Handle device

Abstract

To provide a handle device which has a simple structure and can properly protect an operator.SOLUTION: A handle device S includes a handle 15 and a steering column 45. A column shaft 48 in the steering column includes: a cylinder part 49 incorporating a gas generator 65 capable of supplying an expansion gas to an air bag 26 stored in a boss part; and a shaft body 58 including a piston part 59 disposed in the cylinder part. The gas generator has, on a rear end surface located at the handle side, a gas outflow hole closed by the seal part. At a region of the boss part in the handle, a projection part 21 which may cleave the seal part is disposed. The shaft body is configured to move rearward during a frontal collision of a vehicle. During the frontal collision of the vehicle, the gas generator is pressed by the piston part of the shaft body moving rearward to be moved rearward and cause the seal part to contact with the projection part.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a steering wheel device mounted on a vehicle and including a rotatable steering wheel and a steering column that pivotally supports the steering wheel, and in which an airbag is folded and stored in a region of a boss portion of the steering wheel.

Background Art

[0002] Conventionally, as a steering wheel device, an inflater is disposed near a cylindrical steering column, the inflater is operated when a frontal collision of the vehicle is detected, and inflation gas discharged from the inflater flows into the airbag through the steering column to inflate the airbag (see, for example, Patent Document 1). In this steering wheel device, the inflation gas discharged from the inflater is also used to pull the steering wheel toward the vehicle body side.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional steering wheel device, in order to operate the inflater, it is necessary to dispose a collision detection sensor on the vehicle, which increases the number of parts and the cost.

[0005] The present invention solves the above problems and aims to provide a steering wheel device that can accurately protect a driver with a simple configuration.

Means for Solving the Problems

[0006] The steering wheel device according to the present invention is mounted on a vehicle and includes a rotatable steering wheel and a steering column that pivotally supports the steering wheel. The steering wheel device has a configuration in which an airbag is folded and stored in a region of a boss portion of the steering wheel. The steering column is attached to a region of a boss portion of the steering wheel and includes a column shaft that constitutes a rotation center axis of the steering wheel. The column shaft is disposed on the steering wheel side and is configured as a substantially cylindrical cylinder portion having a built-in gas generator capable of supplying inflation gas to the airbag. is disposed on the vehicle body side separated from the steering wheel and includes a shaft body having a piston portion disposed in the cylinder portion on the rear end side on the steering wheel side. It is configured to include these. The gas generator is configured to have compressed gas sealed therein and a gas outflow hole closed by a seal portion on the rear end surface on the steering wheel side. In a region of the boss portion of the steering wheel, a protrusion that protrudes forward on the gas generator side and can cleave the seal portion when contacting the seal portion is disposed. The shaft body is configured to move rearward when receiving an impact force acting on the vehicle during a frontal collision of the vehicle. During a frontal collision of the vehicle, the gas generator is configured to move rearward and bring the seal portion into contact with the protrusion by being pressed by the piston portion of the shaft body that moves rearward.

[0007] In the steering wheel device of the present invention, when a frontal collision of the vehicle occurs, the shaft body of the steering column is configured to move rearward in response to the impact force acting on the vehicle. Then, when a frontal collision of the vehicle occurs, due to the rearward movement of the shaft body, the gas generator disposed in the cylinder portion of the column shaft is caused to move rearward so as to be pressed by the piston portion provided on the rear end side of the shaft body toward the steering wheel side. The rearwardly moved gas generator comes into contact with the seal portion provided on the rear end surface against the protrusion portion disposed in the region on the boss portion side of the steering wheel. At this time, the protrusion portion causes the seal portion to crack, and the gas generator causes the inflation gas to flow out from the gas outflow hole formed by cracking the seal portion. Then, the inflation gas flowing out from the gas generator flows into the interior, causing the airbag to inflate. That is, in the steering wheel device of the present invention, even if a sensor for operating the gas generator is not provided in the vehicle, by utilizing the impact force acting on the vehicle during a frontal collision of the vehicle and causing the inflation gas to flow out from the gas generator, the airbag can be inflated. Therefore, a simple configuration can be achieved, and the driver seated in the driver's seat can be protected by the inflated airbag.

[0008] Therefore, in the steering wheel device of the present invention, with a simple configuration, the driver can be accurately protected.

[0009] Further, in the steering wheel device of the present invention, if the gas generator is configured to be compressibly deformable by the pressing of the piston portion, even when the rearward movement amount of the shaft body is large, the rearwardly moved gas generator can be further compressed and deformed so as to reduce the length in the front-rear direction, thereby absorbing a certain amount of energy during a collision and absorbing the rearward movement of such a shaft body. Therefore, it is preferable that the steering wheel and the steering column can be suppressed from moving rearward toward the driver side when an impact force acts on the vehicle.

[0010] Furthermore, in the steering wheel device of the present invention, the gas generator may be configured to include a substantially cylindrical peripheral wall portion and a front wall portion that closes the front end side of the peripheral wall portion, and when the front wall portion is pressed by the piston portion, the front wall portion is configured to be movable rearward with respect to the peripheral wall portion. Even with such a configuration, when the rearward movement amount of the shaft body is large, in addition to the rearward movement of the gas generator itself, by moving the front wall portion rearward with respect to the peripheral wall portion, the rearward movement of the shaft body can be absorbed, and it is possible to suppress the steering wheel and the steering column from moving rearward toward the driver side during a frontal collision of the vehicle.

[0011] Furthermore, in the steering wheel device having the above configuration, if the protrusion portion is formed in a cylindrical shape through which the inflation gas can pass and at least the tip side can be inserted into the gas outflow hole, the inflation gas flowing out from the gas outflow hole that is opened by splitting the seal portion can smoothly flow into the airbag through the protrusion portion, which is preferable.

[0012] Furthermore, in the steering wheel device having the above configuration, if a buffer material that can be plastically deformed when the gas generator moves rearward is interposed between the gas generator and the boss portion, it is possible to accurately suppress rattling and abnormal noises from occurring around the gas generator during normal vehicle driving, etc., which is preferable.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the steering wheel device S of the embodiment is mounted on a single-seater vehicle V. This vehicle V is an electric vehicle powered by electricity. In the embodiment, the front-rear, up-down, and left-right directions coincide with the front-rear, up-down, and left-right directions of the vehicle V unless otherwise specified.

[0015] As shown in FIG. 3, the steering wheel device S of the embodiment includes a rotatable steering wheel 15 and a steering column 45 that pivotally supports the steering wheel 15.

[0016] As shown in FIGS. 4 and 6, the steering wheel 15 includes a steering wheel body 16 and an airbag device 25 disposed above (rearward) the boss portion 16b at the center of the steering wheel body 16.

[0017] In the case of the embodiment, the steering wheel body 16 includes a substantially annular ring portion 16a that is gripped when the driver D steers, a boss portion 16b disposed substantially at the center of the ring portion 16a and connected to a column shaft 48 described later, and a plurality of spoke portions 16c that connect the boss portion 16b and the ring portion 16a. Further, the steering wheel body 16 includes a core metal 19 made of a metal such as an aluminum alloy and disposed so as to connect each of the ring portion 16a, the boss portion 16b, and the spoke portion 16c. A coating layer (reference numeral omitted) made of synthetic resin is coated on the portion of the core metal 19 corresponding to the ring portion 16a. Further, as shown in FIGS. 3, 4, and 6, the steering wheel body 16 also includes a lower cover 18 made of synthetic resin that covers the outer peripheral side of the region in front of the core metal 19 (the region between a column cover 46 described later and the core metal 19) when mounted on the vehicle.

[0018] In the core metal 19, at the center of the boss part core metal 19a that constitutes the area of the boss part 16b, as shown in FIGS. 4 and 6, a protrusion 21 protruding forward (towards the gas generator 65 described later) is disposed. When this protrusion 21 comes into contact with a seal part 70 that closes a gas outflow hole 69a (to be described later) at the rear end face 65a of the gas generator 65, it is configured to be able to split the seal part 70 (see A and B in FIG. 7). Also, in the case of the embodiment, the protrusion 21 is formed in a cylindrical shape through which the inflation gas G flowing out from the gas outflow hole 69a opened when the seal part 70 is split can pass. Specifically, in the case of the embodiment, the protrusion 21 has a through-hole part 22 penetrating through the center, and the outer shape is formed in a substantially frustum of a cone shape with a narrow width towards the tip 21a (front end) side on the gas generator 65 side. The tip 21a (front end) has an acute-angled cross-section so that it can break through the seal part 70 when coming into contact with the seal part 70. The through-hole part 22 disposed in the protrusion 21 is formed so as to penetrate the entire front and rear regions including the boss part core metal 19a. This protrusion 21 is disposed so as to enter the cylinder part 49 of a column shaft 48 (to protrude forward from the rear wall part 53 in the cylinder part 49) in the vehicle-mounted state (see A in FIGS. 6 and 7). The outer diameter dimension near the base part 21b (rear end) of the protrusion 21 is set smaller than the inner diameter dimension of the gas outflow hole 69a formed in the gas generator 65, and after the seal part 70 is split, it is configured to be insertable into the gas outflow hole 69a up to the region near the base part 21b (see B in FIG. 7). And in the embodiment, the compressed gas G0 (inflation gas G) enclosed in the gas enclosure part 57 flows into the airbag 26 through the through-hole part 22 of the protrusion 21 penetrating the gas outflow hole 69a and a gas flow path part 37 (to be described later) after the seal part 70 is split (see B and 9 in FIG. 7). The length dimension in the front-rear direction of the protrusion 21 (the protruding amount from the rear wall part 53 of the cylinder part 49 when the vehicle is mounted) is set slightly smaller than the length dimension in the front-rear direction of a buffer material 75 (to be described later), and the protrusion 21 is arranged so as to have a gap with the gas generator 65 (in a non-contact state with the seal part 70) in the vehicle-mounted state (see A in FIGS. 6 and 7).

[0019] In the embodiment, the handle main body 16 (handle 15) is attached to the column shaft 48 of the steering column 45 by connecting the region around the protrusion 21 in the boss core metal 19a to the rear end face side (the rear surface side of the rear wall portion 53) of the cylinder portion 49 in the column shaft 48.

[0020] As shown in FIG. 6, the airbag device 25 includes an airbag 26 that is folded and stored, a case 28 as a storage portion that stores and holds the airbag 26, an airbag cover 33 that covers the folded airbag 26, and a retainer 30 for attaching the airbag 26 to the case 28.

[0021] The airbag 26 is formed in a bag shape from a sheet body (specifically, a woven fabric made of polyester yarn, polyamide yarn, etc.) that is flexible and can be inflated by inflowing inflation gas therein. In the case of the embodiment, the airbag 26 is configured to inflate into a substantially disc shape that can cover the entire rear surface side of the ring portion 16a (see the two-dot chain line in FIG. 3). In the airbag 26, an inflow opening 26a for allowing the inflation gas G flowing out from the gas generator 65 to flow into the interior is formed at the center of the front surface side (front wall portion) when inflation is completed (see FIG. 6). The inflow opening 26a is formed to have a substantially circular opening, although detailed illustration is omitted.

[0022] The case 28 for housing the folded airbag 26 has a substantially box shape with an opening at the rear side (driver's side), and includes a bottom wall portion 28a disposed at the front end side and a substantially square tubular peripheral wall portion 28c extending rearward from the bottom wall portion 28a. A through hole 28b is formed at substantially the center of the bottom wall portion 28a corresponding to the inflow opening 26a formed in the airbag 26 (see FIG. 6). The airbag 26 has the peripheral edge portion of the inflow opening 26a attached to the peripheral edge portion of the through hole 28b in the bottom wall portion 28a of the case 28 using a retainer 30. The retainer 30 is capable of pressing the peripheral edge portion of the inflow opening 26a in the airbag 26, and has bolts 30a protruding at a plurality of radially arranged locations around the inflow opening 26a (specifically 4 locations, detailed illustration is omitted). Using these bolts 30a and nuts 31, the peripheral edge of the inflow opening 26a of the airbag 26 is connected to the peripheral edge portion of the through hole 28b in the bottom wall portion 28a of the case 28 and the rear end 37b of the gas flow path portion 37 described later.

[0023] The airbag cover 33 is made of synthetic resin and, as shown in FIG. 6, includes a ceiling wall portion 33a that covers the rear of the airbag 26 housed in the case 28, and a side wall portion 33b that extends forward from near the outer peripheral edge of the ceiling wall portion 33a and is attached to the peripheral wall portion 28c of the case 28. A door portion (reference numeral omitted) that is pushed open by the expanding airbag 26 is formed in the ceiling wall portion 33a.

[0024] This airbag device 25 is attached to the boss part core metal 19a using mounting bolts 35 (see Fig. 6) for attaching a horn switch (not shown). Although detailed illustration is omitted, these mounting bolts 35 are arranged at a plurality of radially extending positions centered around the center of the case 28 (through-hole 28b). Also, a gas flow path portion 37 for flowing the inflation gas G flowing out from the gas generator 65 toward the airbag 26 side is disposed between the airbag device 25 and the core metal 19 (boss part core metal 19a) (see Fig. 6). The gas flow path portion 37 is formed from a cylindrical body made of a flexible sheet body (specifically, in the case of the embodiment, a woven fabric made of polyester yarn, polyamide yarn, etc., similar to the airbag 26). The rear end 37b side of the gas flow path portion 37 is attached, as described above, together with the peripheral edge of the inflow opening 26a of the airbag 26, to the peripheral edge of the through-hole 28b in the bottom wall portion 28a of the case 28 using the retainer 30. The front end 37a side of the gas flow path portion 37 is attached using bolts 38 to a region near the protrusion 21 in the boss part core metal 19a (specifically, the peripheral edge of the through-hole portion 22 penetrating the protrusion 21). The bolts 38 for attaching the front end 37a side of the gas flow path portion 37 to the peripheral edge of the through-hole portion 22 in the boss part core metal 19a are arranged at four radially extending positions, although detailed illustration is omitted.

[0025] As shown in Figs. 3 and 4, the steering column 45 includes a column shaft 48 that constitutes the rotation center axis of the steering wheel 15, and a column cover 46 that covers the periphery of the region on the rear end side of the column shaft 48. The column cover 46 is made of synthetic resin and is configured to cover substantially the entire outer peripheral side of the region where the column shaft 48 protrudes rearward from the instrument panel (hereinafter abbreviated as "IP") 5.

[0026] The column shaft 48 is inclined downward to the front and, as shown in Figs. 3 and 4, includes a cylinder portion 49 disposed on the steering wheel 15 side (rear side) and a shaft body 58 disposed on the vehicle body side (front side) separated from the steering wheel 15.

[0027] As shown in FIGS. 4, 6, and 8, the cylinder portion 49 has a cylindrical peripheral wall portion 50, a front wall portion 51 and a rear wall portion 53 that close the front end side and the rear end side of the peripheral wall portion 50, and is formed in a cylindrical shape with both front and rear ends closed. In the case of the embodiment, an insertion hole 52 for inserting a main body shaft portion 59 of a shaft main body 58 described later is formed in the front wall portion 51 to open in a substantially hexagonal shape (see FIG. 5). An insertion hole 53a through which a protrusion 21 protruding from a boss portion core metal 19a can be inserted is formed in the rear wall portion 53 (see A in FIGS. 6 and 7). A concave portion 52a is provided on the inner peripheral surface of the insertion hole 52 formed in the front wall portion 51, and two O-rings 55 and 56 that fill the gap between the O-rings and the shaft main body 58 are disposed in the concave portion 52a (see FIG. 4). These O-rings 55 and 56 are disposed to ensure airtightness within the cylinder portion 49 when the inflation gas G flows out from the gas generator 65 to the airbag 26 side (in the case of the embodiment, when moving with respect to the peripheral wall portion 67 of the front wall portion 68 described later).

[0028] The shaft main body 58 includes a main body shaft portion 59 and a piston portion 60 formed to bulge from the main body shaft portion 59 on the rear end 58b side. In the case of the embodiment, the main body shaft portion 59 is formed in a substantially hexagonal column shape that can be inserted into an insertion hole 52 formed in the front wall portion 51 of the cylinder portion 49 (see FIG. 5). The piston portion 60 is disposed within the cylinder portion 49. The shaft main body 58 is configured to be rotatable together with the cylinder portion 49 when the cylinder portion 49 rotates during the rotation operation of the handle 15 by inserting the hexagonal column-shaped main body shaft portion 59 into the insertion hole 52 that opens in a hexagonal shape formed in the front wall portion 51 of the cylinder portion 49. Further, the shaft main body 58 is inserted into the insertion hole 52 so as to be slidable with respect to the cylinder portion 49. In the case of the embodiment, the piston portion 60 is formed in a substantially disc shape with a smaller diameter than the inner diameter dimension of the cylinder portion 49 (peripheral wall portion 50), and the outer diameter dimension is set to a dimension that can press a front wall portion 68 of the gas generator 65 described later and can pass through a peripheral wall portion 67 of the gas generator 65 described later (see A and B in FIG. 8).

[0029] As shown in FIG. 4, a gas generator 65 capable of supplying inflation gas to the airbag 26 is built into the cylinder portion 49. In the case of the embodiment, the gas generator 65 is configured by enclosing compressed gas G0 in a cylindrical enclosure container 66 with both ends closed. The enclosure container 66 is made of metal and includes a cylindrical peripheral wall portion 67, a front wall portion 68 that closes the front end side of the peripheral wall portion 67, and a rear wall portion 69 that closes the rear end side of the peripheral wall portion 67. The outer diameter dimension of the peripheral wall portion 67 of this gas generator 65 is set to be slightly smaller than the inner diameter dimension of the peripheral wall portion 50 in the cylinder portion 49 and to be slidable within the cylinder portion 49.

[0030] A gas outflow hole 69a through which the inflation gas G can flow out is provided in the rear wall portion 69 on the rear end face 65a side of the gas generator 65 (enclosure container 66), and this gas outflow hole 69a is closed by a seal portion 70 (see A in FIGS. 6 and 7). The seal portion 70 is formed of a metal foil and is configured to be cleavable so that it is pierced by the protrusion portion 21 when it comes into contact with the protrusion portion 21 during the rearward movement of the gas generator 65 (see B in FIG. 7). The gas outflow hole 69a is formed to open in a substantially circular shape at one location in the center of the rear wall portion 69. The inner diameter dimension of this gas outflow hole 69a is set to be such that the protrusion portion 21 can be inserted up to the region on the base portion 21b side, as described above. Further, in the embodiment, the gas generator 65 is housed in the cylinder portion 49 so as to provide a gap between it and the rear wall portion 53 of the cylinder portion 49. Specifically, the rear wall portion 69 is positioned forward of the tip 21a (front end) of the protrusion portion 21 (so as to provide a gap between it and the protrusion portion 21). When the gas generator 65 (enclosure container 66) is pressed by the piston portion 60, it moves rearward within the cylinder portion 49. Such movement is completed by the contact between the inner peripheral edge of the gas outflow hole 69a formed by cleaving the seal portion 70 and the outer peripheral surface of the base portion 21b side of the protrusion portion 21 (see B in FIG. 7).

[0031] The front wall portion 68 is separate from the peripheral wall portion 67 and is configured to be movable rearward with respect to the peripheral wall portion 67 when pressed by the piston portion 60 (see A and B in FIG. 8). In the case of the embodiment, the front wall portion 68 is provided with locking ribs 68b protruding forward on the outer peripheral edge 68a over substantially the entire circumference, and caulking portions 67b that surround the periphery (front and inner side) of the locking ribs 68b are provided on the front end 67a side of the peripheral wall portion 67, so that the outer peripheral edge 68a is locked to the front end 67a side of the peripheral wall portion 67, and thus the front wall portion 68 is connected to the peripheral wall portion 67. With such a configuration, the front wall portion 68 of the enclosed container 66 can maintain the locked state of the outer peripheral edge 68a to the peripheral wall portion 67 in the gas generator 65 in a state where compressed gas is enclosed inside, and when pressed by the piston portion 60, the locked state is released and it moves rearward with respect to the peripheral wall portion 67.

[0032] Within the cylinder portion 49, a cushioning material 75 is interposed between the gas generator 65 and the rear wall portion 53 (that is, between the gas generator 65 and the boss portion 16b disposed adjacent to the rear of the rear wall portion 53) (see A in FIGS. 6 and 7). This cushioning material 75 does not deform in the vehicle-mounted state and is configured to be plastically deformable while being compressed when pressed by the rear wall portion 69 of the gas generator 65. In the case of the embodiment, it is composed of a hard foam such as foamed polyurethane. Further, in the case of the embodiment, the cushioning material 75 is formed in a substantially cylindrical shape that can cover the outer peripheral side of the protrusion 21 over the entire circumference (the protrusion 21 can be inserted therein) and is disposed so as to fill the gap between the gas generator 65 and the rear wall portion 53. Also, as described above, the cushioning material 75 has a length dimension in the front-rear direction set to be slightly larger than the length dimension in the front-rear direction of the protrusion 21 (the amount of protrusion from the rear wall portion 53 of the cylinder portion 49 when mounted on the vehicle), and the front end face and the rear end face are respectively configured to abut against the rear end face 65a of the gas generator 65 (the rear surface of the rear wall portion 69) and the front surface of the rear wall portion 53 of the cylinder portion 49. This cushioning material 75, after the rearward movement of the gas generator 65 (when the inner peripheral edge of the gas outflow hole 69a comes into contact with the outer peripheral surface of the base portion 21b side of the protrusion 21 as described above), is crushed while being able to reduce the width dimension in the front-rear direction and will be disposed in the widened state between the rear wall portion 69 of the gas generator 65 and the rear wall portion 53 of the cylinder portion 49 (see B in FIG. 7).

[0033] In the embodiment, the column shaft 48 is supported by a bearing 80 in the region of the cylinder portion 49 (specifically, the region that protrudes rearward from the instrument panel 5 and is covered by the column cover 46 on the outer peripheral side) (see FIGS. 3 and 4). The bearing 80 is connected to a reinforcement 2, which is a member on the vehicle body 1 side, using a bracket 3. Further, as shown in FIG. 3, an intermediate shaft 9 is connected to the front end 58a side of the shaft body 58 via a universal joint 8. The intermediate shaft 9 is arranged to extend downward from the front end 58a of the shaft body 58, and a gearbox 12 is connected to the lower end side of the intermediate shaft 9 via a universal joint 11. The gearbox 12 is connected to the vehicle body 1 side of the vehicle V via a bracket (not shown), and is connected to the front wheels (reference numerals omitted) of the vehicle V via a ball joint or the like (not shown). When the shaft body 58 receives an impact force F (see FIGS. 2 and 3) acting on the vehicle V during a frontal collision of the vehicle V, it moves rearward (see B and 9 in FIG. 8).

[0034] In the steering wheel device S of the embodiment, when a frontal collision of the vehicle V occurs, the shaft body 58 of the steering column 45 itself is configured to move rearward in response to the impact force F acting on the vehicle V. Then, when a frontal collision of the vehicle V occurs, due to the rearward movement of the shaft body 58, the gas generator 65 disposed in the cylinder portion 49 of the column shaft 48 is caused to move rearward so as to be pressed by the piston portion 60 provided on the rear end 58b side of the shaft body 58. The rearwardly moved gas generator 65 comes into contact with the seal portion 70 provided on the rear end surface 65a against the protrusion 21 disposed in the region on the boss portion 16b side of the steering wheel 15. At this time, the protrusion 21 causes the seal portion 70 to split, and the gas generator 65 causes the inflation gas G to flow out from the gas outflow hole 69a formed by splitting the seal portion 70 (see B in FIG. 7). Then, the inflation gas G flows into the interior, and the airbag 26 inflates as shown by the two-dot chain line in FIGS. 9 and 3. That is, in the steering wheel device S of the embodiment, even if no sensor for operating the gas generator is provided in the vehicle, the inflation gas G can be caused to flow out from the gas generator 65 by utilizing the impact force acting on the vehicle V at the time of a frontal collision of the vehicle V, so that the airbag 26 can be inflated. Thus, a simple configuration can be achieved, and the driver D seated in the driver's seat DS can be protected by the inflated airbag 26.

[0035] Therefore, in the steering wheel device S of the embodiment, with a simple configuration, the driver D can be accurately protected.

[0036] Further, in the steering wheel device S of the embodiment, the enclosure 66 of the gas generator 65 includes a substantially cylindrical peripheral wall portion 67 and a front wall portion 68 that closes the front end 67a side of the peripheral wall portion 67. When the front wall portion 68 is pressed by the piston portion 60, the front wall portion 68 is configured to be movable rearward with respect to the peripheral wall portion 67. More specifically, in the steering wheel device S of the embodiment, when the front wall portion 68 starts to move rearward upon receiving the pressing force from the piston portion 60 (see B in FIG. 8), the movement of the front wall portion 68 further increases the internal pressure, causing the entire gas generator 65 to move rearward. As a result, the seal portion 70 provided on the rear wall portion 69 comes into contact with the protrusion portion 21 and tears open (see B in FIG. 7). Then, the inflation gas G flows out from the opened gas outflow hole 69a. Even after the rearward movement of the enclosure 66 (the peripheral wall portion 67 and the rear wall portion 69) is completed, the front wall portion 68 moves rearward within the peripheral wall portion 67 so as to absorb the rearward movement amount of the shaft body 58 (see FIG. 9). Therefore, in the steering wheel device S of the embodiment, even when the rearward movement amount of the shaft body 58 is large, in addition to the rearward movement of the gas generator 65 itself, by moving the front wall portion 68 rearward with respect to the peripheral wall portion 67, the rearward movement of the shaft body 58 can be absorbed, and it is possible to suppress the steering wheel 15 and the steering column 45 from moving rearward toward the driver D side during a frontal collision of the vehicle.

[0037] Further, as the gas generator 65A, one having the configuration shown in FIGS. 10 and 11 may be used. The gas generator 65A is configured to be compressible and deformable by the pressing force of the piston portion 60 after the seal portion 70 is cracked. Specifically, in the gas generator 65A, a metal enclosure 66A having compressed gas sealed therein includes a cylindrical peripheral wall portion 67A, a front wall portion 68A that closes the front end side of the peripheral wall portion 67A, and a rear wall portion 69A that closes the rear end side of the peripheral wall portion 67A. The front wall portion 68A is integrally formed with the peripheral wall portion 67A. And in this gas generator 65A, a bellows portion 85 is formed over substantially the entire length on the peripheral wall portion 67A (see FIG. 10). When the front wall portion 68A is pressed by the piston portion 60, the peripheral wall portion 67A is configured to compress the bellows portion 85 as shown in FIG. 11, thereby reducing the length dimension and being compressed and deformed. Therefore, even when the gas generator 65A having such a configuration is used and the amount of rearward movement of the shaft body 58 is large, the rearwardly moved gas generator 65A (specifically, the peripheral wall portion 67A in the enclosure 66A) is further compressed and deformed so as to reduce the length in the front-rear direction, thereby absorbing a certain amount of energy during a collision and absorbing such rearward movement of the shaft body 58. Therefore, even when the gas generator 65A having such a configuration is used, it is possible to suppress the steering wheel and the steering column from moving rearward toward the driver side during a frontal collision of the vehicle.

[0038] Note that, without considering such a point, as the gas generator, a configuration in which compressed gas is sealed in a cylindrical enclosure that simply closes both the front and rear ends without moving the front wall portion relative to the peripheral wall portion and without compressing and deforming the peripheral wall portion may be used. When using a gas generator having such a configuration, the gas generator can be moved rearward until the inner peripheral edge of the gas outflow hole abuts against the protrusion. However, after the inner peripheral edge of the gas outflow hole comes into contact with the protrusion, as the shaft body moves rearward, the cylinder portion, that is, the steering wheel connected to the cylinder portion, will move rearward through the gas generator.

[0039] Furthermore, in the steering wheel device S of the embodiment, the protrusion 21 is formed in a cylindrical shape through which the inflation gas G can pass, and is configured such that at least the tip 21a side can be inserted into the gas outlet hole 69a. Therefore, the inflation gas G flowing out from the gas outlet hole 69a that is opened by splitting the seal portion 70 can smoothly flow into the airbag 26 through the protrusion 21. If such a point is not considered, the protrusion may not be formed in a cylindrical (hollow) shape, but simply in a needle shape that can pierce the seal portion, and a separate flow path for flowing the inflation gas flowing out from the gas outlet hole may be provided.

[0040] In particular, in the steering wheel device S of the embodiment, since the protrusion 21 is configured to be insertable into the gas outlet hole 69a up to the vicinity of the base portion 21b, compared with the case where only the tip side of the protrusion can be inserted into the gas outlet hole, the amount of movement of the shaft body 58 relative to the cylinder portion 49 of the protrusion 21 can be ensured by the protruding amount (front - rear length) of the protrusion 21. Of course, if such a point is not considered, the protrusion may be configured such that only the tip side can be inserted into the gas outlet hole.

[0041] Furthermore, in the steering wheel device S of the embodiment, a buffer material 75 that can be plastically deformed when the gas generator 65 moves rearward is interposed between the gas generator 65 and the boss portion 16b (the rear wall portion 53 of the cylinder portion 49). Therefore, rattling around the gas generator 65 and the generation of abnormal noises during normal driving and the like can be accurately suppressed. In particular, in the steering wheel device S of the embodiment, the buffer material 75 is formed in a substantially cylindrical shape that can cover the outer peripheral side of the protrusion 21 over the entire circumference, and is disposed so as to fill the gap between the rear end face 65a of the gas generator 65 and the rear wall portion 53 of the cylinder portion 49. Therefore, in the vehicle - mounted state, it is possible to surely prevent the protrusion 21 from coming into contact with the cylinder portion 49, and it is possible to stably suppress the occurrence of rattling around the gas generator 65.

[0042] Note that, without disposing such a cushioning material, as shown in A and B of FIG. 12, an O-ring 82 may be disposed on the outer peripheral side near the rear end of the gas generator 65 (between the peripheral wall portion 50 in the cylinder portion 49) to restrict movement with respect to the cylinder portion 49 during normal driving or the like, and deform when the gas generator 65 is pressed by the piston portion 60 to allow rearward movement of the gas generator 65. Even with such a configuration using the O-ring 82, rattling around the gas generator 65 during normal driving or the like can be accurately suppressed.

[0043] The steering device S of the present invention is mounted on a single-seater electric vehicle. The single-seater electric vehicle has a body that is minimized and lightweight as much as possible, with a short distance from the front end of the body to the steering wheel, and no engine disposed in front of the driver's seat. However, even in such a vehicle, if the steering device S of the present invention is mounted, the airbag 26 can be inflated using the shaft body 58 that moves rearward during a frontal collision with an oncoming vehicle or an object, and a large rearward movement of the shaft body 58 can be suppressed. At the same time, the inflated airbag 26 can accurately protect the driver D. In particular, when the gas generators 65, 65A are configured to be compressed and deformed or the front wall portion is displaced as in the embodiment, the movement of the steering wheel 15 itself toward the driver D side can also be suppressed as the shaft body 58 moves, so it is more suitable for single-seater electric vehicles. Of course, the steering device of the present invention is not limited to single-seater electric vehicles and can also be mounted on multi-seater electric vehicles or the like.

Explanation of Reference Numerals

[0044] 15... Steering wheel, 16... Steering wheel body, 16b... Boss portion, 19... Shaft, 19a... Boss portion shaft, 21... Protrusion, 21a... Tip, 22... Through hole portion, 25... Airbag device, 26... Airbag, 45... Steering column, 48... Column shaft, 49... Cylinder portion, 58... Shaft body, 59... Piston portion, 65, 65A... Gas generator, 65a... Rear end face, 69a... Gas outflow hole, 70... Seal portion, 75... Cushioning material, 85... Bellows, S... Steering device.

Claims

1. A steering wheel device mounted on a vehicle, comprising a rotatable steering wheel and a steering column that pivotally supports the steering wheel, wherein an airbag is folded and stored in a region of a boss portion of the steering wheel. The steering column is attached to a region of the boss portion of the steering wheel and includes a column shaft that forms a rotation center axis of the steering wheel. The column shaft is provided on the steering wheel side and is configured as a substantially cylindrical cylinder portion incorporating a gas generator capable of supplying inflation gas to the airbag. is provided on the vehicle body side separated from the steering wheel and includes a shaft body having a piston portion disposed in the cylinder portion on the rear end side on the steering wheel side. is configured to include The gas generator is configured to enclose compressed gas therein and include a gas outflow hole closed by a seal portion on a rear end surface on the steering wheel side. In a region of the boss portion of the steering wheel, a protrusion that protrudes forward on the gas generator side and is capable of splitting the seal portion when contacting the seal portion is provided. The shaft body is configured to move rearward when receiving an impact force acting on the vehicle during a frontal collision of the vehicle. During a frontal collision of the vehicle, the gas generator is configured to move rearward and bring the seal portion into contact with the protrusion by being pressed by the piston portion of the shaft body that moves rearward.

2. The steering wheel device according to claim 1, wherein the gas generator is configured to be compressibly deformed by the pressing force of the piston portion.

3. The steering wheel device according to claim 1, wherein the gas generator includes a substantially cylindrical peripheral wall portion and a front wall portion that closes the front end side of the peripheral wall portion, and is configured such that the front wall portion can move rearward with respect to the peripheral wall portion when pressed by the piston portion.

4. The steering wheel device according to any one of claims 1 to 3, wherein the protrusion is formed in a cylindrical shape through which the inflation gas can pass and is configured such that at least the tip side can be inserted into the gas outflow hole.

5. The handle device according to claim 1, characterized in that a buffer material that can be plastically deformed when the gas generator moves rearward is interposed between the gas generator and the boss portion.

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