Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1999-02-18
2001-05-29
Aftergut, Jeff H. (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S171000, C156S184000, C156S187000, C074S552000, C029S894100, C264S478000, C264S645000, C264S241000, C264S271100
Reexamination Certificate
active
06238506
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method of manufacturing steering wheel, which has a fiber-reinforced synthetic resin rim, a metal center boss and metal spokes.
2. Description of the Related Art
A vehicle is provided with a steering wheel fitted to the upper part of a steering shaft. The driver of the vehicle rotates this steering wheel to activate a steering mechanism which changes the direction of steered wheels, thereby steering the vehicle.
FIG. 31
shows a framework of a conventional steering wheel. A skeleton
2
of carbon steel or aluminum alloy having a center boss
1
at its center, is first manufactured, and the outer part of this skeleton
2
is then covered by a synthetic resin
3
such as for example polyurethane resin, polypropylene resin or soft PVC resin so as to obtain a steering wheel suitable for steering as shown in FIG.
32
. The steering wheel is then connected to a steering shaft by a center hole
4
formed in the center of the center boss
1
.
To mitigate shocks and protect passengers, an airbag system is provided effectively in the center of the steering wheel. However, when an airbag system is fitted, its weight adds to that of the steering wheel so that the overall weight of the assembly increases.
In this respect, Japanese patent provisional publication No. 59-160666, for example, proposes a steering wheel having a magnesium alloy skeleton which is lighter than aluminum alloy. However this steering wheel was still not sufficiently lightweight. Other Japanese patent provisional publication No. 6206548 proposes a steering wheel wherein prepregs and foam sheets are laminated on a skeleton of low melting point alloy and cured to form a cast, following which the low melting point alloy forming the skeleton was removed by melting. This steering wheel is more lightweight, but it is difficult to manufacture. Further, it is difficult to insert fixing holes in airbag systems, horns and covers.
OBJECTS AND SUMMARY OF THE INVENTION
This invention, which was conceived in view of the above problems, aims to provide a method of manufacturing a steering wheel which is lightweight, has ample strength and shock absorption capacity, and is easy to manufacture.
Another object of this invention is to provide a method of manufacturing a steering wheel, the rim of which is made of a fiber reinfored hollow circular resin tube firmly jointed to a light weight alloy skelton.
A further object of this invention is to provide a method of manufacturing a steering wheel, spokes of which deform plastically for absorbing shock energy when impact force applied.
A still further object of this invention is to provide a method of manufacturing a steering wheel which has a low moment of inertia and is easy to control and has a “sporty” feel.
A still further object of this invention is to provide a method of manufacturing a steering wheel which is suitable to mount an airbag system on it.
A still further object of this invention is to provide a method of manufacturing a steering wheel which requires very little final machining.
A still further object of this invention is to provide a method of manufacturing a steeling wheel on which an unique texture of reinforcing fiber braid appears on the outer surface causing a high commercial value.
The steering wheel comprises:
a rim fabricated from a fiber-reinforced synthetic resin,
a metal center boss having a link portions joined to steering shaft, and
metal spokes joining the rim to the center boss.
The ends of the spokes are firmly joined to the fiber-reinforced synthetic resin rim.
The reinforcing fiber used in the fiber-reinforced synthetic resin of the rim may be carbon fiber, aramid fiber, glass fiber, ultra high molecular weight polyethylene fiber or high strength polyarylate fiber.
The spokes may comprise an aluminum alloy or magnesium alloy.
A counterweight for improving balance may be disposed inside the rim. This counterweight may comprise a metal plate, a solid comprising a resin cured with a metal powder, or metal fibers.
A process for manufacturing this steering wheel, comprises:
a step for covering a mandrel by a tube in which internal pressure is to be applied,
a step for laminating the mandrel covered by the tube with fiber-reinforced prepregs, and then removing it from the mandrel together with the tube so as to obtain a preformer,
a step for pressing and bending this preformer into a cavity of a mold corresponding to a rim of a steering wheel,
a step for setting a metal skeleton comprising a center boss and spokes in a one-piece construction, into this steering wheel mold,
a step for joining link portions at the ends of the spokes of the skeleton to the preformer by fiber-reinforced prepregs, and
a step for clamping the steering wheel mold and heating the preformer, the tube being under internal pressure so as to form the steering wheel.
An invention relating to another method of manufacturing a steering wheel, comprises:
a step for covering a mandrel by a tube in which internal pressure is to be applied,
a step for laminating the mandrel covered by the tube with fiber-reinforced prepregs, and then removing it from the mandrel together with the tube so as to obtain a preformer,
a step for injecting liquid substance into the tube of this preformer, and sealing the open end of the tube,
a step for pressing and bending the preformer into a cavity of a mold corresponding to a rim of a steering wheel,
a step for setting a metal skeleton comprising a center boss and spokes in a one-piece construction, into this steering wheel mold,
a step for joining link portions at the ends of the spokes of this skeleton to the preformer by fiber-reinforced prepregs,
a step for clamping the steering wheel mold and heating the preformer so as to form the steering wheel, and
a step for forming a small hole in the rim of the steering wheel, and heating the rim above the boiling point of the liquid substance so as to remove the same.
An invention relating to yet another method of manufacturing a steering wheel, comprises:
a step for injecting a lightweight foam into a mold having the shape remaining after subtracting the thickness of a fiber-reinforced resin of a rim of a steering wheel, and curing it so as to obtain a core,
a step for laminating fiber-reinforced prepregs on this core so as to obtain a rim preformer,
a step for pressing this preformer into a cavity of a mold corresponding to a rim of a steering wheel,
a step for setting a metal skeleton comprising a center boss and spokes in a one-piece construction, into this steering wheel mold,
a step for joining link portions at the ends of the spokes of this skeleton to the preformer by fiber-reinforced prepregs, and
a step for clamping the steering wheel mold and heating the preformer so as to form the steering wheel.
These inventions therefore provide a steering wheel which is lightweight, has adequate strength and shock absorption capacity, and a method of manufacturing this steering wheel easily.
The resin used in the fiber-reinforced synthetic resin rim of the steering wheel may be an epoxy resin, vinyl ester resin, unsaturated polyester resin, bismaleimide resin, polyimide resin, or a crosslinked polyester amide (CP resin). The fiber used to reinforce this resin may be carbon fiber, glass fiber, aramid fiber, ultra high molecular weight polyethylene fiber or high strength polyarylate fiber, as stated hereabove.
When the metal skeleton, which comprises the center boss and spokes in a one-piece construction, is joined to the rim, the skeleton is preferably protected by a woven prepreg of an insulating material such as glass fiber before making the join with the carbon fiber. This is in order to prevent galvanic corrosion due to contact between the metal of the skeleton and the carbon fiber.
When carbon fiber is used for the purpose of reinforcing, the orientation of the fibers preferably lies within a range of 10°-90°, and more preferably within a range of 30°-60°, relative to a center line through a section of the rim. This is made in order
Kaneko Tohru
Muraoka Tsutomu
Oe Naoki
Satoh Kazuyuki
Suzuki Keizoh
Aftergut Jeff H.
Kanesaka & Takeuchi
Rossi Jessica
Toho Rayon Co. Ltd.
LandOfFree
Method of manufacturing steering wheel does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing steering wheel, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing steering wheel will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2556409