Occupant protection device and vehicle

Abstract

To provide an occupant protection device which can generate an inflation gas for inflating an airbag without using electronic components during a collision of a vehicle.SOLUTION: An occupant protection device 10 includes: a steering wheel 30 having an airbag 40; a gas storage part S which stores an inflation gas and has a gas supply port 45a1 for supplying the inflation gas to the airbag 40; a seal sheet metal 45d which seals the gas supply port 45a1; and a steering shaft 7 having a flange part 7a forming a part of an inner wall of the gas storage part S. When the steering shaft 7 is moved by a collision of a vehicle 1, a spatial volume of the gas storage part S is reduced as the flange part 7a moves and an inner pressure of the gas storage part S increases to break the seal sheet metal 45d and cause the inflation gas to be supplied to the airbag 40 through the gas supply port 45a1.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an occupant protection device for protecting an occupant sitting in the driver's seat of a vehicle, and a vehicle equipped with the occupant protection device.

Background Art

[0002] Conventionally, as described in Patent Document 1, a configuration in which an airbag is mounted on a steering wheel as an occupant protection device for protecting an occupant sitting in the driver's seat of a vehicle is widely known. The airbag described in Patent Document 1 inflates as follows. That is, when a collision of the vehicle is detected by a sensor, the control unit controls the inflator to generate inflation gas from the inflator. The airbag inflates by this inflation gas.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when generating inflation gas from an inflator using electronic components such as sensors and control units during a collision of a vehicle as in the configuration described in Patent Document 1, there is a risk of complicating the vehicle configuration and increasing the manufacturing cost.

[0005] Therefore, an object of the present invention is to provide an occupant protection device capable of generating inflation gas for inflating an airbag without using electronic components during a collision of a vehicle.

Means for Solving the Problems

[0006] A typical configuration of the occupant protection device according to the present invention for solving the above problems is an occupant protection device that protects an occupant sitting in the driver's seat of a vehicle, including a steering wheel having an airbag, a gas storage unit that stores inflation gas for inflating the airbag and has a supply port for supplying the inflation gas to the airbag, a seal member that seals the supply port, and a steering shaft that rotates during the rotational steering of the steering wheel to steer the steered wheels of the vehicle, the steering shaft having an inner wall component that constitutes a part of the inner wall of the gas storage unit. When the steering shaft is moved due to a collision of the vehicle, the space volume of the gas storage unit decreases with the movement of the inner wall component, and the internal pressure of the gas storage unit increases, causing the seal member to break and the inflation gas to be supplied from the supply port to the airbag.

[0007] According to the present invention, in an occupant protection device, it is possible to generate inflation gas for inflating an airbag without using electronic components during a collision of a vehicle.

Brief Description of the Drawings

[0008]

Figure 1

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Figure 7

Figure 8

Best Mode for Carrying Out the Invention

[0009] Hereinafter, the configuration of the occupant protection device 10 according to an embodiment of the present invention will be described. In the following description, the left - right direction means the vehicle width direction of the vehicle 1 on which the occupant protection device 10 is mounted, specifically, the left direction and the right direction as viewed from the occupant M seated in the driver's seat 2. The front - rear direction means the front direction and the rear direction of the vehicle 1, specifically, the front direction and the rear direction as viewed from the occupant M seated in the driver's seat 2. The up - down direction means the vertical direction. Note that the dimensions, materials, shapes, relative arrangements, etc. of the components in the following description are not intended to limit the scope of the present invention only to these unless otherwise specifically stated.

[0010] FIG. 1 is a front view of the vehicle 1 on which the occupant protection device 10 is mounted. FIG. 2 is a left - side view of the vehicle 1. FIG. 3 is a schematic cross - sectional view around the instrument panel 4 (hereinafter referred to as the "IP 4") of the vehicle 1. FIG. 4 is a schematic cross - sectional view around the steering wheel 30 of the vehicle 1. In FIGS. 1 to 4, the occupant M seated in the driver's seat 2 is shown by a two - dot chain line. Also, in FIGS. 3 and 4, the airbag 40 at the completion of inflation is shown by a two - dot chain line.

[0011] As shown in FIGS. 1 to 4, the occupant protection device 10 is mounted on the vehicle 1, and the vehicle 1 of the present embodiment is a single - occupant type with only the driver's seat 2 provided as a seat. The vehicle 1 is an electric vehicle powered by electricity.

[0012] A seat belt 13 for restraining the occupant M is mounted on the driver's seat 2. Also, in front of the driver's seat 2 in the vehicle 1, an IP 4 is provided over the entire left - right direction. Above the IP 4, a front windshield 3 is provided. Behind the IP 4, a steering wheel 30 and a column cover 11 for the occupant M to steer the vehicle 1 are provided. The column cover 11 is held by fitting into the IP 4.

[0013] In addition, inside the instrument panel 4 and the column cover 11, there are provided a steering shaft 7 that rotates to steer the tire 19 (steering wheel) of the vehicle 1 when the steering wheel 30 is rotationally steered, and a gas container 45 that stores inflation gas for inflating the airbag 40 mounted on the steering wheel 30. Further, there are provided a reinforcement 8 for strengthening the rigidity of the front side of the vehicle 1, a bearing 9 for holding the gas container 45, and a bracket 6 that connects the reinforcement 8 and the bearing 9 by being welded to each of them. The bearing 9 supports the gas container 45 so as to allow the rotation of the gas container 45 and restrict the movement of the gas container 45 in the direction of the rotation axis R of the steering shaft 7. Here, the rotation axis R of the steering shaft 7 refers to an imaginary line connecting the rotation center of the steering shaft 7 when the steering wheel 30 is rotationally steered.

[0014] The steering shaft 7 is a member made of metal having a regular hexagonal prism shape. The steering shaft 7 is arranged to extend obliquely upward from the front to the rear. The rear end portion of the steering shaft 7 is a flange portion 7a having a larger diameter than other portions of the steering shaft 7, and the flange portion 7a and the surrounding portions are arranged inside the gas container 45.

[0015] In addition, the rear end portion of an intermediate shaft 16 is connected to the front end portion of the steering shaft 7 via a universal joint 15. The front end portion of the intermediate shaft 16 is connected to a gearbox 18 via a universal joint 17. The gearbox 18 is connected to the body of the vehicle 1 via a bracket (not shown), and is also connected to the tire 19 of the vehicle 1 via a ball joint or the like (not shown). In this way, the steering shaft 7 is connected to the tire 19 via the intermediate shaft 16 and the like, and rotates to steer the tire 19 when the steering wheel 30 is rotationally steered.

[0016] The steering wheel 30 has a steering portion 31 that the occupant M grips when steering, a metal core bar 32 that connects the steering portion 31 and the gas container 45, a resin pad 33 disposed on the rear end side of the steering wheel 30, and a lower cover 34 disposed on the front end side of the steering wheel 30. Further, the steering wheel 30 has an airbag 40, a holder member 41 that holds the airbag 40, an inner tube 42 that forms a flow path for the inflation gas discharged from the gas container 45 and supplied to the airbag 40, and two mounting pins 85 to which a horn unit (not shown) is attached.

[0017] The steering portion 31 has an annular shape, and is formed by covering the outer peripheral portion of the steering core bar portion 32a of the core bar 32 disposed inside the steering portion 31 with urethane resin so that the occupant M can easily grip it. The core bar 32 is composed of a steering core bar portion 32a, a container connection portion 32b that is disposed near the center of the steering wheel 30 and is connected to the gas container 45 by fastening bolts 89 and nuts 90, and a spoke core bar portion 32c that connects the steering core bar portion 32a and the container connection portion 32b. These steering core bar portion 32a, container connection portion 32b, and spoke core bar portion 32c are integrally formed by die casting. The lower cover 34 is fixed to the container connection portion 32b of the core bar 32 by inserting the mounting pins 85 and fastening nuts 86.

[0018] The pad 33 covers the rear of the airbag 40 in the folded state and includes a cover portion 33a that forms part of the exterior of the steering wheel 30, and a connecting portion 33b that extends forward along the direction of the rotation axis R of the steering shaft 7 from the cover portion 33a and is connected to the side wall portion 41b of the holder member 41 by bolts 65 and nuts 67. The cover portion 33a breaks at the time of inflation of the airbag 40 to form an opening 33h, and the airbag 40 is deployed from the opening 33h. The cover portion 33a has a thin-walled portion 33a1 formed with a thin wall to be broken by the pressure received from the inflating airbag 40, and door portions 33a2 and 33a3 that are the upper and lower portions of the thin-walled portion 33a1. When the thin-walled portion 33a1 breaks as the airbag 40 inflates, the upper door portion 33a2 rotates upward and the lower door portion 33a3 rotates downward, thereby forming the opening 33h.

[0019] The airbag 40 is a bag-shaped member formed of a thick base fabric made of synthetic fiber such as nylon and is housed inside the steering wheel 30 in the folded state. An annular sheet metal retainer 43 is housed inside the airbag 40. An air inlet 40h, which is an opening for allowing inflation gas to flow into the airbag 40, is formed on the front surface of the airbag 40. The airbag 40 at the completion of inflation includes a rear wall portion 40a that is the rear portion thereof and receives the occupant M, a front wall portion 40b that is the front portion thereof and is supported by the steering portion 31 of the steering wheel 30, a left wall portion 40c that is the left portion, and a right wall portion 40d that is the right portion. The airbag 40 at the completion of inflation has a shape that covers the entire area of the steering portion 31 of the steering wheel 30 from the rear.

[0020] The holder member 41 includes a substantially rectangular plate-shaped bottom wall portion 41a and side wall portions 41b extending rearward along the rotation axis R direction of the steering shaft 7 from the outer edge of the bottom wall portion 41a. As described above, the connecting portion 33b of the cover portion 33a is connected to the side wall portion 41b by bolts 65 and nuts 67. An airbag 40 and an inner tube 42 are attached to the bottom wall portion 41a. Specifically, the periphery of the gas inlet 40h of the airbag 40 is sandwiched between the retainer 43 and the rear surface of the bottom wall portion 41a of the holder member 41, and with the holder connecting portion 42a of the inner tube 42 pressed against the front surface of the bottom wall portion 41a, bolts 87 are inserted through these members and nuts 88 are tightened. Thereby, the airbag 40 and the inner tube 42 are attached to the bottom wall portion 41a of the holder member 41.

[0021] The inner tube 42 is a cylindrical member formed of a thick base fabric similar to that of the airbag 40, and the inside of the tube serves as a flow path for the inflation gas. The inner tube 42 has a holder connecting portion 42a which is a part on one end side in the rotation axis R direction of the steering shaft 7 and is connected to the bottom wall portion 41a of the holder member 41 by bolts 87 and nuts 88, and a core metal connecting portion 42b which is a part on the other end side and is connected to the container connecting portion 32b of the core metal 32 by bolts 89 and nuts 90. In addition, in order to prevent leakage of the inflation gas, washers (not shown) are provided between the inner tube 42 and the nuts 88, 90. Further, the inner tube 42 has a peripheral wall portion 42c which is a part between the holder connecting portion 42a and the core metal connecting portion 42b in the rotation axis R direction of the steering shaft 7 and forms a cylindrical portion serving as a flow path for the inflation gas. That is, in the inner tube 42, the flow path for the inflation gas extends along the rotation axis R direction of the steering shaft 7, the inflation gas flows in from the core metal connecting portion 42b side, and the inflation gas is discharged from the holder connecting portion 42a side.

[0022] The gas container 45 is a rectangular box-shaped member made of a metal such as aluminum, and an inflation gas such as compressed gas for inflating the airbag 40 is accommodated therein. The gas container 45 has a rectangular rear wall portion 45a at its rear end, which faces the container connection portion 32b of the core metal 32 and is connected to the container connection portion 32b by bolts 89 and nuts 90. Further, the gas container 45 has a rectangular front wall portion 45b at its front end, in which a shaft insertion hole 45b1 through which the steering shaft 7 is inserted is formed. Further, the gas container 45 has side wall portions 45c that connect the rear wall portion 45a and the front wall portion 45b and extend along the rotation axis R direction of the steering shaft 7. The side wall portions 45c are each composed of four rectangular plate-like portions that connect the sides of the rectangular rear wall portion 45a and the front wall portion 45b and extend along the rotation axis R direction of the steering shaft 7, and the upper and lower side wall portions 45c are supported by bearings 9.

[0023] The rear wall portion 45a of the gas container 45 is a through hole that penetrates in the rotation axis R direction of the steering shaft 7, and has a gas supply port 45a1 (supply port) through which the inflation gas is discharged. The gas supply port 45a1 is sealed by a seal sheet metal 45d (seal member) made of a thin circular metal plate in a normal state before the collision of the vehicle 1. The seal sheet metal 45d is fixed to the rear wall portion 45a so as to close the gas supply port 45a1 by inserting the bolt 89 and fastening the nut 90 while being pressed against the rear wall portion 45a. By sealing the gas supply port 45a1 with the seal sheet metal 45d in this way, the inflation gas does not leak from the gas supply port 45a1 to the outside of the gas container 45.

[0024] Also, as shown in FIGS. 5A and 5B, the seal sheet metal 45d is provided with a recessed portion 45d1 that is recessed so that its thickness is thinner than other portions. Note that FIG. 5A is a schematic cross-sectional view around the seal sheet metal 45d of the gas container 45, and FIG. 5B is a schematic view of the seal sheet metal 45d as viewed from the direction of arrow K shown in FIG. 5A. In the present embodiment, the recessed portion 45d1 is composed of a first recessed portion 45d1a that extends intermittently in the circumferential direction of the circular seal sheet metal 45d, a second recessed portion 45d1b that is arranged apart from the first recessed portion 45d1a and extends intermittently in the circumferential direction of the seal sheet metal 45d, and a third recessed portion 45d1c that extends linearly and intermittently so as to connect the first recessed portion 45d1a and the second recessed portion 45d1b. Note that the arrangement of the recessed portion 45d1 is not limited to this, and for example, as shown in FIG. 5C, the recessed portion 45d1 may be arranged to extend intermittently in an arc shape. Further, the seal member that seals the gas supply port 45a1 is not limited to a circular metal plate such as the seal sheet metal 45d, and may have other shapes and materials.

[0025] The shaft insertion hole 45b1 formed in the front wall portion 45b of the gas container 45 is a regular hexagonal through-hole that penetrates in the direction of the rotation axis R of the steering shaft 7. A minute gap 95 is provided between the inner peripheral portion 45b1a of the shaft insertion hole 45b1 and the side surface 7b of the steering shaft 7 so that the steering shaft 7 can move relative to the gas container 45 along the direction of its rotation axis R. Therefore, as will be described later, when the vehicle 1 collides and the steering shaft 7 moves rearward along the direction of its rotation axis R, the amount of entry of the steering shaft 7 into the gas container 45 increases.

[0026] Further, when the steering wheel 30 is rotationally steered and the gas container 45 connected to the container connection portion 32b of the shaft 32 of the steering wheel 30 rotates integrally with the steering wheel 30, the side surface 7b of the steering shaft 7 is pressed against the inner peripheral portion 45b1a of the shaft insertion hole 45b1, causing the two to rotate integrally. That is, when the steering wheel 30 is rotationally steered, the gas container 45 rotates integrally with the steering wheel 30 and the steering shaft 7. In this embodiment, in order to rotate the gas container 45 and the steering shaft 7 integrally, the steering shaft 7 is a regular hexagonal prism and the shaft insertion hole 45b1 is a regular hexagon. However, for example, the fitting portions thereof may be polygons other than regular hexagons or D-cut shapes to integrally rotate the two. In this way, the steering shaft 7 rotates by steering the steering wheel 30, and finally the tire 19 is steered to change the traveling direction of the vehicle 1. Note that the rotation angle of the steering shaft 7 that rotates in response to the rotational steering of the steering wheel 30 is detected by a sensor (not shown), and a steer-by-wire system may be adopted in which the vehicle 1 steers the tire 19 and changes the traveling direction according to the detection result.

[0027] Further, the flange portion 7a of the steering shaft 7 and the surrounding portions thereof are disposed inside the gas container 45. Between the flange portion 7a and the side wall portion 45c of the gas container 45, a C-shaped C-ring 83 formed of a metal plate and an annular O-ring 84 formed of an elastic body such as rubber are provided. The O-ring 84 is disposed adjacent to the rear of the C-ring 83 in the direction of the rotation axis R of the steering shaft 7. The C-ring 83 and the O-ring 84 are positioned with respect to the steering shaft 7 by being disposed in a recess 7a1 formed on the side surface of the flange portion 7a. In this way, the internal space of the gas container 45 is partitioned by the flange portion 7a of the steering shaft 7 and the O-ring 84. The space partitioned by the rear wall portion 45a and the side wall portion 45c of the gas container 45, the flange portion 7a of the steering shaft 7, and the O-ring 84 is a gas storage portion S in which the inflation gas is stored in the gas container 45. That is, the rear wall portion 45a and the side wall portion 45c of the gas container 45 and the flange portion 7a (inner wall component portion) of the steering shaft 7 each constitute a part of the inner wall of the gas storage portion S, and the gap between the side wall portion 45c of the gas container 45 and the flange portion 7a of the steering shaft 7 is sealed by the O-ring 84.

[0028] Here, the above-described steering wheel 30, steering shaft 7, gas container 45, inner tube 42, etc. are members constituting the occupant protection device 10. Hereinafter, the protection operation of the occupant M by the occupant protection device 10 will be described with reference to FIGS. 6 to 8. FIGS. 6, 7, and 8 are schematic views sequentially showing the operation of the occupant protection device 10 when the vehicle 1 collides.

[0029] As shown in FIG. 6, when the vehicle 1 collides with a collision object such as another vehicle or a guard rail, and the collision object collides with the steering shaft 7 or the intermediate shaft 16 from the front side, a rearward load is input to the steering shaft 7 and the intermediate shaft 16. Due to this load, the steering shaft 7 moves rearward along the direction of its rotation axis R, and the flange portion 7a also moves rearward along the direction of the rotation axis R inside the gas container 45. At this time, the flange portion 7a presses the O-ring 84 rearward via the C-ring 83, and the O-ring 84 moves rearward following the flange portion 7a while sliding on the side wall portion 45c of the gas container 45. Thus, when the flange portion 7a moves rearward, the gap between the side wall portion 45c of the gas container 45 and the flange portion 7a is sealed by the O-ring 84.

[0030] When the flange portion 7a moves rearward, the space volume of the gas storage portion S decreases, so the internal pressure of the gas storage portion S increases. Along with this increase in internal pressure, the recess 45d1, which is fragilely configured on the seal sheet metal 45d, breaks. As a result, the sealing of the gas supply port 45a1 by the seal sheet metal 45d is released, and the inflation gas is discharged from the gas supply port 45a1 to the outside of the gas container 45. The inflation gas discharged to the outside of the gas container 45 is supplied to the inside of the airbag 40 through the inside of the tube of the inner tube 42 and the gas inlet 40h of the airbag 40.

[0031] As shown in FIG. 7, when inflation gas is supplied into the airbag 40, the airbag 40 starts to inflate. The inflated airbag 40 first contacts the cover portion 33a of the pad 33 and presses the cover portion 33a. When the thin portion 33a1 of the cover portion 33a breaks due to the pressure of the airbag 40, the door portions 33a2 and 33a3 of the cover portion 33a are pushed open by the airbag 40, and the opening 33h is formed. Thereafter, the airbag 40 is extended from the opening 33h to the outside of the steering wheel 30 to complete inflation. The inflated airbag 40 receives and protects the occupant M who moves forward due to the collision of the vehicle 1. In this way, the occupant protection device 10 protects the occupant M. As shown in FIG. 8, the rearward movement of the steering shaft 7 is restricted by the flange portion 7a contacting the bolts 89 and the rear wall portion 45a of the gas container 45.

[0032] As described above, when the vehicle 1 collides, the occupant protection device 10 of the present embodiment causes the internal pressure of the gas storage portion S to rise and the seal sheet metal 45d to crack by the rearward movement of the steering shaft 7, whereby the inflation gas is supplied from the gas storage portion S to the airbag 40. Therefore, since it is possible to generate the inflation gas for inflating the airbag without using electronic components at the time of collision of the vehicle 1, it is possible to suppress the complication of the configuration of the vehicle 1 and the increase in manufacturing cost.

Description of Reference Numerals

[0033] 1... vehicle, 2... driver's seat, 7... steering shaft, 7a... flange portion (inner wall component), 9... bearing, 10... occupant protection device, 19... tire (steering wheel), 30... steering wheel, 40... airbag, 45a1... gas supply port (supply port), 45d... seal sheet metal (seal member), 84... O-ring (elastic body), M... occupant, S... gas storage portion

Claims

1. In an occupant protection device for protecting an occupant sitting in the driver's seat of a vehicle, a steering wheel having an airbag; a gas storage part that stores inflation gas for inflating the airbag and has a supply port for supplying the inflation gas to the airbag; a seal member for sealing the supply port; a steering shaft that rotates when the steering wheel is rotationally steered to steer the steered wheels of the vehicle, the steering shaft having an inner wall constituent part that constitutes a part of the inner wall of the gas storage part; comprising: When the steering shaft is moved by a collision of the vehicle, the space volume of the gas storage part decreases as the inner wall constituent part moves, and the internal pressure of the gas storage part rises, causing the seal member to break and the inflation gas to be supplied from the supply port to the airbag. An occupant protection device characterized by this.

2. When the steering wheel is rotationally steered, the gas storage part rotates integrally with the steering wheel and the steering shaft. The occupant protection device according to Claim 1, characterized by this.

3. An elastic body is provided between the inner wall constituent part and the other inner wall of the gas storage part, and the space of the gas storage part is partitioned by the inner wall constituent part and the elastic body. The occupant protection device according to Claim 1, characterized by this.

4. a driver's seat; the occupant protection device according to any one of Claims 1 to 3 for protecting an occupant sitting in the driver's seat; A vehicle characterized by comprising this.

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