JPH0858603A - Steering wheel - Google Patents

Abstract

PURPOSE: To provide a steering wheel excellent in touching feeling with its small weight. CONSTITUTION: A reinforcing part 21 made of a rigid resin and a covering part 22 made of a soft resin for covering a rim core metal 16 and the reinforcing part 21 are formed on the outer peripheral surface of a rim core metal 16 formed by bending a cylindrical metal pipe in a circular form. The reinforcing part 21 is formed in an arc shape in section along the inner side part of the rim core metal 16 and almost the full length of the longitudinal direction of the rim core metal 16. A cylindrical part 24 continuous in the circumferential direction of the rim core metal 16 is formed in a part of the reinforcing part 21 in the longitudinal direction. Thus, the thickness dimension of the covering part 22 is secured. The covering part 22 can be also strongly fixed to the rim core metal 16.

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 cored bar covered with a synthetic resin.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Utility Model Laid-Open No. 57-10969.
A steering wheel described in Japanese Patent Publication is known. In this steering wheel, the outer peripheral surface of the rim cored bar of the annular rim portion is covered with an inner layer made of a hard synthetic resin, and the outer peripheral surface of this 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 cored bar and an outer layer made of a soft synthetic resin, the rigidity of the rim portion can be increased even if the diameter of the rim cored bar is reduced. The weight of the steering wheel can be reduced and the outer layer can be fixed to the rim core through the inner layer even when the outer layer made of a material that is not easily fixed to the rim core is used.

However, in the structure of the above publication, the outer diameter of the inner layer is apt to be larger than the outer diameter of the rim core bar in the case where the inner layer is not formed. There is a problem that it is difficult to improve the tactile sensation because the thickness of the outer layer becomes small.

Also, 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 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 soft resin to improve the strength of the steering wheel. Is increasing.

However, even in the structure of this publication, if a reinforcing layer made of a hard resin is formed on the entire core metal of the rim portion, the thickness dimension 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 metal, it is difficult to firmly bond the soft resin and the rim core metal firmly at the portion where the soft resin directly covers the rim core metal. However, there is a problem that the soft resin is likely to rotate in the circumferential direction of the rim cored bar.

[0006]

As described above, in the structure disclosed in Japanese Utility Model Laid-Open No. 57-10969, the outer diameter of the inner layer is larger than the outer diameter of the rim core bar when the inner layer is not formed. The size tends to be large, and if the outer diameter of the rim portion is constant, the thickness of the soft outer layer is small, and it is difficult to improve the tactile sensation. In addition, fair 4
In the configuration described in Japanese Patent Publication No. 27741, when a reinforcing layer made of a hard resin is formed on the entire rim core bar, the thickness dimension of the soft resin becomes small, and it is difficult to improve the feel of the rim core bar. If the reinforcing layer is formed only on the joints with the spoke cores, it becomes difficult to firmly bond the soft resin to the rim cores at the portion where the soft resin directly covers the rim cores. There is a problem that the resin easily rotates in the circumferential direction of the rim cored bar.

The present invention has been made in view of the above points, and an object thereof is to provide a steering wheel which is lightweight and has a good tactile sensation while ensuring rigidity.

[0008]

According to a first aspect of the present invention, there is provided a steering wheel including a rim core metal, a reinforcing portion made of hard resin for covering a part of the rim core metal, and a soft portion for covering the rim core metal and the reinforcing portion. A covering portion made of resin is provided, and the reinforcing portion is formed on a part of the rim cored bar in the circumferential direction and along substantially the entire length of the rim cored bar in the longitudinal direction.

According to another aspect of the steering wheel of the present invention,
The steering wheel according to claim 1, wherein a tubular portion that is continuous in the circumferential direction of the rim cored bar is formed in a part of the reinforcing portion in the longitudinal direction.

A steering wheel according to claim 3 is
The steering wheel according to claim 1 or 2, wherein a film portion having a thickness smaller than that of the reinforcing portion is integrally formed with the reinforcing portion and covers a part of the rim cored bar.

[0011]

In the steering wheel according to the first aspect of the present invention, a reinforcing portion made of hard resin is formed along substantially the entire length of the rim cored bar in the longitudinal direction, and the rim cored bar and the reinforcing portion are covered with a soft resin. Since it is covered, while ensuring rigidity,
It is possible to reduce the diametrical dimension of the rim cored bar, and the covering section is firmly fixed to the rim cored bar through the reinforcing section over substantially the entire length of the rim cored bar in the longitudinal direction. Also,
Since the reinforcing portion is formed on a part of the rim core metal in the circumferential direction, it is easy to secure the thickness dimension of the covering portion.

In the steering wheel according to a second aspect of the invention, in addition to the function of the first aspect, since a tubular portion which is continuous in the circumferential direction of the rim cored bar is formed in a part of the reinforcing portion in the longitudinal direction, The reinforcing portion is more reliably fixed to the rim core metal while suppressing the generation of a portion having a small thickness dimension.

According to the steering wheel of the third aspect, in addition to the action of the first or second aspect, a film-like portion having a thickness smaller than that of the reinforcing portion is integrally formed with the reinforcing portion, and a part of the rim core bar is formed. Since it is covered, the covering portion is firmly fixed to the rim core metal through the film-like portion while suppressing a decrease in thickness of the covering portion.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of one embodiment of the steering wheel of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 1 is a steering wheel, which is composed of a steering wheel body 2 and a pad body 3 mounted on the steering wheel body 2. The steering wheel body 2 has a ring-shaped rim portion 4
And a boss portion 5 located inside the rim portion 4, and a plurality of spoke portions 6 connecting the rim portion 4 and the boss portion 5. The pad body 3 is composed of a cover body 7 that covers a part of the spoke portions 6 and the boss portion 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 is provided with a metal boss 11 fitted on a steering shaft (not shown).
A metal boss plate 12 fixed to the boss 11 by welding or the like is provided. In addition, the spoke portion 6 includes
First spoke cored bar that gently bends a round bar-shaped metal bar
14 and a second round metal rod which is bent into a substantially V shape
Spoke cores 15 and are provided on each boss plate
The 12 front and rear parts are fixed by welding or the like.
Further, the rim portion 4 is provided with a hollow ring-shaped rim core metal (pipe ring) 16 formed by bending a cylindrical metal tube and butt-welding both ends thereof, and the first and second spoke core metals 14 are provided. , 15 are fixed to the ends by welding.

The outer diameter dimension (diameter dimension) of each spoke core metal 14 and 15 is set in the range of 8 mm, and the outer diameter dimension of the rim core metal 16 is set to 16 mm and the wall thickness dimension is set to 1.0 mm. There is.

Then, as shown in FIGS. 1 to 6, the boss plate 12 and the first spoke core metal 14 are substantially entirely, and the second spoke core metal 15 and the rim core metal 16 are partially The cored bar 14, 15, 16 and the reinforcing part are integrally covered with the reinforcing part 21 made of hard synthetic resin.
A portion of the outer peripheral portion of 21 which 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-molding a hard resin such as polypropylene or polypropylene mixed with an inorganic filler. In this embodiment, glass is 30%.
A so-called PPG resin, which is a blended polypropylene, is used. The reinforcing portion 21 includes the entire length of the entire circumference of the first spoke core metal 14 located on the windshield side of the automobile with the steering wheel 1 attached to the steering shaft, and the rear end of the first spoke core metal 14. Second spoke core metal located on the lower side, that is, on the front side of the occupant
The rim core metal 16 side portion of the entire circumference of 15 is formed with a thickness of about 2 mm. Furthermore, this reinforcing portion 21 is
The boss plate in the circumferential direction of the rim core metal 16 over the entire length of 16
The rim cored bar 16 is formed to have a semicircular arc-shaped cross section on the 12 side and covers about half of the surface of the rim cored bar 16. In addition, at one place in the longitudinal direction of the rim core metal 16, a cylindrical portion located on the lower side and having a length dimension of about 10 mm to 20 mm and covering the entire circumference of the rim core metal 16 in the circumferential direction.
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 this embodiment, a brand name Lavalon (SEBS), which is a styrene resin having a hardness of JIS D30 to 40, is used. With the covering portion 22 formed, the outer diameter of the rim portion 4 is such that the diameter dimension of the cross section along the radial direction of the steering wheel 1 is 25 mm to 28 mm and the cross section along the rotational axis direction of the steering wheel 1. Diameter is 28mm-3
It is formed to have a substantially circular or elliptical cross section of 4 mm. Therefore, on the outer side in the radial direction of the steering wheel 1, the thickness of the covering portion 22 is 4.5 mm to 6 mm over substantially the entire length of the rim portion 4 except for the portion where the tubular portion 24 is formed.
The degree is secured.

A pair of mounting fittings 26 on both sides for mounting the pad body 3 are attached to each spoke core metal 14, 15.

According to the steering wheel 1 of this embodiment, the reinforcing portion 21 made of hard resin is formed along substantially the entire length of the rim core metal 16 in the longitudinal direction, and the rim core metal 16 and the reinforcing portion 21 are formed. Since the cover portion 22 made of soft resin is covered, the diameter of the rim core metal 16 can be reduced while ensuring rigidity, and the steering wheel 1 can be made lightweight. That is, by forming a reinforcing portion 21 made of hard resin having a thickness of 2 mm around 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 secured. Therefore, for example, in the conventional structure in which the coating portion made of the soft resin is directly formed around the metal core bar, the steering wheel body 2 has a weight of about 1.5 to 1.8 kg. In the example,
Steering wheel body 2 while ensuring the same rigidity
The weight can be set to about 1.0 to 1.3 kg, and the weight can be reduced to about 0.5 kg. By increasing the diameter dimension of the cylindrical rim core 16 and decreasing the thickness dimension thereof, it is possible to further reduce the weight while ensuring the synthesis. Further, since the covering portion 22 is also made of a thermoplastic elastomer having a lower specific gravity than that of polyvinyl chloride (PVC), the weight can be further reduced.

Since the reinforcing portion 21 made of a hard resin is formed along substantially the entire length of the rim core metal 16 in the longitudinal direction,
Via this reinforcing portion 21 which is mechanically fixed to the rim core metal 16, the covering portion 22 of the soft resin is firmly fixed to the rim core metal 16,
It is possible to prevent the covering portion 22 from rotating in the circumferential direction of the rim core metal 16. That is, the soft coating portion 22 is hard to be directly mechanically or chemically fixed to the metal rim core metal 16, and it is necessary to apply a solvent, a primer, or an adhesive. Since the affinity between the polypropylene reinforcing portion 21 and the thermoplastic elastomer covering portion 22 is good, the covering portion 22 is integrally adhered to the reinforcing portion 21, so that the covering portion 21 is covered with the covering portion 22. 22 to rim core metal 16
In addition to being firmly fixed to, the manufacturing process can be streamlined. Further, since it is possible to dispense with the application of a primer or an adhesive and to omit the use of a solvent, it is possible to improve the working environment and the natural environment.

Since the reinforcing portion 21 is formed in a semicircular shape on the inner side in the circumferential direction of the rim core metal 16, firstly, the reinforcing portion 21 is integrally formed from the spoke core metals 14 and 15 to the rim core metal 16. When the deformation load acts on the rim core metal 16, the reinforcing portion 21 easily follows the direction of the acting force, which is effective in securing the strength. Furthermore, secondly, it is easy to secure the thickness dimension of the soft covering portion 22, that is, the compression stroke, on the outer side portion that greatly affects the tactile sensation when the occupant grips the steering wheel 1, and the rim core metal 16 can be provided in the entire circumferential direction. Compared with the case where the reinforcing portion 21 is formed, the soft feeling and the tactile feeling can be improved. Especially, on the side opposite to the boss plate in the circumferential direction of the rim core metal 16, the covering portion
Since the thickness dimension of 22 can be secured as thick as 4.5 mm, the tactile sensation can be improved.

When the reinforcement portion 21 is insert-molded, the rim core metal 16 is exposed outside the reinforcement portion 21. Therefore, the outer peripheral portion of the rim core metal 16 is regulated in position by Eccentricity of the rim core metal 16 can be prevented.

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

Of the first and second spoke cores 14 and 15 constituting the four spoke portions 6, the second spoke cores 15 located on the front side of the occupant are close to the boss plate 12. 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, bending characteristics equivalent to the bending characteristics of the metal rod-shaped spokes having a diameter of 10 mm and not forming the PPG resin were obtained.

In the above embodiment, the reinforcing portion 21
Although the tubular portion 24 is formed only at one place in the longitudinal direction of FIG.
As shown in FIG. 8 and FIG. 8, it is possible to more reliably fix the reinforcing portion 21 to the rim core metal 16 by forming the cylindrical portions 27 at a plurality of positions in the longitudinal direction of the reinforcing portion 21 at predetermined intervals.

Further, for example, as shown in FIG. 9, the tubular portions 24 and 27 can be formed by wrapping the joint portion 28 in which the rim core metal 16 is butted and butt-welded.

Further, in each of the above embodiments, FIG.
As shown in FIG.
It is also possible to form the burr-like film-like portion 31 having a thickness of about mm to 0.5 mm. Then, by forming the film-shaped portion 31, the covering portion 22 is covered with the rim core metal through the film-shaped portion 31.
It can be attached tightly to 16 and fixed more firmly. Also,
Since the thickness of the film portion 31 is small, it is possible to reduce the influence on the tactile sensation. Therefore, for example, by providing the film-like portion 31 on the side opposite to the boss plate in the circumferential direction of the rim core metal 16, the contact area with the covering portion 22 can be made larger than that in the case where only the reinforcing portion 21 is provided. It is possible to prevent the coating portion 22 made of a soft resin having adhesiveness with the hard resin forming the film-shaped portion 31 and idling in the circumferential direction of the rim core metal 16. Further, as shown in FIG. 11 and FIG. 12, the reinforcing portion is formed by forming a gas vent 33 for venting gas in communication with the portion of the mold forming the film-like portion 31.
The resin material injected into 21 flows in the direction of the arrow in the figure,
Since the tubular portion 24 is filled and then the film portion 31 is filled, the resin weld line 34 generated in the reinforcing portion 21 and the like can be reduced.

Further, in each of the above-mentioned embodiments, as shown in FIG. 13, a pair of both sides for connecting the reinforcing portions 21 integrally with the reinforcing portions 21 for covering the first and second spoke cores 14, 15. By providing the connecting portion 36, it is possible to improve the reinforcing effect and prevent resonance with idling vibration of the vehicle, etc., and also to effectively guide the molten resin to improve the formability of the reinforcing portion 21. You can

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

[0033]

According to the steering wheel of the first aspect of the present invention, a reinforcing portion made of hard resin is formed along substantially the entire length of the rim core metal in the longitudinal direction, and the rim core metal and the reinforcing portion are made of soft resin. Since the rim cored bar is covered with the covering part, it is possible to reduce the diameter size of the rim cored bar while ensuring rigidity, and it is possible to reduce the weight of the rim cored bar. Thus, the covering portion can be firmly fixed to the rim core metal. Further, since the reinforcing portion is formed on a part of the circumferential direction of the rim core metal, it is easy to secure the thickness dimension of the covering portion, and the tactile feel is greater than that when the reinforcing portion is formed on the entire circumferential direction of the rim core metal. Can be improved.

According to the steering wheel of the second aspect, in addition to the effect of the first aspect, since the tubular portion which is continuous in the circumferential direction of the rim cored bar is formed in a part of the reinforcing portion in the longitudinal direction, the tactile feel is improved. It is possible to more reliably fix the reinforcing portion to the rim core metal while suppressing the influence on the rim core metal.

According to the steering wheel of the third aspect, in addition to the effect of the first or second aspect, a film-shaped portion having a thickness smaller than that of the reinforcing portion is integrally formed with the reinforcing portion, which is one of the rim cores. Since the portion is covered, it is possible to more securely fix the covering portion to the rim core metal through the film-like portion without deteriorating the feel.

[Brief description of drawings]

FIG. 1 is a partial perspective view of a rim portion of a steering wheel in which a part is cut away according to an embodiment of the present invention.

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

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

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

5 is a sectional view taken along line I-I of FIG. 3 above.

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

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 is not formed.

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

FIG. 9 is a partially cutaway perspective view showing 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 according to another embodiment of the present invention.

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

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

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

[Explanation of symbols]

 1 Steering wheel 16 Rim core bar 21 Reinforcement part 22 Cover part 24 Cylindrical part 31 Membrane part

Claims (3)

[Claims] 1. A rim core bar, a reinforcing part made of hard resin for covering a part of the rim core bar, and a covering part made of a soft resin for covering the rim core bar and the reinforcing part. The steering wheel is formed on a part of the rim cored bar in the circumferential direction along substantially the entire length of the rim cored bar in the longitudinal direction. 2. The steering wheel according to claim 1, wherein a tubular portion that is continuous in the circumferential direction of the rim cored bar is formed in a part of the reinforcing portion in the longitudinal direction. 3. The steering wheel according to claim 1, wherein a film-shaped portion having a thickness smaller than that of the reinforcing portion is formed integrally with the reinforcing portion and covers a part of the rim cored bar.