Vehicle occupant protection device

Abstract

To improve a vehicle occupant protection device.SOLUTION: An occupant protection device has: a bag case provided rotatably with respect to a steering wheel; an upper airbag and a lower airbag stored in a stacked manner in a vertical direction of a vehicle in the bag case; and an inflator that supplies high-pressure gas to the upper airbag and the lower airbag. The lower airbag has a substantially rod-like expanding shape that horizontally expands. The upper airbag expands in a shape that allows movement in a lateral direction of a vehicle, while being supported on the lower airbag that horizontally expands. In the bag case storing the upper airbag and the lower airbag, an upper portion of the bag case where the upper airbag is stored, is heavier than a lower portion of the bag case where the lower airbag is stored.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a vehicle occupant protection device. [Background technology]

[0002] Patent Documents 1 and 2 disclose passenger protection devices that deploy airbags arranged vertically from a steering device having a steering wheel of an automobile. Patent Document 1 discloses that airbags are provided in a steering device having an irregularly shaped steering wheel that is not a circular ring. In the event of a frontal collision, an airbag is deployed from the steering device of the automobile to support the upper body of the driver who falls forward due to the impact of the collision and absorb the impact. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-049858 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-062714 [Patent Document 3] International Publication No. 2020 / 241079 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a frontal collision, the driver's upper body does not necessarily fall only in the forward direction of the vehicle from the seating position. For example, even if the driver operates the steering wheel to avoid a collision, the vehicle may collide with another vehicle in an offset manner. In such a case, the driver's upper body may fall diagonally forward rather than in the forward direction of the vehicle. Furthermore, with the airbags of Patent Documents 1 and 2, if the driver's upper body falls diagonally forward, it is difficult for the airbag to obtain a reaction force from the steering wheel. If the airbag cannot obtain a reaction force from the steering wheel, the airbag cannot support the driver's upper body. In this case, the driver's upper body, falling diagonally forward, hits the deployed airbag, slides on the airbag, and falls further diagonally forward from the side of the airbag. The problem of the driver falling diagonally forward is similar even when a lower airbag is deployed from the steering device and an upper airbag is deployed from the dashboard, as in Patent Document 3. In particular, in Patent Document 3, two airbags stacked one on top of the other are deployed from different locations, so each airbag receives a reaction force from a different location in response to a load. As a result, even if a load acts on the two airbags in the same direction, the two airbags tend to move differently. It is thought that a twisting force or other force is likely to act on the neck of the driver's head, which hits the upper airbag, and the driver's chest, which hits the lower airbag, due to the relative misalignment between the two airbags, which move differently in response to the load.

[0005] Furthermore, the airbag in Patent Document 1 is attached to an irregularly shaped steering wheel within a substantially rectangular frame, not a circular ring. Therefore, when the steering wheel is turned from the neutral position, the airbag's deployment range also changes accordingly. For example, if a collision occurs after the steering wheel is turned left to avoid a collision, the airbag will deploy tilted to the left. When an offset collision occurs at the right front of the vehicle, the driver's upper body will lean forward to the right. There is a possibility that the driver's upper body will lean left and lean forward to the right without coming into contact with the deploying airbag. This also applies to Patent Document 2, in which two airbags are deployed from a steering device having a ring-shaped steering wheel.

[0006] Furthermore, the airbag in Patent Document 1 is attached to an irregularly shaped steering wheel within a substantially rectangular frame, not a circular ring. In this case, the range in which the airbag can obtain a significant reaction force is different from that in the case of a circular steering wheel. In the case of an irregularly shaped steering wheel within a substantially rectangular frame, the airbag can obtain a reaction force within a narrow range in the vertical direction of the steering wheel. As a result, even if the driver's head and upper body lean forward, the airbag has difficulty obtaining a significant reaction force from the irregularly shaped steering wheel.

[0007] Furthermore, in Patent Document 2, the lower airbag deploys behind the upper airbag. Such a lower airbag is unlikely to receive a reaction force from the pressure applied by the upper airbag even when the driver's weight acts on it, and the lower airbag is likely to deform downward on its own. Even if the lower airbag deforms downward, it is unable to receive a reaction force from below. Even if the driver falls against the downward deforming lower airbag, the driver's upper body is unlikely to be well supported by the lower airbag.

[0008] Thus, improvements are required in vehicle occupant protection devices. [Means for solving the problem]

[0009] A vehicle occupant protection device according to one embodiment of the present invention is a vehicle occupant protection device for protecting a driver seated in a seat in front of which is located a steering device having a steering wheel that is turned by the driver of the vehicle, and comprises a bag case that is rotatable relative to the steering wheel, an upper airbag and a lower airbag that are stored in the bag case in a stacked manner in the vertical direction of the vehicle, and an inflator that supplies high-pressure gas to the upper airbag and the lower airbag, wherein the lower airbag has a roughly rod-shaped deployed shape that deploys horizontally, and the upper airbag deploys into a shape that allows it to move in the left-right direction of the vehicle while being supported on the lower airbag that deploys horizontally, and in the bag case that stores the upper airbag and the lower airbag, an upper part of the bag case that stores the upper airbag is heavier than a lower part of the bag case that stores the lower airbag. [Effects of the Invention]

[0010] In the present invention, an upper airbag and a lower airbag are stored in a steering device having a steering wheel of a vehicle, stacked in the vertical direction of the vehicle. The lower airbag has a generally rod-shaped deployed shape and deploys horizontally. The upper airbag deploys in a shape that allows it to move in the left-right direction of the vehicle while being supported on the horizontally deployed lower airbag. As a result, the horizontally elongated lower airbag and the upper airbag that is supported on the lower airbag and is movable left-right are deployed in front of the driver. When the driver's upper body, including the head, falls forward in a frontal collision, the upper body, including the head, hits the lower airbag and the upper airbag. At this time, the horizontally deployed lower airbag receives a reaction force from the steering wheel of the vehicle and can support the driver's upper body. The upper airbag receives a reaction force from the steering wheel and the lower airbag and can support the driver's head. The upper airbag and the lower airbag can behave in approximately the same way when the driver falls forward. In the present invention, the bag case is provided to be rotatable relative to the steering wheel that is turned by the driver. Therefore, an upper portion of the bag case that houses the upper airbag is heavier than a lower portion of the bag case that houses the lower airbag. As a result, the bag case can rotate under its own weight so that the upper and lower airbags are vertically aligned. As a result, even when the steering wheel is not in a neutral position, the horizontally elongated lower airbag can be deployed horizontally in the left-right direction of the vehicle, and the upper airbag can be deployed above the lower airbag that is deployed horizontally in the left-right direction. As a result, the entire upper body of the driver, including the head, is supported by the upper and lower airbags, and the impact can be absorbed by the deployed upper and lower airbags.

[0011] Furthermore, in the present invention, the upper airbag can move on the lower airbag, which deploys laterally. Therefore, even if the driver's upper body falls diagonally forward during a frontal collision, the upper airbag that hits the driver's head moves to follow the driver's falling direction. The driver's head is less likely to fall off the upper airbag. The upper airbag prevents the driver's head from escaping. Moreover, the lower airbag deploys laterally below the moved upper airbag. The lower airbag may also hit the driver's chest, etc., as the driver falls diagonally forward during a frontal collision. As a result, the upper and lower airbags of the present invention can support the driver's upper body, including the driver's head, and absorb the impact, even if the driver's upper body falls diagonally forward during a frontal collision, and whether the fall is inward or outward. Moreover, because the upper airbag is supported by the lower airbag during the impact absorption, the upper and lower airbags, which are under load, are less likely to behave independently. The upper and lower airbags can accommodate the direction in which the driver falls, and can adequately support the driver and absorb the impact as well as an integrated airbag can.

[0012] As a result, in the present invention, the upper and lower airbags deployed from the steering wheel support the upper body, including the head, of the driver who falls against these airbags, thereby absorbing the impact acting on the upper body, including the head. Even if the steering wheel has an irregular shape other than a circular ring, the upper and lower airbags of the present invention can obtain a reaction force from the steering wheel and support the upper body, including the head, of the driver who falls forward, thereby absorbing the impact. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a schematic side view of an automobile according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic top view of the automobile of FIG. [Figure 3] FIG. 3 is a configuration diagram of the passenger protection device of the automobile shown in FIG. [Figure 4] FIG. 4 is an explanatory diagram of the arrangement of peripheral members of the driver of the automobile of FIG. [Figure 5] FIG. 5 is an explanatory diagram of the steering device of the automobile of FIG. [Figure 6] FIG. 6 is an explanatory diagram of the internal structure of the steering device of FIG. [Figure 7] FIG. 7 is an exploded perspective view of the disk-type inflator and bag case of FIG. [Figure 8] FIG. 8 is a flowchart of the front collision detection control by the control unit of FIG. [Figure 9] FIG. 9 is an explanatory diagram of a state in which the upper airbag and the lower airbag are deployed from the steering device. [Figure 10] FIG. 10 is an explanatory diagram of the deployed state of FIG. 9 as seen from the rear of the automobile. [Figure 11] FIG. 11 is a diagram showing the configuration of an occupant protection device according to the second embodiment of the present invention. [Figure 12] FIG. 12 is an explanatory diagram of the internal structure of the steering device of the second embodiment. [Figure 13]FIG. 13 is a flowchart of the front collision detection control by the control unit of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] [First embodiment] FIG. 1 is a schematic side view of an automobile 1 according to a first embodiment of the present invention. Fig. 2 is a schematic top view of the automobile 1 of Fig. 1. In Fig. 2, the body 2 of the automobile 1 is shown by a dotted line, and the interior of the passenger compartment 3 is shown by a solid line. The automobile 1 is an example of a vehicle. Other examples of vehicles include vans, buses, trucks, and personal mobility vehicles. The automobile 1 in FIG. 1 has a vehicle body 2 and a passenger compartment 3 formed in the vehicle body 2. A windshield 12 and a dashboard 6 are provided at the front of the passenger compartment 3. The passenger compartment 3 also has a driver's seat 4 where a driver who operates the automobile 1 sits, a passenger seat 5 where a passenger sits, and the like. A steering wheel 7 is provided in front of the driver's seat 4. The steering wheel 7 is provided so as to protrude rearward from the dashboard 6.

[0016] As shown in Fig. 1, some automobiles 1 deploy an airbag 8 from a steering device having a steering wheel 7. In the event of a frontal collision, the airbag 8 deploys from the steering device of the automobile 1, thereby supporting the upper body of the driver who falls forward due to the impact of the collision and absorbing the impact. However, in a frontal collision, the driver's upper body does not necessarily fall only forward from the seating position in the driver's seat 4 toward the vehicle 1. For example, even if the driver operates the steering wheel 7 to avoid a collision, the vehicle 1 may collide with another vehicle 70 in an offset manner. In such a case, the driver's upper body may fall diagonally forward rather than forward toward the vehicle 1 as shown in FIG. 1. For example, as shown in FIG. 2, if an offset collision occurs at the left front of the vehicle 1, the driver's upper body may fall toward the left front as indicated by the thick solid arrow in FIG. 2. The driver's upper body may fall toward the left front without coming into contact with the airbag 8, which tilts to the right and deploys. Conversely, if an offset collision occurs at the right front of the vehicle 1, the driver's upper body may fall toward the right front as indicated by the thick dashed arrow in FIG. 2. When the driver's upper body falls diagonally forward, the airbag 8 deployed from the steering device has difficulty receiving a reaction force from the steering wheel 7. If the airbag 8 cannot receive a reaction force from the steering wheel 7, it cannot support the driver's upper body. In this case, the driver's upper body, falling diagonally forward, hits the deployed airbag 8, slides on the airbag 8, and falls further diagonally forward from the side of the airbag 8. In particular, when the steering wheel 7 is operated from the neutral position, the deployment range of the airbag 8 also changes accordingly. For example, if a collision occurs after the steering wheel 7 is turned to the right to avoid a collision, the deployment direction of the airbag 8 will tilt to the right. The driver's upper body may tilt to the right and fall forward to the left without coming into contact with the airbag 8 that is deploying. Furthermore, as shown in FIG. 5 (described later), the steering wheel 7 of the automobile 1 may have an irregular shape that is not circular but is substantially rectangular. In this case, the range in which the airbag 8 can receive a significant reaction force from the steering wheel 7 is narrower in the vertical direction than in the case of a circular steering wheel 7. The range in which the airbag 8 can receive a reaction force from the irregularly shaped steering wheel 7 in the vertical direction is narrow. As a result, even if the driver's head and upper body lean forward as shown in FIG. 1, the airbag 8 has difficulty receiving a significant reaction force from the irregularly shaped steering wheel 7. As such, improvements are required in the passenger protection device for the automobile 1.

[0017] FIG. 3 is a configuration diagram of the passenger protection device 20 of the automobile 1 of FIG. The passenger protection device 20 of FIG. 3 includes a steering position detection sensor 21, a seat position detection sensor 22, a driver sensor 23, a collision detection sensor 24, an outside camera 25, a timer 26, a control unit 27, and an airbag device 28. Each part of the occupant protection device 20 in FIG.

[0018] The steering position detection sensor 21 detects the position of the steering wheel 7 adjusted by a tilt mechanism or a telescopic mechanism. The tilt mechanism is a mechanism for adjusting the position of the steering wheel 7 in the up-down direction. The telescopic mechanism is a mechanism for adjusting the position of the steering wheel 7 in the front-to-rear direction. The driver sitting in the driver's seat 4 can adjust the position of the steering wheel 7 to suit his or her physique using the tilt mechanism or the telescopic mechanism. The steering position detection sensor 21 may detect the up-down position and the front-to-rear position of the steering wheel 7 after adjustment. The steering position detection sensor 21 may directly detect the actually adjusted position of the steering wheel 7, or may indirectly detect the position of the steering wheel 7 based on the state of the tilt mechanism or the telescopic mechanism.

[0019] The seat position detection sensor 22 detects the front-rear position and seat back angle of the driver's seat 4. The driver adjusts the front-rear position and seat back angle of the driver's seat 4 to suit his or her physique. The seat position detection sensor 22 may detect the front-rear position and seat back angle of the driver's seat 4 after adjustment. The seat position detection sensor 22 may directly detect the actually adjusted front-rear position and the like of the driver's seat 4, or may indirectly detect the front-rear position and the like of the driver's seat 4 based on the state of an adjustment mechanism for adjusting the front-rear position and the seat back angle of the driver's seat 4.

[0020] The driver sensor 23 detects the driver seated on the driver's seat 4. The driver sensor 23 may be, for example, a pressure sensor embedded in the seat portion of the driver's seat 4. The pressure sensor can detect the load of the driver seated on the driver's seat 4. The sheet-shaped pressure sensor can detect the load distribution of the driver on the driver's seat 4.

[0021] In this way, the steering position detection sensor 21, the seat position detection sensor 22, and the driver sensor 23 function as occupant sensors for detecting not only the presence or absence of a driver seated in the driver's seat 4, but also the driver's physique and seating state. For example, a small driver adjusts the driver's seat 4 forward based on the position of a pedal (not shown). The seat position detection sensor 22 can detect the front-rear position of the driver's seat 4 that has been adjusted forward. Furthermore, a small driver adjusts the steering wheel 7 to a position that is closer to the front and upper side than the standard position. The steering position detection sensor 21 can detect the position of the steering wheel 7 that is adjusted closer to the front and upper side. In contrast, a large driver adjusts the driver's seat 4 rearward based on the position of a pedal (not shown). The seat position detection sensor 22 can detect the front-rear position of the driver's seat 4 that has been adjusted rearward. Furthermore, a large driver may adjust the steering wheel 7 to a position that is lower and rearward compared to the standard position. The steering position detection sensor 21 can detect the position of the steering wheel 7 that is adjusted to be lower and rearward.

[0022] The collision detection sensor 24 detects a collision such as a frontal collision of the automobile 1. The collision detection sensor 24 may be, for example, a three-axis acceleration sensor. The collision detection sensor 24 may also be an impact sensor stored in a bumper (not shown) of the automobile 1. The collision detection sensor 24 may detect that a collision such as a frontal collision of the automobile 1 has occurred when, for example, an acceleration equal to or greater than a threshold value that would not occur during normal driving of the automobile 1 is input.

[0023] Exterior camera 25 captures images of the surroundings of automobile 1. Exterior camera 25 may be a monocular camera, a compound eye camera, or a 360-degree camera. It is preferable that exterior camera 25 captures images of the front side, which is the direction of travel of automobile 1. This allows exterior camera 25 to capture and detect objects that may collide head-on with body 2 of automobile 1, such as other automobile 70 in FIG. 1, before detecting a frontal collision of automobile 1. Exterior camera 25 can also capture and detect a frontal collision between body 2 of automobile 1 and other automobile 70.

[0024] In this way, the collision detection sensor 24 and the outside camera 25 function as a collision sensor for predicting or detecting a collision such as a frontal collision of the automobile 1.

[0025] The timer 26 measures the time or duration.

[0026] The airbag device 28 is attached to the steering device 50, and as will be described later, has an upper airbag 32, a lower airbag 31, and an inflator 62 that injects high-pressure gas into these airbags.

[0027] The control unit 27 may be configured, for example, by a CPU (Central Processing Unit) and a memory. The CPU reads and executes a program recorded in the memory. In this way, the CPU functions as the control unit 27 of the driver protection device. The control unit 27 controls the operation of an airbag device 28 to protect the driver from a frontal collision of the automobile 1 .

[0028] FIG. 4 is an explanatory diagram of the arrangement of peripheral members of the driver of the automobile 1 of FIG. FIG. 4 shows the driver of the car 1 of FIG. 1 as seen from the left side. A dashboard 6, a windshield 12, and a steering device 50 are provided in front of the driver seated in the driver's seat 4.

[0029] FIG. 5 is an explanatory diagram of the steering device 50 of the automobile 1 of FIG. A steering device 50 shown in FIGS. 4 and 5 has a steering wheel 7 in the shape of a substantially rectangular frame, a boss portion 51, and a cover member 9. As shown in FIG. 4, the boss portion 51 of the steering device 50 is fixed to the rear end of the steering shaft 10 that passes through the dashboard 6 in the front-rear direction. The steering wheel 7, which has a substantially rectangular frame shape, is an irregular shape that is not a circular ring shape. The steering wheel 7, which has a substantially rectangular frame shape, is fixed to the boss portion 51 at the center of its upper edge. This allows the driver to rotate the steering wheel 7 by holding, for example, both the left and right edges of the substantially rectangular frame-shaped steering wheel 7 with both hands. The boss portion 51 and the steering shaft 10 also rotate together with the steering wheel 7. The rotation of the steering shaft 10 is detected, for example, by an encoder (not shown), and is used to control the direction of the steered wheels of the automobile 1. The steering shaft 10 may also be used to drive the steering device of the automobile 1 through a gear mechanism. Furthermore, as indicated by the dashed arrows in FIG. 4 , the steering device 50 can be adjusted using a tilt mechanism and a telescopic mechanism. The tilt mechanism and telescopic mechanism may be provided inside the cover member 9. While seated in the driver's seat 4, the driver can adjust the position of the steering wheel 7 to suit his or her physique by operating the tilt mechanism or telescopic mechanism. The steering position detection sensor 21 may detect the up-down position and the fore-aft position of the steering wheel 7 after adjustment. Note that the steering position detection sensor 21 may directly detect the actually adjusted position of the steering wheel 7, or may indirectly detect the position of the steering wheel 7 based on the state of the tilt mechanism or telescopic mechanism.

[0030] FIG. 6 is an explanatory diagram of the internal structure of the steering device 50 of FIG. FIG. 6 shows the right half of the steering device 50 as viewed from the left side of the automobile 1. The boss portion 51 of the steering device 50 has a disk-type inflator 62 of the airbag device 28, a bag case 53, an upper airbag 32, a lower airbag 31, and a weight member 55 arranged thereon.

[0031] The disc-type inflator 62 has a substantially cylindrical inflator housing 57. The inflator housing 57 is fixed to a boss portion 51 of a steering device 50 having a steering wheel 7. An inflator 62 that supplies high-pressure gas to the upper airbag 32 and the lower airbag 31 is provided inside the inflator housing 57.

[0032] A bag case 53 having a generally cylindrical frame shape is provided on top of the rear side of the inflator housing 57. The bag case 53 having a generally cylindrical frame shape is rotatably supported by a plurality of stay members 61 fixed to the boss portion 51 of the steering device 50. As a result, the bag case 53 is rotatably supported with respect to the steering wheel 7. A weight member 55 is provided at the bottom of the bag case 53, which has a substantially cylindrical frame shape. This makes the bottom of the bag case 53 heavier than the top. Even when the steering wheel 7 is rotated, the bag case 53, which has a substantially cylindrical frame shape, rotates relative to the steering wheel 7 as shown by the dashed arrow in FIG. 7. The bag case 53, which has a substantially cylindrical frame shape, can maintain a position in which the top of the bag case 53 is positioned above the bottom of the bag case 53.

[0033] The folded upper airbag 32 and the folded lower airbag 31 are provided inside the bag case 53 having a substantially cylindrical frame shape, stacked in the vertical direction of the automobile 1. The bag case 53 having a substantially cylindrical frame shape rotates with respect to the steering wheel 7, so that the upper airbag 32 can maintain a state of being stacked above the lower airbag 31. The upper part of the bag case 53 that stores the upper airbag 32 is heavier than the lower part of the bag case 53 that stores the lower airbag 31.

[0034] A through hole 54 is formed in the cylindrical frame-shaped bag case 53 at the center of rotation of the bag case 53 . A substantially columnar nozzle portion 58 is formed in a substantially cylindrical inflator housing 57. A plurality of supply holes 59 are formed in the peripheral surface of the substantially columnar nozzle portion 58 and aligned in the circumferential direction. A substantially cylindrical nozzle portion 58 of the inflator housing 57 is inserted into the through-hole 54 of the bag case 53. This allows the high-pressure gas generated by the inflator 62 to be supplied to the upper airbag 32 and the lower airbag 31 inside the bag case 53 through multiple supply holes 59 of the nozzle portion 58. Furthermore, a circular plate-shaped heat sealing member 60 is interposed between the peripheral portion of the through hole 54 of the bag case 53 and the peripheral portion of the nozzle portion 58 of the inflator housing 57. The heat sealing member 60 softens without melting due to the heat of the high-pressure gas of the inflator 62. The softened heat sealing member 60 seals the gap between the peripheral portion of the through hole 54 of the bag case 53 and the peripheral portion of the nozzle portion 58 of the inflator housing 57. The high-pressure gas of the inflator 62 can be supplied to the upper airbag 32 and the lower airbag 31 inside the bag case 53 without leaking from this gap.

[0035] FIG. 8 is a flowchart of the front collision detection control by the control unit 27 of FIG. The control unit 27 repeatedly executes the frontal collision detection control of FIG. 8 to protect the driver based on the detection of a frontal collision of the automobile 1.

[0036] In step ST11, the control unit 27 acquires the latest detection information from the collision detection sensor 24.

[0037] In step ST12, the control unit 27 determines whether or not a frontal collision of the vehicle has been detected based on the latest detection information of the collision detection sensor 24 acquired in step ST11. If a frontal collision of the host vehicle has been detected, the control unit 27 advances the process to step ST13. If a frontal collision of the host vehicle has not been detected, the control unit 27 ends this control.

[0038] In step ST13, the control unit 27 deploys the upper airbag 32 and the lower airbag 31 to protect the driver from the impact of a frontal collision. The control unit 27 outputs an activation signal to the airbag device 28. This causes the airbag device 28 to deploy the upper airbag 32 and the lower airbag 31 rearward from the steering member. The upper airbag 32 and the lower airbag 31 deploy in front of the driver seated in the driver's seat 4. Thereafter, the control unit 27 ends this control.

[0039] FIG. 9 is an explanatory diagram showing a state in which the upper airbag 32 and the lower airbag 31 are deployed from the steering device 50. As shown in FIG. Fig. 10 is an explanatory diagram showing the unfolded state of Fig. 9 as viewed from the rear of the automobile 1. Note that in Fig. 10, only the seat portion of the driver's seat 4 is shown, and the back panel portion is omitted.

[0040] As shown in FIG. 9, the upper airbag 32 and the lower airbag 31 are deployed in front of the driver seated in the driver's seat 4 so that the upper airbag 32 is deployed above the lower airbag 31. As shown in FIG. 10, the lower airbag 31 has a generally rod-like deployed shape that is elongated horizontally and is equal to or greater than the width of the seat on which the driver sits. The upper airbag 32 deploys above the lower airbag 31 in a shape that allows it to move left and right in the automobile 1. The upper airbag 32 may deploy, for example, in a substantially spherical shape, a conical shape, or a truncated conical shape with the top of a cone cut off. The rollable deployed upper airbag 32 is supported on the lower airbag 31 that deploys horizontally. The upper airbag 32 deploys in front of the driver's head so as to protrude further rearward than the lower airbag 31 in the automobile 1.

[0041] When the upper airbag 32 and the lower airbag 31 are deployed, the driver falls forward and his / her head may hit the upper airbag 32 before his / her chest. The upper airbag 32, on which the load of the head acts, can move in the left and right directions of the automobile 1 above the lower airbag 31 in accordance with the load, as shown by the dashed arrow in FIG. Thereafter, the driver's chest collapses into the lower airbag 31. The lower airbag 31 receives a resistance force from the irregularly shaped steering wheel 7. At this time, the upper airbag 32, on which the weight of the head acts, is supported by the lower airbag 31, which receives a resistance force from the irregularly shaped steering wheel 7. The upper airbag 32 may become unable to move in the left-right direction of the automobile 1 on the lower airbag 31. Therefore, even if the driver falls forward to the left, as shown by the thick arrow in Fig. 10, the upper airbag 32 moves to the left accordingly (the position indicated by the dashed line on the left side of Fig. 10) to support the driver's head, and the lower airbag 31 supports the driver's chest. After hitting the upper airbag 32 and the lower airbag 31, the driver slides on the upper airbag 32 and the lower airbag 31, making it difficult for the driver to fall forward to the left. Furthermore, even if the driver falls forward to the right as shown by the thick dashed arrow in Fig. 10, the upper airbag 32 moves to a position to the right accordingly (the position indicated by the dashed line on the right side in Fig. 10) to support the driver's head, and the lower airbag 31 can support the driver's chest. After hitting the upper airbag 32 and the lower airbag 31, the driver slides on the upper airbag 32 and the lower airbag 31, making it more difficult for the driver to fall forward to the right. In this way, the upper airbag 32 and the lower airbag 31 of this embodiment function as a single airbag 8 that receives the resistance force from the irregularly shaped steering wheel 7, and can effectively support the upper body, including the head, of the driver who falls forward due to the impact of a collision. The impact on the driver can be absorbed.

[0042] As described above, in this embodiment, the steering device 50 having the steering wheel 7 of the automobile 1 stores the upper airbag 32 and the lower airbag 31 stacked in the vertical direction of the automobile 1. The lower airbag 31 has a generally rod-like deployed shape and deploys horizontally in a shape that is longer than or equal to the left-right width of the driver's seat 4 on which the driver sits. The upper airbag 32 is deployed in a shape that is movable in the left-right direction of the automobile 1 while being supported on the lower airbag 31 that deploys horizontally, and deploys in front of the driver's head. As a result, the horizontally elongated lower airbag 31 and the upper airbag 32 that is supported on the lower airbag 31 and is movable in the left-right direction are deployed in front of the driver. When the driver's upper body, including the head, falls forward in a frontal collision, the upper body, including the head, comes into contact with the lower airbag 31 and the upper airbag 32. At this time, the lower airbag 31 that deploys horizontally receives a reaction force from the steering wheel 7 of the automobile 1 and can support the driver's upper body. The upper airbag 32 can support the driver's head by receiving a reaction force from the steering wheel 7 and the lower airbag 31. The upper airbag 32 and the lower airbag 31 can behave in substantially the same way in response to a load when the driver falls forward. In this embodiment, the cylindrical frame-shaped bag case 53 is provided rotatably with respect to the steering wheel 7 that is turned by the driver. An upper portion of the bag case 53 that houses the upper airbag 32 is heavier than a lower portion of the bag case 53 that houses the lower airbag 31. As a result, the cylindrical frame-shaped bag case 53 can rotate by its own weight so that the upper airbag 32 and the lower airbag 31 are vertically aligned. As a result, even when the steering wheel 7 is not in the neutral position, the horizontally elongated lower airbag 31 can be deployed horizontally in the left-right direction of the automobile 1, and the upper airbag 32 can be deployed above the lower airbag 31 that is deployed horizontally in the left-right direction. As a result, the entire upper body of the driver, including the head, is supported by the upper airbag 32 and the lower airbag 31, and the impact can be absorbed by the deployed upper airbag 32 and lower airbag 31.

[0043] Moreover, in this embodiment, the upper airbag 32 can move on the lower airbag 31, which deploys laterally. Therefore, even if the driver's upper body falls diagonally forward during a frontal collision, the upper airbag 32 that hits the driver's head moves to follow the driver's falling direction. The driver's head is unlikely to fall off the upper airbag 32. The upper airbag 32 does not allow the driver's head to escape. Moreover, below the moved upper airbag 32, the lower airbag 31 deploys laterally in a width greater than or equal to the width of the seat on which the driver sits. The lower airbag 31 may also hit the driver's chest as he falls diagonally forward. As a result, the upper airbag 32 and the lower airbag 31 of this embodiment can support the driver's upper body, including the head, and absorb the impact, even if the driver's upper body falls diagonally forward during a frontal collision, and whether the fall is inward or outward. Moreover, since the upper airbag 32 is supported by the lower airbag 31 during the impact absorption, the upper airbag 32 and the lower airbag 31, on which the load is acting, are unlikely to behave independently. The upper airbag 32 and the lower airbag 31 can absorb the impact by adequately supporting the collapsing driver in the same way as the integrated airbag 8 while adapting to the direction in which the driver falls.

[0044] As a result, in this embodiment, the upper airbag 32 and the lower airbag 31 deployed from the steering wheel 7 support the upper body, including the head, of the driver who falls against these airbags 8, thereby absorbing the impact acting on the upper body, including the head. Even if the steering wheel 7 has an irregular shape other than a circular ring shape, the upper airbag 32 and the lower airbag 31 of this embodiment can obtain a reaction force from the steering wheel 7 and support the upper body, including the head, of the driver who falls forward, thereby absorbing the impact.

[0045] In this embodiment, a through hole 54 is formed in the cylindrical frame-shaped bag case 53 at the rotation center of the bag case 53. The inflator 62 has an inflator housing 57 having a substantially cylindrical nozzle portion 58 that is inserted into the bag case 53 through the through hole 54, and a plurality of supply holes 59 that are formed and aligned in the circumferential direction of the substantially cylindrical nozzle portion 58. As a result, the inflator 62 does not rotate together with the bag case 53, and can be firmly fixed to the steering device 50 having the steering wheel 7. The signal line for transmitting an activation signal to the inflator 62 does not need to rotate together with the bag case 53. Furthermore, even when the bag case 53 is rotating, the inflator 62 can supply high-pressure gas for deployment to the upper airbag 32 and the lower airbag 31 from a plurality of supply holes 59 formed in a row in the circumferential direction of the substantially cylindrical nozzle portion 58. Moreover, at this time, the peripheral portion of the through-hole 54 in the bag case 53 and the peripheral portion of the nozzle portion 58 in the inflator housing 57 are tightly sealed together by the heat sealing member 60, which softens but does not melt due to the heat of the high-pressure gas from the inflator 62. The high-pressure gas does not leak from between the bag case 53 and the inflator housing 57. The upper airbag 32 and the lower airbag 31 can be deployed into the desired shapes by the high-pressure gas from the inflator 62.

[0046] In this embodiment, the bag case 53 is formed in a substantially cylindrical frame shape and is rotatably attached to the steering wheel 7 using a stay member 61. In addition, a weight member 55 is provided at the bottom of the substantially cylindrical frame-shaped bag case 53 to make the lower part of the bag case 53 heavier than the upper part. As a result, the bag case 53 can automatically maintain a state in which the upper airbag 32 overlaps the upper side of the lower airbag 31 due to its own weight, regardless of the state of rotation of the steering wheel 7. In this embodiment, no control is required to maintain the bag case 53 in a position in which the upper airbag 32 is above the lower airbag 31.

[0047] In this embodiment, the upper airbag 32 that is deployed in a movable shape is deployed so as to protrude further rearward than the lower airbag 31 toward the rear of the automobile 1 . As a result, the upper airbag 32 can come into contact with the head of the driver who is collapsing forward due to a frontal collision before the driver's chest comes into contact with the lower airbag 31. When the driver's chest comes into contact with the lower airbag 31 after that, the upper airbag 32 can move on the horizontally elongated lower airbag 31 so as to follow the direction in which the driver's head is collapsing. With the upper airbag 32 moving as desired, the upper airbag 32 and the lower airbag 31 can support the upper body, including the head, of the driver who is collapsing.

[0048] [Second embodiment] In the above-described embodiment, the inflator housing 57 is fixed to the steering device 50 having the steering wheel 7. On the other hand, the bag case 53 is rotatably attached to the steering device 50 having the steering wheel 7. In this embodiment, an example will be described in which the inflator housing 57 and the bag case 53 are rotatably attached to a steering device 50 having a steering wheel 7.

[0049] FIG. 11 is a diagram showing the configuration of an occupant protection device 20 according to a second embodiment of the present invention. An upper airbag device 29 and a lower airbag device 30 are connected to the control unit 27 of the occupant protection device 20 of FIG.

[0050] FIG. 12 is an explanatory diagram of the internal structure of a steering device 50 according to the second embodiment. 12, the inflator housing 57 of the disk-type inflator 62 is fixed to the bag case 53, unlike in FIG. 6. A ring-shaped heat sealing member 60 may be interposed between the inflator housing 57 and the bag case 53. Inside the inflator housing 57, an upper inflator 66 of the upper airbag device 29 and a lower inflator 67 of the lower airbag device 30 are arranged side by side one above the other. Furthermore, the folded upper airbag 32 and the folded lower airbag 31 are provided inside the bag case 53 having a substantially cylindrical frame shape, stacked in the vertical direction of the automobile 1. The bag case 53 having a substantially cylindrical frame shape rotates relative to the steering wheel 7, so that the upper airbag 32 can maintain a state of being stacked above the lower airbag 31. The upper part of the bag case 53 that stores the upper airbag 32 is heavier than the lower part of the bag case 53 that stores the lower airbag 31. The upper inflator 66 of the upper airbag device 29 is connected to the upper airbag 32 and supplies high-pressure gas to the upper airbag 32 . The lower inflator 67 of the lower airbag device 30 is connected to the lower airbag 31 and supplies high-pressure gas to the lower airbag 31 . The upper airbag 32 and the lower airbag 31 can be deployed separately.

[0051] The inflator housing 57 and the bag case 53 are rotatably supported by a plurality of stay members 61 fixed to the boss portion 51 of the steering device 50. As a result, the inflator housing 57 and the bag case 53 are rotatably supported with respect to the steering wheel 7. A weight member 55 is provided at the bottom of the bag case 53, which has a substantially cylindrical frame shape. This makes the bottom of the bag case 53 heavier than the top. Even when the steering wheel 7 is rotated, the bag case 53, which has a substantially cylindrical frame shape, rotates relative to the steering wheel 7 as shown by the dashed arrow in FIG. 7. The bag case 53, which has a substantially cylindrical frame shape, can maintain a position in which the top of the bag case 53 is positioned above the bottom of the bag case 53.

[0052] FIG. 13 is a flowchart of the front collision detection control by the control unit 27 of FIG. The control unit 27 repeatedly executes the frontal collision detection control of FIG. 13 to protect the driver based on the detection of a frontal collision of the automobile 1. The processing from step ST11 to step ST12 is the same as in Fig. 8. However, if a frontal collision of the host vehicle is detected in step ST12, the control unit 27 advances the processing to step ST21.

[0053] In step ST21, the control unit 27 first deploys the lower airbag 31 to protect the driver from the impact of a frontal collision. The control unit 27 outputs an activation signal to the lower airbag device 30. This causes the lower airbag device 30 to deploy the lower airbag 31 rearward from the steering member. The lower airbag 31 deploys in front of the driver seated in the driver's seat 4.

[0054] In step ST22, the control unit 27 then deploys the upper airbag 32 to protect the driver from the impact of a frontal collision. The control unit 27 outputs an activation signal to the upper airbag device 29. This causes the upper airbag device 29 to deploy the upper airbag 32 rearward from the steering member. The upper airbag 32, together with the lower airbag 31, deploys in front of the driver seated in the driver's seat 4. The period from when the deployment of the lower airbag 31 starts in step ST21 to when the deployment of the upper airbag 32 starts in step ST22 may be measured by the timer 26. In this case, the control unit 27 uses the timer 26 to measure the elapsed time from when the activation signal is output to the lower airbag device 30 in step ST21, and when a predetermined elapsed time has been measured by the timer 26, outputs an activation signal to the upper airbag device 29 in step ST22. The upper airbag 32 and the lower airbag 31 can be deployed in the states shown in FIGS. Thereafter, the control unit 27 ends this control.

[0055] As described above, in this embodiment, the bag case 53 is fixed to the inflator housing 57. The bag case 53 and the inflator housing 57 are rotatably supported with respect to the steering wheel 7 using the stay member 61. Inside the substantially cylindrical nozzle portion 58 of the inflator housing 57, an upper inflator 66 that supplies high-pressure gas to the upper airbag 32 and a lower inflator 67 that supplies high-pressure gas to the lower airbag 31 are arranged side by side. In this embodiment, the control unit 27 deploys the lower airbag 31 before the upper airbag 32. As a result, even if the upper airbag 32 is not fully deployed, it can move on the lower airbag 31 which has already deployed horizontally below the upper airbag 32. Even in the middle of deployment, the upper airbag 32 can move on the horizontally elongated lower airbag 31 in response to the load of the driver collapsing, and can move in the direction of the driver collapsing.

[0056] The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes are possible within the scope that does not deviate from the gist of the invention. [Explanation of symbols]

[0057] 1...automobile (vehicle), 2...vehicle body, 3...vehicle interior, 4...driver's seat, 5...passenger seat, 6...dashboard, 7...steering wheel, 8...airbag, 9...cover member, 10...steering shaft, 12...windshield, 20...occupant protection device, 21...steering position detection sensor, 22...seat position detection sensor, 23...driver sensor, 24...collision detection sensor, 25...exterior camera, 26...timer, 27...control unit, 28...airbag device, 29...upper airbag device, 30...lower airbag device, 31...lower airbag, 32...upper airbag, 50...steering device, 51...boss portion, 53...bag case, 54...through hole, 55...weight member, 57...inflator housing, 58...nozzle portion, 59...supply hole, 60...heat sealing member, 61...stay member, 62...inflator, 66...upper inflator, 67...lower inflator, 70...other automobile

Claims

1. An occupant protection device for a vehicle for protecting a driver seated in a seat of the vehicle, a steering device disposed in front of the seat and having a steering wheel that is rotated by the driver; a bag case provided rotatably with respect to the steering wheel; an upper airbag and a lower airbag that are stored in the bag case in a stacked manner in the vertical direction of the vehicle; an inflator that supplies high-pressure gas to the upper airbag and the lower airbag; and the lower airbag has a deployed shape that is substantially rod-shaped and deployed horizontally, the upper airbag is deployed in a shape movable in the left-right direction of the vehicle while being supported on the lower airbag which is deployed in a horizontally elongated manner, In the bag case storing the upper airbag and the lower airbag, an upper portion of the bag case that stores the upper airbag is heavier than a lower portion of the bag case that stores the lower airbag; Vehicle occupant protection devices.

2. The bag case has a through hole formed at the center of rotation of the bag case, The inflator is an inflator housing having a supply portion having a substantially cylindrical shape that is inserted into the through hole of the bag case; a plurality of supply holes formed in a line in the circumferential direction of the substantially cylindrical supply portion, a heat sealing member that is softened by heat of the high-pressure gas in the inflator is interposed between a peripheral portion of the through hole of the bag case and a peripheral portion of the supply portion of the inflator housing; 2. A vehicle occupant protection device according to claim 1.

3. the bag case, which is attached to the steering wheel so as to be rotatable with respect to the steering wheel, has a substantially cylindrical frame shape; A weight member is provided at the lower part of the bag case, which has a substantially cylindrical frame shape, to make the lower part heavier than the upper part of the bag case.

3. A vehicle occupant protection device according to claim 2.

4. the upper airbag, which is deployed above the lower airbag in a shape movable in the left-right direction of the vehicle, is deployed so as to protrude rearward of the vehicle from the lower airbag; 4. A vehicle occupant protection device according to claim 1.

5. The lower airbag deploys before the upper airbag.

5. A vehicle occupant protection device according to claim 4.

6. The steering wheel has an irregular shape different from a circular ring shape.

6. A vehicle occupant protection device according to claim 5.

Images