JPH0952565A - Lower cover for steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lower cover which little prevents the deformation of a spoke according to the impact on a steering wheel, and in which the spoke can sufficiently demonstrate the impact mitigating function. SOLUTION: A lower cover 19 stores a spoke having an impact mitigating part 18 so as to mitigate the impact through the deformation when the impact is applied to a steering wheel 11. A part of the lower cover 19 which is close to the impact mitigating part 18 is provided with a pass permitting part which is less in the strength compared with other parts, broken through the contact with the impact mitigating part 18, and permits the pass of the impact mitigating part 18. The impact mitigating part 18 is long, and bent toward a side wall part 22 of the lower cover 19 when the impact is applied. The pass permitting part consists of a thin-walled part 27 extending in the longitudinal direction of the impact mitigating part 18 before deformation in the lower cover 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel of a vehicle or the like, and a lower cover for accommodating a spoke having a shock absorbing portion which is deformed when a shock is applied to absorb the shock. .

[0002]

2. Description of the Related Art Hitherto, in the field of vehicles, various techniques have been proposed and put into practical use for mitigating the impact when the steering wheel is impacted. As one of them, there is one that tries to mitigate the impact by retracting the spokes forming a part of the steering wheel. In this technique, as shown in FIGS. 5 and 6, a boss 53 is provided on a bottom portion 52 of a resin lower cover 51, and spokes 54 are fastened thereto by bolts 55 or the like. An annular thin portion 56 is formed around the boss 53 in the bottom portion 52.
Are formed, and the strength is lower than other parts. When an impact is applied to the steering wheel 57 from the front, the impact is transmitted to the lower cover 51 via the spoke 54 and the boss 53. The thin portion 56 breaks, the boss 53 falls off the bottom portion 52, and the spoke 54 retracts.

[0003]

However, in the prior art described above, although the impact applied to the steering wheel 57 can be alleviated to some extent by the boss 53 coming off from the lower cover 51, the intermediate portion 54a of the spoke 54 is affected by the impact. If an attempt is made to bend toward the side wall portion 58, the impact may not be sufficiently mitigated. This is because if the intermediate portion 54a of the spoke 54 comes into contact with the side wall portion 58 of the lower cover 51 during its deformation, the side wall portion 58 prevents further deformation of the spoke 54. Therefore, in this case, there is a problem that the intended impact mitigation effect cannot be obtained.

The present invention has been made in view of the above-described circumstances, and an object thereof is to prevent deformation of the spokes in response to an impact on the steering wheel and prevent the spokes from sufficiently exerting an impact absorbing function. It is to provide a lower cover for a steering wheel that can be used.

[0005]

In order to achieve the above object, a first aspect of the present invention according to claim 1 is that when a shock is applied to the steering wheel, the steering wheel is deformed to absorb the shock. For accommodating a spoke having a portion, and at a location near the shock absorbing portion,
A passage permitting portion is provided that has lower strength than other portions and is broken by contact with the impact absorbing portion and is allowed to pass through the impact absorbing portion.

When a shock is applied to the steering wheel using the lower cover of the first invention, the shock absorbing portions of the spokes are deformed in response to the shock, and the shock is attempted to be alleviated. During this deformation, the shock absorbing portion comes into contact with the passage permitting portion of the lower cover. Since the strength of the passage permitting portion is lower than the strength of other portions of the lower cover, the passage permitting portion is broken by the load caused by the contact, and the passage of the impact relaxation portion is permitted. Therefore, even though the passage permitting portion is located in the vicinity of the impact absorbing portion, it is unlikely to hinder the deformation of the impact absorbing portion. As a result, the shock absorbing portion projects from the broken passage permitting portion and is deformed as intended, effectively absorbing the impact applied to the steering wheel.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the impact absorbing portion has a long shape and bends toward the lower cover when an impact is applied. The passage permitting portion is composed of a thin portion extending along the length direction of the impact absorbing portion before deformation in the lower cover.

According to the second aspect of the invention, when a shock is applied to the steering wheel, the elongated shock absorbing portion bends toward the lower cover. The impact absorbing portion comes into contact with the lower cover during the bending. The thin portion is broken by the load caused by the contact at this time. At this time, since the thin-walled portion extends along the length direction of the shock absorbing portion before deformation, the thin-walled portion breaks along the same direction. The lower cover is expanded at this break portion, and the shock absorbing portion passes through the portion. At this time, the impact absorbing portion can pass through the passage permitting portion only by expanding the fractured portion of the lower cover so that the width of the expanding portion is slightly larger than the width of the impact absorbing portion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment in which the first and second inventions are embodied will be described below with reference to FIGS.

As shown in FIGS. 1 and 3, a boss plate 12 of a steering wheel 11 is mounted on a steering shaft (not shown) rotatably supported by the vehicle. A plurality of elongated spokes 13 (for example, 4) are fixed to the boss plate 12 at their base end portions 14, respectively. The body portion 15 following these base end portions 14 is bent, and the front side (the left side in FIG. 1) is formed so that the distance from the body portions 15 of the other spokes 13 increases toward the tip side.
Extending towards. The tip of each body portion 15 is fixed to a ring portion 16 located in front of the boss plate 12. About half of each main body 15 on the tip side and the entire ring 16 are covered with a coating layer 17 made of synthetic resin, and about half of each main body 15 on the base end side is exposed. When the steering wheel 11 is impacted from the front, the exposed portion of the main body portion 15 of the plurality of spokes 13 located below is bent and deformed outward (downward in the figure) to prevent the impact. It is a shock absorbing portion 18 for relaxing.

A lower cover 19 for accommodating the shock absorbing portion 18 is arranged outside the shock absorbing portion 18. The lower cover 19 includes a substantially annular bottom portion 21 that is located on the rear side of the base end portion 14 of the spoke 13 and around the boss plate 12,
It is composed of a side wall portion 22 located near the outside of each impact absorbing portion 18. A boss 23 is projectingly provided on the bottom portion 21, and the base end portion 14 of the spoke 13 is fastened thereto by a bolt 24. A locking projection 25 is formed at the tip of the side wall portion 22, and the projection 25 is locked in the recess 26 of the coating layer 17.

A portion of the lower cover 19 near the impact absorbing portion 18 has a lower strength than the other portions, and a passage permitting portion which is broken by contact with the impact absorbing portion 18 and allows the impact absorbing portion 18 to pass therethrough. Is provided. The passage permitting portion here has a constant width w and a constant thickness t (see FIG. 2), and is configured by a thin portion 27 extending along the length direction of the pre-deformation impact absorbing portion 18 in the sidewall portion 22 and the bottom portion 21. Has been done. One end of the thin portion 27 is located at the inner end 21a of the bottom portion 21, and the other end is located at the outer end 22a of the side wall portion 22. Further, the portions near both sides of the thin portion 27 are a pair of inclined portions 28 whose thickness gradually decreases as they approach the thin portion 27.

The member indicated by the chain double-dashed line in FIG. 1 is a pad 29 that elastically deforms when a pressing force is applied by the driver of the vehicle. In the space on the rear side of the pad 29, a horn switch, an energy absorbing member (neither is shown), etc. are arranged.

When the steering wheel 11 incorporating the lower cover 19 is used normally, the lower cover 19 is also used.
Thus, the base end portions 14 of the spokes 13 and the impact absorbing portion 18 are covered. In addition, when an impact is applied to the steering wheel 11 from the front, the spokes 1 respond to the impact.
The impact absorbing portion 18 of No. 3 bends to the side wall portion 22 side (lower side in the figure) as shown by the chain double-dashed line in FIG. During this bending, the shock absorbing portion 18 contacts the thin portion 27 of the lower cover 19. Since the strength of the thin portion 27 is lower than the strength of the other portions of the lower cover 19, the thin portion 27 is broken by the load caused by the contact, and the lower cover 19 is expanded at the breaking portion, so that the shock absorbing portion 18 Is allowed to pass. Therefore, although the thin portion 27 is located in the vicinity of the shock absorbing portion 18,
It is unlikely that the shock absorbing portion 18 will be hindered from bending. As a result, the shock absorbing portion 18 protrudes from the broken thin wall portion 27 and is deformed, so that the shock to the steering wheel 11 is reduced.

Here, if the thin portion 27 is the shock absorbing portion 18,
When extending in a direction intersecting the length direction of the impact absorbing portion 18, for example, in a direction orthogonal thereto, the impact absorbing portion 18 must expand the fractured side wall portion 22 by an amount greater than the width of the impact absorbing portion 18. For example, it cannot stick out from the lower cover 19. However, in the present embodiment, since the thin portion 27 extends along the length direction of the shock absorbing portion 18 before deformation, when a shock is applied to the steering wheel 11, the bottom portion 21 and the side wall portion 22 move in the same direction. Fracture along. The fractured portion is expanded, and the shock absorbing portion 18 passes through the expanded portion. The width of the expanded portion of the shock absorbing portion 18 is the same as that of the shock absorbing portion 1.
It is possible to pass by simply expanding the thin portion 27 so as to be slightly larger than the width of 8. Therefore, the energy taken for the expansion can be minimized, and the shock absorbing portion 18 can be deformed as intended to efficiently absorb the impact on the steering wheel 11.

The present invention can be embodied in another embodiment shown below. You may change the shape of the thin part 27 and its vicinity part suitably. For example, as shown in FIG. 4 (a), a pair of inclined portions 28 are directly connected to each other at a portion having the smallest wall thickness, and the connecting portion is a thin portion 27, or as shown in FIG. 4 (b). Both inclined portions 28 may be omitted. As shown in FIG. 4C, the thin portion 27 may be formed at an intermediate portion of the lower cover 19 in the thickness direction. Further, as shown in FIG. 4D, a groove 30 extending along the thin portion 27 may be formed near the side of the thin portion 27. In this case, the lower cover 19 is easily bent outward at the bottom of the groove 30 when the thin portion 27 is broken and the shock absorbing portion 18 passes. Therefore, the lower cover 1
As compared with the case where 9 is not bent, the force that tries to obstruct the passage of the shock absorbing portion 18 is further reduced.
Is more easily deformed.

[0017]

As described above in detail, when the lower cover of the first invention is used, the shock absorbing portion of the spoke is covered during normal use of the steering wheel, and when the impact is applied to the steering wheel, the shock absorbing portion is provided. It is easily broken by contact and allows passage along with the deformation of the shock absorbing part. Therefore, the deformation of the spokes due to the impact on the steering wheel is less likely to be hindered,
It is possible to fully exert the shock absorbing function on the spokes.

According to the second invention, in addition to the effect of the first invention, it is possible to break the lower cover in the thin portion in accordance with the deformation of the shock absorbing portion of the spoke. The shock absorbing portion can be projected from the lower cover without widening the broken portion. Therefore, it is possible to minimize the energy taken for the expansion and to deform the impact absorbing portion as intended to efficiently absorb the impact on the steering wheel.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of a steering wheel in which a lower cover is incorporated.

2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a partial front view of a lower cover.

FIG. 4A to FIG. 4D are partial cross-sectional views showing another form of the thin portion.

FIG. 5 is a partial front view of a conventional lower cover.

6 is an enlarged sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

11 ... Steering wheel, 13 ... Spoke, 18 ...
Impact absorbing portion, 19 ... Lower cover, 27 ... Thin wall portion as passage permitting portion.

Claims (2)

[Claims] 1. A housing for accommodating a spoke (13) having a shock absorbing portion (18), which is deformed when a shock is applied to a steering wheel (11) and absorbs the shock. The strength of the portion close to the shock absorbing portion (18) is lower than that of the other portion, and the shock absorbing portion (18) is broken due to contact with the shock absorbing portion (18).
A lower cover for a steering wheel provided with a passage permitting portion (27) for permitting passage of the vehicle. 2. The impact absorbing portion (18) has a long shape and bends toward the lower cover (19) when an impact is applied, and the passage permitting portion is deformed in the lower cover (19). The steering wheel lower cover according to claim 1, wherein the lower cover for a steering wheel comprises a thin portion (27) extending along a length direction of the front impact absorbing portion (18).