Crew protection devices and vehicles

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 that protects an occupant seated in a 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 is widely known as an occupant protection device for protecting an occupant seated in the driver's seat of a vehicle. The airbag described in Patent Document 1 inflates as follows. That is, when a collision of the vehicle is detected by a sensor, a control unit controls an inflator to cause the inflator to generate inflation gas. The airbag is inflated by this inflation gas.

Prior Art Literature

Patent Literature

[0003]

Patent Literature 1

Summary of the Invention

Problem to be Solved by the Invention

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

[0005] Accordingly, 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 vehicle collision.

Means for Solving the Problem

[0006] A typical configuration of the occupant protection device according to the present invention for solving the above problems is an occupant protection device for protecting an occupant seated in the driver's seat of a vehicle, comprising: a steering wheel having an airbag; a gas storage section having a supply port for storing inflation gas for inflating the airbag and supplying the inflation gas to the airbag; a sealing member for sealing the supply port; and a steering shaft that rotates when the steering wheel is rotated to steer the steering wheels of the vehicle, and having an inner wall component that constitutes a part of the inner wall of the gas storage section, wherein when the steering shaft is moved due to a collision of the vehicle, the spatial volume of the gas storage section decreases with the movement of the inner wall component, and the internal pressure of the gas storage section increases, causing the sealing member to rupture and the inflation gas to be supplied to the airbag from the supply port.

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

[0008] [Figure 1] This is a front view of a vehicle equipped with an occupant protection device according to one embodiment of the present invention. [Figure 2] This is a left side view of the vehicle. [Figure 3] This is a schematic cross-sectional view of the area around the instrument panel of a vehicle. [Figure 4] This is a schematic cross-sectional view of the area around the steering wheel of a vehicle. [Figure 5] Figure 5A shows a schematic cross-sectional view of the seal sheet metal surrounding the gas container, and a schematic diagram of the seal sheet metal viewed from the direction of arrow K. [Figure 6] This is a schematic diagram illustrating the operation of occupant protection devices in the event of a vehicle collision. [Figure 7] This is a schematic diagram illustrating the operation of occupant protection devices in the event of a vehicle collision. [Figure 8] This is a schematic diagram illustrating the operation of occupant protection devices in the event of a vehicle collision. [Modes for carrying out the invention]

[0009] The configuration of the occupant protection device 10 according to one embodiment of the present invention will be described below. In the following description, the left-right direction refers to the width direction of the vehicle 1 on which the occupant protection device 10 is installed, specifically the left and right directions as seen from the perspective of occupant M seated in the driver's seat 2. The front-rear direction refers to the front and rear directions of the vehicle 1, specifically the front and rear directions as seen from the perspective of occupant M seated in the driver's seat 2. The up-down direction refers to 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 this invention to those unless specifically stated.

[0010] Figure 1 is a front view of vehicle 1 equipped with the occupant protection device 10. Figure 2 is a left side view of vehicle 1. Figure 3 is a schematic cross-sectional view of the area around the instrument panel 4 (hereinafter referred to as "instrument panel 4") of vehicle 1. Figure 4 is a schematic cross-sectional view of the area around the steering wheel 30 of vehicle 1. In Figures 1 to 4, the occupant M seated in the driver's seat 2 is indicated by a dashed line. Also, in Figures 3 and 4, the airbag 40 when fully inflated is indicated by a dashed line.

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

[0012] The driver's seat 2 is equipped with a seat belt 13 to restrain occupant M. In addition, an instrument panel 4 is provided in front of the driver's seat 2 in the vehicle 1, extending across the entire left-right direction. Above the instrument panel 4 is a front windshield 3. Behind the instrument panel 4 are a steering wheel 30 and a column cover 11 for occupant M to steer the vehicle 1. The column cover 11 is held in place by fitting into the instrument panel 4.

[0013] Furthermore, inside the instrument panel 4 and column cover 11, there is a steering shaft 7 that rotates to steer the tires 19 (steering wheels) of the vehicle 1 when the steering wheel 30 is rotated, and a gas container 45 that contains inflation gas to inflate the airbag 40 mounted on the steering wheel 30. In addition, there is a reinforcement 8 that strengthens the rigidity of the front of the vehicle 1, a bearing 9 that holds the gas container 45, and a bracket 6 that connects the reinforcement 8 and the bearing 9 by welding them to each other. The bearing 9 supports the gas container 45 so as to allow its rotation and restrict its movement in the direction of the rotation axis R of the steering shaft 7. The rotation axis R of the steering shaft 7 referred to here is an imaginary line connecting the centers of rotation of the steering shaft 7 when the steering wheel 30 is rotated.

[0014] The steering shaft 7 is a hexagonal prism-shaped metal component. The steering shaft 7 is positioned to extend diagonally upward from the front to the rear. The rear end of the steering shaft 7 has a flange portion 7a with a larger diameter than the rest of the steering shaft 7, and the flange portion 7a and its surrounding area are located inside the gas container 45.

[0015] Furthermore, the rear end of an intermediate shaft 16 is connected to the front end of the steering shaft 7 via a universal joint 15. The gearbox 18 is connected to the front end of the intermediate shaft 16 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 tires 19 of the vehicle 1 via a ball joint (not shown). In this way, the steering shaft 7 is connected to the tires 19 via the intermediate shaft 16, etc., and rotates to steer the tires 19 when the steering wheel 30 is turned.

[0016] The steering wheel 30 includes a steering section 31 that the occupant M grips when steering, a metal core 32 that connects the steering section 31 to the gas container 45, a resin pad 33 positioned at the rear end of the steering wheel 30, and a lower cover 34 positioned at the front end of the steering wheel 30. The steering wheel 30 also includes an airbag 40, a holder member 41 that holds the airbag 40, an inner tube 42 that forms a passage 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 section 31 is annular in shape and is formed by covering the outer circumference of the steering core section 32a of the core metal 32, which is placed inside the steering section 31 for easy gripping by the occupant M, with urethane resin. The core metal 32 consists of a steering core section 32a, a container connecting section 32b located near the center of the steering wheel 30 and connected to the gas container 45 by fastening a bolt 89 and a nut 90, and a spoke core metal section 32c that connects the steering core metal section 32a and the container connecting section 32b. These steering core metal section 32a, container connecting section 32b, and spoke core metal section 32c are integrally molded by die casting. The lower cover 34 is fixed to the container connecting section 32b of the core metal 32 by inserting a mounting pin 85 and fastening a nut 86.

[0018] The pad 33 covers the rear of the folded airbag 40, 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 from the cover portion 33a along the rotational axis R direction of the steering shaft 7 and is connected to the side wall portion 41b of the holder member 41 by a bolt 65 and a nut 67. The cover portion 33a breaks to form an opening 33h when the airbag 40 is inflated, allowing the airbag 40 to be deployed out of the opening 33h. The cover portion 33a includes a thin-walled portion 33a1 formed to be thin so as to be broken by the pressure received from the inflating airbag 40, and door portions 33a2 and 33a3 which 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 a folded state. A retainer 43, which is an annular sheet metal, is housed inside the airbag 40. A gas inlet 40h, which is an opening for allowing inflation gas to flow into the interior of the airbag 40, is formed on the front surface of the airbag 40. When inflation is completed, the airbag 40 includes a rear wall portion 40a which is a rear portion thereof and a portion for receiving an occupant M, a front wall portion 40b which is a front portion thereof and a portion supported by the steering portion 31 of the steering wheel 30, a left wall portion 40c which is a left-side portion thereof, and a right wall portion 40d which is a right-side portion thereof. When inflation is completed, the airbag 40 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 a side wall portion 41b extending rearward from the outer edge of the bottom wall portion 41a along the direction of the rotation axis R of the steering shaft 7. As described above, the connecting portion 33b of the cover portion 33a is connected to the side wall portion 41b by a bolt 65 and a nut 67. The airbag 40 and the inner tube 42 are attached to the bottom wall portion 41a. Specifically, in a state where the peripheral edge of the gas inlet 40h of the airbag 40 is clamped between the retainer 43 and the rear surface of the bottom wall portion 41a of the holder member 41, and the holder connecting portion 42a of the inner tube 42 is pressed against the front surface of the bottom wall portion 41a, a bolt 87 is inserted through these members and a nut 88 is fastened. Accordingly, 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 inner space of the cylinder serves as a flow path for inflation gas. The inner tube 42 has: a holder connecting portion 42a, which is located at one end side of the steering shaft 7 in the direction of the rotation axis R and connected to the bottom wall portion 41a of the holder member 41 via a bolt 87 and a nut 88; and a core metal connecting portion 42b, which is located at the other end side and connected to the container connecting portion 32b of the core metal 32 via a bolt 89 and a nut 90. In order to prevent leakage of inflation gas, unillustrated washers are provided between the inner tube 42 and the nuts 88 and 90. Further, the inner tube 42 has a peripheral wall portion 42c, which is a portion between the holder connecting portion 42a and the core metal connecting portion 42b in the direction of the rotation axis R of the steering shaft 7 and forms a cylindrical portion serving as the flow path for inflation gas. That is, in the inner tube 42, the flow path for inflation gas extends along the direction of the rotation axis R of the steering shaft 7: inflation gas flows in from the core metal connecting portion 42b side, and 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 contains an inflation gas such as compressed gas for inflating the airbag 40. The gas container 45 has a rectangular rear wall portion 45a at its rear end, which faces the container connecting portion 32b of the core metal 32 and is connected to the container connecting portion 32b by bolts 89 and nuts 90. The gas container 45 also has a rectangular front wall portion 45b at its front end, through which a shaft insertion hole 45b1 is formed, through which the steering shaft 7 is inserted. The gas container 45 also has a side wall portion 45c that connects the rear wall portion 45a and the front wall portion 45b and extends along the rotation axis R direction of the steering shaft 7. The side wall portion 45c is composed of four rectangular plate-like parts that connect the sides of the rectangular rear wall portion 45a and the front wall portion 45b, respectively, and extend along the rotation axis R direction of the steering shaft 7. The upper and lower side wall portions 45c are supported by bearings 9.

[0023] The rear wall portion 45a of the gas container 45 has a through-hole that penetrates in the direction of the rotation axis R of the steering shaft 7, and has a gas supply port 45a1 (supply port) from which expansion gas is discharged. In the normal state before collision of the vehicle 1, the gas supply port 45a1 is sealed by a sealing sheet 45d (sealing member) made of a thin circular metal plate. The sealing sheet 45d is fixed to the rear wall portion 45a by inserting a bolt 89 while it is pressed against the rear wall portion 45a and fastening a nut 90 to close the gas supply port 45a1. By sealing the gas supply port 45a1 with the sealing sheet 45d in this way, expansion gas is prevented from leaking from the gas supply port 45a1 to the outside of the gas container 45.

[0024] Furthermore, as shown in Figures 5A and 5B, the seal sheet metal 45d is provided with recesses 45d1 that are thinner than other parts. Figure 5A is a schematic cross-sectional view of the area around the seal sheet metal 45d of the gas container 45, and Figure 5B is a schematic view of the seal sheet metal 45d as seen from the direction of arrow K shown in Figure 5A. In this embodiment, the recess 45d1 consists of a first recess 45d1a that extends intermittently in the circumferential direction of the circular seal sheet metal 45d, a second recess 45d1b that is located away from the first recess 45d1a and extends intermittently in the circumferential direction of the seal sheet metal 45d, and a third recess 45d1c that extends intermittently in a straight line connecting the first recess 45d1a and the second recess 45d1b. The arrangement of the recesses 45d1 is not limited to this, and for example, as shown in Figure 5C, the recesses 45d1 may be arranged to extend intermittently in an arc shape. Furthermore, the sealing member that seals the gas supply port 45a1 is not limited to a circular metal plate such as the sealing sheet metal 45d, but may be of other shapes or 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 small gap 95 is provided between the inner circumference portion 45b1a of the shaft insertion hole 45b1 and the side surface 7b of the steering shaft 7, allowing the steering shaft 7 to move relative to the gas container 45 along its rotation axis R. Therefore, as described later, when the vehicle 1 collides and the steering shaft 7 moves backward along its rotation axis R, the amount the steering shaft 7 penetrates the gas container 45 increases.

[0026] Furthermore, when the steering wheel 30 is rotated and the gas container 45 connected to the container connecting portion 32b of the core metal 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 circumference 45b1a of the shaft insertion hole 45b1, causing both to rotate integrally. In other words, when the steering wheel 30 is rotated, the gas container 45 rotates integrally with the steering wheel 30 and the steering shaft 7. In this embodiment, the steering shaft 7 is made into a regular hexagonal prism and the shaft insertion hole 45b1 is made into a regular hexagon in order to rotate the gas container 45 and the steering shaft 7 integrally, but for example, these fitting parts may be made into polygons other than regular hexagons or D-cut shapes to allow them to rotate integrally. In this way, the steering shaft 7 rotates when the steering wheel 30 is steered, and finally the tires 19 are steered, changing the direction of travel of the vehicle 1. Furthermore, a steer-by-wire system may be employed in which a sensor (not shown) detects the rotation angle of the steering shaft 7, which rotates in accordance with the rotational steering of the steering wheel 30, and the vehicle 1 steers the tires 19 to change its direction of travel according to this detection result.

[0027] Furthermore, the flange portion 7a of the steering shaft 7 and the surrounding area are located inside the gas container 45. Between the flange portion 7a and the side wall portion 45c of the gas container 45, there is a C-shaped C-ring 83 made of a metal plate and an annular O-ring 84 made of an elastic material such as rubber. The O-ring 84 is located 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 O-ring 84 are positioned relative to the steering shaft 7 by being placed 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 and O-ring 84 of the steering shaft 7. The space partitioned by the rear wall portion 45a and side wall portion 45c of the gas container 45 and the flange portion 7a and O-ring 84 of the steering shaft 7 is the gas storage portion S in the gas container 45 where the expansion gas is contained. In other words, the rear wall portion 45a and the side wall portion 45c of the gas container 45, and the flange portion 7a (inner wall component) of the steering shaft 7 each constitute a part of the inner wall of the gas storage section 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 an O-ring 84.

[0028] The steering wheel 30, steering shaft 7, gas container 45, inner tube 42, etc., mentioned above are components that make up the occupant protection device 10. The protective operation of the occupant M by the occupant protection device 10 will be explained below using Figures 6 to 8. Figures 6, 7, and 8 are schematic diagrams that sequentially show the operation of the occupant protection device 10 when the vehicle 1 is involved in a collision.

[0029] As shown in Figure 6, when vehicle 1 collides with another vehicle or an object such as a guardrail, and the object collides with the steering shaft 7 and intermediate shaft 16 from the front, a rearward load is applied to the steering shaft 7 and intermediate shaft 16. Due to this load, the steering shaft 7 moves rearward along its rotation axis R, and the flange portion 7a also moves rearward along 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 against the side wall portion 45c of the gas container 45. As the flange portion 7a moves rearward in this way, 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] As the flange portion 7a moves backward, the spatial volume of the gas containment section S decreases, causing the internal pressure of the gas containment section S to increase. This increase in internal pressure causes the fragile recess 45d1 of the sealing sheet metal 45d to rupture. This releases the seal of the gas supply port 45a1 by the sealing sheet metal 45d, and the expansion gas is discharged from the gas supply port 45a1 to the outside of the gas container 45. The expansion gas discharged to the outside of the gas container 45 is supplied to the inside of the airbag 40 through the inside of the inner tube 42 and the gas inlet 40h of the airbag 40.

[0031] As shown in Figure 7, when inflation gas is supplied to the inside of the airbag 40, the airbag 40 begins to inflate. When the inflating airbag 40 begins to inflate, it first contacts the cover portion 33a of the pad 33 and presses against the cover portion 33a. When the thin-walled portion 33a1 of the cover portion 33a is ruptured by the pressure of the airbag 40, the door portions 33a2 and 33a3 of the cover portion 33a are pushed open by the airbag 40, forming an opening 33h. After that, the airbag 40 extends out of the steering wheel 30 through the opening 33h and completes its inflation. The inflated airbag 40 catches and protects the occupant M as it 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 Figure 8, the rearward movement of the steering shaft 7 is restricted by the flange portion 7a contacting the bolt 89 and the rear wall portion 45a of the gas container 45.

[0032] As described above, in this embodiment, when the vehicle 1 collides, the steering shaft 7 moves backward, causing the internal pressure of the gas reservoir S to rise and the seal sheet metal 45d to rupture, thereby supplying inflation gas from the gas reservoir S to the airbag 40. Therefore, since inflation gas for inflating the airbag can be generated without using electronic components when the vehicle 1 collides, it is possible to suppress the complexity of the vehicle 1's structure and the increase in manufacturing costs. [Explanation of Symbols]

[0033] 1...Vehicle, 2...Driver's seat, 7...Steering shaft, 7a...Flange section (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 (sealing component), 84...O-ring (elastic body), M...Occupant, S...Gas storage section

Claims

1. In an occupant protection device that protects the occupant seated in the driver's seat of a vehicle, A steering wheel with an airbag, A gas storage unit that houses inflation gas for inflating the airbag and has a supply port for supplying the inflation gas to the airbag, A sealing member for sealing the supply port, A steering shaft that rotates when the steering wheel is rotated to steer the steering wheels of the vehicle, the steering shaft having an inner wall component that forms part of the inner wall of the gas containment section, Equipped with, An occupant protection device characterized in that, when the steering shaft is moved due to a collision of the vehicle, the internal volume of the gas containment decreases as the internal wall component moves, and the internal pressure of the gas containment increases, causing the sealing member to rupture and the inflation gas to be supplied to the airbag from the supply port.

2. The occupant protection device according to claim 1, characterized in that when the steering wheel is rotated, the gas containment unit rotates integrally with the steering wheel and the steering shaft.

3. The occupant protection device according to claim 1, characterized in that an elastic body is provided between the inner wall component and the other inner wall of the gas containment, and the space of the gas containment is partitioned by the inner wall component and the elastic body.

4. The driver's seat and, An occupant protection device according to any one of claims 1 to 3, which protects the occupant seated in the driver's seat, A vehicle characterized by being equipped with the following features.

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