the first and second transition regions comprise weft and warp threads that are not woven together between the front and rear panels (28A, 28B), and the additional transition region comprises only warp threads between the front and rear panels (28A, 28B).

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