air bag

Abstract

An airbag (50) is mounted on a steering wheel (10) having a grip (1) held by an occupant (M) and a boss (2) connected to the steering shaft (35) of the vehicle (30). The airbag (50) is inflated by being supplied with inflatable gas and covers the entire area of ​​the grip (1) from the rear when fully inflated. When fully inflated, it has the following components: an occupant side panel (51) which is located at the rear and is configured to support the occupant (M); a steering wheel side panel (52) which is located at the front and is supported in contact with the grip; and side panels (53, 54) which are stitched to the occupant side panel (51) and the steering wheel side panel (52) to connect the occupant side panel (51) and the steering wheel side panel (52). The width of the side panels (53, 54) in the front-rear direction along the rotation axis (R) of the steering shaft (35) is wider than the width of the occupant side panel (51) in the left-right direction.

Description

Technical Field

[0001] This invention relates to an airbag mounted on the steering wheel of a vehicle. Background Technology

[0002] Currently, as described in Japanese Patent Application Publication No. 2024-121558, the following structure is widely known: an airbag is mounted on the steering wheel of a vehicle, which is used to absorb and protect the occupants during a vehicle collision.

[0003] The Japanese Patent Application Publication No. 2024-121558 describes an airbag whose fully inflated shape is wider in the lateral direction than in the longitudinal direction. In this configuration, when the occupant is heavy or the vehicle travels at high speeds during a collision, the airbag deforms due to the forward load, significantly reducing its longitudinal width. This can easily lead to a situation where the occupant makes contact with the steering wheel grip area through the airbag, a phenomenon known as "bottoming." Summary of the Invention

[0004] The purpose of this invention is to provide an airbag that can prevent occupants from contacting the steering wheel grip area through the airbag during a vehicle collision.

[0005] The following is a representative structure of the airbag that is used to solve the above-mentioned problems according to the present invention.

[0006] An airbag is mounted on a steering wheel having: a grip portion for an occupant to hold; and a boss portion connected to the steering axis of the vehicle. The airbag inflates by being supplied with inflatable gas and, upon full inflation, covers the entire area of ​​the grip portion from the rear. Upon full inflation, the airbag has the following components: an occupant side panel disposed at the rear to support the occupant; a steering wheel side panel disposed at the front and supported in contact with the grip portion; and a side panel stitched to the occupant side panel and the steering wheel side panel, connecting the occupant side panel and the steering wheel side panel. The width of the side panel in the longitudinal direction along the rotation axis of the steering axis is wider than the width of the occupant side panel in the lateral direction. Attached Figure Description

[0007] Figure 1 This is a view of the area around the driver's seat of a vehicle equipped with an airbag, viewed from the left.

[0008] Figure 2 This is a front view of the vehicle's steering wheel.

[0009] Figure 3 Therefore Figure 2 The diagram shown is a cross-sectional view of the steering wheel cut by section AA.

[0010] Figure 4 This is a left view of the steering wheel with the airbag fully inflated.

[0011] Figure 5 This is a front view of the steering wheel with the airbag fully inflated.

[0012] Figure 6 This is a plan view of the panels that make up the airbag.

[0013] Figure 7 This is a plan view of the steering wheel with the airbag fully inflated. Detailed Implementation

[0014] The structure of an airbag 50 according to one embodiment of the present invention will now be described with reference to the accompanying drawings. The airbag 50 is mounted on the steering wheel 10 of the vehicle 30. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative arrangements of the structural components described below are not intended to limit the scope of the invention.

[0015] Figure 1 This is a view of the area around the driver's seat 39 of the vehicle 30 from the left side, with the driver M, who is seated in the driver's seat 39, indicated by a double-dotted line. Figure 2 This is a front view of the steering wheel 10 mounted on vehicle 30. Figure 3 Therefore Figure 2 The AA section shown is a cross-sectional view of the steering wheel 10. Figure 4 This is a left view of the steering wheel 10 with the airbag 50 fully inflated. Figure 5 This is a front view of the steering wheel 10 with the airbag 50 fully inflated.

[0016] In the following explanation, unless otherwise specified, the directions front, back, up, down, left, and right refer to... Figure 1 The directions shown are based on vehicle 30. That is, the front-to-back direction is the direction of travel of vehicle 30 when traveling straight, and the opposite direction. The left-to-right direction is the left and right sides of vehicle 30 when traveling straight, which can also be referred to as the width direction of vehicle 30. The up-down direction is the vertical direction.

[0017] like Figure 1 As shown, the steering wheel 10 is connected to the steering shaft 35 of the vehicle 30. The vehicle 30 has a steering column 36, which is composed of a column tube 36a that partially covers and supports the outer periphery of the steering shaft 35; and a column cover 36b that covers the portion of the steering shaft 35 that protrudes rearward from the instrument panel 37. The steering wheel 10 is mounted on the rear end 35a of the steering shaft 35 that protrudes rearward from the instrument panel 37.

[0018] like Figures 2 to 5As shown, the steering wheel 10 has: a grip portion 1, which is gripped by the driver M when steering the vehicle 30; a boss portion 2, which is connected to the steering shaft 35; and a spoke portion 3, which connects the grip portion 1 and the boss portion 2. Additionally, the steering wheel 10 has: a cover 5, which covers the boss portion 2 from the rear and forms part of the rear exterior of the steering wheel 10; a lower cover 6, which forms the front exterior of the steering wheel 10; and an airbag unit 40, which has an airbag 50, through which the driver M is protected.

[0019] The grip portion 1 comprises the following components: a metal core 1a; an intermediate part 1b made of synthetic resin such as polyurethane, which covers the core 1a; and a surface part 1c such as leather, which is wrapped around the outer periphery of the intermediate part 1b. The driver M rotates the steering shaft 35 by gripping the grip portion 1 and performing a rotational steering operation, thereby changing the direction of travel of the vehicle 30. Furthermore, in this embodiment, the grip portion 1 is annular, but it can also be of other shapes.

[0020] The boss 2 is a metal component that connects to the steering shaft 35 and has a shaft hole 2a into which the steering shaft 35 is inserted. The steering shaft 35 is inserted into the shaft hole 2a and engaged, and the two are secured by a nut 38, thereby connecting the boss 2 and the steering shaft 35.

[0021] The disc spoke portion 3 is composed of the following components: a left disc spoke portion 3a and a right disc spoke portion 3b, which extend to the left and right respectively from the boss portion 2; and a lower disc spoke portion 3c, which extends downward. The disc spoke portion 3 has: a metal core material 3x1, which connects the core material 1a of the grip portion 1 and the boss portion 2; and a resin disc spoke cover 3x2, which covers the core material 3x1. The core material 1a of the grip portion 1, the boss portion 2, and the core material 3x1 of the disc spoke portion 3 are integrally formed by die casting.

[0022] The cover 5 covers the rear of the folded airbag 50 and has: a roughly rectangular cover 5a that forms part of the exterior of the steering wheel 10; and a connecting portion 5b that extends forward from the cover 5a and connects to the housing 43 of the airbag unit 40. An insertion hole 5b1 for inserting the housing 43 is formed on the front end side of the connecting portion 5b of the cover 5. Furthermore, in this embodiment, the cover 5 is made of synthetic resin.

[0023] The cover portion 5a of the cover 5 breaks off due to the pressure from the airbag 50 when the airbag 50 inflates, forming an opening 5h through which the airbag 50 is discharged. The cover portion 5a has an approximately rectangular door portion 5ad that rotates upwards upon breaking off. The airbag 50 inflates and contacts the door portion 5ad, which rotates in the aforementioned manner, thereby forming the opening 5h in the cover portion 5a. Furthermore, the periphery of the door portion 5ad of the cover portion 5a becomes a thinner, not shown, fragile portion cut from the back side, so that it is easy to break off when subjected to pressure from the airbag 50.

[0024] The airbag unit 40 includes: an airbag 50; an inflator 42 that supplies inflation gas to the airbag 50; a housing 43 that holds the airbag 50 and the inflator 42; and a retainer 44 for securing the airbag 50 and the inflator 42. Additionally, the airbag unit 40 includes: a control device (not shown) that controls the operation of the inflator 42; and an acceleration sensor (not shown) for collision detection of the vehicle 30. The control device and the acceleration sensor are disposed in predetermined locations inside the vehicle 30.

[0025] The inflator 42 is an approximately cylindrical component that generates and releases expansion gas, and has a nozzle 42a at its rear side for ejecting the expansion gas. The portion of the inflator 42 with the nozzle 42a is disposed inside the airbag 50. Furthermore, the inflator 42 has a flange 42b as a connection point to the outer casing 43, which extends radially from the surface with the nozzle 42a. The inflator 42 is electrically connected to a control device (not shown) and operates by receiving a signal from the control device, generating expansion gas and ejecting it from the nozzle 42a.

[0026] The airbag 50 is a bag-shaped component that is stored inside the steering wheel 10 in the folded state, specifically in the area between the cover 5 and the boss 2. A gas inlet 50h is formed on the front side of the airbag 50 in the folded state. This gas inlet 50h is an opening for inserting the part of the inflator 42 that has the nozzle 42a.

[0027] When fully inflated, the airbag 50 has: a rear wall portion 50a1 disposed at the rear and configured to support the driver M; a front wall portion 50a2 disposed at the front and supported in contact with the grip portion 1 of the steering wheel 10; a left wall portion 50a3 disposed on the left side; and a right wall portion 50a4 disposed on the right side. When fully inflated, the airbag 50 is configured to cover the entire area of ​​the grip portion 1 of the steering wheel 10 from the rear.

[0028] Furthermore, a pleat 50a3a is provided below the left wall portion 50a3, which narrows the width of the left wall portion 50a3 in the left-right direction by pleating. A pleat 50a4a is provided below the right wall portion 50a4, which narrows the width of the right wall portion 50a4 in the left-right direction by forming pleats. The aforementioned pleats 50a3a and 50a4a are positioned at the same location in the left-right direction. As described above, by utilizing the pleats 50a3a and 50a4a to narrow the width of the lower part of the left wall portion 50a3 and the lower part of the right wall portion 50a4 in the left-right direction, it is easier for the airbag 50 to enter between the lower part of the grip portion 1 of the steering wheel 10 and the chest of the driver M.

[0029] Additionally, a strap 57 is provided inside the airbag 50. The strap 57 is a component that defines the width of the airbag 50 in the front-rear direction when it is fully inflated. The strap 57 is configured to extend in the front-rear direction along the rotation axis R of the steering shaft 35 when the airbag 50 is fully inflated.

[0030] The outer casing 43, formed of a thin metal sheet, holds the airbag 50, the inflator 42, and the cover 5. The outer casing 43 is fixed to the core material 3x1 of the disc-spoke portion 3 via a pin of a horn switch unit (not shown). The outer casing 43 has a cuboid bottom wall portion 43a and a side wall portion 43b extending rearward from the outer edge of the bottom wall portion 43a. The bottom wall portion 43a has an insertion hole 43a1 for inserting the inflator 42. The side wall portion 43b and the bottom wall portion 43a of the outer casing 43 are sequentially inserted into the insertion hole 5b1 of the connecting portion 5b of the cover 5, thereby holding the cover 5 to the outer casing 43 by using the side wall portion 43b to prevent the connecting portion 5b from detaching.

[0031] The retainer 44 is a roughly square ring-shaped metal component used for fixing the airbag 50, etc., and is disposed inside the airbag 50. The retainer 44 has an insertion hole 44a for inserting the inflator 42. When the airbag 50 and the inflator 42 are fixed to the housing 43, the inflator 42 is inserted into the insertion hole 43a1 of the housing 43, the gas inlet 50h of the airbag 50, and the insertion hole 44a of the retainer 44. The bolt 45 is inserted into the screw holes formed at the periphery of the gas inlet 50h of the airbag 50, the bottom wall portion 43a of the housing 43, and the flange portion 42b of the inflator 42, respectively, and tightened with a nut 46. Thus, the periphery of the gas inlet 50h of the airbag 50 is held by the front surface of the retainer 44 and the rear surface of the bottom wall portion 43a of the housing 43, and the flange portion 42b of the inflator 42 is held by the front surface of the bottom wall portion 43a and the nut 46. This secures the airbag 50 and the inflator 42 to the bottom wall 43a of the outer casing 43.

[0032] When the airbag unit 40 protects the driver M, firstly, if the vehicle 30 is involved in a collision, an acceleration sensor (not shown) detects the collision as acceleration. If the acceleration detected by the acceleration sensor is above a specified value, a control device (not shown) determines that the vehicle 30 has been involved in a collision and sends an operating signal to the inflator 42.

[0033] Next, the inflator 42 operates to release inflation gas. This supplies inflation gas to the inside of the airbag 50, causing the airbag 50 to inflate. Then, the driver M, who is moving forward due to the impact of the vehicle 30 and is about to collide with the grip part 1 of the steering wheel 10, is blocked and protected by the rear wall 50a1 of the airbag 50.

[0034] Next, the detailed structure of airbag 50 will be explained. Figure 6 This is a plan view of the panels that make up the airbag 50. Figure 7 This is a plan view of the steering wheel 10 with the airbag 50 fully inflated, and the driver M's face is shown by double-dotted lines.

[0035] like Figure 6 As shown, the airbag 50 is formed into a bag shape by sewing the peripheries of the four panels—rear wall panel 51, front wall panel 52, left wall panel 53, and right wall panel 54—to each other. In this embodiment, the rear wall panel 51, front wall panel 52, left wall panel 53, and right wall panel 54 are formed of a flexible fabric made of materials such as polyester yarn.

[0036] The rear wall panel 51 (occupant side panel) is a panel that forms the rear wall portion 50a1 when the airbag 50 has fully inflated. Therefore, the rear wall panel 51 can be described as a panel that is disposed on the rear side when the airbag 50 has fully inflated, and is configured to support the driver M.

[0037] The front wall panel 52 (steering wheel side panel) is the panel that forms the front wall portion 50a2 when the airbag 50 is fully inflated. Therefore, the front wall panel 52 can be described as a panel that is positioned on the front side when the airbag 50 is fully inflated, and is supported in contact with the grip portion 1 of the steering wheel 10. The front wall panel 52 has an opening, namely a gas inlet 50h, for inserting the inflator 42.

[0038] The left wall panel 53 (side panel, left side panel) is the panel that forms the left wall portion 50a3 when the airbag 50 is fully inflated. When the airbag 50 is formed into a bag shape, the left wall panel 53 is sewn to the rear wall panel 51 at the pre-sewn portion 53a and to the front wall panel 52 at the pre-sewn portion 52b. Furthermore, the left wall panel 53 and the right wall panel 54 are connected by sewing the pre-sewn portions 53c and 54c of the left wall panel 53 and 53d of the right wall panel 54. Therefore, the left wall panel 53 can be described as a panel that is positioned on the left side when the airbag 50 is fully inflated, sewn to the rear wall panel 51, the front wall panel 52, and the right wall panel 54, and connecting the rear wall panel 51 and the front wall panel 52.

[0039] Here, the pre-sewing portion 53a of the left wall panel 53 and the pre-sewing portion 51a of the rear wall panel 51 have the same curvature. Similarly, the pre-sewing portion 53b of the left wall panel 53 and the pre-sewing portion 52a of the front wall panel 52 have the same curvature. This allows the left wall panel 53 and the rear wall panel 51 to be sewn together, or the left wall panel 53 and the front wall panel 52 to be sewn together, thus improving workability. Furthermore, the pleats 50a3a of the left wall portion 50a3 are formed by sewing the pre-sewing portions 53e and 53f around the through hole 53h formed in the left wall panel 53 while folding the left wall panel 53.

[0040] The right wall panel 54 (side panel, right side panel) is the panel that forms the right wall portion 50a4 when the airbag 50 is fully inflated. When the airbag 50 is formed into a bag shape, the right wall panel 54 is sewn to the rear wall panel 51 at the pre-sewn portion 54a, and to the front wall panel 52 at the pre-sewn portion 52b. Furthermore, as described above, the left wall panel 53 and the right wall panel 54 are connected by sewing the pre-sewn portions 53c and 54c of the left wall panel 53, and the pre-sewn portions 53d and 54d of the right wall panel 54. Therefore, the right wall panel 54 can be described as a panel that is positioned on the right side when the airbag 50 is fully inflated, and is sewn to the rear wall panel 51, the front wall panel 52, and the left wall panel 53, thus connecting the rear wall panel 51 and the front wall panel 52.

[0041] Here, the pre-sewing portion 54a of the right wall panel 54 and the pre-sewing portion 51b of the rear wall panel 51 have the same curvature. Similarly, the pre-sewing portion 54b of the right wall panel 54 and the pre-sewing portion 52b of the front wall panel 52 have the same curvature. Therefore, when sewing the right wall panel 54 and the rear wall panel 51, or when sewing the right wall panel 54 and the front wall panel 52, they can be sewn together planarly, thus improving workability. Furthermore, the pleats 50a4a of the right wall portion 50a4 are formed by sewing the pre-sewing portions 54e and 54f around the through hole 54h formed in the right wall panel 54 while folding the right wall panel 54.

[0042] Furthermore, the tether 57 disposed inside the airbag 50 is formed by a front tether panel 58 and a rear tether panel 59. The front tether panel 58 has an insertion port 58h for inserting the portion of the inflator 42 having the nozzle 42a. Additionally, when the airbag 50 is fully inflated, the front tether panel 58 is positioned in front of the rear tether panel 59. Furthermore, in this embodiment, the front tether panel 58 and the rear tether panel 59 are formed of a flexible fabric, such as polyester yarn.

[0043] When the airbag 50 is formed into a pouch shape, the front tether panel 58 is sewn to the front wall panel 52 at the pre-sewn portion 58a, and the rear tether panel 59 is sewn to the rear wall panel 51 at the pre-sewn portion 59a. Furthermore, by sewing the pre-sewn portions 58b and 59b of the front tether panel 58 and 59c of the rear tether panel 59, the front tether panel 58 and 59c of the rear tether panel 59 are connected. Thus, the rear wall panel 51, front wall panel 52, left wall panel 53, right wall panel 54, front tether panel 58, and rear tether panel 59 are connected to form the airbag 50 in its pre-folded state.

[0044] Here, in this embodiment, as Figure 7 As shown, when the airbag 50 is fully inflated, the width L1 of the left wall panel 53 and the right wall panel 54 in the front-rear direction along the rotation axis R of the steering axis 35 is configured to be wider than the width L2 of the rear wall panel 51 in the left-right direction (see also...). Figure 4 , Figure 5 This achieves the following effect.

[0045] That is, assuming that the aforementioned width L1 is narrower than the aforementioned width L2, then if the driver M is heavier or the vehicle 30 is traveling at a higher speed during the collision, the airbag 50 will deform due to the forward load input to it, causing its width to shrink significantly in the rear-to-rear direction. This can easily lead to a so-called bottom contact, where the driver M contacts the grip portion 1 of the steering wheel 10 through the airbag 50. The bottom contact referred to here means that the driver M contacts the grip portion 1 of the steering wheel 10 through the rear wall portion 50a1 and the front wall portion 50a2, thus making contact between the driver M and the grip portion 1 of the steering wheel 10.

[0046] In contrast, in this embodiment, the width L1 is configured to be wider than the width L2, thus allowing for a larger allowable deformation in the longitudinal direction of the airbag 50 up to the point of bottom contact. Therefore, even when the airbag 50 deforms and its longitudinal width is significantly reduced due to the forward load input to it when bearing the load of the driver M, bottom contact is less likely to occur. Therefore, the airbag 50 according to this embodiment can suppress contact between the driver M and the grip portion 1 of the steering wheel 10 via the airbag 50 during a collision with the vehicle 30.

[0047] Furthermore, when the airbag 50 is fully inflated, the seam portion 50v1 between the left wall panel 53 and the right wall panel 54, formed by stitching together the pre-stitched portion 53c of the left wall panel 53 and the pre-stitched portion 54c of the right wall panel 54, extends in the front-rear direction along the rotation axis R of the steering shaft 35. Similarly, when the airbag 50 is fully inflated, the seam portion 50v2 between the left wall panel 53 and the right wall panel 54, formed by stitching together the pre-stitched portion 53d of the left wall panel 53 and the pre-stitched portion 54d of the right wall panel 54, extends in the front-rear direction along the rotation axis R of the steering shaft 35. Moreover, the seam portion 50v2 is located directly below the seam portion 50v1 when the airbag 50 is fully inflated.

[0048] As described above, the stitching portions 50v1 and 50v2 extend in the longitudinal direction along the rotation axis R of the steering shaft 35. Therefore, when the airbag 50 deforms by reducing its width in the longitudinal direction due to the forward load input to it when the vehicle 30 is in contact with the driver M, tension is easily generated in the left wall panel 53 and right wall panel 54 to suppress this deformation. Thus, it is possible to more effectively prevent the driver M from contacting the grip portion 1 of the steering wheel 10 through the airbag 50 during a collision.

[0049] Furthermore, the structures in which the stitches 50v1 and 50v2 extend in the front-back direction along the rotation axis R of the steering shaft 35, as described here, include not only structures in which the stitches 50v1 and 50v2 extend linearly in the front-back direction along the rotation axis R of the steering shaft 35, but also structures in which they extend linearly within a range of ±20 degrees in the left-right or up-down direction relative to the front-back direction along the rotation axis R of the steering shaft 35. Additionally, the linearly extending structures described here also include structures in which the stitches are sutured linearly as a whole, even if the stitches are serrated.

[0050] Furthermore, in the airbag 50, a stitched portion 50v3 is formed by stitching the pre-stitched portion 53a of the left wall panel 53 and the pre-stitched portion 51a of the rear wall panel 51, and a stitched portion 50v4 is formed by stitching the pre-stitched portion 53b of the left wall panel 53 and the pre-stitched portion 52a of the front wall panel 52. Additionally, in the airbag 50, a stitched portion 50v5 is formed by stitching the pre-stitched portion 54a of the right wall panel 54 and the pre-stitched portion 51b of the rear wall panel 51, and a stitched portion 50v6 is formed by stitching the pre-stitched portion 54b of the right wall panel 54 and the pre-stitched portion 52b of the front wall panel 52.

Claims

1. An airbag (50) mounted on a steering wheel (10) having: a grip (1) for a passenger (M) to hold; and a boss (2) connected to a steering shaft (35) of a vehicle (30), the airbag (50) being inflated by being supplied with inflatable gas, and upon completion of inflating, covering the entire area of ​​the grip (1) from the rear. The airbag (50) has the following components when fully inflated: The passenger side panel (51) is located on the rear side and is configured to support the passenger (M). Steering wheel side panel (52), which is disposed at the front and supported in contact with the grip portion; and Side panels (53, 54) are stitched to the passenger side panel (51) and the steering wheel side panel (52) to connect the passenger side panel (51) and the steering wheel side panel (52). The width of the side panels (53, 54) in the front-rear direction along the rotation axis (R) of the steering shaft (35) is wider than the width of the occupant side panel (51) in the left-right direction.

2. The airbag (50) according to claim 1, wherein, The side panels (53, 54) have: A left side panel (53), disposed on the left side, is stitched to the passenger side panel (51) and the steering wheel side panel (52), connecting the passenger side panel (51) and the steering wheel side panel (52); and The right side panel (54), which is located on the right side, is separately formed from the left side panel (53) and is stitched to the passenger side panel (51), the steering wheel side panel (52) and the left side panel (53), connecting the passenger side panel (51) and the steering wheel side panel (52). The seam (50v1, 50v2) between the left side panel (53) and the right side panel (54) extends in the front-back direction along the axis of rotation (R).

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