JPS639534A - Production of steering wheel made of fiber-reinforced plastic - Google Patents

Abstract

PURPOSE:To enable a rim and spokes to be connected in a body through stiff and lightweight joints, by a method wherein a stepped part of the rim and the spoke are made to about on each other, a pair of punched metallic joint pieces light in weight and high in stiffness are placed respectively on the upper and lower sides of the abutting part, the joint pieces are press-fitted to each other to connect them in a body, knitted or braided members fitted over the joint parts thus connected are impregnated with a thremosetting resin, and the resin is hardened. CONSTITUTION:Upper and lower joint pieces 9a, 9b having punched holes and recessed parts and projected parts to be fitted to each other are opposed to each other at a jointing part for a rim 1 and a spoke 2, and upper and lower mating surfaces 11a, 11b are so mated that chambered parts of the projected parts 12a, 12b are matched to recessed parts 14b, 14a. The resultant assembly is pressed between metallic dies, whereby the projected parts 12a, 12b and the recessed parts 14b, 14a are firmly engaged to each other through plastic deformation under pressure because the projected parts 12a, 12b are larger than the recessed parts 14b, 14a, resulting in that the rim 1 and the spokes 2 are connected to each other in a body. Shot knitted or braided tubular belts 2-5cm in length which are previously fitted over the rim 1 are fitted over the connected parts, from positions slightly outside the ends of the rim part to the vicinity of the spoke 2, then the resultant assembly is placed in a metallic mold, a sufficient vacuum is drawn, a liquid thermosetting resin is poured into the mold to impregnate the tubular melts with the resin, and the resin is hardened to complete the connection of the rim and the spokes in a body.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a steering wheel made of m-fiber reinforced plastic, and in particular to a method for manufacturing its rim and connection to metal spokes.

[Conventional technology]

FIG. 8 is a front view showing a conventional steering wheel. In the figure, (1) is a ring-shaped rim that serves as a grip, (2) is a spoke provided to protrude inside the rim (1), and is connected to the boss (3) that is the attachment part of the steering shaft. It is a connecting part. (4) is a joint piece that joins the spokes (2) and the rim (1). 9th
10 and 10 are perspective views showing the state in which the rim (1) and the spokes (2) are joined by the joining piece (4), with FIG. 9 showing the state before joining and FIG. 10 showing the state after joining. In the figure, (5) is the butt piece of the spoke (2). 11th
The figure is a perspective view showing a state in which a braided bag band is braided around a coiled core material that is the core material of the rim (1). In the figure, (6
) is a core material made of a lightweight material, such as urethane foam, formed into a coil shape, and is provided with a small-diameter stepped portion (7). (8) is a braided bag band that is braided around the outer periphery of this core material (6), and is made of single or composite unidirectional fibers such as carbon fiber, glass fiber, or aramid wt fiber.

The conventional method of manufacturing a steering wheel is to first form a lightweight material into a coil shape and then create a core material (6) having a single stepped portion (7).
) to form. Next, as shown in Figure 11, this core material (
6) Form a braided bag band (8) by braiding unidirectional fibers around the outer periphery of the fabric, cut it at a predetermined length near the stepped part (7), and secure both ends to form a ring shape. As shown in Figure 9, the butt piece (5) of the spoke (2) is
) and swage the joint piece (4) against the rim (1) as shown in FIG. 10 to integrate the rim (1), spokes (2), and boss (3).

Next, it is placed in a mold (not shown), and after vacuuming, liquid thermosetting resin is injected to impregnate and harden.
1), spokes (2) and bosses (3) are integrally cured,
Further, if necessary, an outer layer mold (not shown) is applied to the outside of the rim (1) to form an uneven slip prevention part and the like.

[Problem that the invention seeks to solve]

The conventional manufacturing method for steering wheels is as described above.
In order to increase the rigidity of the joint between the rim (1) and the spokes (2), the stepped part (7) of the rim (1) and the spokes (2) are tightened by caulking the metal joint piece (4). Because the butt piece (5) was integrated, the weight ratio of this joint within the rim (1) was high, causing an imbalance and lowering the resonance point, making the steering wheel more likely to vibrate when driving at high speeds. This has the problem of reducing operational stability and causing discomfort to the driver.

This invention was made to solve the above-mentioned problems, and provides a method for manufacturing a fiber-reinforced plastic steering wheel that allows the rim and spokes to be integrated using a rigid and lightweight joint. The purpose is to obtain.

[Means for solving problems]

A method for manufacturing a steering wheel according to the present invention includes a ring-shaped rim that serves as a grip portion, a boss that is an attachment portion to a steering shaft, and spokes that integrally connect the rim and the boss. , the process of braiding unidirectional fibers into a sleeve shape into a coiled lightweight core material having a small-diameter stepped section, cutting the core material braided with the unidirectional fibers into an arbitrary ring-shaped length, and cutting both ends. A process of lashing and fixing to form a rim, a process of abutting the stepped part of the rim and the spokes, and having a divided shape corresponding to the abutting part of the rim and the spokes, and having a fitting part on the mating surface. This method includes the steps of integrating a rim and spokes by overlapping and press-fitting a joining piece made of punched metal onto the abutting portions of the rim and spokes, and a step of vacuum impregnating and curing thermosetting resin.

[For production]

In the method for manufacturing a fiber-reinforced plastic steering wheel according to the present invention, unidirectional fibers are braided into a sleeve shape around a coiled lightweight core material, and then cut into a ring shape and secured to form a rim. By butting the attached part and the spoke, stacking lightweight and highly rigid punching metal joint pieces on the butting part, press-fitting them to integrate them, and impregnating them with thermosetting resin and hardening them. .

A fiber-reinforced plastic steering wheel that is lightweight and has a well-balanced weight will be manufactured.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
6 to 6 show an embodiment of the present invention, FIG. 1 is a front view in cross section of a part of a steering wheel manufactured by a method according to an embodiment of the invention, and FIG. 3 is a sectional view taken along B-B in FIG. 1, FIG. 4 is a perspective view showing the joined state at the abutting portion of the rim and spokes before joining, and FIG. FIG. 6 is a front view of a part of the joint piece, and in the figure, (1) to (3) and (5) to (8) indicate the same or equivalent parts as in FIGS. 8 to 11. (9a) and (9b) are rims (1)
The stepped part (7) and the butt piece (5) of the spoke (2)
A lightweight and highly rigid joining piece divided into upper and lower parts for joining with punched holes in iron or aluminum, etc. (10)
It is made of punched metal with a large number of holes, and has a divided shape corresponding to the butt part of the rim (1) and the spokes (2), and has concave and convex shapes alternately on the mutual mating surfaces (lla) and (llb). Mochi, each convex part (12a
).

(12b) has a trapezoidal shape in which the tip dimension a is slightly larger than the root dimension, and has a chamfered portion (13) at the tip, and the concave portions (14a) and (14b) have the root dimension C at the tip. It has a trapezoidal shape larger than the part dimension d, and has a convex part (12a
), (12b) whose trapezoidal external dimensions are the concave portion (14
a).

It is slightly larger than the trapezoidal shape of (14b), and the mating surface (lla) of the upper and lower joint pieces (9a) and (9b) is
), (llb) are combined, the upper and lower convex portions (12a
), (12b) and the recesses (14b), (14a) are located opposite to each other, and have a structure that allows forcible press-fitting by press pressure.

(15) is a press-fitted upper and lower joint piece (9a), (
9b) A short braided bag band made by laminating the outer peripheral ends of (16)
is a lightweight core material covered with braided bag bands (8) and (15) (
6) is a thermosetting resin mold impregnated on the outer periphery.

The manufacturing method for a fiber-reinforced plastic steering wheel begins with molding a lightweight core material (6) having a single stepped portion (7), as in the conventional case, and braiding unidirectional fibers into a sleeve shape around the outer circumference of the core material (6). After forming a braided bag band (8), it is cut at one step part (7) and both ends are tied and fixed to form a ring shape to form a rim (1).

Next, as shown in Fig. 4, the butting pieces (5) of the spokes (2) are butted against the rim (1) at the stepped portions (7), and the punched holes (10) and the unevenness in which each fits are formed. The upper and lower joining pieces (9a) and (9b) are overlapped, and the upper and lower mating surfaces (lla) and (llb) are aligned to form a convex part (12a).
, the chamfered part (13) of (12b) is recessed part (14b)
, (14a), and when placed in a mold (not shown) and pressurized, a convex portion (12a) is formed.

The external dimensions of (12b) are recessed parts (14b) and (14a
), the rim (1) and spokes (2) are plastically deformed by press-fitting and mesh tightly as shown in Figure 5.
are integrated. Then, a short braided bag band (15) with a length of 2 to 5 cm, which has been inserted in advance into the rim (1), is attached to the spokes ( 2) is inserted up to the rim (1) near the rim (1) and laminated, then placed in a mold (not shown), sufficiently evacuated, and injected with liquid thermosetting resin to impregnate and harden. to form a thermosetting resin mold (16). At this time, at this butt part, the short braided bag f (15) is heat-cured from the punched hole (10), and further from the punched hole (10) to the braided bag g (8) below the joint pieces (9a) and (9b). As the resin penetrates and hardens, it is firmly fixed, producing a lightweight and highly rigid steering wheel. In this case, the joint piece (9a).

(9b) Short braided bag belt (
15), the joining pieces (9a) and (9
Stress changes due to rapid changes in Young's modulus near b) can be alleviated.

In addition, in the above embodiment, the short braided bag band (15) is connected to the joint piece (
9a) and (9b), but this may also be on the underside of the bonded pieces (9a) and (9b), and instead of the braided bag band (15), a woven fabric or unidirectional fibers may be wrapped. It's okay.

Moreover, the unevenness of the joint pieces (9a) and (9b) is the mating surface (ll
Instead of being formed around the entire circumference of a) and (llb), it may be provided only on the rim (1) and fixed by spot welding on the abutting piece (5) of the spoke (2).

Furthermore, in the above embodiment, the mating surfaces (lla) and (llb) of the joint pieces (9a) and (9b) were engaged and fixed to alternate unevenness in the direction perpendicular to the plate thickness, but as shown in FIG. A lap part (17) is provided on the mating surfaces (lla) and (llb) so that the mating surfaces (lla) and (llb) are lapped in the plate thickness direction and fitted by press pressure fitting,
A similar effect can be obtained even if the parts are fixed by fitting.

〔Effect of the invention〕

As described above, according to the present invention, there is a step of braiding unidirectional fibers into a sleeve shape in a coiled lightweight core material serving as the core material of the rim, and a step of braiding the core material with the unidirectional fibers braided into an arbitrary ring shape. The process of cutting the spokes to length and lashing them at both ends, the process of butting the spokes and the rim together, and the process of aligning the upper and lower joined pieces, which are lightweight, highly rigid, and have numerous punch holes at the butt part. The process includes the process of overlapping and press-fitting joint pieces with fitting parts that can be press-fitted with press pressure on the surfaces, and the process of vacuum impregnating and curing thermosetting resin, so the rim part is void-free and highly rigid. It is possible to manufacture lightweight rims, and at the joints with the spokes, the thermosetting resin can penetrate and impregnate the braided bag band through the punched holes without voids, and the thermosetting resin can be strengthened by press-fitting the irregularities of the joint piece and the thermosetting resin can be applied to the punched holes. By penetrating the steering wheel, it is possible to obtain strength against bending and torsion, and it is lightweight as a steering wheel, has sufficient rigidity, maintains a weight balance, and has a high resonance point, is less likely to vibrate, and has good steering stability. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a front view showing a cross section of a part of a steering wheel manufactured by a method according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. -B sectional view, Figure 4 is a perspective view showing the joined state of the rim and spokes before joining, Figure 5 is a perspective view showing the joined state of the rim and spokes after joining, Figure 6 is a front view of a part of the joined piece, and Figure 7 is the other FIG. 8 is a front view showing a conventional steering wheel, and FIGS. 9 to 11 are perspective views showing a conventional manufacturing method. In each figure, the same reference numerals indicate the same or corresponding parts, (1)
is the rim, (2) is the spoke, (3) is the boss, (4). (9a), (9b) are joint pieces, (6) are core materials, (8)
is a braided bag belt, (10) is a punched hole, (lla), (
llb) is the mating surface, (12a). (12b) is a convex portion, (14a) and (14b) are concave portions, (15) is a short braided bag band, and (16) is a thermosetting resin mold.

Claims (4)

[Claims] (1) In the method for manufacturing a steering wheel that consists of a ring-shaped rim that serves as a grip, a boss that is an attachment part to the steering shaft, and spokes that integrally connect the rim and boss, a small-diameter stepped part is A process of braiding unidirectional fibers into a sleeve shape into a coiled lightweight core material, and cutting the core material braided with the unidirectional fibers into an arbitrary ring-shaped length and securing both ends to form a rim. a step of forming a stepped part of the rim and a spoke, and a joining piece made of punched metal having a split shape corresponding to the butting part of the rim and spokes and a fitting part on the mating surface. A fiber-reinforced plastic steering wheel characterized by comprising a step of integrating the rim and spokes by overlapping and press-fitting the butt portions of the rim and spokes, and a step of vacuum impregnating and hardening a thermosetting resin. How to manufacture wheels. (2) The fiber reinforcement according to claim 1, wherein the joint piece has irregularities that alternately engage with the mating surfaces thereof, and the convex portion is slightly larger than the concave portion and has a shape that allows press-fitting. How to make a plastic steering wheel. (3) The method for manufacturing a fiber-reinforced plastic steering wheel according to claim 1 or 2, wherein the joint piece is made of iron or aluminum. (4) The method for manufacturing a fiber-reinforced plastic steering wheel according to any one of claims 1 to 3, characterized in that the joint pieces are welded at the butt portions of the spokes.