Airbag device

Abstract

An airbag device mounted on a lower cover includes: an airbag body that is inflated and deployed by gas; and a box-shaped cover member that houses the airbag body and has a bottom wall positioned on the forward direction side of the moving body, an upper wall extending in the backward direction of the moving body from the upper end of the bottom wall, a lower wall extending in the backward direction from the lower end of the bottom wall, and an opening facing the backward direction, a steering wheel is provided with: a rim section that is held by an occupant of a moving body; and a hub portion surrounded by at least a portion of the rim portion, the lower cover being attached to the forward direction side of the hub portion, and the airbag body passing through a passage region between the rim portion and the hub portion to expand and deploy.

Description

[0001] Cross-referencing of related applications

[0002] This application claims priority based on Japanese Patent Application No. 2024-153649, filed on September 6, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to an airbag device. Background Technology

[0004] Various airbag devices mounted on steering wheels have been proposed. For example, Japanese Patent Application Publication No. 2016-088173 discloses an airbag device mounted in the wheel hub of the steering wheel. By rupturing the upper cover (also called a "pad") covering the surface of the wheel hub, the bag-shaped airbag body expands and deploys outward.

[0005] An attempt was made to mount a rigid structure such as a display or smartphone stand on the upper cover. However, if the airbag device disclosed in Japanese Patent Application Publication No. 2016-088173 is applied to this structure, it may hinder the inflation and deployment of the airbag body. Summary of the Invention

[0006] This invention can be implemented in the following ways.

[0007] According to one aspect of the present invention, an airbag device for a lower cover of a steering wheel mounted on a mobile body is provided. The airbag device comprises: an airbag body that expands and deploys by gas supplied from an inflator; and a box-shaped cover member that houses the airbag body, having a bottom wall, an upper wall, a lower wall, and an opening, the bottom wall being located on the forward direction side of the mobile body, the upper wall extending in a backward direction from an upper end of the bottom wall, the lower wall extending in the backward direction of the mobile body from a lower end of the bottom wall, and the opening facing the backward direction. The steering wheel has: a rim portion held by an occupant of the mobile body; and a hub portion surrounded by at least a portion of the rim portion, the lower cover being mounted on the forward direction side of the hub portion, and the airbag body expanding and deploying through the area between the rim portion and the hub portion.

[0008] This invention can be implemented in various ways. For example, it can be implemented as a steering wheel equipped with an airbag, a moving body equipped with an airbag, etc. Attached Figure Description

[0009] Figure 1 This is a perspective view of a steering wheel equipped with the airbag device of the first embodiment of the present invention.

[0010] Figure 2 It means Figure 1 A cross-sectional view of line II-II.

[0011] Figure 3 It is used for Figure 2 The diagram illustrates the inflated and deployed state of the airbag body.

[0012] Figure 4 This is a front view of the airbag body as seen from the forward direction.

[0013] Figure 5 This is a front view of the airbag body viewed from the rearward direction.

[0014] Figure 6 This is a perspective view of the cover component.

[0015] Figure 7 This is a cross-sectional view used to explain the airbag device of the second embodiment.

[0016] Figure 8 This is a diagram showing the state in which the airbag body of the airbag device of the third embodiment is inflated and deployed.

[0017] Figure 9 This is a diagram used to illustrate the main body of the airbag. Detailed Implementation

[0018] A. Implementation Method 1:

[0019] <Overall Structure>

[0020] Figure 1 This is a perspective view of a steering device 200 equipped with an airbag device 100 according to one aspect of the present invention. The steering device 200 serves as part of a steering control device for indicating the direction of travel of a vehicle. The steering device 200 has a rim portion 210, a hub portion 220, and a lower cover 230.

[0021] Furthermore, in this invention, the direction of vehicle travel is referred to as the "forward direction," and the direction opposite to the forward direction is referred to as the "reverse direction." Additionally, both the forward and reverse directions are collectively referred to as the "front-back direction." Furthermore, from the perspective of the driver of the vehicle, the vertical direction is referred to as the "up-down direction." Sometimes, the "up-down direction" is also referred to as the "height direction." Additionally, the direction along the left-right direction (width direction) of the vehicle is referred to as the "left-right direction."

[0022] The "front and back direction", "up and down direction", and "left and right direction" are directions that intersect with each other.

[0023] <Structure of Steering Device 200>

[0024] The rim portion 210 is held by the vehicle occupants. In this embodiment, the rim portion 210 has a U-shaped appearance when viewed in the longitudinal direction. The rim portion 210 has a left handle portion 211, a right handle portion 212, and a connecting portion 213. The left handle portion 211 extends vertically and can be held by the occupant's left hand. The right handle portion 212 extends vertically and can be held by the occupant's right hand. The connecting portion 213 extends horizontally and connects the lower ends of the left handle portion 211 and the right handle portion 212 to each other.

[0025] The hub portion 220 is configured to be mounted on the upper part of both the left handlebar portion 211 and the right handlebar portion 212. Alternatively, in this embodiment, the hub portion 220 is positioned between the left handlebar portion 211 and the right handlebar portion 212. Furthermore, the hub portion 220 is surrounded by at least a portion of the rim portion 210. Additionally, the hub portion 220 is positioned between the rim portion 210 and the lower cover 230 (described later). The hub portion 220 has a rectangular plate-like shape that is longer in the left-right direction. The hub portion 220 is separate from the connecting portion 213. In this embodiment, a display is provided on the rearward side of the hub portion 220. The display shows any information, such as vehicle information and information related to the vehicle's surrounding environment.

[0026] The lower cover 230 is located on the forward direction side of the wheel hub portion 220. In this embodiment, the lower cover 230 has a box-shaped appearance. The lower cover 230 houses the airbag device 100. A door portion 231 is provided on the lower surface of the lower cover 230. The door portion 231 opens when the airbag device 100 is activated, thereby causing the airbag body 110 of the airbag device 100 to expand and deploy outwards from the lower cover 230. The vehicle's steering shaft 240 is connected to the forward direction side of the lower cover 230. In this embodiment, the steering shaft 240 is parallel to the longitudinal direction.

[0027] <Structure of airbag device 100>

[0028] Figure 2 It means Figure 1 A cross-sectional view of line II-II. That is, Figure 2 This is a diagram showing a cross-section of the steering device 200 obtained by cutting through a plane that passes through the center of the steering shaft 240 and is parallel to the vertical and longitudinal directions. Figure 2 This indicates that the airbag body 110 is not inflated and deployed. Figure 3 It is used for Figure 2 The diagram illustrates the inflated and deployed state of the airbag body 110. Furthermore, in... Figure 3For ease of explanation, the remaining portion 320 is exaggerated. In the event of a detected or predicted vehicle collision, the airbag device 100 reduces the impact on the occupants. The airbag device 100 is mounted on the lower cover 230. The airbag device 100 includes an airbag body 110, an inflator 120, and a cover component 300.

[0029] <Structure of the airbag body 110>

[0030] Gas is supplied from the inflator 120, causing the airbag body 110 to inflate and deploy. Hereinafter, the inflated state of the airbag body 110 will also be referred to as the "inflated state." The airbag body 110 has a bag-like external shape. The airbag body 110 is manufactured by sewing together a base fabric made of nylon, polyamide, etc. Figure 3 As shown, the airbag body 110 of the present invention expands and deploys by passing through the region R between the rim portion 210 and the hub portion 220. The region R is located lower than the center in the vertical direction of the steering device 200. Figure 2 As shown, the airbag body 110 is folded multiple times and stored in the metal shell 150 and the cover component 300. In this invention, this state is referred to as the "stored state".

[0031] Figure 4 This is a front view of the airbag body 110 as viewed from the forward direction. Figure 5 This is a front view of the airbag body 110 as viewed from the rearward direction. Figure 4 and Figure 5 This indicates the uninflated, expanded state of the airbag body 110. The airbag body 110 has a conduit portion 111 and a main inflation portion 112.

[0032] like Figure 4 As shown, the conduit portion 111 hangs down from the central portion of the main expansion portion 112 like a tongue. The conduit portion 111 is connected to the main expansion portion 112. An insertion hole 113 for inserting an inflator 120 is provided in the conduit portion 111. Around the insertion hole 113, four fixing holes 114 are provided for inserting fixing components for securing the inflator 120. The fixing components are, for example, bolts. The conduit portion 111 is connected to the inflator 120 and supplies gas to the main expansion portion 112. Figure 3 As shown, in the expanded state, the conduit section 111 is disposed from the inflator 120 to the passage area R. In this embodiment, the capacity of the conduit section 111 is smaller than the capacity of the main expansion section 112. That is, the conduit section 111, which is located upstream of the main expansion section 112 and has a smaller capacity than the main expansion section 112, completes its expansion and deployment before the main expansion section 112 has completed its expansion and deployment.

[0033] like Figure 5As shown, the main expansion section 112, before expansion, has a shell-like shape. Gas supplied from the inflator 120 is introduced into the main expansion section 112 via the conduit 111. Figure 3 As shown, the main expansion section 112 expands and unfolds further in the rearward direction than the steering device 200. While the expanded main expansion section 112 receives a reaction force from the steering device 200, it also supports the occupants.

[0034] <Structure of Inflator 120>

[0035] The inflator 120 supplies gas to the airbag body 110. More specifically, in the event of a detected or predicted collision with the vehicle, the inflator 120 begins supplying gas to the airbag body 110 upon receiving a signal from the vehicle's ECU. In this embodiment, the inflator 120 is mounted on the upper surface of the metal housing 150. A wiring harness 122 is connected to the inflator 120 via a connector 121. If a collision with the vehicle is detected or predicted, a signal is transmitted from the vehicle's ECU to the wiring harness 122. Upon receiving such a signal, the inflator 120 ejects gas downwards.

[0036] <Structure of Cover Component 300>

[0037] Figure 6 This is a perspective view of the cover component 300. The cover component 300 houses the airbag body 110. The cover component 300 has a box-like shape and an opening 310 facing the rearward direction. The cover component 300, like the airbag body 110, is manufactured by sewing together a base fabric. The cover component 300 has a bottom wall 301, a pair of side walls 302 and 303, an upper wall 304, a lower wall 305, a remaining portion 320, and a strap portion 330.

[0038] The bottom wall 301 is located on the forward direction side of the vehicle. A pair of side walls 302 and 303 extend backward from the left and right ends of the bottom wall 301, respectively. The upper wall 304 extends backward from the upper end of the bottom wall 301. The upper wall 304 is provided with: mounting holes 306 for mounting the inflator 120; and four fixing holes 307 for inserting fixing components. The lower wall 305 extends backward from the lower end of the bottom wall 301. The upper wall 304 and the lower wall 305 are approximately the same size. The opening 310 is divided by the backward-direction ends of the pair of side walls 302 and 303, the upper wall 304, and the lower wall 305. The airbag body 110 expands and unfolds outward from the cover component 300 through the opening 310.

[0039] The remaining portion 320 extends from the rearward-direction end of the lower wall 305. The remaining portion 320 is configured such that the forward-direction end is a fixed end E1 and the rearward-direction end is a free end E2, enabling the opening and closing of at least a portion of the opening 310. Figure 2 As shown, in the retracted state of the airbag body 110, the remaining portion 320 covers the surface of the main expansion portion 112 on the retracting side. Furthermore, in the retracted state, the free end E2 is sandwiched between the duct portion 111 and the main expansion portion 112.

[0040] like Figure 3 As shown, in the inflated and deployed state of the airbag body 110, the remaining portion 320 is positioned between the lower wall 305 and the connection portion 213 of the rim portion 210. Specifically, the airbag body 110 inflates and deploys, pressing the remaining portion 320 backward. At this time, the remaining portion 320 extends towards the fixed end E1. Figure 2 and Figure 3 Rotate clockwise. If the free end E2 side contacts the upper surface of the rim portion 210, frictional resistance is generated between the remaining portion 320 and the rim portion 210, and the free end E2 side is engaged with the rim portion 210. The remaining portion 320, thus positioned, restricts the expansion direction of the airbag body 110 to the rearward direction.

[0041] like Figure 6 As shown, the strap portion 330 has a strap-like shape. The strap portion 330 is sewn along the left-right direction on the lower surface SF1 of the fixed end E1 side of the remaining portion 320. In addition, through holes 331 are provided at one end and the other end of the strap portion 330. One end and the other end of the strap portion 330 are arranged such that the through holes 331 and the fixing holes 307 of the upper wall 304 overlap. Specifically, the strap portion 330 is arranged such that two of the four fixing holes 307 on the forward direction side overlap with the through holes 331. The fixing member is inserted into the fixing holes 114 of the airbag body 110, the fixing holes 307 of the upper wall 304, and the through holes 331, and the fixing member is fastened to the lower cover 230, thereby fixing the above-mentioned member to the lower cover 230. In the inflated and deployed state of the airbag body 110, the strap portion 330 pulls the remaining portion 320 towards the upper wall 304. Therefore, the pressure of the expanded airbag body 110 can be used to suppress the free end E2 side of the remaining part 320 from deviating from the upper surface of the rim part 210, and the remaining part 320 can be easily maintained between the lower wall 305 and the rim part 210.

[0042] The airbag device 100 described above is mounted on a lower cover 230 installed on the forward direction side of the wheel hub 220. Therefore, compared with the structure in which the airbag device 100 is mounted inside the wheel hub 220, the wheel hub 220 can be constructed to be thinner. As a result, the appearance of the steering device 200 can be improved.

[0043] Furthermore, according to the airbag device 100 of the first embodiment, the airbag body 110 expands and deploys by passing through the region R between the hub portion 220 and the rim portion 210. Therefore, even if a rigid structure such as a display is disposed on the upper cover of the steering device 200, the airbag body 110 can expand and deploy without causing such a structure to break. That is, it is possible to suppress the situation where such a rigid structure hinders the expansion and deployment of the airbag body 110.

[0044] In addition, according to the airbag device 100 of the first embodiment, the cover member 300 has an opening 310 facing the rearward direction. Therefore, compared with the structure of the cover member 300 having an opening 310 in a direction other than the rearward direction, the airbag body 110 can inflate and deploy earlier toward the occupant on the rearward side of the steering device 200.

[0045] Furthermore, according to the airbag device 100 of the first embodiment, the inflator 120 is mounted on the upper wall 304, and the remaining portion 320 extends from the rearward side end of the lower wall 305, so the gas ejected from the inflator 120 is directed towards the remaining portion 320. The airbag body 110, which expands and unfolds with such gas, is subjected to a reaction force generated by the remaining portion 320, restricting its expansion and unfolding in the forward and downward directions. As a result, the airbag body 110 can more easily pass between the rim portion 210 and the hub portion 220.

[0046] In addition, according to the airbag device 100 of the first embodiment, the capacity of the conduit portion 111 is smaller than the capacity of the main expansion portion 112. Therefore, compared with the structure in which the capacity of the conduit portion 111 is greater than or equal to the capacity of the main expansion portion 112, the amount of gas required to inflate and expand the airbag body 110 as a whole can be reduced, and the time required for the overall inflation and expansion of the airbag body 110 can be shortened.

[0047] Furthermore, according to the airbag device 100 of the first embodiment, the smaller-capacity conduit section 111 is disposed from the inflator 120 to the passage area R. Therefore, the conduit section 111 completes its expansion earlier than the main expansion section 112, and can fill the space from the inflator 120 to the passage area R. As a result, the main expansion section 112, during expansion, can pass through the passage area R more easily.

[0048] Furthermore, according to the airbag device 100 of the first embodiment, in the inflated and deployed state of the airbag body 110, the remaining portion 320 is positioned between the lower wall 305 and the rim portion 210. Therefore, compared to a structure in which the remaining portion 320 is not positioned between the lower wall 305 and the rim portion 210, the reaction force applied to the airbag body 110 from the remaining portion 320 can be further increased. As a result, it is possible to suppress the airbag body 110 from avoiding movement in directions other than the rearward direction.

[0049] Furthermore, according to the airbag device 100 of the first embodiment, the cover member 300 has a strap portion 330, so compared with a structure without the strap portion 330, the reaction force applied to the airbag body 110 from the remaining portion 320 can be further increased. As a result, it is possible to further suppress the airbag body 110 from avoiding directions other than the rearward direction.

[0050] Furthermore, according to the airbag device 100 of the first embodiment, the inflator 120 is mounted on the upper wall 304 and sprays gas downwards, so the lower part of the airbag body 110 can inflate and deploy earlier than the upper part of the airbag body 110. Therefore, the airbag body 110 can provide support to the lower parts of the occupant's body earlier than the upper part. More specifically, for example, regarding the structure of the main inflator 112 supporting the occupant's abdomen to head, the lower part of the main inflator 112 inflates and deploys earlier than the upper part, thereby allowing the main inflator 112 to support the occupant's abdomen earlier.

[0051] Furthermore, according to the airbag device 100 of the first embodiment, when the airbag body 110 is housed in the cover member 300, the remaining portion 320 covers the main expansion portion 112, and the free end E2 is clamped between the guide portion 111 and the main expansion portion 112, thus delaying the expansion and deployment of the main expansion portion 112. This suppresses the expansion of the main expansion portion 112 between the inflator 120 and the passage area R, making it easier for the main expansion portion 112 to pass between the rim portion 210 and the hub portion 220.

[0052] Furthermore, according to the airbag device 100 of the first embodiment, the through holes 331 at one end and the other end of the belt portion 330 are configured to overlap with the fixing holes 307 provided on the forward direction side among the plurality of fixing holes 307 provided on the upper wall 304. Therefore, compared with the structure in which the through holes 331 are configured to overlap with the fixing holes 307 provided on the backward direction side, the belt portion 330 can exert a stronger pulling force on the remaining portion 320.

[0053] B. Second Implementation Method:

[0054] Figure 7 This is a cross-sectional view used to explain the airbag device 100b of the second embodiment. Figure 7 Zhongyu Figure 3Similarly, the remaining portion 320b is exaggerated. The airbag device 100b of the second embodiment has a structure similar to that of the airbag device 100 of the first embodiment, which is reversed vertically. Specifically, the airbag device 100b of the second embodiment differs from the airbag device 100 of the first embodiment in the direction of the gas ejected by the inflator 120b. Furthermore, the steering device 200b of the airbag device 100b of the second embodiment differs from the steering device 200 of the first embodiment in the position of the hub portion 220b. Structures not specifically described below are the same as those of the airbag device 100 and steering device 200 of the first embodiment.

[0055] In the second embodiment, the hub portion 220b of the steering device 200b is mounted on the lower part of both the left handlebar portion 211 and the right handlebar portion 212 in the left-right direction. Furthermore, the connecting portion 213b connects the upper ends of both the left handlebar portion 211 and the right handlebar portion 212 to each other. Therefore, the region Rb is located higher than the center in the vertical direction of the steering device 200b.

[0056] The inflator 120b is mounted on the metal casing 150. The inflator 120b sprays gas upwards.

[0057] The remaining portion 320b extends from the rear end of the upper wall 304b. In the inflated and deployed state of the airbag body 110b, the free end E2b of the remaining portion 320b contacts the lower surface of the rim portion 210b.

[0058] According to the airbag device 100b of the second embodiment described above, the inflator 120b is mounted on the lower wall 305b and sprays gas upwards, so the upper part of the airbag body 110b can inflate and deploy earlier than the lower part of the airbag body 110b. Therefore, the airbag body 110b can protect the upper part of the occupant's body earlier than the lower part. More specifically, for example, in a structure where the main inflator 112b protects the occupant's abdomen to head, the upper part of the main inflator 112b inflates and deploys earlier than the lower part, thereby allowing the main inflator 112b to protect the occupant's head earlier.

[0059] C. Third implementation method:

[0060] Figure 8 This is a diagram showing the inflated and deployed state of the airbag body 110c of the airbag device 100c according to the third embodiment. Figure 9 This is a diagram used to illustrate the airbag body 110c. For illustration purposes, Figure 9The diagram shows a cross-section obtained by cutting the center of the airbag body 110c in the left-right direction with a plane parallel to the vertical and front-back directions. The airbag device 100c of the third embodiment differs from the airbag device 100 of the first embodiment in that the airbag body 110c also has a partition member 400. Furthermore, for the purpose of explanation, in Figure 9 The partition member 400 is shown with a cross-sectional line. Structures not described below are the same as those in the airbag device 100 of the first embodiment. Furthermore, the airbag body 110c of the third embodiment can be combined with the airbag device 100b of the second embodiment.

[0061] like Figure 8 and Figure 9 As shown, the partition member 400 divides the main expansion portion 112c into a first chamber 510 and a second chamber 520. The partition member 400, like the airbag body 110c, is made of a base fabric. The partition member 400 has a first partition portion 410 and a second partition portion 420.

[0062] The first partition 410 extends in both the front-to-back and left-to-right directions. The front end of the first partition 410 is located higher than the connection between the conduit portion 111c and the main expansion portion 112c. The rear end of the first partition 410 is located at the center of the main expansion portion 112c in the front-to-back direction. The left and right ends of the first partition 410 are connected to the left and right ends of the main expansion portion 112c, respectively.

[0063] The second partition 420 extends in both vertical and horizontal directions. The upper end of the second partition 420 connects to the rear end of the first partition 410. The lower end of the second partition 420 connects to the lower end of the main expansion section 112c. The left and right ends of the second partition 420 connect to the left and right ends of the main expansion section 112c, respectively. A vent 421 is provided in the second partition 420, located lower than the center in the vertical direction and at the center in the horizontal direction. The vent 421 is a passage for gas supplied by the inflator 120.

[0064] The main expansion section 112c is divided into a first chamber 510 and a second chamber 520 by a partition member 400. The first chamber 510 is connected to the conduit section 111c. In the expanded state of the main expansion section 112c, the first chamber 510 corresponds to the front and lower portion. The second chamber 520 is connected to the first chamber 510. The second chamber 520 corresponds to the portion of the main expansion section 112c excluding the first chamber 510. The capacity of the second chamber 520 is greater than the capacity of the first chamber 510. Gas supplied from the inflator 120 arrives sequentially at the conduit section 111c, the first chamber 510, and the second chamber 520.

[0065] The airbag device 100c of the third embodiment described above includes: a first chamber 510 connected to the conduit portion 111c; and a second chamber 520 connected to the first chamber 510, the second chamber 520 having a larger capacity than the first chamber 510. Therefore, when the airbag body 110c inflates and deploys, the first chamber 510 inflates and deploys first, followed by the second chamber 520. This allows the smaller first chamber 510 to inflate and deploy earlier. Therefore, by configuring the portion of the main inflator 112c that is desired to inflate and deploy earlier as the first chamber 510, the main inflator 112c can more effectively support the occupant.

[0066] Furthermore, the airbag device 100c of the third embodiment has a vent 421 located lower than the center in the vertical direction in the second partition 420. Therefore, in the structure where the inflator 120 sprays gas downwards, the gas supplied to the first chamber 510 can be supplied to the second chamber 520 more effectively. As a result, the main expansion section 112c can expand and unfold more smoothly.

[0067] Furthermore, in the airbag device 100c of the third embodiment, the first chamber 510 is located in front of and below the main expansion section 112c, so the main expansion section 112c can be deployed downward earlier.

[0068] D. Other implementation methods:

[0069] (D1) In the above embodiments, the rim portion 210 of the steering device 200 is U-shaped, but the present invention is not limited to this. The shape of the rim portion 210 can be not only an open shape like a U, but also a ring shape such as a circle or a D. In addition, in the above embodiments, the hub portions 220 and 220b are configured as a left handle portion 211 and a right handle portion 212 respectively mounted on the rim portions 210 and 210b, but the present invention is not limited to this. For example, the hub portions 220 and 220b can be structures that do not directly contact the rim portions 210 and 210b. With such a structure, the hub portions 220 and 220b can be connected to the rim portions 210 and 210b, for example, through spokes. In addition, the hub portions 220 and 220b can be surrounded by the rim portions 210 and 210b throughout the entire circumference when the steering device 200 is viewed from the front. Furthermore, in the above embodiments, the steering shaft 240 is mounted on the forward direction side of the lower cover 230, but the present invention is not limited to this. The steering shaft 240 can be directly mounted to the wheel hub portions 220, 220b. Alternatively, the steering shaft 240 can also be mounted to the wheel rim portions 210, 210b via any connecting component.

[0070] (D2) In the above embodiments, a display is provided on the rearward side of the hub portion 220, but the present invention is not limited thereto. Any structure such as a smartphone holder or a switch can be provided on the rearward side of the hub portion 220.

[0071] (D3) In the above embodiments, uneven surfaces for increasing the coefficient of friction can be provided on the surfaces of the remaining portions 320, 320b that contact the rim portions 210, 210b. Additionally, uneven surfaces for increasing the coefficient of friction can be provided on the surfaces of the rim portions 210, 210b that contact the remaining portions 320, 320b. In this way, it is possible to prevent the remaining portions 320, 320b from shifting position due to being pressed by the inflated airbag bodies 110, 110b, 110c.

[0072] (D4) In the above embodiments, the cover components 300 and 300b may also be without the remaining portions 320 and 320b. Even with this structure, the openings 310 of the cover components 300 and 300b face the rearward direction, so the airbag bodies 110, 110b, and 110c can expand and deploy towards the rearward direction where the occupant is located earlier.

[0073] (D5) In the above embodiments, the airbag bodies 110, 110b, and 110c may not have conduit portions 111 and 111c, but may consist only of main expansion portions 112, 112b, and 112c. Even with this structure, the airbag bodies 110, 110b, and 110c can expand and deploy in the rearward direction of the steering devices 200 and 200b by passing through the passage regions R and Rb.

[0074] (D6) In the above embodiments, the remaining portions 320, 320b may not be mounted between the upper walls 304, 304b or the lower walls 305, 305b and the rim portions 210, 210b. Even with this structure, the remaining portions 320, 320b can still exert a reaction force on the inflated airbag bodies 110, 110b, 110c.

[0075] (D7) In the above embodiments, the cover components 300 and 300b may not have the strap portion 330. Even with this structure, the remaining portions 320 and 320b can still exert a reaction force on the inflated airbag bodies 110, 110b, and 110c.

[0076] (D8) In the above embodiments, the free ends E2 and E2b of the remaining portions 320 and 320b may not be sandwiched between the conduit portions 111 and 111c and the main expansion portions 112, 112b and 112c.

[0077] (D9) In the above embodiments, the cover components 300 and 300b are box-shaped with a pair of sidewalls 302 and 303, but the present invention is not limited to this. The cover components 300 and 300b can also be of any shape. In addition, the cover components 300 and 300b may not have a pair of sidewalls 302 and 303.

[0078] (D10) In the above embodiments, the belt portion 330 can be of any shape. For example, the belt portion 330 may have a wider width than other portions in the part overlapping with the remaining portions 320, 320b. In this way, the durability of the portion of the belt portion 330 overlapping with the remaining portions 320, 320b can be improved, and the pulling force on the remaining portions 320, 320b can be enhanced. In addition, for example, the width of the end of the belt portion 330 may be smaller than other portions. In this way, the belt portion 330 can be made lightweight. In addition, in the above embodiments, one end and the other end of the belt portion 330 are configured such that the through hole 331 and the fixing hole 307 overlap, but the present invention is not limited to this. One end and the other end of the belt portion 330 may also be connected to the metal housing 150.

[0079] (D11) In the above embodiments, the steering shaft 240 is parallel to the front-rear direction, but the present invention is not limited thereto. The steering shaft 240 may also be arranged in a direction parallel to any axis.

[0080] (D12) In the above embodiments, the airbag devices 100, 100b, and 100c can be installed on any moving body other than a vehicle. Such moving bodies include, for example, ships, airplanes, spacecraft, and so-called flying cars. Furthermore, the moving body is not limited to an object that achieves real movement, but can also be an object that achieves virtual movement, such as a simulator.

[0081] This invention is not limited to the embodiments described above and can be implemented in various structures without departing from its spirit. For example, in order to solve some or all of the above problems, or to achieve some or all of the above effects, the technical features in the embodiments can be appropriately replaced or combined. In addition, if a technical feature is not described as an essential technical feature in this specification, it can be appropriately deleted. For example, this invention can be implemented by the following description.

[0082] (1) According to one aspect of the present invention, an airbag device for a lower cover of a steering wheel mounted on a mobile body is provided. The airbag device comprises: an airbag body that expands and deploys by gas supplied from an inflator; and a box-shaped cover member that houses the airbag body, having a bottom wall, an upper wall, a lower wall, and an opening, the bottom wall being located on the forward direction side of the mobile body, the upper wall extending from an upper end of the bottom wall toward the backward direction, the lower wall extending from a lower end of the bottom wall toward the backward direction of the mobile body, the opening facing the backward direction, the steering wheel having: a rim portion held by an occupant of the mobile body; and a hub portion surrounded by at least a portion of the rim portion, the lower cover being mounted on the forward direction side of the hub portion, the airbag body expanding and deploying through the area between the rim portion and the hub portion, i.e., through the area.

[0083] According to this type of airbag device, the airbag body expands and deploys by passing through the area between the wheel hub and the wheel rim. Therefore, even if a rigid structure such as a display is mounted on the upper cover of the steering wheel, the airbag body can expand and deploy without breaking such a structure. In other words, it can suppress situations where such a rigid structure hinders the expansion and deployment of the airbag body.

[0084] In addition, the cover component has an opening facing the rearward direction, so compared with a structure in which the cover component has an opening in a direction other than the rearward direction, the airbag body can inflate and deploy earlier toward the occupant on the rearward side of the steering wheel.

[0085] Furthermore, since the airbag device in this design is mounted on a lower cover installed on the forward-direction side of the wheel hub, the wheel hub can be constructed thinner compared to a structure where the airbag device is mounted inside the wheel hub. This improves the appearance of the steering wheel.

[0086] (2) In the airbag device of the above manner, the inflator may be installed on one of the upper wall and the lower wall, and the cover component may also have a remainder extending from the end of the other wall on the retracting direction side.

[0087] In this type of airbag device, the inflator is mounted on one of the upper and lower walls, and the cover component has a remainder extending from the rearward side of the other wall. Therefore, the airbag body is subjected to a reaction force generated by the remainder, thereby restricting the direction of inflation. This allows the airbag body to pass more easily between the rim and the hub.

[0088] (3) In the airbag device of the above manner, the airbag body may also have: a main expansion section that supports the occupant of the moving body by expanding and unfolding; and a conduit section that is connected to the inflator to supply the gas to the main expansion section, and the conduit section having a smaller capacity than the main expansion section. In the expanded state of the airbag body, the conduit section is disposed from the inflator to the passage area.

[0089] According to this method of airbag device, the capacity of the conduit section is smaller than the capacity of the main expansion section. Therefore, compared with the structure in which the capacity of the conduit section is greater than or equal to the capacity of the main expansion section, the amount of gas required to make the airbag body expand and deploy as a whole can be reduced, and the time required for the airbag body to expand and deploy as a whole can be shortened.

[0090] Furthermore, the smaller duct section is positioned from the inflator to the passage area, so it expands and unfolds earlier than the main expansion section, filling the space from the inflator to the passage area. Therefore, the main expansion section, during expansion, passes through the passage area more easily.

[0091] (4) In the airbag device described above, the remaining part may cover the main expansion part when the airbag body is housed in the cover component. The remaining part has: a fixed end, which is the end on the forward direction side; and a free end, which is the end on the backward direction side. The free end is sandwiched between the conduit part and the main expansion part.

[0092] In this type of airbag device, the remaining portion covers the main expansion portion in the retracted state, and the free end of the remaining portion is clamped between the guide tube and the main expansion portion, thus delaying the expansion and deployment of the main expansion portion. This suppresses the expansion of the main expansion portion between the inflator and the passage area, making it easier for the main expansion portion to pass between the rim and the hub.

[0093] (5) In the airbag device described above, the remaining part may also be mounted between the other wall and the rim in the inflated and deployed state.

[0094] In this type of airbag device, the remaining portion is positioned between the other wall and the rim portion in the inflated and deployed state. Therefore, compared to a structure where the remaining portion is not positioned between the other wall and the rim portion, the reaction force exerted from the remaining portion on the airbag body is greater. This further suppresses the airbag body from deviating in directions other than the backward direction.

[0095] (6) In the airbag device described above, the cover component may also have a strap that pulls the remaining portion toward one of the walls in the inflated and deployed state.

[0096] According to this method of airbag device, the cover component also has a strap that pulls the remaining portion towards one wall side when inflated and deployed. Therefore, compared to a structure where the cover component does not have a strap, the reaction force applied to the inflated and deployed airbag body is stronger. As a result, it is possible to further suppress the airbag body from deviating in a direction other than the backward direction.

[0097] (7) In the airbag device described above, the inflator may be installed on the upper wall to spray the gas downward.

[0098] In this type of airbag device, the inflator is mounted on the upper wall and sprays gas downwards, so the lower part of the airbag body can inflate and deploy earlier than the upper part. Therefore, the airbag body can provide earlier protection to the lower parts of the occupant's body compared to the upper part. More specifically, for example, in a structure where the main inflator protects from the occupant's abdomen to the head, the lower part of the main inflator inflates and deploys earlier than the upper part, thus allowing the main inflator to protect the occupant's abdomen earlier.

[0099] (8) In the airbag device of the above manner, the main expansion part may also have: a first chamber connected to the conduit part; a second chamber connected to the first chamber, the second chamber having a capacity greater than that of the first chamber; and a partition member that separates the first chamber and the second chamber and is provided with a vent.

[0100] According to this type of airbag device, the main inflator has: a first chamber connected to a conduit; and a second chamber connected to the first chamber, the second chamber having a larger capacity than the first chamber, so that the smaller first chamber can inflate and deploy earlier. Therefore, by configuring the portion of the main inflator that is desired to inflate and deploy as the first chamber, the main inflator can more effectively support the occupant.

Claims

1. An airbag device mounted to a lower cover of a steering wheel of a mobile body, the airbag device having: an airbag main body that is inflated and deployed by a gas supplied from an inflator; and a cover member that houses the airbag main body, having a bottom wall on a forward direction side of the mobile body, an upper wall extending from an upper end of the bottom wall toward a rear direction side of the mobile body, a lower wall extending from a lower end of the bottom wall toward the rear direction side, and an opening toward the rear direction side, the steering wheel having: a rim portion held by an occupant of the mobile body; and a hub portion surrounded by at least a portion of the rim portion, the lower cover being mounted to the forward direction side of the hub portion, the airbag main body being inflated and deployed through a passage region between the rim portion and the hub portion.

2. The airbag device according to claim 1, wherein the inflator is mounted to one of the upper wall and the lower wall, the cover member further has a remaining portion extending from an end of the other of the upper wall and the lower wall on the rear direction side.

3. The airbag device according to claim 2, wherein the airbag main body has: a main inflation portion that receives the occupant of the mobile body by being inflated and deployed; and a conduit portion that is connected to the inflator to supply the gas to the main inflation portion, and has a capacity smaller than that of the main inflation portion, in an inflated and deployed state in which the airbag main body is inflated and deployed, the conduit portion is disposed from the inflator to the passage region.

4. The airbag device according to claim 3, wherein the remaining portion covers the main inflation portion in a housed state in which the airbag main body is housed in the cover member, the remaining portion has: a fixed end that is an end on the forward direction side; and a free end that is an end on the rear direction side, the free end is interposed between the conduit portion and the main inflation portion.

5. The airbag device according to claim 4, wherein the remaining portion is erected between the other wall and the rim portion in the inflated and deployed state.

6. The airbag device according to claim 5, wherein the cover member further has a belt portion that pulls the remaining portion toward the one wall side in the inflated and deployed state.

7. The airbag device according to claim 6, wherein the inflator is mounted to the upper wall to eject the gas toward the lower side.

8. The airbag device according to claim 7, wherein the main inflation portion has: a first chamber connected to the conduit portion; a second chamber connected to the first chamber, having a capacity larger than that of the first chamber; and a partition member that partitions the first chamber and the second chamber, provided with a vent hole.

Images