JPH11268653A - Steering wheel core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease the size of the boss of a steering wheel and decrease manufacturing costs. SOLUTION: A steel plate is press formed and a core material portion 31 is integrally formed having a cylindrical portion 33 and a flange portion 34. A serrated portion 35 and a core material tapered portion 37 are formed on the inside of the cylindrical portion 33. The core material portion 31 is arranged in a mold and a die-cast portion 34 is integrally formed. An extending portion 41 is formed protruding downward from the core material portion 31 in the die-cast portion 34. The die-cast tapered portion 43 connected to the core material tapered portion 37 is formed on the inside of the extending portion 41. At the lower end of the extending portion 41 is formed a cancel pin receiving portion 44.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core of a steering wheel connected to, for example, a steering shaft of an automobile.

[0002]

2. Description of the Related Art Conventionally, a steering wheel of an automobile is provided with a boss constituting a metal core for connecting a steering wheel body to a steering shaft. The boss is formed by forging or the like into a substantially cylindrical shape having a fitting hole into which the steering shaft is fitted, and the fitting hole is provided with a serration that meshes with the steering shaft and prevents rotation in the circumferential direction. And a tapered portion whose diameter decreases toward the upper end. Further, a cancel pin receiving portion, into which a cancel pin for returning the operation lever of the direction indicator is engaged, is recessed at the lower end of the boss.

[0003] However, the configuration by forging has a problem that it is difficult to reduce the manufacturing cost.

In this regard, as disclosed in Japanese Patent Application Laid-Open No. 5-673, a steel plate is machined to form a cylindrical boss, and the outer periphery of the boss is covered with a die-cast portion to reduce the manufacturing cost. The configuration is known.

[0005]

However, in the configuration described in Japanese Patent Application Laid-Open No. Hei 5-673, the cylindrical boss is formed substantially flush with the upper and lower portions of the die-cast portion. Therefore, at the lower end portion where the tapered portion is expanded, since the die casting portion is formed on the outer periphery of the tapered portion, the diameter of the boss portion tends to be large, and there is a problem that the arrangement of parts around the boss is limited. doing. In particular, when the cancel pin receiving portion is formed at the lower end of the boss, there is a problem that the diameter of the boss tends to be large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mandrel of a steering wheel capable of reducing the manufacturing cost and reducing the size.

[0007]

According to a first aspect of the present invention, there is provided a steering wheel core bar having a serration portion on which a steering shaft is fitted and a core taper portion expanding from the serration portion provided on an inner peripheral side. A core portion integrally formed with a cylindrical portion, and a flange portion protruding from the cylindrical portion to the outer peripheral side; and covering the outer peripheral portion of the cylindrical portion and a part of the flange portion, and the core material taper. And a die-casting portion that extends from the expanded side of the portion to form a continuous die-casting tapered portion.

In this configuration, the core portion can be formed by pressing a thin plate, and the manufacturing cost is reduced. And since the outer periphery of the cylindrical part of the core part is covered with the die-cast part, the strength is secured. In addition, since a part of the flange portion protruding from the cylindrical portion to the outer peripheral side is covered with the die cast portion, the core material portion and the die cast portion are firmly connected. Furthermore, since the die-casting taper portion is continuously formed on the expanding side of the core material taper portion, the core material does not exist at the end of the core metal on the expanding side, and the diameter can be reduced. .

According to a second aspect of the present invention, in the core of the steering wheel according to the first aspect, the die-cast portion has a cancel pin receiving portion that opens at an end of the die-cast taper portion on the expanding side. It was done.

In this configuration, since the cancel pin receiving portion is formed at the end of the die casting taper portion on the expanding side where no core material portion exists, the diameter can be reduced.

According to a third aspect of the present invention, the core of the steering wheel according to the first or second aspect is such that the core portion is formed by pressing an iron plate.

In this configuration, the manufacturing cost can be reduced, and the flange can be easily formed into a complicated shape by press cutting.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a steering wheel according to an embodiment of the present invention;

In FIG. 2, reference numeral 1 denotes a steering wheel of an automobile. The steering wheel 1 includes a steering wheel main body 2, an airbag device 3 attached to the occupant side of the steering wheel main body 2, and the like. . In addition, the steering wheel 1
It is attached to a steering shaft that can be adjusted as appropriate, and is usually used in an inclined state,
Hereinafter, the occupant side to which the airbag device 3 is attached is referred to as the upper side or the front side, the vehicle body side is referred to as the lower side or the back side, and the direction toward the lower side along the steering shaft is referred to as the attachment direction. In the present embodiment, the steering wheel body 2 includes an annular rim portion 5, a boss portion 6 located inside the rim portion 5, and a plurality of rim portions 5 and the boss portion 6 connected to each other. It is formed of four spokes 7 and the like.

As shown in FIGS. 3 and 4, a boss 11 is provided below the boss portion 6 as a metal core to be fitted to the steering shaft. The mandrel 12 is integrally connected, and further, the mandrel 12 of the spoke portion 7 is connected to the mandrel of the rim portion 5. A covering portion 14 made of a soft resin or the like is provided on a portion of the spoke portion 7 on the rim portion 5 side and an outer peripheral portion of the rim portion 5.
Are formed. The lower side of the boss 6 is covered with a lower cover 15. On the other hand, the airbag device 3 mounted on the boss 6 includes a base plate 21, a cover body 22 attached to the base plate 21, a bag-shaped airbag 23, and an inflator 24 for injecting gas into the airbag 23. , And a retainer 25 for fixing the airbag 23 and the like.

The boss 11 is connected to the boss 11 shown in FIGS.
As shown in (1), a core material part 31 formed by press molding is inserted into a mold, and a die casting part 32 is formed integrally with the outer periphery of the core material part 31.

That is, the core 31 has a thickness of 1.0 mm.
An iron plate of about 3.2 mm is pressed to form a substantially cylindrical tubular portion 33, and a flange portion 34 protruding from the upper end of the tubular portion 33 to the outer periphery is integrally formed. I have. Also,
Inside the cylindrical portion 33, a serration portion 35 having a groove formed in the upper portion along the axial direction is provided.
On the lower side of 35, there is formed a straight relief portion 36 having a straight tubular cylindrical surface, and on the lower side of this straight relief portion 36, there is formed a core taper portion 37 that expands downward. Have been. Further, the flange portion 34 is bent via the step portion 38, and the upper surface around the cylindrical portion 33 is
A nut mounting surface 39 is provided.

The die casting part 32 is formed by press-fitting a molten metal such as an aluminum (Al) alloy or a magnesium (Mg) alloy into a mold in which the core part 31 is arranged, and simultaneously with the core metal 12 of the spoke part 7. Is formed. At this time, the pair of dies is clamped and opened by the partition line PL, and the nut mounting surface 39 of the flange portion 34 is respectively provided.
The die-cutting metal is cut out by using the outer peripheral edge and the lower end corner of the core material tapered portion 37 of the tubular portion 33.
Accordingly, the core portion 31 is such that the flange portion 34 excluding the nut mounting surface 39 and the outer peripheral portion of the cylindrical portion 33 are covered with the die-cast portion 32, and the die-cast portion 32 is a lower end portion of the core portion 31. Further, an extended portion 41 extending substantially in a cylindrical shape is formed further below. A die-casting tapered portion 43 is formed on the inner surface of the extending portion 41 so as to expand continuously with the core material tapered portion 37. Further, at the lower end of the extending portion 41, a cancel pin receiving portion (notch portion for canceling) 44 which opens downward in a circular hole shape is formed integrally with a die in three places by using a die. .

Then, the steering shaft is inserted into the cylindrical portion 33 of the boss 11 from below, and a nut is screwed and tightened from above the steering shaft, so that the serration portion of the steering shaft becomes the boss.
In addition to engaging with the serrations 35 of the eleventh portion to prevent rotation, the boss 11 is held between the tapered portion of the steering shaft and the nut, and the steering wheel 1 is fixed to the steering shaft.

When the steering wheel 1 is mounted on the steering shaft, as shown in FIG. 3, an annular connecting device 46 is disposed on the outer peripheral side of the cylindrical portion 33 of the boss 11, and The airbag device 3 and the horn switch of the wheel 1 are electrically connected to electric components on the vehicle body side.

According to this embodiment, the core 31 of the boss 11 can be easily formed by pressing a thin iron plate, and the die casting 32 can be easily formed by casting.
Manufacturing costs can be reduced as compared with forging. And the core part
Since the outer periphery of the cylindrical portion 33 of the 31 is covered with the die cast portion 32, the strength can be secured. Also, since a part of the flange portion 34 which protrudes from the cylindrical portion 33 to the outer peripheral side and further forms the step portion 38 is covered with the die casting portion 32, the core material portion 31 and the die casting portion 32 can be strongly connected, The tubular portion 33 of the boss 11 and this tubular portion
It can be firmly fixed to the connection part with the upper boss plate of 33 without the need for extra space. Further, since a thin plate is used, the flange portion 34 can easily form a complicated shape by press cutting.

Also, the die-cutting is performed by cutting the upper surface of the flange portion 34 of the core portion 31 and the core material taper portion 37 into a core material portion.
Die casting part 32 is extended downward from 31 and core material taper part
Since the die-casting tapered portion 43 is formed continuously below 37, the core material portion 31 does not exist at the lower end portion which is the end of the boss 11 on the expanding side, the thickness is reduced, and the diameter of the boss 11 is reduced. Can be smaller. Therefore, the degree of freedom of arrangement of the connection device 46 and the like located around the boss 11 can be improved.

Further, the cancel pin receiving portion 44 is also provided with the extended portion 41 of the die casting portion 32 without increasing the diameter.
And the manufacturing cost can be reduced.

In this way, it is possible to provide the steering wheel 1 which can reduce the manufacturing cost and has a high degree of freedom in arranging the parts.

In addition to the shapes of the above-described embodiment, the boss 11 can take various shapes. For example, the flange portion 34 can be formed in various shapes corresponding to the molding of the boss portion 6 of the steering wheel body 1. It can be formed into a shape.

Further, in the shape of the above embodiment, the boss
Although the core metal 12 of the spoke part 7 is formed integrally with the die casting part 32 of FIG. 11, a separate core metal A can be welded to the core material part 31 as shown by a two-dot chain line in FIG. .

Further, the cancel pin receiving portion 44 can also take various shapes according to the shape of the cancel pin. For example, as shown in FIG. 6, notched cancel pin receiving portions 44 communicating not only below but also on the inner and outer circumferences may be formed at two locations of the extending portion 41 of the die casting portion 32. As shown in FIG. 7, the notched cancel pin receiving portion 44
May be formed in three places.

[0028]

According to the first aspect of the present invention, the core portion can be formed by pressing a thin plate, and the manufacturing cost can be reduced as compared with forging. And since the outer periphery of the cylindrical part of the core part is covered with the die-cast part, the strength can be secured. Further, since a part of the flange portion projecting from the cylindrical portion to the outer peripheral side is covered with the die casting portion, the core material portion and the die casting portion can be firmly connected. Furthermore, since the die-casting taper portion is formed continuously on the expanding side of the core material taper portion, the core material portion does not exist at the end of the core metal on the expanding side, and the diameter can be reduced. Therefore, components can be easily arranged around the cored bar.

According to the second aspect of the present invention, in addition to the effect of the first aspect, in addition to the effect of the first aspect, a cancel pin receiving portion is provided at the end of the die casting taper portion where the core portion does not exist on the expanding side of the die casting taper portion. Formed, the diameter can be reduced.

According to the third aspect of the present invention, in addition to the effects of the first and second aspects, since the iron plate is formed by pressing the iron plate and the core portion is formed by pressing the iron plate, the manufacturing cost is reduced. In addition to the reduction, the flange portion can easily form a complicated shape by press cutting.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a core of a steering wheel according to the present invention.

FIG. 2 is a plan view of the steering wheel.

FIG. 3 is a sectional view of the steering wheel, taken along the line II in FIG. 2;

FIG. 4 is a perspective view of the same core seen from below.

FIG. 5 is a perspective view of a core part of the core metal.

FIG. 6 is a partial perspective view showing another embodiment of the cored bar of the present invention.

FIG. 7 is a partial perspective view showing still another embodiment of the cored bar of the present invention.

[Explanation of symbols]

 1 Steering wheel 11 Boss as core metal 31 Core part 32 Die cast part 33 Cylindrical part 34 Flange part 35 Serration part 37 Core part taper part 43 Die cast taper part 44 Cancel pin receiving part

Claims (3)

[Claims] 1. A cylindrical portion having a serration portion to which a steering shaft is fitted, a core tapered portion expanding from the serration portion provided on an inner peripheral side, and a projecting portion protruding from the cylindrical portion to an outer peripheral side. A core portion integrally formed with a flange portion, and a die-cast taper portion that covers the outer peripheral portion of the cylindrical portion and a part of the flange portion and that extends continuously to an expanding side of the core material taper portion. A core metal for a steering wheel, comprising: a formed die-cast portion. 2. The core metal for a steering wheel according to claim 1, wherein the die-casting portion has a cancel pin receiving portion that opens at an end of the die-casting tapered portion on the expanding side. 3. The core metal for a steering wheel according to claim 1, wherein the core member is formed by pressing an iron plate.