JPS62275801A - Rim for wheel and manufacture thereof - Google Patents

Abstract

PURPOSE:To aim at improvement in strength and the promotion of lightweightiness in combination, by forming the spoke supporting part alone to be thicker than other parts, in case of a rim consisting of fiber reinforced plastics. CONSTITUTION:A rim 1 is formed into an almost heart-shaped cross-section form with hollow fiber reinforced plastics, and a tire 2 is fitly attached to the concave outer surface. And, metallic eyelets 3 for stretching a spoke 4 are attached to this rim 1 at a constant pitch in the longitudinal direction. In this case, a part, where each eyelet 3 is attached, of the rim 1, namely, a support part of the spoke 4 is formed to be thicker than other parts. With this constitution, only the required part of the rim 1 is formed in a thicker wall, making it fully resistible to stretching force of the spoke 4, whereby improvement in strength and the promotion of lightweightiness both come to fruition.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Industrial Field of Application This invention (Jl) relates to a wheel rim A5 and a method for making the rim, more specifically, to hold it during rotation [1- A rim 3'3 which is suitable as a rim for a bicycle drace, and a manufacturing method thereof.

Conventional technology rims are found in automobiles, motorcycles, bicycles, etc., and form a groove in the wheel together with spokes, tires, etc., and support the vehicle d3 and the passenger's small items, as well as transmit driving force and braking force to the tires.

By the way, due to the nature of road racing, when it comes to road racing bicycles, the gravity of the rim is reduced to make the wheels faster and, by extension, the weight of the bicycle lighter, as well as made thinner to reduce air resistance as much as possible. Efforts are being made to improve driving performance, especially acceleration performance, and to reduce energy consumption by racers. Needless to say, vehicles are required to have strength and rigidity that can withstand increased loads associated with high-speed running, especially impacts.

Now, rims are generally made of light alloys such as aluminum alloys, not just for low-race bicycles. This shaft alloy rim is lighter than other metal rims. However, even though it is a light alloy, it is still a metal, and it does not have particularly high specific strength or specific rigidity, so it is difficult to significantly reduce the weight.

On the other hand, JP-A-56-122 and JP-A-59-325
Publication No. 03 describes a rim made of fiber-reinforced plastic (FRP) made by reinforcing resin with reinforcing fibers and having a uniform wall thickness throughout the rest. This FRP
′! Since FRP has higher specific strength and specific rigidity than light alloy, the A-rim seems to be considerably lighter than one made of shaft alloy. However, this is not necessarily the case.

That is, the rim has a perforated spoke support part for stretching the spokes, and the support part must, of course, be able to sufficiently withstand the tension of the spokes. is made to have a uniform wall thickness throughout, so if you design the wall thickness with the strength of the spoke support part in mind, the other parts will have more wall thickness than necessary, resulting in an increase in weight. If you ignore it, 1q will be lost.

Problems to be Solved by the Invention This invention solves the above-mentioned drawbacks of conventional FRP rims,
Lightweight and high-strength wheel rim Onibiso'bU)I
The purpose is to provide an E-method.

Means for Solving the Problems In order to achieve the above objects, the present invention provides a rim made of fiber-reinforced plastic made by reinforcing resin with reinforcing fibers, and in which the spoke support portions are lower than the round portions. There is also provided a wheel rim characterized by having a thick wall.

In addition, in this invention, a plurality of wire rods each having small diameter portions formed at an arbitrary constant pitch are passed through an elastic tube with the small diameter portions aligned, and a rod-shaped core material is inserted into the elastic tube. Push the wire rod through the core 4.
Arrange the wire rod on the outer peripheral surface of A, wrap reinforcing fibers impregnated with resin around the outer peripheral surface of the elastic tube and at a position corresponding to the small diameter portion of the wire rod, and roughly wrap around the outer peripheral surface.
However, this time, the resin-impregnated reinforcing fiber is wound around the entire length of the elastic tube, the core material is pulled out, and the wire is drawn out, and then the resin is cured while pressurizing the inside of the elastic tube in a mold. A method of manufacturing a rim for a middle wheel is provided. However, reinforcing fibers impregnated with resin are wrapped around the outer peripheral surface of the elastic tube and over the entire length of the elastic tube, and the resin-impregnated reinforcement is applied roughly around the outer peripheral surface, but this time at a position corresponding to the small diameter portion of the wire rod. It is also possible to wrap fibers around it.

Embodiment In FIG. 1 and FIG. 2, a rim 1 is made of hollow FRP made by reinforcing fat with reinforcing fibers, and has a substantially heart-shaped cross-sectional shape, and has a tire 2 on its concave outer surface. The rim 1 is fitted with metal eyelets 3 at a constant pitch in the longitudinal direction to extend the spokes 4, and the outer surface of the rim receives surface pressure from the tie V2. It is being taken.

However, this eyelet 3 is not necessarily necessary.However, the part of the rim 1 where the eyelet 3 is provided, that is, the support part 5 of the spoke 4 is thicker than the pond part. It is made in

In the above, FRP uses high-strength, high-modulus fibers such as carbon fiber, glass fiber, aramid fiber, alumina fiber, and silicon carbide fiber as reinforcing fibers, and uses such reinforcing fibers to infuse epoxy resin, unsaturated polyester resin, etc. , thermosetting resins such as vinyl ester resins and phenolic resins, and thermoplastic resins such as nylon resins, polyester resins, polysulfone resins, polyether sulfur resins, polyolefin resins, and polybutylene terephthalate resins. This is what I did. The above reinforcing fibers are arranged in the vertical direction (
In order to minimize compressive deformation of the rim in the vertical direction in Fig. 1, the longitudinal direction of the rim is ±30° relative to the longitudinal direction in order to minimize torsional deformation.
It is preferable that they are arranged in two directions in the bias direction of ~60°, preferably ±40 to 50°. It is most preferable that the longitudinal reinforcing fibers are correctly aligned in the direction Oo with respect to the longitudinal direction, but angles up to about ±10' are permissible. The bias direction reinforcing fibers extend continuously in a spiral shape in the longitudinal direction of the rim so as to wrap around the rim.

The longitudinal direction and bias direction reinforcing fibers may be mixed in the same plane or may be layered. For example, layered configurations can be explored in which bias direction reinforcing fibers form an inner layer, on which longitudinal reinforcing fibers are arranged as an outer layer.

The ratio of the bias direction reinforcing fibers depends on the arrangement angle, so it cannot be determined unconditionally, but it is 0.2 to 0.2 of the longitudinal direction reinforcing fibers.
Preferably, it is about twice as large. Generally preferred is 0
．． It is 5 to 1 times. In other words, in order to balance deformation due to vertical loads and deformation due to bending, twisting, and buckling due to side forces, there is an optimal range for the ratio of longitudinal reinforcing fibers to bias direction reinforcing fibers. . However, the range varies depending on the thickness of the rim, the cross-sectional shape, etc., so the optimal range that balances both should be selected.

In the embodiment described above, a hollow rim having a substantially heart-shaped cross-sectional shape has been described, but the cross-sectional shape of the rim can be appropriately selected depending on the application and the like.

The rim of the present invention as described above is manufactured as follows.

That is, first, as shown in FIGS. 3 and 4, an elastic tube 8 such as a rubber tube or a silicone tube is
To attach the spokes, a plurality of wire rods 7 having small diameter portions formed at an arbitrary constant pitch according to the pitch are passed through the elastic tube 8 with the small diameter portions aligned.
A rod-shaped core material 6 is passed through the wire rods 7 while pushing them apart so that the wire rods 7 are arranged in contact with each other on the outer peripheral surface of the core material 6.

That is, the wire rod 7 passed through earlier and the core material 6 passed through later constitute what is called a core body 9.
By selecting and using an elastic tube 8 having an inner diameter slightly smaller than the size of the circumscribed circle, four parts are formed on the outer peripheral surface of the elastic tube 8 corresponding to the positions of the small diameter portions of the line U7. However, it is not always necessary to form this recess.

Next, prepreg, which is made by impregnating reinforcing fibers with resin and pre-curing, is placed on the outer circumferential surface of the elastic tube 8 at positions corresponding to the small diameter parts of the wire 7, that is, at the four parts mentioned above, so as to fill the recesses. Wrap it until it runs out. This part is
This is the part that forms the thick spoke support part.

Next, the prepreg is roughly wrapped around the outer peripheral surface of the elastic tube 8, but this time over the entire length of the elastic tube 8, until it reaches a desired thickness, and then the body 9 is pulled off. This pulling is done by first pulling the material 6 and then pulling the wire 7.

Next, the elastic tube 8 wrapped with prepreg is
It is bent into a split mold having a ring-shaped cavity with a desired cross-sectional shape, and heated while pressurizing the inside of the elastic tube 8 with a pressure air shade to harden the resin of the prepreg. After curing, the pressure inside the elastic tube 8 is released, the mold is removed, and the elastic tube 8 is roughly handled to obtain a rim of the present invention of II:1. The rim after being removed is ring-shaped, but it is not a single piece, so the edge
For example, they are joined together by adhesive or by polu 1 to make a complete ring. Additionally, attach eyelets if necessary.

In the above, prepreg is first wound around the recess (-1(
We have explained the case where the prepreg is wrapped around the entire length of the elastic tube to eliminate the level difference. However, it is also possible to first wrap the prepreg to a uniform thickness over the entire length of the elastic tube, and then wrap the prepreg around the recess to eliminate the level difference. In this case, after the recess is wound, the prepreg may be wound again over the entire length as necessary, thereby forming a so-called outermost layer.

Further, instead of using prepreg, a method generally called the filament 1 winding method may be used, in which the reinforcing fibers are immersed in a resin bath and run around, thereby winding the reinforcing fibers impregnated with resin. That is, the resin-impregnated reinforcing fiber used in this invention may or may not be prepreg-formed.

Hereinafter, this invention will be explained in more detail based on Examples.

Example A silicone tube with an inner diameter of 14 mm and an outer diameter of 15 mm,
Passed multiple wires. The wire rod is made by joining stainless steel tubes with an outer diameter of 2.7 mm and a length of 42 mrn at intervals of 17 mm to a hardened rod wire with an outer diameter of 1 mm.

Next, an iron core material having an outer diameter of 11 mm was passed through the silicone tube while pushing the wire material apart. As a result, as shown in FIGS. 3 and 4, the silicone tube is placed over the core body 9, which is formed by arranging vAvJ' 7 on the outer circumferential surface of the core material 6. , four parts with a length of 17 mm were formed at a pitch of 61 mm.

Next, around the outer periphery of the silicone tube and in the recess, a prepreg made by impregnating and pre-curing a carbon fiber trading card T-300 manufactured by Toshi Co., Ltd. with an epoxy resin was hoop-wound until there was no difference in level.

Next, the prepreg is applied to the outer peripheral surface of the silicone tube, but now over its entire length, so that the direction of the carbon fibers is first aligned with the longitudinal direction of the silicone tube.
Roll it so that the angle is 15° and the thickness is 3mm, then roughly roll it on top of it, this time in the direction of ±1
It was wound so that the angle was 5° and the thickness was Q, 5 mm.

Next, the core material is pulled out, the wire is roughly drawn to the center, and the silicone tube wrapped with the prepreg is formed into a ring shape with a width of approximately heart-shaped in cross section.
The prepreg was placed in a mold and heated at about 140'C for about 2 hours while pressurizing the inside of the silicone tube with pressurized air to harden the prepreg (wound fat).

After cooling, the pressure inside the silicone tube was reduced to 5M to remove the mold, and the silicone tube was pulled to the center. To this, J:S, with a pitch of 61 mm, a thickness of 1 over a length of 17 mm.
．． A spoke support part of 3 mm was formed, and the other parts were made with a thinner thickness of 01 gmrn than the rim of the present invention.

Effects of the Invention The rim of the present invention has only the spoke support portions thicker than the other portions to sufficiently withstand the expansion tension of the spokes, and therefore has a long life despite its high strength. In other words, conventional FRP rims are made to have a uniform thickness throughout, so the thickness needs to be designed to match the strength of the spoke support. However, in this invention, IJ
5. The drawbacks of the conventional FRpv rim are solved by making only the spoke support portions thicker.

Furthermore, such a rim can be made by arranging wire rods with small diameter sections formed at arbitrary constant pitches on the outer circumferential surface of a rod-shaped core material, making it possible to use the general molding technology for FRP bent pipes as is. Can be easily manufactured.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams showing one embodiment of the wheel tsum of the present invention.
° Figure 2 is a longitudinal sectional view, Figures 3 and 4 are schematic diagrams showing the method of manufacturing the rim of the present invention, Figure 3 is a longitudinal sectional view, and Figure 4 is the same as in Figure 3 above. Make sure it is a 1-A sectional view. 1: Rim 2: Tire 3: Eyelet 4 Varnish bore 5 Varnish bore support part 6: Core material 7: Wire rod 8: Bow shell/I raw tube 9: Core body

Claims (3)

[Claims] (1) A wheel rim, which is made of fiber-reinforced plastic made by reinforcing resin with reinforcing fibers, and characterized in that spoke support parts are made thicker than other parts. (2) Pass a plurality of wire rods with small diameter portions formed at arbitrary constant pitches through an elastic tube with the small diameter portions aligned, and insert a rod-shaped core material into the elastic tube while pushing the wire rods apart. The wire is placed on the outer peripheral surface of the core material through the elastic tube, reinforcing fibers impregnated with resin are wrapped around the outer peripheral surface of the elastic tube and at a position corresponding to the small diameter portion of the wire, and further on the outer peripheral surface, however, Next, the resin-impregnated reinforcing fiber is wound around the entire length of the elastic tube, the core material is pulled out, and the wire rod is pulled out, and then the resin is cured while pressurizing the inside of the elastic tube in a mold. A method for manufacturing wheel rims. (3) Pass a plurality of wire rods with small diameter portions formed at arbitrary constant pitches through an elastic tube with the small diameter portions aligned, and insert a rod-shaped core material into the elastic tube while pushing the wire rods apart. The wire rod is placed on the outer circumferential surface of the core material through the elastic tube, reinforcing fibers impregnated with resin are wrapped around the outer circumferential surface of the elastic tube and over the entire length of the elastic tube, and then the wire rod is placed on the outer circumferential surface of the elastic tube. The resin-impregnated reinforcing fiber is wound around a position corresponding to the small diameter part of the elastic tube, the core material is pulled out, the wire rod is pulled out, and then the resin is cured while pressurizing the inside of the elastic tube in a mold. A method for manufacturing wheel rims.