JP2877700B2 - Steering wheel - 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 having a rim core covered with a synthetic resin.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Laid-Open No. 57-10969.
There is known a steering wheel described in Japanese Unexamined Patent Publication (Kokai) No. H11-15095. In this steering wheel, the outer peripheral surface of the rim core of the annular rim portion is covered with an inner layer made of a hard synthetic resin, and the outer peripheral surface of the inner layer is covered with an outer layer made of a soft synthetic resin. By providing an inner layer made of a hard synthetic resin between the rim mandrel and an outer layer made of a soft synthetic resin, the rigidity of the rim portion can be increased even when the diameter of the rim mandrel is reduced. In addition, the weight of the steering wheel can be reduced, and the outer layer can be fixed to the rim core via the inner layer even when an outer layer made of a material that is not easily fixed to the rim core is used.

However, in the configuration disclosed in the above publication, the outer diameter of the inner layer is likely to be larger than the outer diameter of the rim core when the inner layer is not formed. However, there is a problem that the thickness of the outer layer becomes small and it is difficult to improve the tactile sensation.

Further, for example, a steering wheel described in Japanese Utility Model Publication No. 4-27741 is known.
In this steering wheel, a reinforcing layer made of a hard resin is formed so as to cover the joint between the rim core metal and the spoke core metal, and the reinforcing layer is covered with a soft resin, thereby improving the strength of the steering wheel. Is increasing.

However, even in the configuration of this publication, if a reinforcing layer made of a hard resin is formed on the entire rim core, the thickness of the soft resin becomes small, and it is difficult to improve the tactile sensation. If the reinforcing layer is formed only at the joint between the core metal and the spoke core, it is difficult for the soft resin to directly adhere to the rim core at the portion where the soft resin directly covers the rim core. In addition, there is a problem that the soft resin tends to rotate in the circumferential direction of the rim core.

[0006]

As described above, in the configuration described in Japanese Utility Model Laid-Open No. 57-10969, the outer diameter of the inner layer is smaller than the outer diameter of the rim core when the inner layer is not formed. If the size is likely to be large and the outer diameter of the rim portion is constant, the thickness of the soft outer layer becomes small, and there is a problem that it is difficult to improve the tactile sensation. In addition, real fairness 4
In the configuration described in Japanese Patent No. 277741, if a reinforcing layer made of a hard resin is formed on the entire rim core, the thickness of the soft resin becomes small, and it is difficult to improve the tactile sensation. If the reinforcement layer is formed only at the joint with the spoke core, it becomes difficult for the soft resin to directly cover the rim core at the portion where the soft resin directly covers the rim core. There is a problem that the resin tends to rotate in the circumferential direction of the rim core.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a lightweight and tactile steering wheel with sufficient rigidity.

[0008]

According to a first aspect of the present invention, there is provided a steering wheel comprising: an annular rim core; a reinforcing portion made of a hard resin covering a part of an outer peripheral portion of the rim core; A cover portion made of a soft resin that covers an outer peripheral portion of the metal and the reinforcing portion, wherein the reinforcing portion is provided on an inner portion toward a center of a ring that is a part of a circumferential direction of the rim core bar, It is formed in a semicircular shape along substantially the entire length in the longitudinal direction of gold.

[0009] The steering wheel according to claim 2 is
The steering wheel according to claim 1, wherein a tubular portion that is continuous in a circumferential direction of the rim core is formed in a part of the reinforcing portion in a longitudinal direction.

The steering wheel according to claim 3 is
3. The steering wheel according to claim 1, wherein the film-shaped portion having a thickness smaller than the thickness of the reinforcing portion formed along the outer peripheral portion of the rim core extends along the outer peripheral portion of the rim core. The rim is formed integrally with the reinforcing portion and covers a part of the rim core.

[0011]

In the steering wheel according to the first aspect, a reinforcing portion made of a hard resin is formed along substantially the entire length of the rim core in the longitudinal direction, and the rim core and the reinforcing portion are covered with a covering portion made of a soft resin. Because it covered, while securing the rigidity,
The diameter of the rim core can be reduced, and the covering portion is firmly fixed to the rim core via the reinforcing portion over substantially the entire length in the longitudinal direction of the rim core. Also,
Reinforcing portion, since a semicircular arc to the inner portion towards the center of the ring that is part of the circumferential direction of the rim core metal, varying the rim cored bar
When a form load acts, the direction of the acting force
Reinforcement part is easy to follow, effective in securing strength
In addition, it is easy to secure the thickness dimension of the outer portion of the covering portion, which greatly affects the tactile sensation when the occupant grips the steering wheel.

In the steering wheel according to the second aspect, in addition to the function according to the first aspect, a cylindrical portion continuous in the circumferential direction of the rim core is formed in a part of the reinforcing portion in the longitudinal direction. The reinforcing portion is more reliably fixed to the rim core while suppressing the occurrence of a portion having a small thickness dimension.

According to a third aspect of the present invention, in addition to the function of the first or second aspect, in addition to the function of the first or second aspect, a film having a thickness smaller than the thickness of the reinforcing portion formed along the outer peripheral portion of the rim core is provided. Since the portion is formed integrally with the reinforcing portion along the outer peripheral portion of the rim core and partially covers the rim core, a reduction in the thickness dimension of the coating portion is suppressed, and the coating portion is formed via the film portion. Is firmly fixed to the rim core.

[0014]

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. The steering wheel 1 is composed of a steering wheel main body 2 and a pad body 3 mounted on the steering wheel main body 2. The steering wheel body 2 is provided with an annular rim portion 4.
And a boss 5 located inside the rim 4, and a plurality of spokes 6 connecting the rim 4 and the boss 5. The pad body 3 is composed of a cover body 7 that covers a part of the spoke part 6 and the boss part 5, and an airbag device or a shock absorber (not shown) provided below the cover body 7. .

As shown in FIGS. 3 and 4, the boss portion 5 of the steering wheel body 2 has a metal boss 11 fitted to a steering shaft (not shown).
A boss plate 12 made of metal and fixed to the boss 11 by welding or the like is provided. In addition, the spokes 6
First spoke core bar with a round metal rod gently bent
14 and a second round bar-shaped metal rod bent in a substantially V-shape.
The spoke core metal 15 is provided, and each has a boss plate
It is fixed to the front side and rear side of 12 by welding or the like.
Further, the rim portion 4 is provided with a hollow annular rim core (pipe ring) 16 formed by bending a cylindrical metal tube and butt-welding both ends thereof. The first and second spoke cores 14 are provided. , 15 are fixed by welding or the like.

The outer diameter (diameter) of each of the spoke cores 14 and 15 is set to a range of 8 mm, the outer diameter of the rim core 16 is set to 16 mm, and the wall thickness is set to 1.0 mm. I have.

As shown in FIGS. 1 to 6, substantially all of the boss plate 12 and the first spoke mandrel 14, and a part of the second spoke mandrel 15 and a part of the rim mandrel 16, It is integrally covered with a reinforcing portion 21 made of a hard synthetic resin, and the metal cores 14, 15, 16 and the reinforcing portion
A portion of the outer peripheral portion of the portion 21 that is not covered with the pad body 3 is integrally covered with a covering portion 22 made of a soft synthetic resin.

The reinforcing portion 21 is formed by insert-forming a hard resin such as polypropylene or polypropylene containing an inorganic filler.
A so-called PPG resin which is a blended polypropylene is used. The reinforcing portion 21 is provided with the entire circumference of the first spoke mandrel 14 located on the windshield side of the automobile with the steering wheel 1 attached to the steering shaft, and the rear of the first spoke mandrel 14. A second spoke core bar located on the lower side, that is, in front of the occupant
The rim core 16 on the entire circumference of 15 is formed to a thickness of about 2 mm. Further, the reinforcing portion 21 is
Boss plate in the circumferential direction of rim core 16 over the entire length of 16
The rim 12 has a semicircular cross section on the side 12 and covers about half of the surface of the rim core 16. In addition, at one location in the longitudinal direction of the rim core 16, a cylindrical portion which is located below and covers the entire circumference of the rim core 16 in a length dimension of about 10 mm to 20 mm.
24 are integrally formed.

On the other hand, the covering portion 22 is formed by insert-forming a soft resin such as a thermoplastic elastomer (TPE).
In the present embodiment, Lavalon (SEBS), a styrene-based resin having a hardness of JISD 30 to 40, is used. In the state where the covering portion 22 is formed, the outer diameter of the rim portion 4 is 25 mm to 28 mm in the cross section along the radial direction of the steering wheel 1, and the cross section along the rotation axis direction of the steering wheel 1 is Diameter is 28mm ~ 3
It is formed in a substantially circular or substantially elliptical cross section of 4 mm. Therefore, on the radially outer portion of the steering wheel 1, the thickness of the covering portion 22 is set to 4.5 mm to 6 mm over almost the entire length of the rim portion 4 except for the portion where the cylindrical portion 24 is formed.
Degree is secured.

A pair of mounting brackets 26 for mounting the pad body 3 are mounted on each of the spoke cores 14 and 15.

According to the steering wheel 1 of the present embodiment, the reinforcing portion 21 made of a hard resin is formed along substantially the entire length of the rim core 16 in the longitudinal direction, and the rim core 16 and the reinforcing portion 21 are formed. Is covered with the covering portion 22 made of a soft resin, the rigidity can be ensured, the diameter of the rim core 16 can be reduced, and the steering wheel 1 can be reduced in weight. That is, by forming a reinforcing portion 21 made of a hard resin having a thickness of 2 mm around the metal spoke cores 14 and 15 having a diameter of 8 mm, a metal rod-shaped spoke core having a diameter of 10 mm is formed. Similar strength and rigidity can be ensured. Thus, for example, in a conventional configuration in which a covering portion made of a soft resin is directly formed around a metal core, the steering wheel body 2 weighs about 1.5 to 1.8 kg. In the example,
While maintaining the same rigidity, the steering wheel body 2
Can be about 1.0 to 1.3 kg, and a weight reduction of about 0.5 kg can be achieved. In addition, by increasing the diameter of the cylindrical rim core 16 and decreasing the thickness, the rigidity can be ensured and the weight can be further reduced. Further, since the covering portion 22 is made of a thermoplastic elastomer having a specific gravity lower than that of polyvinyl chloride (PVC), the weight can be further reduced.

Since the reinforcing portion 21 made of a hard resin is formed substantially along the entire length of the rim core 16 in the longitudinal direction,
Via this reinforcing portion 21 which is mechanically fixed to the rim core 16, the covering portion 22 of the soft resin is firmly fixed to the rim core 16,
It is possible to prevent the covering portion 22 from rotating around the rim core 16 in the circumferential direction. That is, the soft covering portion 22 is hard to directly and mechanically and chemically fixed to the metal rim core 16 and requires the application of a solvent, a primer, or an adhesive. Since the affinity between the reinforcing part 21 made of polypropylene and the covering part 22 made of a thermoplastic elastomer is good, the covering part 22 is integrally adhered to the reinforcing part 21 so that the covering part is formed through the reinforcing part 21. 22 rim core metal 16
And the manufacturing process can be rationalized. Further, since the application of a primer or an adhesive can be omitted, and the use of a solvent can be omitted, the working environment and the natural environment can be improved.

Further, since the reinforcing portion 21 is formed in a semicircular shape inside the circumferential direction of the rim core 16, first, the reinforcing portion 21 is integrally formed from the spoke cores 14 and 15 to the rim core 16. In addition, when a deformation load is applied to the rim core 16, the reinforcing portion 21 can easily follow the direction of the applied force, which is effective in securing strength. Secondly, it is easy to secure the thickness dimension of the soft covering portion 22, that is, the compression stroke, on the outer portion that greatly affects the tactile sensation when the occupant grips the steering wheel 1. Compared with the case where the reinforcing portion 21 is formed, the soft feeling and the tactile sensation can be improved. In particular, on the side of the rim core 16 opposite the boss plate in the circumferential direction, the covering portion
Since the thickness of 22 can be as large as 4.5 mm, the tactile sensation can be improved.

When the reinforcing portion 21 is subjected to insert molding, the rim core 16 is exposed outside the reinforcing portion 21. Therefore, by regulating the position of the outer peripheral portion of the rim core 16, The eccentricity of the rim core 16 can be prevented.

Further, since a cylindrical portion 24 continuous in the circumferential direction of the rim core 16 is formed in a part of the reinforcing portion 21 in the longitudinal direction,
The reinforcing portion 21 can be mechanically more securely fixed to the rim core 16. Further, since the reinforcing portion 21 is disposed below the front side and has a length of 10 mm to 20 mm, the reinforcing portion 21 can be securely fixed while suppressing the influence on the tactile sensation.

Then, of the first and second spoke cores 14 and 15 constituting the four spoke portions 6, the boss plate 12 of the second spoke core 15 located on the front side of the occupant is approached. Since the reinforcing portion 21 is not formed around the portion, when the occupant collides with the steering wheel 1, the second spoke core metal 15 bends under a predetermined force (self-aligning effect). ), It is possible to prevent the impact from being concentrated on the lower abdomen of the occupant. In this example, a bending characteristic corresponding to the bending characteristic of a metal rod-shaped spoke having a diameter of 10 mm without forming a PPG resin was obtained.

In the above embodiment, the reinforcing portion 21
The cylindrical portion 24 is formed only at one position in the longitudinal direction of FIG.
As shown in FIG. 8, the tubular portions 27 are formed at predetermined intervals at a plurality of locations in the longitudinal direction of the reinforcing portion 21, so that the reinforcing portion 21 can be more securely fixed to the rim core 16.

Further, for example, as shown in FIG. 9, the cylindrical portions 24 and 27 can be formed so as to wrap the joint 28 formed by butt welding the rim cores 16 and butt welding.

Further, in each of the above embodiments, FIG.
As shown in FIG.
A burr-like film-like portion 31 having a thickness of about mm to 0.5 mm can be formed. Then, by forming the film-shaped portion 31, the covering portion 22 is connected to the rim core metal via the film-shaped portion 31.
16 and can be fixed more firmly. Also,
Since the thickness of the film-shaped portion 31 is small, it is possible to reduce the influence on the tactile sensation. Therefore, for example, by providing the film-shaped portion 31 on the side opposite to the boss plate in the circumferential direction of the rim core 16, the contact area with the covering portion 22 can be increased compared to the case where only the reinforcing portion 21 is provided. The covering portion 22 made of a soft resin having an adhesive property to the hard resin forming the film-shaped portion 31 can be prevented from idling in the circumferential direction of the rim core 16. Further, as shown in FIGS. 11 and 12, a gas vent 33 for venting gas is formed in communication with a mold portion forming the film-shaped portion 31, thereby forming a reinforcing portion.
The resin material injected into 21 flows in the direction of the arrow in the figure,
After the cylindrical portion 24 is filled, the film-shaped portion 31 is filled, so that the resin weld line 34 generated in the reinforcing portion 21 and the like can be reduced.

In each of the above embodiments, as shown in FIG. 13, a pair of reinforcing members 21 covering the first and second spoke cores 14 and 15 are integrally formed with a pair of reinforcing members 21 on both sides. By providing the connecting portion 36, the reinforcing effect can be improved, the resonance with the idling vibration of the vehicle can be prevented, and the molten resin can be effectively guided to improve the formability of the reinforcing portion 21. Can be.

By setting the outer diameter (diameter) of each of the spoke cores 14 and 15 in the range of 8 mm to 12 mm, it is possible to achieve both reduction in weight and securing rigidity.
The outer diameter of the rim core 16 is set in the range of 12 mm to 16 mm, more preferably 14 mm to 16 mm.
By setting the thickness dimension in the range of 0.8 mm to 2.0 mm, and more preferably in the range of 0.8 mm to 1.6 mm, both weight reduction and securing of rigidity can be achieved. By setting the thickness of the reinforcing portion 21 in the range of 1.0 mm to 5.0 mm, and more preferably in the range of 2.0 mm to 3.0 mm, it is possible to ensure both rigidity and tactile sensation. it can. Further, the outer diameter of the rim portion 4, that is, the outer diameter of the covering portion 22 is set to 25 mm to 30 mm, more preferably 25 mm to 28 mm in the direction along the radial direction of the steering wheel main body 2. 25 mm to 35 mm, more preferably 28 mm to 3 mm in the direction along the rotation axis direction.
By setting it to 4 mm, a good operational feeling can be obtained.

[0033]

According to the steering wheel of the first aspect, a reinforcing portion made of a hard resin is formed along substantially the entire length of the rim core in the longitudinal direction, and the rim core and the reinforcing portion are made of a soft resin. Since it is covered with a covering portion, it is possible to reduce the diameter of the rim core while securing rigidity, and it is possible to reduce the weight, and to provide the reinforcing portion over substantially the entire length of the rim core in the longitudinal direction. Through this, the covering portion can be firmly fixed to the rim core. Furthermore, since the reinforcing portion is formed in a semicircular shape on the inner side toward the center of the ring, which is a part of the rim core in the circumferential direction, it is transformed into a rim core.
When a load is applied, the direction of the applied force is compensated.
Since the strong parts are easy to follow, it is effective in securing strength
In addition, it is easy to secure the thickness of the outer part of the covering part that greatly affects the tactile sensation when the occupant grips the steering wheel, compared to the case where the reinforcing part is formed in the entire circumferential direction of the rim core, Tactile sensation can be improved.

According to the steering wheel of the second aspect, in addition to the effect of the first aspect, a cylindrical portion that is continuous in the circumferential direction of the rim core is formed at a part of the reinforcing portion in the longitudinal direction. The reinforcement portion can be more reliably fixed to the rim core while suppressing the influence on the rim core.

According to the steering wheel of the third aspect, in addition to the effects of the first or second aspect, in addition to the thickness dimension of the reinforcing portion formed along the outer peripheral portion of the rim core, the thickness dimension is smaller. Since the film-like portion is formed integrally with the reinforcing portion along the outer peripheral portion of the rim core and partially covers the rim core, the coating portion can be more reliably formed without reducing the tactile sensation through this film-like portion. It can be fixed to the rim core.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a rim portion of a steering wheel showing one embodiment of the present invention.

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

FIG. 3 is a plan view of the steering wheel in a state where a covering portion is not formed.

FIG. 4 is a perspective view of a boss of the steering wheel.

FIG. 5 is a sectional view taken along the line II of FIG. 3;

FIG. 6 is a sectional view taken along the line II-II of FIG. 3;

FIG. 7 is a plan view showing a steering wheel according to another embodiment of the present invention in a state where a covering portion of a steering wheel is not formed.

FIG. 8 is a sectional view taken along the line III-III of FIG. 7;

FIG. 9 is a partially cut-away perspective view of a steering wheel according to another embodiment of the present invention in a state where a covering portion is not formed.

FIG. 10 is a partially cutaway perspective view of a steering wheel showing another embodiment of the present invention.

FIG. 11 is an explanatory diagram showing a manufacturing process of the steering wheel.

FIG. 12 is an explanatory diagram showing a manufacturing process of the steering wheel.

FIG. 13 is a partially cutaway perspective view of a steering wheel showing another embodiment of the present invention.

[Explanation of symbols]

 1 Steering wheel 16 Rim core 21 Reinforcing part 22 Coating part 24 Tubular part 31 Film part

Continuation of the front page (56) References JP-A-62-64670 (JP, A) JP-A-60-115172 (JP, U) JP-A-64-26575 (JP, U) JP-A-48-113134 (JP) (U, U) Shokai 57-10969 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B62D 1/04-1/11

Claims (3)

(57) [Claims] An annular rim core, a reinforcing portion made of a hard resin covering a part of an outer peripheral portion of the rim core, and a soft resin covering an outer peripheral portion of the rim core and the reinforcing portion. A coating portion, and the reinforcing portion has a semi-circular shape along an almost entire length in a longitudinal direction of the rim core metal on an inner portion toward a center of a ring which is a part of the rim core metal in a circumferential direction. steering wheel, characterized in that formed. 2. The steering wheel according to claim 1, wherein a cylindrical portion continuous in a circumferential direction of the rim core is formed at a part of the reinforcing portion in the longitudinal direction. 3. A film-like portion having a thickness smaller than the thickness of the reinforcing portion formed along the outer peripheral portion of the rim core is integrated with the reinforcing portion along the outer peripheral portion of the rim core. 3. The steering wheel according to claim 1, wherein the steering wheel is formed and covers a part of the rim core.