JPH09109898A - Steering wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a steering wheel by effectively absorbing the shock through deformation of an air bag device and a steering wheel body. SOLUTION: An air bag device 4 is arranged on the upper side of a boss part 6. The air bag device 4 is fitted to a spoke part. A protective cover 47 is fitted to a bottom part of an inflator 46 of the air bag device 4. A projected part 63 to protect a cord 46f of the inflator 46 is projected on a bottom part of the protective cover 47. The projected part 63 consists of a plurality of holding pieces 66 capable of being deformed whose one end is free. When an automobile is collided, the primary shock is absorbed by an air bag 42 which is inflated and developed, and the secondary shock is absorbed by the deformation of the spoke part. When the spoke part is deformed and the inflator 46 is tilted, the projected part 63 abutted on other members is easily deformed to secure the deformation stroke.

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.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Publication No. 6-45330, for example, a steering wheel in which an airbag device is mounted above a boss portion of a steering wheel body is used in an automobile or the like. .
The airbag device includes a metal base plate, and an inflator for injecting gas, a bag-shaped airbag folded and stored, and a cover body for covering the airbag and the like are attached to the base plate. There is. A protective cover made of resin is attached to the bottom of the inflator. A cord protecting portion is integrally provided on the protective cover so as to project toward the bottom surface, and protects the cord led out from the center of the bottom of the inflator while guiding the cord laterally.

When a vehicle collides, a controller (not shown) detects the impact and activates the inflator. Then, due to the pressure of the gas injected by the inflator, the airbag is inflated and deployed while breaking the cover body, and projects toward the front of the occupant. In this state, the occupant thrown to the front side is received by the inflated and expanded airbag, and the so-called primary impact is absorbed. Continuously, the spokes etc. are deformed so as to allow the inclination of the rim of the steering wheel body, so-called secondary impact is absorbed,
The occupants are protected.

[0004]

SUMMARY OF THE INVENTION In the above conventional configuration,
When the spokes etc. are deformed and absorb the secondary impact, the airbag device tilts so as to reduce the space inside the boss portion, so depending on the size of the space below the protective cover of the airbag device. As a result, the deformation stroke of the steering wheel body is limited. Therefore, in the structure in which the protective cover having the cord protecting portion provided in a protruding manner is attached to the bottom of the inflator, there is a problem that it becomes difficult to downsize the steering wheel. Particularly, in a so-called sensor-integrated airbag steering wheel in which a controller is housed in the boss portion of the steering wheel body, there is a problem that the space inside the boss portion becomes small and the steering wheel tends to become large.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a steering wheel that can effectively absorb a shock by a deformation of an airbag device and a steering wheel main body and can be downsized. To aim.

[0006]

A steering wheel according to a first aspect of the present invention includes a boss portion fixed to a steering shaft, an operating rim portion, and a spoke portion connecting the boss portion and the rim portion. A wheel body, an airbag, an inflator for introducing gas into the airbag, and a protective cover for covering the boss portion side of the inflator, and an airbag device attached to the steering wheel body, The protective cover is provided with a deformable projecting portion that projects toward the boss side of the steering wheel body.

In this construction, the inflator is protected by the protective cover, and the cord protruding from the inflator is protected by the protruding portion of the protective cover. Also, when a shock such as a collision is applied,
The occupant temporarily absorbs the impact by the airbag inflated and expanded by the gas introduced from the inflator, and further, the boss portion of the steering wheel body or the spoke portion is deformed to allow the rim portion to tilt. As a result, the shock is secondarily absorbed. Since the protruding portion of the protective cover can be deformed when it comes into contact with another member, the protective cover and the boss portion are arranged close to each other, or the controller of the airbag device is arranged on the boss portion. Then, even when the space on the boss side of the protective cover becomes small, it is possible to secure a large deformation stroke of the rim portion of the steering wheel body, and it is possible to make the steering wheel compact.

[0008] The steering wheel according to claim 2 is
In the steering wheel according to the first aspect, the protruding portion includes a holding piece having one end that is a free end.

In this structure, the protruding portion is easily deformed when it comes into contact with another member, and the rim portion is smoothly tilted.

The steering wheel according to claim 3 is
In the steering wheel according to the first aspect of the present invention, the projecting portion is formed with a fragile portion that can be broken.

Further, in this configuration, the protruding portion is broken at the fragile portion so that it can be easily deformed in a state of being in contact with another member, and in other states, the protruding portion is projected from the inflator and the inflator. It is possible to cover the cords and the like and to surely protect them.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a steering wheel according to the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 denotes a steering wheel of an automobile. The steering wheel 1 is a steering wheel main body 2 and an airbag device (airbag module) mounted on an upper side of the steering wheel main body 2 which is an occupant side. 4 and so on.

The steering wheel body 2 is
As shown in FIGS. 2 to 4, a ring-shaped rim portion (ring portion) 5 and a boss portion 6 located inside the rim portion 5.
And four spoke portions 7 connecting the rim portion 5 and the boss portion 6 to each other. Further, a boss 8 fitted to a steering shaft (not shown) is provided on the lower portion of the boss portion 6 on the vehicle body side, and a boss plate 9 is fixed to the boss 8 by welding or the like.
Then, the core metal 7a of the spoke 7 is attached to the boss plate 9.
Are fixed by welding or the like, or extended integrally. Further, the core metal 5a of the rim portion 5 is fixed to the core metal 7a of the spoke portion 7 by welding or the like. Further, a skin portion 10 made of soft skin-integrated polyurethane foam is formed on the outer peripheral portion of the core metal 5a of the rim portion 5 and the outer peripheral portion of the spoke metal portion 7a of the spoke portion 7 on the rim portion 5 side. Has been done.

The lower side of the boss 6 is covered with a lower cover 11 made of resin. And this bottom cover
11 has working openings on both sides and rear side, respectively.
12, 12, 14 are formed, and these work openings 12, 12, 14 are respectively removable lids 15, 15, 16
Are covered by. Further, a lower opening 17 through which the boss 8 is inserted is formed in the lower cover 11, and a connecting device attaching portion 18 is formed around the lower opening 17 and the connecting device attaching portion 18 is formed. Further, a connecting device such as a clock spring for electrically connecting the vehicle body side and the steering wheel 1 side is attached.

Further, the steering wheel body 2 is provided with a pair of horn switch devices 21, 21 on both sides. That is, from both sides of the boss plate 9,
A pair of front mounting seats 23, 23 on both sides are extended toward the front, and rear mounting seats 24, 24 are formed on the core metal 7a of the rear spoke 7. The mounting seats 23, 24 are provided with fixed contacts (not shown), respectively, and four stepped bolts 25 screwed into the mounting seats 23, 24 are used to form a pair of horn plates 26 on both sides. , 26 are vertically guided in a predetermined range so that they can move back and forth. The horn plates 26 are formed by pressing a metal plate into a substantially box shape with the longitudinal direction in the front-rear direction, and movable contacts that are brought into contact with and separated from the fixed contacts are provided near the front and rear ends. And these horn plates
26 is biased upward by a coil spring 27, which serves as a biasing means and is wound around each stepped bolt 25, so that the movable contact and the fixed contact are separated from each other. Further, a pair of upper and lower insulators 28 and 29 are attached to the front and rear portions of each horn plate 26, and each stepped bolt 25 and coil spring 27 are insulated from the horn plate 26. Further, from the outer side of these horn plates 26, the air bag mounting piece portions are respectively directed downward.
31 are extended, and nuts 32 opened to the outside are fixed by welding or caulking to the inside of the attachment holes formed in these airbag attachment pieces (extended portions) 31.

Then, the horn plate 26,
The airbag device 4 is fastened and fixed to 26, and the airbag device 4 located above the boss portion 6 is supported via these horn switch devices 21. Therefore, by pushing the airbag device 4 downward against the biasing force of the coil spring 27, the movable contact comes into contact with the fixed contact, and the horn is blown.

Further, a controller 35 is fixed to the upper side of the boss plate 9 by a plurality of bolts 34. The controller 35 has a built-in impact sensor, and detects the deceleration of the vehicle transmitted to the steering wheel body 2 through the steering shaft to operate the airbag device 4.

As shown in FIGS. 2 and 5, the air bag device 4 is provided with a base plate 41. The air bag 42, the retainer 43, and the cover body 44 are attached from the upper side of the base plate 41 while the base plate 41 is attached. The inflator 46 and the protective cover 47 are attached from the lower side.

The base plate 41 is a flat plate formed by pressing a metal plate to form an upper plate portion 41a having a substantially rectangular shape in plan view and a peripheral wall portion 41b extending downward from the peripheral edge portion of the upper plate portion 41a. It is shaped like a simple box. In addition, the upper plate portion 41a has a circular hole-shaped inflator mounting hole in the central portion.
41c is formed, and a plurality of bolt through holes 41d and rivet through holes (not shown) are formed around the inflator mounting hole 41c. further,
A supporting piece portion (extending portion) 41e extends downward from the peripheral wall portions 41b on both sides, and the mounting hole 41 is provided in the supporting piece portion 41e.
f is formed. In addition, a rivet hole 41g and a locking hole 41h are formed in the peripheral wall portion 41b on the four sides.

The inflator 46 has a substantially columnar inflator body 46a, and a plurality of gas injection ports 46b for injecting gas are formed at predetermined intervals on the upper side of the inflator body 46a. And this inflator body
A flange portion 46c, which extends toward the outer peripheral side, projects from the portion 46a, and a plurality of bolt through holes 46d are formed in the flange portion 46c. Further, a protrusion 46e protruding downward is formed on the bottom of the inflator body 46a, and a cord 46f is led out from the protrusion 46e, and a connector 46g is provided at the tip of the cord 46f. There is.

On the other hand, the air bag 42 is formed in a bag shape by stacking two circular woven cloths and sewn on the outer periphery thereof,
A circular hole-shaped opening 42a is formed in the central portion of the lower surface, and a plurality of bolt through holes 42b and rivet through holes (not shown) are formed around the opening 42a.

Further, the retainer 43 is provided with a retainer body 43a having a substantially U-shaped cross section, and the retainer body 43a is
A stud bolt 43b protruding downward is fixed by welding or the like. A nut 43c is screwed into each stud bolt 43b.

The cover body 44 is made of synthetic resin such as various soft elastomers and covers the boss 6 of the steering wheel body 2 and the like, and the cover 44a.
A mounting piece portion 44b protruding downward from the back surface of a is integrally formed by injection molding. Further, the back surface side of the covering portion 44a is recessed in a substantially H-shaped plane, and a tear line 44c which is weaker than other portions of the covering portion 44a is formed. The mounting piece portion 44b has a substantially rectangular tube shape that fits outside the peripheral wall portion 41b of the base plate 41, and the rivet hole 41 of the peripheral wall portion 41b is formed.
A rivet hole 44d communicating with g is formed, and an unillustrated locking projection that engages with the locking hole 41h is formed.

Further, the protective cover 47 is integrally formed of synthetic resin, and as shown in FIGS. 2 and 5 to 7, has a substantially cylindrical shape which is fitted to the lower side of the inflator body 46a. It has a section 51. Further, from the upper end portion of the cylindrical portion 51, a flange portion 52 is formed which is generally rectangular in a plane and extends outward. Then, from the outer peripheral portion of the flange portion 52, an upper flange portion 53 is provided so as to project upward, and is located inside the upper flange portion 53,
A mounting hole 55 is formed in which a radial locking projection 54 is provided, the upper surface of which is inclined so as to descend toward the center. Also,
From the lower end of the cylindrical portion 51, a pair of substantially flange-shaped bottom flange portions 56 that abut the bottom portion of the inflator body 46a.
And a bottom contact portion 57 having a substantially fan shape are provided so as to protrude inward.

Further, a substantially rectangular plate-like member which is located at the center of the cylindrical portion 51 and below the bottom flange portion 56 and the bottom contact portion 57 and which faces the bottom projection 46e of the inflator body 46a. An eggplant bottom protection portion 61 is formed. In addition, the bottom protection portion 61 has a bottom contact portion through the inclined plate portion.
It is supported in line with 57.

Further, a projecting portion 63 is formed on the protective cover 47 from the bottom protecting portion 61 side toward the outer peripheral side, and by this projecting portion 63, a cord 46f led out from the projecting portion 46e.
Is protected and is guided to the outer peripheral side.
The protruding portion 63 is composed of a groove portion 64 which is formed by cutting out the bottom contact portion 57, and a plurality of holding pieces 66, 66 which are protruded from one edge portion of the groove portion 64. Also, each holding piece 66
Is an inclined portion extending downward from the bottom contact portion 57.
The cords 46f are arranged between the bottom of the inflator body 46a and the horizontal portions 66b of the holding pieces 66. The cords 46f are composed of a horizontal portion 66b and a horizontal portion 66b extending substantially horizontally from the tip of the inclined portion 66a. It is like this. Further, each holding piece 66 is formed to be elastically deformable in the vertical direction or to be rupturable when a predetermined force or more is applied.

When assembling the airbag device 4, first, the retainer 43 is inserted into the inside of the airbag 42 through the opening 42a, and the stud bolts 43b are inserted into the bolt through holes 42b of the airbag 42, respectively. . Subsequently, the stud bolt 43b protruding from the airbag 42 is inserted into the bolt through hole 41d of the base plate 41 from above. In this state, the retainer 43 and the base plate 41 are caulked and fixed by using a rivet (not shown), etc.
The airbag 42 is clamped and fixed between the 43 and the base plate 41.

Subsequently, the airbag 42 is attached to the base plate.
The base plate 41 is covered with a cover body 44 so as to cover the airbag 42 by folding the airbag 41 above. And
Attach the mounting piece 44b of the cover body 44 to the peripheral wall of the base plate 41.
41b, and the plurality of rivets R are attached to the rivet holes 44d, 41d with the locking projections engaged with the locking holes 41h and positioned.
Insert into the g and caulk, and fix the mounting piece portion 44b of the cover body 44 to the peripheral wall portion 41b of the base plate 41.

Further, from the lower side of the base plate 41,
The inflator body 46a of the inflator 46 is attached to the airbag 42 via the inflator mounting hole 41c of the base plate 41.
The stud bolt 43b protruding downward of the base plate 41 is inserted into the bolt through hole 46d of the flange portion 46c, and the nut 43c is screwed and fixed from the lower side.

Subsequently, the protective cover 47 is fitted from below the inflator 46 fixed to the base plate 41. That is, the cylindrical portion 51 is fitted into the inflator body 46a, and the stud bolts 43b are press-fitted into the respective mounting holes 55. Then, each mounting hole 55 is inserted into the thread groove of the stud bolt 43b.
The radial locking projections 54 are engaged with each other to fix the protective cover 47. Further, in this state, the bottom flange portion 56 and the bottom contact portion 57 contact the bottom portion of the inflator body 46a. Further, in this state, the bottom protector 61 faces the protrusion 46e at the bottom of the inflator 46 to protect the protrusion 46e, and the protrusion formed by a plurality of holding pieces 66.
The cord 46f guided from the protrusion 46e is protected by the 63 and guided to the outer peripheral side. Then, the connector 46g provided at the tip of the cord 46f is electrically connected to a connecting device such as a clock spring.

In the air bag device 4 thus assembled, a mounting bolt (not shown) inserted in the mounting hole 41f of the base plate 41 is screwed into the nut 32 of the air bag mounting portion 31 of each horn plate 26. By vertically tightening, the boss portion 6 of the steering wheel main body 2 is supported above the controller 35 so as to be vertically movable, and by pushing the airbag device 4 downward, the horn is blown. .

When the vehicle collides, the controller 35 detects the impact of the collision transmitted through the steering shaft and outputs a signal. This signal is then transmitted to the inflator 46 via the code 46f. In this state, the igniter is activated and the filled propellant reacts, so that an inert gas such as nitrogen gas is rapidly injected from the peripheral gas injection port 46b into the airbag 42,
The folded airbag 42 expands rapidly. Then
Due to the inflation pressure of the airbag 42, the covering portion 44a of the cover body 44 is split along the tear line 44c into a substantially H shape,
As shown in FIG. 1, a pair of front and rear door pieces 68a, 68b are formed. Further, the door pieces 68a and 68b are rotated back and forth to form the projecting port 70 of the airbag 42.
The air bag 42 projects from the air bag 70 and inflates and deploys to the front of the occupant. In this state, the occupant thrown forward is the airbag
It is received by 42 and the primary impact of the collision (primary impact) is absorbed.

Then, when a force for moving the occupant forward is applied, a force is applied to the spoke portion 7 via the rim portion 5, and the core metal 7a of the spoke portion 7 or the boss plate 9 is deformed and the rim portion 5 is deformed. By tilting, the secondary impact of the collision (secondary impact) is absorbed. When absorbing the secondary impact, the core metal 7a of the two spokes 7 on the front side with respect to the occupant is deformed by so-called belly striking in which the abdomen of the occupant abuts on the lower rear side of the rim part 5. Then, the space on the near side in the boss portion 6 is reduced. In this state, 2 on the front side
The inflator 46 supported by the spokes 7 of the book tilts, and the protective cover 47 attached to the inflator 46.
The protruding portion 63 contacts the controller 35 fixed to the boss plate 9 side. Then, each holding piece 66 forming the protruding portion 63 is elastically deformed, and the deformation stroke of the inflator 46, that is, the boss portion 6 is enlarged. Then, if the deformation stroke of the boss portion 6 is enlarged even slightly, the deformation stroke of the rim portion 5 can be secured large, and the secondary impact can be sufficiently secured.

As described above, according to the steering wheel 1 of the present embodiment, when a shock such as a collision is applied, the primary shock is absorbed by the airbag 42 which is inflated and expanded by the gas introduced from the inflator 46. Thus, the occupant can be protected, and the rim portion 5 can be tilted by the deformation of the spokes 7 of the steering wheel body 2 and the secondary impact can be absorbed to protect the occupant.

Further, the inflator 46 can protect the inflator body 46a and the cord 46f by the protective cover 47 attached to the bottom of the inflator body 46a. further,
The projecting portion 63 that protrudes to the lower side of the protective cover 47 includes a plurality of holding pieces 66 that are elastically deformable in the vertical direction with the tip as a free end.
Since it is formed by and is easily deformed when it comes into contact with other members, even if the space under the protective cover 47 is made small, the so-called collective mounting of sensors in which the controller 35 is arranged above the boss plate 9 is particularly important. Also in the type airbag steering wheel, a large deformation stroke of the steering wheel main body 2 can be secured, and the steering wheel 1 that smoothly and sufficiently absorbs an impact can be downsized.

In the above embodiment, the projecting portion 63 is formed by a plurality of holding pieces 66 that are elastically deformable in the vertical direction with the tip being the free end. The section may be provided with a fragile portion. For example, as in the second to fourth embodiments shown in FIGS. 8 to 10, the protruding portion 71 having a substantially U-shaped arch shape, 72, 73 can also be formed. Then, in the second embodiment shown in FIG. 8, a thin fragile portion 71a is formed along the root portion of the protruding portion 71, that is, the connecting portion to the bottom contact portion 57, and the third weak portion 71a shown in FIG. In the embodiment, a thin fragile portion 72a is formed in the center of the bottom of the protruding portion 71 along the longitudinal direction, and FIG.
In the fourth embodiment shown in FIG. 7, a plurality of fragile portions 73a opened at predetermined intervals are formed at both corners of the bottom of the protruding portion 73.

Therefore, in these second to fourth embodiments, the projecting portion 7 that protrudes to the back side and serves as the cord protecting portion.
Since the fragile fragile portions 71a, 72a, 73a are formed in the 1, 72, 73, when the secondary cover is applied and the protective cover 47 is tilted together with the inflator 46, these protruding portions 71, 72,
In a state where 73 is in contact with another member and a predetermined force or more is applied, each fragile portion 71a, 72a, 73a is broken and easily deformed, the rim portion 5 is smoothly tilted, and the impact is smoothed. Can be absorbed. In addition, when no force that deforms the spokes 7 is applied, the arch-shaped protrusion 7
1, 72, 73 can cover and protect the inflator 46 and the cord 46f projecting from the inflator 46 without fail.

[0039]

According to the steering wheel of the first aspect, the inflator can be protected by the protective cover, and the cord protruding from the inflator can be protected by the protruding portion of the protective cover. Also,
When a shock such as a collision is applied, the airbag that is inflated and expanded by the gas introduced from the inflator can temporarily absorb the shock and protect the occupant, and the spokes etc. of the steering wheel body can be deformed. As a result, tilting of the rim portion is allowed, and the impact is secondarily absorbed to protect the occupant. And the protruding part of the protective cover is
Since it deforms when it comes into contact with another member, a large deformation stroke of the steering wheel main body can be ensured and the steering wheel can be downsized even if the space on the boss side of the protective cover is small.

According to the steering wheel of the second aspect, in addition to the effect of the first aspect, since the projecting portion is provided with the holding piece whose one end is a free end, the steering wheel is projected when it comes into contact with another member. The installation part is easily deformed and the rim part is tilted smoothly,
Shock can be absorbed smoothly.

According to the steering wheel of the third aspect, in addition to the effect of the first aspect, since the fragile portion which can be broken is formed in the projecting portion, the projecting portion is in contact with another member. The fragile part breaks and is easily deformed, the rim part can be tilted smoothly, and shocks can be absorbed smoothly.In other states, the inflator and the cord protruding from the inflator are covered. It can be surely protected.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an operation of a vehicle during a collision showing an embodiment of a steering wheel of the present invention.

FIG. 2 is a sectional view of the steering wheel taken along the line II of FIG.

FIG. 3 is a plan view of the same steering wheel main body.

FIG. 4 is an exploded perspective view of the same steering wheel body.

FIG. 5 is an exploded perspective view of the same airbag device.

FIG. 6 is a plan view of the same protective cover.

FIG. 7 is a perspective view of the same protective cover as viewed from the back surface side.

FIG. 8 is an explanatory view showing a second embodiment of the protective cover of the present invention. 8A is a perspective view seen from the back side, and FIG. 8B is a sectional view taken along line II-II of FIG. 8A.

FIG. 9 is an explanatory view showing a third embodiment of the protective cover of the present invention. 9A is a perspective view seen from the back side, and FIG. 9B is a sectional view taken along line III-III in FIG. 9A.

FIG. 10 is an explanatory view showing a fourth embodiment of the protective cover of the present invention. 10A is a perspective view seen from the back side, and FIG. 10B is a sectional view taken along the line IV-IV in FIG.

[Explanation of symbols]

 1 Steering wheel 2 Steering wheel main body 4 Air bag device 5 Rim part 6 Boss part 7 Spoke part 42 Air bag 46 Inflator 47 Protective cover 63, 71, 72, 73 Protruding part 66 Holding piece 71a, 72a, 73a Fragile part

Claims (3)

[Claims] 1. A steering wheel main body having a boss portion fixed to a steering shaft, an operating rim portion, and a spoke portion connecting the boss portion and the rim portion, an airbag, and a gas for the airbag. An inflator to be introduced, and a protective cover for covering the boss side of the inflator, and an airbag device attached to the steering wheel main body, wherein the protective cover has a boss side of the steering wheel main body. A steering wheel characterized in that a deformable projecting portion projecting to the inside is provided. 2. The steering wheel according to claim 1, wherein the protruding portion includes a holding piece having one end that is a free end. 3. The steering wheel according to claim 1, wherein the protruding portion is formed with a fragile portion that can be broken.