JPH0530179B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is a steering wheel core material formed from a resin-impregnated fiber bundle of continuous filaments and used in a vehicle such as an automobile after completion as a product. It relates to its manufacturing method.

<Prior Art> Recently, steering wheels of vehicles such as automobiles are often made of synthetic resin materials such as polyurethane resin and polypropylene resin in order to reduce weight. However, since these resin materials alone lack strength, a metal material is also used as a reinforcing material (core material) for molding. Therefore, for example, metal materials such as iron pipes and iron bars increase the total weight of the steering wheel, impairing the lightweight effect, and also not providing good vibration characteristics.

On the other hand, a continuous fiber bundle such as glass fiber or carbon fiber impregnated with a synthetic resin such as polyester resin or epoxy resin is wrapped around a predetermined mold, laminated and cured, and then used as a steering core material. Attempts were made to manufacture wheels;
Various manufacturing methods have been proposed.

<Problems to be Solved by the Invention> However, the resin-impregnated fiber bundles used in this method have lower rigidity than steel, which is the conventional core material. It is required to increase the overall strength by increasing the number of spokes. Therefore, it is considered that this type of steering wheel core material should have core materials 11 and 12 having a structure having three or four spokes, as shown in FIGS. 7 and 8, for example. This is more clearly confirmed by the results of the bending strength test of the steering wheel core material. This test is performed, for example, as shown in FIG. 10, by applying a load W to one spot on the ring portion of the steering wheel core 9 from above and measuring the amount of deflection δ of the steering wheel core 9 at this time. . FIG. 9 shows the relationship between the load W and the amount of deflection δ for each of the above-mentioned fiber-reinforced resin steering wheel core materials having two, three, and four spokes. From this figure, it can be seen that the larger the number of spokes, the more difficult the steering wheel core material is to bend and the more advantageous it becomes in terms of bending strength.
However, if a steering wheel is designed with too many spokes, when it is installed inside a car, it will be difficult for the driver to see the instruments at the front of the car, and the visibility of the instrument panel will deteriorate. Furthermore, an increase in the number of spokes goes against measures to reduce the weight of the steering wheel.

Now, in consideration of the above circumstances, the irregular two-spoke type steering wheel core material 10 shown in FIG. A steering wheel core material 10 has been proposed in which the steering wheel core material 10 has a structure in which the core material is branched from two locations of the ring part 2, and one part is stretched over the upper part of the boss part 3 and the other part is stretched over the lower part of the boss part 3. There is. However, in a torsion test, the steering wheel core material with this structure showed that when force F was applied to the ring part 3 in the tangential direction,
It was found that an extremely large bending moment acts on the branching portion between the boss portion 3 and the spoke portion 4, and it was confirmed that there are still problems in terms of strength and rigidity. Furthermore, this type of steering wheel was never satisfactory in terms of visibility and aesthetics of the instrument panel.

The first object of the present invention is to solve the above-mentioned problems, and provide a steering wheel using continuous fibers that has sufficient rigidity and strength, is lighter than conventional ones, and has good visibility on the instrument panel. Our goal is to provide wheel core materials.

A second object of the present invention is to provide a method for manufacturing a steering wheel core material that can reliably manufacture the above-mentioned steering wheel core material that has high rigidity, high strength, and is lightweight.

<Means for Solving the Problems> The steering wheel core material of the present invention is a two-spoke core material made of resin-impregnated continuous fibers, and the left and right spoke portions are adjacent to the ring portion, respectively. This core material has a structure that branches from two places and converges near the boss. That is, the steering wheel core material of the present invention is formed by repeatedly winding a resin-impregnated fiber bundle of continuous filaments to form a boss portion at the center of the core material, a ring portion around the outer periphery of the core material, and spoke portions connecting these parts, and The spoke portion is formed such that two sets of resin-impregnated fiber bundles on each of the left and right sides of the core material diverge from two mutually adjacent locations of the ring portion and converge near the boss portion. It is characterized by this.

In addition, the method for manufacturing a steering wheel core material of the present invention is an effective method for manufacturing the above-mentioned steering wheel core material, in which a bundle of continuous long fibers is impregnated with a resin and then repeatedly wound around a predetermined shape material. A boss portion, a ring portion around the outer periphery of the core material, and a spoke portion connecting these are formed, and at this time, two sets of fiber bundles are branched from two mutually adjacent locations of the ring portion on each of the left and right sides of the core material. Moreover, the spoke part is formed by spanning between the ring part and the boss part so as to converge near the boss part, and then the resin is cured.

<Function> In the steering wheel core material of the present invention, the spoke portion is formed by branching resin-impregnated fiber bundles from two locations on the left and right sides of the ring portion and extending them to the boss portion, respectively, to reduce bending stress. When stress is applied to the ring part, the stress is dispersed through the four spokes, so the amount of deflection is very small. That is, the steering wheel core material of the present invention has a bending rigidity comparable to that of the three-spoke conventional steering wheel core material shown in FIG.

Moreover, the steering wheel core material of the present invention is
The spoke part has a structure in which two sets of resin-impregnated fiber bundles are converged into a single bundle near the boss part,
The spoke portion is extremely thick near the boss portion. Therefore, the core material of the present invention can sufficiently withstand even when a considerable bending moment is concentrated at the branching portion between the boss portion and the spoke portion and a large torsional stress is applied to that portion.

Furthermore, the steering wheel core material of the present invention is basically a two-spoke type steering wheel core material, and like the conventional two-spoke type steering wheel, the steering wheel core material of the present invention is a steering wheel core material of a two-spoke type. The structure is easy to see.

<Example> Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the steering wheel core material 1 of the embodiment is made by repeatedly winding resin-impregnated fiber bundles of continuous long fibers such as carbon fibers and glass fibers.
A boss part 3 at the center of the core material, a ring part 2 around the outer periphery of the core material, and spoke parts 4 connecting these parts are molded, and the boss part 3 is made of a resin-impregnated fiber bundle attached to a boss metal fitting 6 for fitting into the steering wheel shaft. In the spoke part 4, two sets of resin-impregnated fiber bundles 5, 5 are branched from two positions close to each other in the ring part 2 on each of the left and right sides of the core material, and the spoke part 4 has two sets of resin-impregnated fiber bundles 5, 5 branched from two places close to each other in the ring part 2, as shown in FIG. The fiber bundles 5 are stretched so as to converge into a bundle near the boss portion 3, and each set of fiber bundles 5 is further tied together with a binding fitting 8 after winding. That is, the steering wheel core material 1 of the embodiment has a structure in which the fiber bundles 5 of the spoke portions 4 are branched from two locations on each of the left and right sides of the ring portion 2, and the spoke portions 4 are arranged in the vicinity of the boss portion as shown in FIG. As shown in the figure, the shape is thick in the direction in which torsional stress is applied.

This steering wheel core material 1 is first made of continuous long fibers (8 to 15 μm in diameter) such as glass fibers.
A bundle of 30,000 fibers is immersed in a resin solution such as epoxy resin or polyester resin to impregnate the bundle of continuous filaments with the resin, and then the resin-impregnated fiber bundle 5 is molded into a predetermined mold (including the boss metal fitting 6). The boss portion 3, the ring portion 2, and the spoke portion 4 are formed by repeatedly winding the fiber bundles 5, 5 on each of the left and right sides.
are branched from two places close to each other on the ring part 2 and converged near the boss part 3 to form a bundle between the ring part 2 and the boss part 3 to form the spoke part 4, Thereafter, it is manufactured by curing epoxy resin or the like by heating, for example. The repeated winding of the fiber bundle 5 is carried out, for example, according to the three winding procedures shown in FIGS. 5a to 5c.

Then, as shown in FIG. 10, a load W is applied from above to the ring portion 2 of the steering wheel core material 1.
, the amount of deflection δ of the core material 1 was as small as that of a conventional three-spoke steering wheel core material. Furthermore, when the steering wheel core material 1 was subjected to the above-mentioned torsion test (see Fig. 11), it was found that it could sufficiently withstand even when a large bending moment was applied to the branching portions of the boss portion 3 and the spoke portions 4, and the steering wheel core material 1 could withstand torsion. It was confirmed that the resistance against the steering wheel core material 10 was improved by about 10% compared to the steering wheel core material 10 shown in FIG.

In addition, in the steering wheel core material 1, since the amount of fiber bundles 5 around the boss portion differs depending on the direction, the boss metal fitting 6 has irregularly shaped flanges 7, 7 as shown in FIGS. 4 and 5. It is preferable that the In addition, the shape of the flange 7 of the boss metal fitting 6 (particularly the length a), the diameter b and width c of the shaft, etc. are determined by the diameter and number of windings of the fiber bundle 5 and the structure of the steering wheel (spoke opening angle, inclination). angle).

<Effects of the Invention> The steering wheel core material of the present invention is made of a resin-impregnated fiber bundle of continuous long fibers, and the left and right spoke portions are branched from two adjacent locations of the ring portion, respectively, and the spoke portions are formed in the vicinity of the boss portion. By using a two-spoke steering wheel core material with a converging structure, it can withstand strong bending stress even if strong bending stress is applied to the core material, and even if a large bending moment is concentrated at the branching part between the boss and spoke parts. It has extremely high strength and rigidity, and is also lighter than conventional materials. Furthermore, the shape of the instrument panel makes it easy for the driver to see the instruments, and the visibility of the instrument panel is good, and it also has an excellent aesthetic appearance.

Moreover, the method for manufacturing a steering wheel core material of the present invention can reliably manufacture the above-mentioned steering wheel core material that has high rigidity, high strength, and is lightweight.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a steering wheel core material according to an embodiment of the present invention, FIG. 2 is a perspective view showing the vicinity of the boss portion of the steering wheel core material in FIG. 1, and FIG. 4 is a front view showing the boss metal fitting used for the steering wheel core material in FIG. 1, and FIG.
Sectional view taken along the - line in the figure, Figures 6 a to c
are diagrams showing the winding procedure of the resin-impregnated fiber bundle in the manufacturing process of the steering wheel core material in Figure 1, respectively, and Figures 7 and 8 are the basics of three-spoke and four-spoke steering wheel core materials. Figure 9 is a diagram showing the results of bending tests for various steering wheel core materials, Figure 10 is a diagram showing the method of torsion testing of steering wheel core materials, and Figure 11 is a diagram showing the conventional fiber-reinforced core material. FIG. 2 is a front view showing a resin steering wheel core material and a torsion test method.

Claims (1)

[Scope of Claims] 1. A boss part at the center of the core material, a ring part around the outer periphery of the core material, and spoke parts connecting these parts are formed by repeatedly winding a resin-impregnated fiber bundle of continuous long fibers, and the spoke parts are On each of the left and right sides of the core material, two sets of resin-impregnated fiber bundles are formed so as to branch from two mutually adjacent locations of the ring portion and converge near the boss portion. Steering wheel core material. 2. A fiber bundle of continuous long fibers is impregnated with resin and then repeatedly wound around a predetermined shape material to form a boss part at the center of the core material, a ring part around the outer periphery of the core material, and spoke parts connecting these parts, and at this time, the left side of the core material and the right side, the two sets of fiber bundles are branched from two points close to each other on the ring portion and are strung between the ring portion and the boss portion so as to converge near the boss portion to form the spoke portion. A method for producing a steering wheel core material, which comprises forming the core material and then curing the resin.