airbag

Abstract

The present invention provides an airbag that can prevent occupants from coming into contact with the steering wheel grip via the airbag during a vehicle collision. [Solution] The airbag 50, when fully inflated, comprises a rear wall panel 51 positioned at the rear and configured as an occupant-side panel to receive the occupant, the driver M; a front wall panel 52 positioned at the front and supported by contact with the grip portion 1 of the steering wheel 10; and a left wall panel 53 and a right wall panel 54 as side panels sewn to the rear wall panel 51 and the front wall panel 52, connecting the rear wall panel 51 and the front wall panel 52. The front-rear width L1 of the left wall panel 53 and the right wall panel 54 along the rotation axis R of the steering shaft 35 is wider than the left-right width L2 of the rear wall panel 51.

Description

Technical Field

[0001] The present invention relates to an airbag mounted on the steering wheel of a vehicle.

Background Art

[0002] Conventionally, as in the configuration described in Patent Document 1, a configuration in which an airbag is mounted on the steering wheel of a vehicle and the airbag receives and protects an occupant during a vehicle collision is widely known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The shape of the airbag at the completion of inflation described in Patent Document 1 is configured such that the width in the left-right direction is wider than the width in the front-rear direction. In such a configuration, when the weight of the occupant is heavy or the speed at the time of vehicle collision is high, the airbag is deformed so that the width in the front-rear direction is greatly reduced by the forward load input to the airbag when receiving the occupant, and so-called bottoming occurs easily where the occupant contacts the grip portion of the steering wheel through the airbag.

[0005] Therefore, an object of the present invention is to provide an airbag capable of suppressing contact between an occupant and the grip portion of the steering wheel through the airbag during a vehicle collision.

Means for Solving the Problems

[0006] A typical configuration of the airbag according to the present invention for solving the above problems is an airbag mounted on a steering wheel having a grip portion for the occupant to grasp and a boss portion connected to the steering shaft of the vehicle, which inflates when inflation gas is supplied and covers the entire grip portion from the rear when inflation is complete, wherein the airbag when inflation is complete comprises an occupant-side panel positioned at the rear and configured to receive the occupant, a steering wheel-side panel positioned at the front and supported in contact with the grip portion, and a side panel sewn to the occupant-side panel and the steering wheel-side panel and connecting the occupant-side panel and the steering wheel-side panel, wherein the width of the side panel in the front-rear direction along the rotation axis of the steering shaft is wider than the width of the occupant-side panel in the left-right direction.

[0007] According to the airbag of the present invention, it is possible to prevent occupants from coming into contact with the steering wheel grip via the airbag during a vehicle collision. [Brief explanation of the drawing]

[0008] [Figure 1] This is a view from the left side of the area around the driver's seat of a vehicle equipped with an airbag system. [Figure 2] This is a front view of the vehicle's steering wheel. [Figure 3] This is a cross-sectional view of the handle taken along the AA section shown in Figure 2. [Figure 4] This is a left side view of the steering wheel with the airbag fully inflated. [Figure 5] This is a front view of the steering wheel with the airbag fully inflated. [Figure 6] This is a plan view of each panel that makes up the airbag. [Figure 7] This is a plan view of the steering wheel with the airbag fully inflated. [Modes for carrying out the invention]

[0009] The configuration of an airbag 50 according to one embodiment of the present invention will be described below with reference to the drawings. The airbag 50 is mounted on the steering wheel 10 of the vehicle 30. Unless otherwise specifically stated, the dimensions, materials, shapes, and relative arrangements of the components described below are not intended to limit the scope of this invention to those specific components.

[0010] Figure 1 is a view from the left side of the area around the driver's seat 39 of the vehicle 30, with the driver M seated in the driver's seat 39 indicated by a dashed line. Figure 2 is a front view of the steering wheel 10 mounted on the vehicle 30. Figure 3 is a cross-sectional view of the steering wheel 10 cut along the cross-section AA shown in Figure 2. Figure 4 is a left side view of the steering wheel 10 with the airbag 50 fully inflated. Figure 5 is a front view of the steering wheel 10 with the airbag 50 fully inflated.

[0011] In the following explanation, unless otherwise specified, the forward, backward, up, down, left, and right directions refer to directions relative to the vehicle 30 shown in Figure 1. That is, the forward and backward direction is the direction of travel of the vehicle 30 when it is traveling straight and the opposite direction. The left and right directions are the left and right directions when the vehicle 30 is traveling straight, and can also be said to be the width direction of the vehicle 30. The up and down direction is the vertical direction.

[0012] As shown in Figure 1, the steering wheel 10 is connected to the steering shaft 35 of the vehicle 30. The vehicle 30 includes a steering column 36 which consists of a column tube 36a that partially covers the outer circumference of the steering shaft 35 and supports 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 attached to the rear end 35a of the steering shaft 35 that protrudes rearward from the instrument panel 37.

[0013] As shown in Figures 2 to 5, the steering wheel 10 includes a grip portion 1 that is held by the driver M when steering the vehicle 30, a boss portion 2 connected to the steering shaft 35, and spoke portions 3 that connect the grip portion 1 and the boss portion 2. The steering wheel 10 also includes a pad 5 that covers the boss portion 2 from the rear and forms part of the rear exterior of the steering wheel 10, a lower cover 6 that forms the front exterior of the steering wheel 10, and an airbag unit 40 which has an airbag 50 and protects the driver M with the airbag 50.

[0014] The gripping portion 1 is composed of a metal core material 1a, an intermediate material 1b made of synthetic resin such as polyurethane that covers the core material 1a, and a surface material 1c such as leather wrapped around the outer circumference of the intermediate material 1b. The driver M changes the direction of travel of the vehicle 30 by gripping the gripping portion 1 and rotating it to steer the steering shaft 35. In this embodiment, the gripping portion 1 is annular, but it may have other shapes.

[0015] The boss portion 2 is a metal component connected to the steering shaft 35 and has a shaft hole 2a through which the steering shaft 35 is inserted. The boss portion 2 and the steering shaft 35 are connected when the steering shaft 35 is inserted through the shaft hole 2a and fitted together, and the two are fixed with a nut 38.

[0016] The spoke section 3 consists of a left spoke section 3a and a right spoke section 3b extending to the left and right from the boss section 2, respectively, and a lower spoke section 3c extending downward. The spoke section 3 has a metal core material 3x1 that connects the core material 1a of the gripping section 1 and the boss section 2, and a resin spoke cover 3x2 that covers the core material 3x1. The core material 1a of the gripping section 1, the boss section 2, and the core material 3x1 of the spoke section 3 are integrally molded by die-casting.

[0017] The pad 5 includes a substantially rectangular parallelepiped cover portion 5a that covers the rear of the folded airbag 50 and forms part of the exterior of the steering wheel 10, and a connecting portion 5b that extends forward from the cover portion 5a and is connected to the case 43 of the airbag unit 40. An insertion hole 5b1 through which the case 43 is inserted is formed at the tip side of the connecting portion 5b of the pad 5. In this embodiment, the pad 5 is formed of a synthetic resin.

[0018] The cover portion 5a of the pad 5 breaks due to the pressure received from the airbag 50 when the airbag 50 inflates, forming an opening 5h, and the airbag 50 is fed out from the opening 5h. The cover portion 5a has a substantially rectangular door portion 5ad that rotates upward when broken. When the airbag 50 inflates and contacts the door portion 5ad, and the door portion 5ad rotates as described above, an opening 5h is formed in the cover portion 5a. The periphery of the door portion 5ad of the cover portion 5a is a fragile portion (not shown) that is cut out from the back side to be thin so as to be easily broken when receiving pressure from the airbag 50.

[0019] The airbag unit 40 includes an airbag 50, an inflater 42 that supplies inflation gas to the airbag 50, a case 43 that holds the airbag 50 and the inflater 42, and a retainer 44 used for fixing the airbag 50 and the inflater 42. The airbag unit 40 also includes a control device (not shown) that controls the operation of the inflater 42 and the like, and an acceleration sensor (not shown) used for detecting a collision of the vehicle 30. The control device and the acceleration sensor are disposed at a predetermined position inside the vehicle 30.

[0020] The inflator 42 is a substantially cylindrical member that generates and discharges inflation gas, and has a discharge port 42a for discharging the inflation gas on the rear side. The portion where the discharge port 42a of the inflator 42 is formed is disposed inside the airbag 50. Further, the inflator 42 includes a flange portion 42b that extends in the radial direction of the cylindrical shape from the surface where the discharge port 42a is formed as a portion connected to the case 43. The inflator 42 is electrically connected to a control device (not shown), and operates when a signal is input from the control device to generate inflation gas and discharge it from the discharge port 42a.

[0021] The airbag 50 is a bag-shaped member, and is stored in a folded state inside the handle 10, specifically in the region between the pad 5 and the boss portion 2. On the front side of the airbag 50 in the folded state, a gas inlet 50h is formed, which is an opening for inserting the portion where the discharge port 42a of the inflator 42 is formed.

[0022] The airbag 50 when inflation is completed has a rear wall portion 50a1 disposed on the rear side and configured to receive the driver M, a front wall portion 50a2 disposed on the front side and supported by contacting the gripping portion 1 of the handle 10, a left wall portion 50a3 disposed on the left side, and a right wall portion 50a4 disposed on the right side. The airbag 50 when inflation is completed is configured to cover the entire gripping portion 1 of the handle 10 from the rear.

[0023] Further, below the left wall portion 50a3, a tack 50a3a is provided that forms a knob to narrow the width of the left wall portion 50a3 in the left-right direction. Below the right wall portion 50a4, a tack 50a4a is provided that forms a knob to narrow the width of the right wall portion 50a4 in the left-right direction. These tacks 50a3a and 5ta4a are disposed at the same position in the left-right direction. By narrowing the widths of the lower portions of the left wall portion 50a3 and the right wall portion 50a4 in the left-right direction by the tacks 50a3a and 50a4a in this way, it becomes easier to insert the airbag 50 between the lower portion of the gripping portion 1 of the handle 10 and the chest of the driver M.

[0024] Furthermore, a tether 57 is provided inside the airbag 50. The tether 57 is a component that defines the width of the airbag 50 in the front-to-rear direction when inflation is complete. The tether 57 is positioned to extend in the front-to-rear direction along the rotation axis R of the steering shaft 35 when inflation is complete.

[0025] The case 43 is made of sheet metal and holds the airbag 50, the inflator 42, and the pad 5. The case 43 is fixed to the core material 3x1 of the spoke portion 3 via pins of a horn switch unit (not shown). The case 43 comprises a rectangular parallelepiped 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 through which the inflator 42 is inserted. The side wall portion 43b and the bottom wall portion 43a of the case 43 are inserted sequentially through the insertion hole 5b1 of the connecting portion 5b of the pad 5, and the pad 5 is held in place by the side wall portion 43b preventing the connecting portion 5b from coming loose.

[0026] The retainer 44 is a roughly rectangular, annular metal member used to secure the airbag 50 and the like, and is positioned inside the airbag 50. The retainer 44 has a through hole 44a through which the inflator 42 is inserted. When the airbag 50 and the inflator 42 are fixed to the case 43, the inflator 42 is inserted through the through hole 43a1 of the case 43, the gas inlet 50h of the airbag 50, and the through hole 44a of the retainer 44, and bolts 45 are inserted through screw holes formed in the periphery of the gas inlet 50h of the airbag 50, the bottom wall portion 43a of the case 43, and the flange portion 42b of the inflator 42, respectively, and fastened with nuts 46. As a result, the periphery of the gas inlet 50h of the airbag 50 is sandwiched between the front surface of the retainer 44 and the rear surface of the bottom wall 43a of the case 43, and the flange portion 42b of the inflator 42 is sandwiched between the front surface of the bottom wall 43a and the nut 46. In this way, the airbag 50 and the inflator 42 are fixed to the bottom wall 43a of the case 43.

[0027] When the airbag unit 40 protects the driver M, first, when a collision occurs with the vehicle 30, an acceleration sensor (not shown) detects this collision as acceleration. If the acceleration detected by the acceleration sensor is above a predetermined level, the control device (not shown) determines that the vehicle 30 has collided and sends an activation signal to the inflator 42.

[0028] Next, the inflator 42 activates and releases inflation gas. This supplies inflation gas to the inside of the airbag 50, causing the airbag 50 to inflate. Subsequently, the driver M, who is moving forward due to the impact of the collision of the vehicle 30 and is about to collide with the grip portion 1 of the steering wheel 10, is caught and protected by the rear wall portion 50a1 of the airbag 50.

[0029] Next, the detailed configuration of the airbag 50 will be described. Figure 6 is a plan view of each panel that makes up the airbag 50. Figure 7 is a plan view of the steering wheel 10 when the airbag 50 has finished inflating, and the driver M's face is shown by a dashed line.

[0030] As shown in Figure 6, the airbag 50 is formed into a bag shape by sewing together the edges of four panels: a rear wall panel 51, a front wall panel 52, a left wall panel 53, and a right wall panel 54. In this embodiment, the rear wall panel 51, front wall panel 52, left wall panel 53, and right wall panel 54 are made of a flexible woven fabric made of polyester yarn or the like.

[0031] The rear wall panel 51 (occupant-side panel) is a panel that constitutes the rear wall section 50a1 when the airbag 50 has finished inflating. Therefore, the rear wall panel 51 can be said to be a panel that is positioned at the rear when the airbag 50 has finished inflating, and is configured to support the driver M.

[0032] The front wall panel 52 (handle-side panel) is a panel that constitutes the front wall portion 50a2 when the airbag 50 has finished inflating. Therefore, the front wall panel 52 is positioned at the front when the airbag 50 has finished inflating, and is a panel that contacts and is supported by the grip portion 1 of the handle 10. The front wall panel 52 has a gas inlet 50h, which is an opening for inserting the inflator 42.

[0033] The left wall panel 53 (side panel, left side panel) is a panel that constitutes the left wall section 50a3 when the airbag 50 has finished inflating. When the airbag 50 is formed into a bag shape, the left wall panel 53 is sutured to the suture section 51a of the rear wall panel 51 at the suture section 53a, and sutured to the suture section 52a of the front wall panel 52 at the suture section 53b. In addition, the left wall panel 53 and the right wall panel 54 are connected by suture section 53c of the left wall panel 53 and suture section 54c of the right wall panel 54 being sutured, and suture section 53d of the left wall panel 53 and suture section 54d of the right wall panel 54 being sutured. Therefore, the left wall panel 53 is positioned on the left side when the airbag 50 has finished inflating, and is sewn to the rear wall panel 51, the front wall panel 52, and the right wall panel 54, and can be described as a panel that connects the rear wall panel 51 and the front wall panel 52.

[0034] Here, the planned suture area 53a of the left wall panel 53 and the planned suture area 51a of the rear wall panel 51 have the same curvature. Similarly, the planned suture area 53b of the left wall panel 53 and the planned suture area 52a of the front wall panel 52 have the same curvature. This allows for planar suturing when suturing the left wall panel 53 to the rear wall panel 51 or the left wall panel 53 to the front wall panel 52, thereby improving work efficiency. The tuck 50a3a of the left wall portion 50a3 is formed by suturing the planned suture area 53e and planned suture area 53f around the periphery of the through hole 53h formed in the left wall panel 53 while pinching the left wall panel 53.

[0035] The right wall panel 54 (side panel, right side panel) is a panel that constitutes the right wall section 50a4 when the airbag 50 has finished inflating. When the airbag 50 is formed into a bag shape, the right wall panel 54 is sutured to the suture section 51b of the rear wall panel 51 at the suture section 54a, and sutured to the suture section 52b of the front wall panel 52 at the suture section 54b. Furthermore, as described above, the left wall panel 53 and the right wall panel 54 are connected by suture section 53c of the left wall panel 53 and suture section 54c of the right wall panel 54 being sutured, and suture section 53d of the left wall panel 53 and suture section 54d of the right wall panel 54 being sutured. Therefore, the right wall panel 54 is positioned on the right side when the airbag 50 has finished inflating, and is sewn to the rear wall panel 51, the front wall panel 52, and the left wall panel 53, and can be described as a panel that connects the rear wall panel 51 and the front wall panel 52.

[0036] Here, the planned suture area 54a of the right wall panel 54 and the planned suture area 51b of the rear wall panel 51 have the same curvature. Similarly, the planned suture area 54b of the right wall panel 54 and the planned suture area 52b of the front wall panel 52 have the same curvature. This allows for planar suturing when suturing the right wall panel 54 to the rear wall panel 51 or the right wall panel 54 to the front wall panel 52, thereby improving work efficiency. The tuck 50a4a of the right wall portion 50a4 is formed by suturing the planned suture area 54e and planned suture area 54f at the periphery of the through hole 54h formed in the right wall panel 54 while pinching the right wall panel 54.

[0037] Furthermore, the tether 57 provided 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, which is an opening for inserting the portion where the discharge port 42a of the inflator 42 is formed. Also, when the airbag 50 is fully inflated, the front tether panel 58 is positioned in front of the rear tether panel 59. In this embodiment, the front tether panel 58 and the rear tether panel 59 are formed from a flexible woven fabric made of polyester yarn or the like.

[0038] When forming the airbag 50 into a bag shape, the front tether panel 58 is sutured to the sutured portion 52c of the front wall panel 52 at the sutured portion 58a, and the rear tether panel 59 is sutured to the sutured portion 51c of the rear wall panel 51 at the sutured portion 59a. The front tether panel 58 and the rear tether panel 59 are connected by sutured the sutured portion 58b of the front tether panel 58 to the sutured portion 59b of the rear tether panel 59, and by sutured the sutured portion 58c of the front tether panel 58 to the sutured portion 59c of the rear tether panel 59. In this way, 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, and the airbag 50 is formed in its pre-folded state.

[0039] In this embodiment, as shown in Figure 7, when the airbag 50 has completed inflation, the front-to-rear width L1 along the rotation axis R of the steering shaft 35 in the left wall panel 53 and the right wall panel 54 is wider than the left-to-right width L2 of the rear wall panel 51 (see also Figures 4 and 5). This provides the following effects.

[0040] In other words, if the above-mentioned width L1 is narrower than the above-mentioned width L2, when the driver M is heavy or when the vehicle 30 is moving at a high speed during a collision, the airbag 50 deforms so that its width in the front-to-back direction is greatly narrowed due to the forward load input to the airbag 50 when it receives the driver M, making it easier for so-called bottoming out to occur, in which the driver M comes into contact with the grip portion 1 of the steering wheel 10 via the airbag 50. Here, bottoming out refers to the rear wall portion 50a1 that receives the driver M coming into contact with the front wall portion 50a2, causing the driver M to come into contact with the grip portion 1 of the steering wheel 10 via the rear wall portion 50a1 and the front wall portion 50a2.

[0041] In contrast, in this embodiment, since the width L1 is wider than the width L2, the allowable deformation amount in the front-rear direction of the airbag 50 before bottoming out can be set to be larger. Therefore, even if the airbag 50 deforms so that its width in the front-rear direction is greatly narrowed by the forward load input to the airbag 50 when it catches the driver M, bottoming out becomes less likely. Accordingly, with the airbag 50 of this embodiment, it is possible to suppress the driver M from coming into contact with the grip portion 1 of the steering wheel 10 via the airbag 50 during a collision with the vehicle 30.

[0042] Furthermore, when the airbag 50 has finished inflating, the suture portion 50v1 between the left wall panel 53 and the right wall panel 54, formed by the stitching of the planned stitching portion 53c of the left wall panel 53 and the planned stitching 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 has finished inflating, the suture portion 50v2 between the left wall panel 53 and the right wall panel 54, formed by the stitching of the planned stitching portion 53d of the left wall panel 53 and the planned stitching portion 54d of the right wall panel 54, extends in the front-rear direction along the rotation axis R of the steering shaft 35. Note that the suture portion 50v2 is located directly below the suture portion 50v1 when the airbag 50 has finished inflating.

[0043] As the sutures 50v1 and 50v2 extend along the longitudinal direction parallel to the rotation axis R of the steering shaft 35, when the airbag 50 attempts to deform in such a way that its width in the longitudinal direction narrows due to the forward load applied to it when it receives the driver M, tension is more likely to be generated in the left wall panel 53 and the right wall panel 54 to suppress this deformation. Therefore, it is possible to more effectively prevent the driver M from coming into contact with the grip portion 1 of the steering wheel 10 via the airbag 50 during a collision of the vehicle 30.

[0044] Furthermore, the configuration in which the sutured portions 50v1 and 50v2 extend along the front-rear direction along the rotation axis R of the steering shaft 35 includes not only the configuration in which the sutured portions 50v1 and 50v2 extend linearly along the front-rear direction along the rotation axis R of the steering shaft 35, but also the configuration in which they extend linearly with a deviation of ±20 degrees in the left-right or up-down direction relative to the front-rear direction along the rotation axis R of the steering shaft 35. In addition, the configuration in which they extend linearly includes configurations in which the stitching is zigzag but the overall stitching is linear.

[0045] Furthermore, in the airbag 50, a sutured portion 50v3 is formed when the planned sutured portion 53a of the left wall panel 53 and the planned sutured portion 51a of the rear wall panel 51 are sutured together, and a sutured portion 50v4 is formed when the planned sutured portion 53b of the left wall panel 53 and the planned sutured portion 52a of the front wall panel 52 are sutured together. In addition, in the airbag 50, a sutured portion 50v5 is formed when the planned sutured portion 54a of the right wall panel 54 and the planned sutured portion 51b of the rear wall panel 51 are sutured together, and a sutured portion 50v6 is formed when the planned sutured portion 54b of the right wall panel 54 and the planned sutured portion 52b of the front wall panel 52 are sutured together. [Explanation of symbols]

[0046] 1…Grip section, 2…Boss section, 10…Steering wheel, 30…Vehicle, 35…Steering shaft, 50…Airbag, 50v1, 50v2…Suture section, 51…Rear wall panel (occupant side panel), 52…Front wall panel (steering wheel side panel), 53…Left wall panel (side panel, left side panel), 54…Right wall panel (side panel, right side panel), M…Driver (occupant)

Claims

1. An airbag mounted on a steering wheel, which has a grip portion for the occupant to grasp and a boss portion connected to the vehicle's steering shaft, inflates when an inflation gas is supplied, and covers the entire grip portion from the rear when inflation is complete, When inflation is complete, the airbag A crew-side panel positioned at the rear and configured to receive the occupant, A handle-side panel positioned at the front and supported in contact with the gripping portion, A side panel is sewn to the occupant-side panel and the steering-side panel, connecting the occupant-side panel and the steering-side panel, Equipped with, An airbag characterized in that the width of the side panel in the front-rear direction along the rotation axis of the steering shaft is wider than the width of the occupant-side panel in the left-right direction.

2. The aforementioned side panel is A left side panel is positioned on the left side and is sewn to the occupant side panel and the steering wheel side panel to connect the occupant side panel and the steering wheel side panel, A right side panel is positioned on the right side, is constructed separately from the left side panel, and is sewn to the occupant side panel, the steering wheel side panel, and the left side panel to connect the occupant side panel and the steering wheel side panel. It has, The airbag according to claim 1, characterized in that the seam between the left side panel and the right side panel extends along the front-rear direction along the axis of rotation.

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