Occupant restraint structure

Abstract

Provided is an occupant protection structure capable of obtaining a reaction force surface capable of appropriately and sufficiently supporting an airbag cushion during inflation even when an instrument panel is shrunk. An occupant restraint structure (100) is provided with: an airbag cushion (10) which is housed in an instrument panel (2) in order to protect an occupant (P), and which is inflated and deployed toward the occupant (P) from an opening (41) formed in the upper side of the instrument panel (2); and an airbag cushion (20) that is inflated and deployed from an opening (42) formed in the lower side of the instrument panel (2) toward the occupant (P). Furthermore, in the occupant restraint structure (100), the relationship represented by L2u > = Lib (1) is satisfied when the occupant restraint structure (100) is expanded and expanded. Wherein L2u represents the accuracy of the upper end (20u) of the airbag cushion (20), and Lib represents the accuracy of the rear end (2b) of the instrument panel (2).

Description

Technical Field

[0001] The present invention relates to an occupant restraint structure equipped with an airbag that expands and deploys toward the occupants in the event of an emergency. Background Technology

[0002] As an example of such airbag cushions, Patent Document 1 discloses an occupant protection device that combines a passenger-side airbag and a knee airbag. This device inflates by injecting gas from the dashboard towards the upper body and legs of the occupant. The device is configured such that, with both the passenger-side and knee airbags fully inflated, the upper part of the knee airbag is positioned at least 50 mm higher than the lower part of the passenger-side airbag. This allows the lower part of the passenger-side airbag to embed between the inflated upper part of the knee airbag and the occupant, thereby suppressing movement of the passenger-side airbag. Consequently, it inhibits forward movement of the occupant's waist, providing adequate protection during a vehicle collision.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2003-034215 Summary of the Invention

[0004] The problem the invention aims to solve However, traditional dashboards are typically located in front of the seats where occupants sit. Furthermore, vehicle seats are often semi-fixed and can move forward and backward to ensure the occupants face forward in the direction of travel. Therefore, various devices and components need to be housed within the dashboard, resulting in a larger size and volume. Consequently, when occupant airbags, especially the passenger-side airbag, inflate and deploy during an emergency, the upper surface of the dashboard, in particular, functions as part of the reaction surface to retain the airbag cushions.

[0005] On the other hand, with the future development of technologies such as autonomous driving, the freedom of movement of vehicle seats will likely increase, resulting in more spacious and flexible interiors. Consequently, the shape and volume of the dashboard may also shrink. This means the upper surface of the dashboard, which functions as part of the reaction surface of the traditional airbag cushion, can also become narrower. Therefore, a new structure that can adequately and properly support the airbag cushion is urgently needed. However, even with the aforementioned traditional airbag cushion structure, the lower end of the passenger-side airbag is embedded between the upper end of the knee airbag and the occupant. Therefore, the lower support of the passenger-side airbag is essentially ensured primarily by the occupant's legs. Thus, in the traditional airbag cushion structure, with the shrinking dashboard, there may be a situation where the reaction surface of the passenger-side airbag cannot be adequately and properly maintained, potentially failing to cope with the development of autonomous driving and other technologies.

[0006] Therefore, this disclosure was made in view of the above circumstances, and its purpose is to provide an occupant restraint (protection) structure that can provide a reaction surface that can properly and adequately support the airbag cushion when it inflates and deploys, even if the dashboard is reduced in size as autonomous driving and other technologies develop in the future.

[0007] Problem Solving Methods To address the aforementioned issues, one example of the occupant restraint structure disclosed herein is designed to protect occupants within a vehicle interior. The occupant restraint structure, housed in a dashboard located at the front of the vehicle interior (in normal circumstances), comprises: a first airbag that expands toward the occupant from a first opening formed on the upper side of the dashboard (in the event of an emergency); and a second airbag that expands toward the occupant from a second opening formed on the lower side of the dashboard.

[0008] Furthermore, in this crew constraint structure, the following relationship is satisfied during expansion and unfolding, as shown in equation (1).

[0009] L2u ≧ Lib …(1) Where L2u represents the upper level of the second airbag cushion, and Lib represents the rear level of the dashboard.

[0010] In this structure, the first airbag cushion expands from the upper side of the dashboard toward the occupant's upper portion (e.g., the portion including the head and / or upper body). Conversely, the second airbag cushion expands from the lower side of the dashboard toward the occupant's lower portion (e.g., the portion including the legs). At this time, the expansion of the first and second airbag cushions causes the upper end of the second airbag cushion to be positioned above the rear end of the dashboard. Therefore, when the first airbag cushion expands toward the occupant's upper portion, the lower surface of the first airbag cushion is reliably held in place by the upper surface of the second airbag cushion. Thus, even if the shape and volume of the dashboard housing the first and second airbag cushions are reduced, the upper surface of the second airbag cushion during expansion can function as a reaction surface that appropriately and sufficiently supports the first airbag cushion during expansion. In other words, according to the structure of this disclosure, when the first and second airbag cushions expand, the lower surface of the first airbag cushion is reliably supported by at least a portion of the upper surface of the dashboard and at least a portion of the upper surface of the second airbag cushion.

[0011] As a result, occupant safety can be fully ensured in situations such as autonomous driving, contributing to the development of future vehicle structures and driving methods. Furthermore, this prevents the second airbag cushion from being crushed by the first airbag cushion. Therefore, the second airbag cushion facilitates the optimization of the expansion volume and shape of the first airbag cushion, and also allows for a reduction in the airbag cushion's capacity. Moreover, since the restraint force on the occupant passing through the first and second airbag cushions can be increased, appropriately suppressing the movement of various parts of the occupant's body contributes to improved safety. Attached Figure Description

[0012] Figure 1 This is a schematic side view showing the state of the airbag cushion in its normal state, together with the instrument panel and the occupant, regarding the occupant restraint structure according to the embodiments of this disclosure.

[0013] Figure 2 This is a schematic side view showing the state of the airbag cushion when it is inflated and deployed, together with the instrument panel and the occupants, regarding the occupant restraint structure according to the embodiments of this disclosure.

[0014] Figure 3 This is a schematic side view showing the state of the airbag cushions when inflated and deployed, together with the instrument panel and the occupants, regarding the occupant restraint structure according to other embodiments of this disclosure. Detailed Implementation

[0015] <Definitions and Implementation Summary of Terms> The occupant restraint structure according to a preferred embodiment of the present invention will now be described with reference to the accompanying drawings. In this specification, the terms up / down, left / right, and front / back are defined as follows: When occupant P is seated in a proper posture on a vehicle seat S having a backrest S1 and a seat surface S2, the direction occupant P faces is called forward Df, and the opposite direction is called rearward Db. These two directions (coordinate axes) are referred to as the front / back direction. Similarly, when occupant P is seated in a proper posture on the vehicle seat S, the right side of occupant P is called the right direction, and the left side of occupant P is called the left direction. These two directions (coordinate axes) are referred to as the left / right direction. Likewise, when occupant P is seated in a proper posture on the vehicle seat S, the direction of occupant P's head is called upward Du, and the direction of occupant P's waist is called downward Dd. These two directions (coordinate axes) are referred to as the up / down direction.

[0016] Additionally, in this specification, "occupant" refers to an "occupant" with a physique comparable to that of the average male in the United States, conforming to the mannequin used in frontal crash tests (according to the Hybrid III AM50 / NHTSA "National Highway Traffic Safety Administration" standard [49 CFR Part 572 Subpart E and 0]), with approximate dimensions of 175 cm in height, 88 cm in seat height, and 78 kg in weight. Furthermore, "when inflated" refers to the time from the start of inflation of each airbag to the end of inflation, "level" refers to the vertical position, and "end" refers to the perimeter of the airbag, including at least the "end".

[0017] first, Figure 1 This is a schematic side view showing the occupant restraint structures 100 and 200 according to embodiments of this disclosure, together with the instrument panel 2 and the occupant P, in their normal state. Figure 1 As shown, the occupant restraint structure 100 involved in the embodiment includes airbag cushions 10 and 20, which inflate and deploy from the dashboard 2 located at the front Df inside the vehicle compartment 1 toward the occupant P (e.g., the passenger in the front seat) in the event of a vehicle emergency. The airbag cushions 10 and 20 are typically folded or rolled up and housed in the housings H1 and H2 of the dashboard 2, respectively.

[0018] In a vehicle emergency, airbag cushion 10 (first airbag cushion) receives gas from inflator 31 and protrudes diagonally upwards (Du) from the inside of windshield 3 (front windshield) (inside vehicle compartment 1). As a result, airbag cushion 10 inflates and deploys towards the upper part of occupant P (e.g., including the head Ph and / or upper body Pj). On the other hand, airbag cushion 20 (second airbag cushion) receives gas from inflator 32 in a vehicle emergency and protrudes downwards (Dd) from the inside of windshield 3. As a result, airbag cushion 20 inflates and deploys towards the lower part of occupant P (e.g., including the legs Pk). These situations will be described in detail in the descriptions of the various embodiments described later. Furthermore, the term "vehicle emergency" can include, for example, a collision with the front of the vehicle (Df) or a rollover, but is not limited to these situations.

[0019] <Implementation Method 1> then, Figure 2 This is a schematic side view showing the state of the airbag cushions 10 and 20 when inflated and deployed, together with the instrument panel 2 and the occupant P, regarding the occupant restraint structure 100 according to the embodiments of this disclosure. Figure 2 As shown, in the occupant restraint structure 100, the airbag cushions 10 and 20 expand and deploy from the opening 41 (first opening) formed on the upper side of the instrument panel 2 and the opening 42 (second opening) formed on the lower side of the instrument panel 2, respectively. Furthermore, the occupant restraint structure 100 is configured to satisfy the relationship shown in the following equation (1) when it expands and deploys.

[0020] L2u ≧ Lib …(1) Here, as shown in the figure, L2u represents the accuracy of the upper end 20u of the airbag cushion 20, and Lib represents the accuracy of the rear end 2b of the instrument panel 2. That is, in this embodiment, when the airbag cushions 10 and 20 inflate and deploy, the height of the upper end 20u of the airbag cushion 20 is greater than or equal to the height of the rear end 2b of the instrument panel 2.

[0021] According to the occupant restraint structure 100 configured in this way, the lower surface of the airbag cushion 10, which expands towards the upper part of the occupant P, is reliably held on the upper surface of the airbag cushion 20. Therefore, even if the shape and volume of the instrument panel 2, which normally houses the airbag cushions 10 and 20, are reduced compared to the past, the upper surface of the airbag cushion 20 can still properly and sufficiently retain the reaction force surface of the airbag cushion 10 during expansion.

[0022] <Implementation Method Two> In addition, such as Figure 1As shown, the lower surface of the airbag cushion 10 of the occupant restraint structure 100 is held by at least a portion of the upper surface of the instrument panel 2 and at least a portion of the upper surface of the airbag cushion 20. In this respect, the occupant restraint structure 100 can more appropriately and reliably hold the airbag cushion 10 during inflation.

[0023] <Implementation Method 3> Furthermore, such as Figure 1 As shown, the occupant constraint structure 100 is configured to satisfy the relationship shown in equation (2) when it expands.

[0024] L2u = Lob ± Δn …(2) As shown in the figure, Lob represents the accuracy of the rear end 41b of the opening 41, and Δn = the absolute value of (Lob - L2u) / 2. Furthermore, Δn is not particularly limited to a specific value; preferably, it can be around ±50 (mm).

[0025] According to the occupant restraint structure 100 configured in this way, since the upper surface of the airbag cushion 20 expands to near the rear end 2b of the instrument panel 2, the lower surface of the airbag cushion 10 can be pushed further upward by the airbag cushion 20, so that the airbag cushion 10 can be held more properly and reliably during expansion.

[0026] <Implementation Method Four> then, Figure 3 This is a schematic side view showing the state of the airbag cushions 10, 20 when inflated and deployed, together with the instrument panel 2 and the occupant P, regarding the occupant restraint structure 200 involved in other embodiments of this disclosure.

[0027] like Figure 3 As shown, the occupant restraint structure 200 is roughly the same as the airbag cushions 10 and 20, except for the difference in the degree of expansion and deployment. Figure 2 The occupant restraint structure 100 shown is configured similarly. That is, in the occupant restraint structure 200, the airbag cushions 10 and 20 also expand and unfold from the opening 41 on the upper side of the instrument panel 2 and the opening 42 on the lower side of the instrument panel 2 toward the upper and lower parts of the occupant P, respectively. Furthermore, the occupant restraint structure 200 of the fourth embodiment is configured to satisfy the relationship expressed by the following formula (3) when it expands and unfolds. In addition, regarding L2u and Lob, refer to the explanation of the above formulas (1) and (2).

[0028] L2u ≧ Lob …(3) According to the occupant restraint structure 200 configured in this way, when the airbag cushions 10 and 20 inflate and deploy, the height of the upper end 20u of the airbag cushion 20 is above the height of the rear end 2b of the instrument panel 2. Therefore, the lower surface of the airbag cushion 10 can be pushed further upward by the airbag cushion 20, thereby allowing the airbag cushion 10 to be held more appropriately and reliably during inflation.

[0029] <Implementation Method Five> Here, as Figure 2 and Figure 3 As shown, when either of the occupant restraint structures 100 or 200 expands and deploys, the upper end 20u of the airbag cushion 20 is also configured to abut against the lower surface of the airbag cushion 10. With this configuration, the lower surface of the airbag cushion 10 can be supported by a large area through the upper end of the airbag cushion 20, thus maintaining the airbag cushion 10 more stably and reliably during expansion.

[0030] <Implementation Method Six> In addition, such as Figure 2 and Figure 3 As shown, when either of the occupant restraint structures 100 or 200 expands and deploys, a recess 23 is also formed in a portion of the lower surface of the airbag cushion 10, for the upper end of the airbag cushion 20 to be embedded and abutted. With this configuration, the lower surface of the airbag cushion 10 can be supported by a larger area through the upper end of the airbag cushion 20, and the airbag cushions 10 and 20 are fixed in a manner that can be described as loosely interlocking, thus facilitating the simultaneous stability of both airbag cushions 10 and 20. As a result, both airbag cushions 10 and 20 are more stable during expansion, and can be held together more reliably.

[0031] <Implementation Method Seven> Furthermore, the configuration of the sixth embodiment can also be represented from another viewpoint as follows. That is, in Figure 2 and Figure 3 When any of the occupant restraint structures 100 and 200 shown expands and unfolds, the upper end 20u of the airbag cushion 20 is located in the front-rear direction between the lower ends 10d1 and 10d2 (the first lower end and the second lower end) formed on the lower surface of the airbag cushion 10, respectively.

[0032] <Implementation Method Eight> In addition, such as Figure 2 and Figure 3As shown, when either of the occupant restraint structures 100 or 200 expands and deploys, the virtual straight line VL extending through the front end 20f and rear end 20b of the airbag cushion 20 intersects with the vehicle seat S where the occupant P sits. That is, as shown in the figure, if the shape or volume of the dashboard 2 is smaller than before, the protrusion of the dashboard 2 towards the occupant P side will naturally be smaller, and therefore the angle at which the airbag cushion 20 deploys relative to the horizontal direction is also smaller than before (becomes gentler), making it easier to adopt the structure of this embodiment. Therefore, the structures of the occupant restraint structures 100 and 200 of the present invention described in the first to seventh embodiments provide significantly better benefits than before as reaction force surface structures for maintaining the airbag cushion 10.

[0033] <Implementation Method Nine> In addition, Figure 2 and Figure 3 In either of the occupant constraint structures 100 and 200 shown, the relationship shown in equation (4) is also configured to satisfy the following relationship when expanding.

[0034] P2>P1 …(4) Wherein, P1 represents the internal pressure of airbag cushion 10, and P2 represents the internal pressure of airbag cushion 20. That is, since the internal pressure P2 of airbag cushion 20 is higher than the internal pressure P1 of airbag cushion 10, airbag cushion 20 can easily push airbag cushion 10 upwards, overcoming the downward vertical pressure of airbag cushion 10. Therefore, it has the advantage of easily enabling airbag cushion 20 to further function as the reaction force surface of airbag cushion 10.

[0035] <Implementation Method 10> In addition, Figure 2 and Figure 3 Preferably, in any of the occupant restraint structures 100 and 200 shown, the airbag cushion 10 completes its expansion and deployment after the airbag cushion 20 has finished expanding and deploying. More specifically, in this case, the start and end times of gas supply to the airbag cushions 10 and 20 can be appropriately adjusted based on the expansion volume of the airbag cushions 10 and 20, the amount of gas supplied from the inflators 31 and 32 to the airbag cushions 10 and 20, and the gas supply rate. If this structure is adopted, the expansion and deployment of the airbag cushion 20 can be completed before the expansion and deployment of the airbag cushion 10 is finished. Therefore, it is particularly easy for the upper surface of the airbag cushion 20 to function as a reaction force surface for maintaining the airbag cushion 10.

[0036] The embodiments described above are for the purpose of understanding the present invention and are not intended to limit or explain the present invention. The elements, their configurations, materials, conditions, shapes, and dimensions, etc., of each embodiment are not limited to the illustrated elements and can be appropriately modified, and the structures of each embodiment can be combined with each other. For example, an additional airbag cushion may be further included, wherein the additional airbag cushion may unfold from the same region as the openings 41, 42, or from a different region. Furthermore, the recesses formed on the airbag cushion 10 are not limited to... Figure 2 and Figure 3 The recess 23, which is concave in the front-rear direction, can also be configured to be concave in the left-right direction (vehicle width direction). Furthermore, an exhaust port mechanism for venting internal gas to the outside can be provided on each (both) or either of the contact surfaces of the airbag cushions 10 and 20. This effectively suppresses the outflow of internal gas from the airbag cushions 10 and 20, and easily maintains an internal pressure P1 and P2 suitable for protecting the occupant P.

[0037] Additional considerations regarding various implementation methods> [Implementation Method 1] An occupant restraint structure, for the purpose of protecting occupants inside the vehicle, is housed in a dashboard located at the front of the vehicle interior, and includes the following features: The first airbag cushion expands and deploys toward the occupant from a first opening formed on the upper side of the dashboard; The second airbag cushion expands and deploys toward the occupant from a second opening formed on the lower side of the dashboard; The expansion and unfolding satisfy the relationship expressed by the following equation (1): L2u ≧ Lib …(1) L2u: The upper end accuracy of the second airbag cushion. Lib: The back-end accuracy of the dashboard. [Implementation Method Two] The occupant restraint structure as described in Embodiment 1, wherein, during the expansion and deployment, the lower surface of the first airbag cushion is held by at least a portion of the upper surface of the dashboard and at least a portion of the upper surface of the second airbag cushion.

[0038] [Implementation Method 3] The occupant constraint structure as described in Embodiment 1 or 2, wherein... The following relationship, expressed by equation (2), is satisfied during the expansion: L2u = Lob ± Δn …(2) Lob: Rear end alignment of the first opening Δn: Absolute value of (Lob-L2u) / 2 [Implementation Method Four] The occupant constraint structure as described in Embodiment 1 or 2, wherein... The following relationship, expressed by equation (3), is satisfied during the expansion: L2u ≧ Lob …(3) [Implementation Method Five] The occupant constraint structure as described in any one of embodiments one through four, wherein... During the expansion and deployment, the upper end of the second airbag abuts against the lower surface of the first airbag.

[0039] [Implementation Method Six] The occupant constraint structure as described in any one of embodiments one through four, wherein... During the expansion and deployment, a recess is formed in a portion of the lower surface of the first airbag, which is then inserted into and abutted by the upper end of the second airbag.

[0040] [Implementation Method Seven] As described in Embodiment 5 or 6, the occupant constraint structure, wherein... During the expansion and deployment, the upper end of the second airbag is located between the first lower end and the second lower end of the lower surface of the first airbag, respectively, formed in the front-rear direction of the upper end.

[0041] [Implementation Method Eight] The occupant constraint structure as described in any one of embodiments one through seven, wherein... The virtual straight line extending from the front and rear ends of the second airbag cushion as it expands intersects with the vehicle seat where the occupant sits.

[0042] [Implementation Method Nine] The occupant constraint structure as described in any one of embodiments one through eight, wherein... The following relationship, expressed by equation (4), is satisfied during the expansion: P2>P1 …(4) P1: Internal pressure of the first airbag cushion P2: Internal pressure of the second airbag cushion [Implementation Method Ten] The occupant constraint structure as described in any one of embodiments one through nine, wherein... After the second airbag has expanded and deployed, the first airbag has also expanded and deployed.

[0043] Symbol Explanation 1…cabin 2…dashboard 2b…rear end 3…windshield 10… Airbag cushion (first airbag cushion) 10d1…Lower end (first lower end) 10d2…lower end (second lower end) 20… airbag cushion (second airbag cushion) 20b…backend 20f…frontend 20u…upper end 23…recessed part 31, 32… Inflators 41…Opening (First opening) 41b…backend 42… Opening (Second opening) 100, 200… Occupant restraint structure Db… Rear of vehicle Dd…below the vehicle Df…front of the vehicle Du…H1, H2…shell above the vehicle P…Occupant P1, P2…Internal pressure Ph…head Pj…upper body Pk…Legs S…Vehicle Seats S1…backrest S2…seat VL…virtual straight line

Claims

1. An occupant restraint structure, for the purpose of protecting occupants inside a vehicle interior, is housed in a dashboard located at the front of the vehicle interior, and comprises; The first airbag cushion expands and deploys toward the occupant from a first opening formed on the upper side of the dashboard; The second airbag cushion expands and deploys toward the occupant from a second opening formed on the lower side of the dashboard; When expanded, the following equation (1) is satisfied: L2u ≧ Lib …(1) L2u: The upper end accuracy of the second airbag cushion. Lib: The back-end accuracy of the dashboard.

2. The occupant constraint structure as described in claim 1, wherein, During the expansion and deployment, the lower surface of the first airbag cushion is held by at least a portion of the upper surface of the dashboard and at least a portion of the upper surface of the second airbag cushion.

3. The occupant restraint structure as described in claim 1 or 2, wherein, The following relationship, expressed by equation (2), is satisfied during the expansion: L2u = Lob ± Δn …(2) Lob: Rear end alignment of the first opening Δn: (Lob-L2u) absolute value / 2.

4. The occupant restraint structure as described in claim 1 or 2, wherein, The following relationship, expressed by equation (3), is satisfied during the expansion: L2u ≧ Lob …(3).

5. The occupant restraint structure as described in claim 1 or 2, wherein, During the expansion and deployment, the upper end of the second airbag abuts against the lower surface of the first airbag.

6. The occupant restraint structure as described in claim 1 or 2, wherein, During the expansion and deployment, a recess is formed in a portion of the lower surface of the first airbag, which is then inserted into and abutted by the upper end of the second airbag.

7. The occupant restraint structure as described in claim 1 or 2, wherein, During the expansion and deployment, the upper end of the second airbag is located between the first lower end and the second lower end of the lower surface of the first airbag, respectively, formed in the front-rear direction of the upper end.

8. The occupant restraint structure as described in claim 1 or 2, wherein it is configured as follows: A virtual straight line extending from the front and rear ends of the second airbag cushion during expansion intersects with the vehicle seat where the occupant sits.

9. The occupant restraint structure as described in claim 1 or 2, wherein, The following relationship, expressed by equation (4), is satisfied during the expansion: P2>P1 …(4) P1: Internal pressure of the first airbag cushion P2: The internal pressure of the second airbag cushion.

10. The occupant restraint structure as described in claim 1 or 2, wherein it is configured as follows: After the second airbag has expanded and deployed, the first airbag has also expanded and deployed.

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