JP3431008B2 - Steering wheel with airbag device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering wheel provided with an airbag device for a vehicle, and more particularly to a three-spoke type steering wheel provided with an airbag device.

Unless otherwise specified, the up-down direction in this specification means the up-down direction along the axial direction of the steering shaft when the steering wheel is mounted on the vehicle. Unless otherwise specified, refers to the front, rear, left, and right directions of the vehicle along the direction orthogonal to the axis of the steering shaft during straight steering after the steering wheel is mounted on the vehicle.

[0003]

2. Description of the Related Art Conventionally, in a three-spoke steering wheel equipped with an air bag device, a steering wheel core metal of a steering wheel main body is used as known from Japanese Patent Application Laid-Open No. 10-100907. A ring mandrel arranged in the ring part for gripping during steering, a boss mandrel connected to the steering shaft, and a spoke mandrel connecting the boss mandrel and the ring mandrel, Was composed of. The spoke cores extend left and right from the boss core and are connected to the ring core, and the left front and right front cores extend from the boss core to the rear and are connected to the ring core. And a rear core metal part.

A covering layer made of a synthetic resin or the like is provided on the ring mandrel and the spoke mandrel near the ring mandrel in order to improve the feel. The airbag device was arranged at the upper center of the steering wheel body so as to cover the portion of the rear core metal portion where the coating layer was not formed.

In this air bag device, when the spoke cores are connected and supported, the rigidity of each part of the spoke cores becomes high and it becomes difficult to self-align. Therefore, the spoke cores are difficult to align. It was connected and supported at two places, the left front and right front core metal parts.

The self-aligning means the ring portion which is the upper surface side of the ring portion when a substantially horizontal frontal impact force acts on the rear portion of the ring portion of the steering wheel after the vehicle is mounted. It refers to plastically deforming the steering wheel core metal so that the surface approaches the vertical surface.

However, even if the airbag device is connected and supported at two positions of the left front and right front core bars of the spoke core bar, plastic deformation of the left front and right front core bars is insufficient during self-aligning. If so, the upper surface of the airbag device may not approach the vertical plane, and in the conventional steering wheel, the upper surface of the airbag device at the time of self-aligning is
There was room for improvement in that it was displaced following the ring surface.

The present invention solves the above-mentioned problems, and provides a steering wheel provided with an airbag device which makes it easy for the upper surface of the airbag device during self-aligning to follow the displacement of the ring surface. The purpose is to provide.

[0009]

A steering wheel according to the present invention comprises a ring core metal bar arranged in a ring part for the steering wheel main body to grip during steering,
A steering wheel core metal comprising a boss core metal connected to the steering shaft and a spoke core metal connecting the boss core metal and the ring core metal, the spoke core metal A left front / right front core bar extending from the boss core to the left and right sides and connected to the ring core, and a rear front extending from the boss core to the rear and connecting to the ring core An air bag device, which comprises a core metal part and is connected to and supported by the spoke core metal, is disposed above the steering wheel body, and plastically deforms the steering wheel core metal during self-alignment. And a steering wheel provided with a three-spoke type airbag device capable of displacing the ring portion surface so as to approach the vertical surface, wherein the front portion of the rear core metal portion is bifurcated in the left-right direction. Branches into two branches which are connected respectively to front left front-right front cored bar is formed,
The airbag device is coupled and supported only to the two branch portions, and a portion in front of the coupling support portion of the airbag device in the two branch portions is configured to be plastically deformable during self-aligning. Characterize.

The two branching portions are arranged with their front end sides facing downward so that they are respectively disposed above the connecting portions with the left front and right front cored bar portions, and the two branching portions are respectively attached to the left front and right front cored bar portions. It is desirable to connect them.

[0011]

In the steering wheel according to the present invention, the airbag device at the two branch portions during self-alignment in which a substantially horizontal frontal impact force acts on the rear portion of the ring portion after the vehicle is mounted. Since the front part of the connection support part of the plastic deformation, the rear part of the rear core metal part from the plastic deformation part is displaced together with the ring core metal, and the rear part of the rear core metal part
Only, the airbag device connected and supported will also be displaced following the ring surface.

Therefore, in the steering wheel according to the present invention, the upper surface of the airbag device during self-alignment can easily follow the displacement of the ring surface.

In the steering wheel according to the present invention, the airbag device is connected and supported only at the two branch portions.
Since the airbag device is not connected to and supported by the left front and right front core metal parts of the spoke core metal, the boss holes and the like conventionally provided for attaching the air bag device are not required. Therefore, it is not necessary to provide means (ribs, etc.) for preventing lowering of rigidity due to the provision of these boss holes, etc., on these two front left and front right core bar portions. It is possible to reduce the weight and cost.

Further, as described in claim 2, the two front end sides are arranged downward so that each of the two branch portions is disposed above the connection portion with the left front and right front cored bar portions. If it is configured so that it is connected to the left front and right front cores, interference with the column side of the steering wheel core during self-alignment can be reduced as much as possible, and the ring surface becomes more vertical. It can be self-aligned as it approaches.

That is, at the time of self-aligning, the front portion of the connecting portion of the airbag device at the two branch portions is plastically deformed, so that the rear portion of the plastic deformation portion of each branch portion is the plastic deformation portion. It will be displaced downward so as to rotate about. However, each branch part is located above the connection part with the left front / right front core metal part, and the part behind the plastic deformation part in each branch part is located as much as possible on the upper side, This is because it is less likely to interfere with the column side.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, the steering wheel W of the embodiment has a ring portion R gripped at the time of steering in an annular shape, a boss portion B arranged at the center of the ring portion R, and a ring portion R. Three spokes S that connect to the boss B
The steering wheel body 1 and the airbag device 20 arranged above the boss B are arranged on the components.

The steering wheel body 1 includes a steering wheel core metal 2 arranged so as to connect the ring portion R, the boss portion B, and the spoke portion S, and a lower cover 17 so as to cover the lower portion of the boss portion B. It is configured with.

The steering wheel core metal 2 is shown in FIG.
As shown in FIGS. 6 and 7, the ring portion core metal 3 arranged in the ring portion R and having an inverted U-shaped cross section, and the steering shaft 40.
(See FIGS. 2 and 8), the boss core metal 4 and the three spoke core cores 5 connecting the boss core metal 4 and the ring core metal 3 to each other. The ring core metal 3 and each spoke core metal 5 on the ring core metal 3 side are covered with a synthetic resin coating layer 15.

The boss core metal 4 is the steering shaft 4.
It is made of a steel boss 4a connected to 0 and an aluminum alloy / magnesium alloy etc. which is die-cast integrally with the ring core metal 3 and the spoke core metal 5 so as to cover the periphery of the boss 4a in a cylindrical shape. And a covering portion 4b.

The spoke cores 5 are arranged so as to extend from the cover 4b of the boss core 4 to the ring core 3 side obliquely above and extend from the cover 4b to the left and right sides. And a front left and right front cored bar portions 6 and 7 connected to the ring cored bar 3 and a rear cored bar 8 extending rearward from the covering part 4b and connected to the ring cored bar 3. Has been done.

The left front and right front core bars 6 and 7 are respectively
At the end on the side of the core metal 3 of the ring portion, the deformable portion 6 having a narrow width is formed.
a * 7a is formed. These planned deformation parts 6a
The portion 7a is a portion that causes stress concentration during the self-aligning and is torsionally plastically deformed. In addition, the steering shaft 4 is provided on the boss core 4 side of each front core 6 and 7.
The puller hole used when removing from 0 is formed. Incidentally, 6c and 7c are mounting holes for screwing the lower cover 17.

The rear mandrel portion 8 occupies the portion of the latter half,
A single plate-shaped main body 9 connected to the ring core 3;
It occupies substantially the front half of the body, and bifurcates in the left-right direction from the front end of the main body 9 to form the front end 11a at the left front / right front core bar 6
・ Two branch parts 10 ・ 10 connected to 7 respectively,
It consists of

The respective branch portions 10 are located in the vicinity of the boss core metal bar 4 in the left front / right front core metal parts 6 and 7 so as to be disposed above the connecting portions 11a with the left front / right front core metal parts 6 and 7, respectively. Longitudinal portions 11 extending upward from the rear edge of each
From the upper end 11b of the horizontal portion 12 toward the rear of the ring core metal 3 side while approaching each other, and the rear end 12e of the horizontal portion 12
The rear plate portion 1 which is slightly lowered from and is connected to the main body portion 9
3 and.

A rectangular plate-shaped mounting plate portion 12a extending downward is provided on each inner side edge of each lateral frame portion 12 on the side facing each other, and the airbag device 20 is mounted on each mounting plate portion 12a. Mounting hole 1 for inserting mounting bolt 18 for connecting and supporting
2b is formed. Each mounting plate portion 12a has a lower end 12
d is arranged above the lower end (front end) 11a of the longitudinal bone portion 11 connected to the left front and right front cored bar portions 6 and 7.

Further, each mounting plate portion 12a is brought into contact with and supported by a connecting piece portion 37 of a support plate 32 which will be described later.
The airbag device 20 is attached to the steering wheel body 1 mounted on the inclined steering shaft 40.
When connecting and supporting the parts, the connecting pieces 37 of the supporting plate 32, which will be described later, on the side of the airbag device 20 approach each other toward the rear side so that they can be stably abutted and supported, and the boss core bar 4 side Is formed so as to approach. In the case of the embodiment, in a state where the steering wheel body 1 is mounted on the inclined steering shaft 40, the substantial center between the mounting plate portions 12a is substantially lower than the center of gravity of the airbag device 20 in the vertical direction or slightly. Each mounting plate portion 12a is configured so that the airbag device 20 does not drop from the steering wheel body 1 even if the airbag device 20 is placed at the rear position and the hand is released from the airbag device 20.

Further, in the embodiment, each vertical frame portion 11 is constructed so as to be rapidly raised from the left front and right front core metal portions 6 and 7 so that stress concentration is likely to occur, and each vertical frame portion 11 faces downward. The front end 11a is a plastically deformable portion 14 that rotates below the rear core metal portion 8 during self-alignment.

As shown in FIGS. 2 and 3, the airbag device 20 comprises an inflatable bag-shaped airbag 21,
An inflator 23 that supplies inflation gas to the airbag 21, a pad 24 that covers the folded airbag 21,
The steering wheel body 1 includes the bag holder 25 that holds the airbag 21, the inflator 23, and the pad 24, the horn switch mechanism 30, and the airbag device 20.
And a support plate 32 for connecting and supporting to the.

The inflator 23 has a substantially cylindrical main body portion 23a having a gas discharge port 23b on its upper portion, and a main body portion 23.
and a flange portion 23c protruding from the outer peripheral surface of a.

The pad 24 is made of a synthetic resin, and a ceiling wall portion 24 that breaks a predetermined portion when the airbag 21 is inflated.
a and a side wall portion 24b having a substantially hexagonal tubular shape extending downward from the vicinity of the outer peripheral edge of the ceiling wall portion 24a. On the inner peripheral surface of the side wall portion 24b, locking claws 27 provided on a side wall portion 27 of a bag holder 25 described later are provided at predetermined positions.
A locking portion 24c (see FIG. 2) for locking a is formed. Further, on the lower surface of the ceiling wall portion 24a, a plurality of ribs (not shown) that come into contact with a mounting piece portion 28 of the bag holder 25 described later are formed.

In order to hold the airbag 21 and the inflator 23 by the bag holder 25, the annular retainer 22 arranged in the airbag 21 is provided with a plurality of bolts 22a extending downward, and these bolts 22a are attached to the airbag 21. The bag holder 25 and the flange portion 23c of the inflator 23 are passed through and the nut 22b is fixed to the bag holder 25. The pad holder 24 is held by the bag holder 25 by the rivet 29 of the pad side wall portion 24b and the locking claw 27a being locked to the locking portion 24c.

As shown in FIGS. 1 to 4, the bag holder 25 is made of die casting made of magnesium or the like in consideration of weight saving and shape shaping, and the inflator main body 2 is provided at the center.
The horizontal plate portion 26 is provided with an insertion hole 26a into which the 3a can be inserted from below, and side wall portions 27 extending vertically from the left and right sides near the front edge side and the rear edge of the horizontal plate portion 26. . The retainer 2 is provided around the insertion hole 26a of the lateral plate portion 26.
A through hole 26b is formed to insert each of the two bolts 22a.

A locking claw 27a that is locked to the locking portion 24c of the pad side wall 24b is formed at a predetermined position on each side wall 27, and the pad side wall 24b is fixed by a rivet 29 at a predetermined position. A mounting hole 27b (see FIG. 2) for forming is formed.

At the upper end of each side wall portion 27, three mounting piece portions 28 extending laterally outward are formed, and each of these mounting piece portions 28 is mounted on a supporting plate 32 at a lower position thereof, which will be described later. A portion where the horn switch mechanism 30 is disposed is provided between the mounting piece portion 28 and the portion 35, and a screw hole 28a for fastening a stepped bolt 30d of the horn switch mechanism 30, which will be described later, is formed in each mounting piece portion 28. .

A lead wire (not shown) is connected to the bag holder 25 so as to be electrically connected to the positive electrode side of the horn operation circuit.

As shown in FIGS. 1 to 3, the horn switch mechanism 30 is arranged at three positions on the back surface side of the periphery of the pad 24 in the vicinity of the spokes S and supports the attachment pieces 28 of the bag holder 25. The plate 32 is arranged between each of the mounting pieces 35. Then, each horn switch mechanism 30 is operated by pressing the pad 24 to contact the contact points 30.
The a and 30b are brought into contact with each other to operate the horn. In addition, each horn switch mechanism 30
Is the contact 3 due to the coil spring 30c when the horn is not operating.
The contacts 0a and 30b are separated from each other, and the contact bolts 30a and 30b are separated from each other by a stepped bolt 30d with a washer. The stepped bolts 30d are attached to the mounting piece 2 of the bag holder 25 from below the mounting piece 35 of the support plate 32.
8 is screwed into the screw hole 28a.

The support plate 32 is made of sheet metal and is shown in FIG.
As shown in FIGS. 3 to 5, a U-shaped connecting rod portion 33 when viewed from above, and three vertical plate portions 34 extending upward from positions near the respective attachment piece portions 28 of the bag holder 25 in the connecting rod portion 33.
And three attachment piece portions 35 that extend laterally outward from the upper ends of the vertical plate portions 34 and that are arranged below the attachment piece portions 28,
The connecting rod portion 33 is provided with connecting piece portions 37 that extend downward from the inner edges of the left and right sides of the connecting rod portion 33.

At the center of each mounting piece 35, there is formed a mounting hole 35a which is opened in a shape such that the oblique side of a substantially right-angled triangular hole is attached to both edges of the circular hole at symmetrical positions. The stepped bolt 30d of the horn switch mechanism 30 is inserted through each of the mounting holes 35a. Further, on the outer edge side of each attachment piece portion 35, an abutment piece portion 36 that abuts and is supported by the coating layer 15 of each spoke portion S is formed.

A nut 37b is fixed to each of the connecting piece portions 37 on the mutually opposing surface side, and the airbag device 20 is fixed to the mounting plate portion 12a of each lateral plate portion 12 of the spoke core metal 5 with the bolt 18. A connecting hole 37a is formed to allow the connection.

To mount the steering wheel W of the embodiment on a vehicle, the lower cover 17 is screwed to the steering wheel core metal 1 on which the coating layer 15 has been formed by die casting, and in that state. The steering wheel body 1 is attached to the steering shaft 40 of the vehicle by externally fitting the boss 4a of the boss core metal 4 and fixing the nut 41. The steering shaft 40 is inclined by about 30 ° from the horizontal direction so that the upper end faces upward.

The lead wire (not shown) of the horn switch mechanism 30 extending from the airbag device 20 is connected to a connector (not shown) on the steering wheel body 1 side, and the airbag device 20 is assembled in advance.
The contact piece portions 36 of the support plate 32 of FIG. 3 are brought into contact with and supported by the coating layer 15 of the spoke portion S, and the connecting piece portions 37, 37 are attached to the mounting plate portions of the branch portions 10 of the rear core metal portion 8. The inner surface 12c of 12a is brought into contact.

Next, the mounting bolts 18 are inserted from the insertion holes 17a of the lower cover 17 to the mounting holes 12 of the mounting plate portion 12a.
The steering wheel W can be assembled and attached to the steering shaft 40 by being screwed into the connection hole 37a of the connection piece portion 37 via b.

In the steering wheel W assembled as described above, the pad 24 is pushed to push the airbag device 2
If 0 is pushed down, it resists the biasing force of the coil spring 39,
The contact 30a of the horn switch mechanism 30 comes into contact with the contact 30b, and the horn is operated.

If the inflator 23 operates,
The inflation gas from the inflator 23 is the airbag 21.
When the air bag 21 flows in, the ceiling wall portion 24a of the pad 24 is pushed open and greatly expanded.

When an impact force F to the front side in the substantially horizontal direction acts on the rear portion Rb of the ring portion after mounting on the vehicle, as shown by the chain double-dashed line in FIGS. Left front and right front core metal parts 6 and 7 deformation target parts 6a and 7
a is twisted and plastically deformed, and a portion 11a in front of the connecting support portion 12a of the airbag device 20 in each branch portion 10 of the rear core metal portion 8 has a crossing angle between the front core metal portions 6 and 7 and the vertical frame portion 11. Since the plastic deformation is performed so as to widen the area, the rear core metal portion 8 has a rear portion 1 with respect to the plastic deformation portion 11a (14).
2.13.9 will be displaced together with the ring core 3, and the airbag device 20 connected and supported only to the rear portion 12a of the rear core 8 will also follow the ring surface P. Will be displaced.

Therefore, in the steering wheel W of the embodiment, the airbag device 2 during self-alignment is used.
The upper surface 20a of 0 can easily follow the displacement of the ring surface P.

Further, in the embodiment, the two branch portions 10
The air bag device 20 is connected and supported only to the air bag device 10, and the air bag device 20 is not connected and supported to the left front and right front metal core parts 6 and 7 of the spoke core metal 5, so that the air bag conventionally provided in these There is no need for a boss hole for mounting the device. Therefore, it is not necessary to provide any means (ribs or the like) for preventing lowering of rigidity due to the provision of these boss holes or the like on these two left front and right front core metal parts 6 and 7. It is also possible to reduce the weight of the wheel core metal 1 and reduce the cost.

Then, in the steering wheel W of the embodiment, the two branch portions 10 and 10 are provided at the left front and
A vertical frame part 11 extending upward from the left front / right front core bar parts 6 and 7 so as to be arranged above the connection part 11a with the right front core bar parts 6 and 7, and a ring part from the upper end 11b of the vertical frame part 11. The cross section 12 that is directed toward the core metal 3 side is provided, and the airbag device 20 is coupled and supported by the mounting plate portions 12a and 12a located above the coupling portion 11a. for that reason,
Plastic deformation portion 14 (11
The rearward portion 12.13.9 a) is the plastic deformation portion 1
Even if it is displaced downward so as to rotate about 4, the plastic deformation portion 1 in each branch portion 10
Since the parts 12, 13 and 9 on the rear side of 4 are located on the upper side as much as possible, it is difficult to interfere with the column C side, and the ring surface P is self-aligned so as to be closer to the vertical surface. It will be possible.

Of course, the connecting plate portions 12a, 12a for connecting and supporting the airbag device 20 are also located above the connecting portion 11a, and the connecting piece of the support plate 32 is such that the airbag device 20 is the lower end portion thereof. In the part of part 37,
Since it is connected to and supported by the connecting plates 12a and 12a, the airbag device 20 itself is less likely to interfere with the column C side during self-alignment, and the ring surface P can be made closer to the vertical plane. Become.

In the embodiment, at the time of self-aligning, the lower end (front end) 1 of the longitudinal bone portion 11 in each branch portion 10
Although 1a is the plastic deformation portion 14, the plastic deformation portion may be formed in the vicinity of the upper end 11b of the longitudinal bone portion 11 which intersects with the horizontal bone portion 12. Further, a plastically deformed portion may be provided near the vertical middle portion of the longitudinal bone portion 11 by changing the cross-sectional area or bending so that the longitudinal bone portion 11 can be bent and plastically deformed.

Further, although it is easy to interfere with the column C side, the left front and right front cored bar portions 6 in which the vertical ribs 11 are not provided are provided.
・ Branch part 10 ・ 1 so as to extend rearward from the rear edge side of 7.
You may comprise 0.

[Brief description of drawings]

FIG. 1 is a plan view of a steering wheel according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of the steering wheel of the same embodiment, showing a II-II portion in FIG. 1.

FIG. 3 is a schematic cross-sectional view of the steering wheel,
The III-III site | part of FIG. 1 is shown.

FIG. 4 is a plan view of a bag holder used in the airbag device of the same embodiment.

FIG. 5 is a plan view of a support plate used in the airbag device of the same embodiment.

FIG. 6 is a plan view of a steering wheel core metal according to the same embodiment.

FIG. 7 is a perspective view illustrating plastic deformation of the steering wheel core metal of the embodiment.

FIG. 8 is a schematic cross-sectional view illustrating the steering wheel of the same embodiment during self-alignment.

[Explanation of symbols]

1 ... Steering wheel body, 2 ... Steering wheel core, 3 ... Ring core 4 ... boss core metal, 5 ... Spoke core 6 ... left front core metal part, 7 ... right front core metal part, 8 ... rear core metal part, 10 ... branch, 11a ... front end (lower end), 12a ... (connecting support part) mounting plate part, 20 ... Airbag device, 20a ... the upper surface, 40 ... Steering shaft, R ... ring part, S ... Spoke part, P ... Ring surface, W ... Steering wheel.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-59435 (JP, A) JP-A-4-201759 (JP, A) JP-A-10-100907 (JP, A) Actual Kaihei 2- 66368 (JP, U) Patent 2760201 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60R 21/20 B62D 1/04 B62D 1/08

Claims (2)

(57) [Claims] 1. A steering wheel main body, a ring portion core metal arranged in a ring portion for gripping during steering,
A steering wheel core metal including a boss core metal connected to the steering shaft and a spoke core metal connecting the boss core metal and the ring core metal, the spoke core metal A left front / right front core bar extending from the boss core to the left and right sides and connected to the ring core, and a rear front extending from the boss core to the rear and connecting to the ring core An air bag device, which is composed of a core metal part and is connected to and supported by the spoke core metal, is disposed above the steering wheel body, and plastically deforms the steering wheel core metal during self-alignment. And a steering wheel provided with a three-spoke type airbag device capable of displacing the ring portion surface so as to approach the vertical surface. Branch off again,
Two branch portions are formed to connect the front end to the left front and right front core bar portions, respectively, and the airbag device is coupled and supported only to the two branch portions, and the airbag device is coupled to the two branch portions. A steering wheel equipped with an airbag device, characterized in that a portion forward of the support portion is configured to be plastically deformable during self-aligning. 2. The left front and right front core bars are arranged with their front end faces downward so that the two branch parts are respectively disposed above the connection parts with the left front and right front core bars. The steering wheel provided with the airbag apparatus according to claim 1, wherein the steering wheel is connected to the portion.