JPH04254201A - Resinous wheel - Google Patents

Abstract

PURPOSE:To reduce weight of a resinous wheel and improve the strength. CONSTITUTION:A resinous wheel is formed of fiber reinforcing thermoplastic resin by means of injection molding or injection compression molding so as to be in one united body, and ornamental holes are not arranged in a disk part. That is, the resinous wheel is formed in a blind patch shape without holes except that an axle shaft hole or the axle shaft hole and a bolt hole are arranged. The resinous wheel is of lightweight, and has high strength, and is excellent in mass production.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a resin wheel, and is a resin wheel that is particularly excellent in mechanical properties such as impact strength, bending strength, rigidity, heat resistance, fatigue resistance, and creep resistance, and is lightweight and suitable for mass production. Regarding wheels.

0002

[Prior Art] Conventionally, wheels for automobiles, for example, are generally made of steel or light alloy (aluminum alloy, etc.).
Manufactured from magnesium alloy).

[0003] Steel wheels are manufactured by press or roll forming, but there are many variations in forming dimensions, and there are disadvantages in that the roundness of the bead seat part of the rim tends to be irregular, and the weight is high. Since it is heavy, it is not desirable in terms of weight and in terms of reducing the weight of automobile parts.

On the other hand, light alloy wheels have stable molded dimensions, and are about 100% lighter than steel wheels in terms of weight.
Although the weight is significantly reduced by /3, the disadvantage is that the material cost is 3 to 5 times higher than that of steel wheels.

By the way, from the viewpoint of energy saving, which has been emphasized in recent years, reducing the weight of automobile parts is an extremely important requirement, and in particular, unsprung members such as wheels,
Further weight reduction is desired in order to improve fuel efficiency and maneuverability.

[0006] Against this background, recently,
A resin wheel was proposed as a wheel that satisfies light weight, molding stability, and low cost. The resin wheel is
F, which is a mixture of thermosetting resin with short or long reinforcing fibers.
Molded using RP as the main material, it is lighter than metal wheels and has superior stability in molded dimensions. It also has good productivity, reduces product costs, and has better design such as coloring. Expectations are high that it will also be extremely good.

[0007] Characteristics required of such a resin wheel include: (1) high impact strength in order to prevent breakage; ■ Creep must be small to prevent the tire from coming off the wheel. ■ Excellent heat resistance against the heat of the brake drum. ■ Excellent uniformity. That is, since wheels are one of the important parts for automobiles, molded products with uneven or defective parts cannot be used as wheels. ■
Capable of mass production. can be mentioned.

[0008] Generally, a wheel is composed of a rim part 1, a disc part 2, etc., as shown in Fig. 6 (upper half sectional view) and Fig. 7 (perspective view). A hole 3, a hub bolt hole 4 and a decorative hole 5 are provided. However, if commercially available aluminum wheels are classified from a structural perspective, there are two types of wheels: one-piece wheels in which the rim part 1 and disc part 2 are molded integrally, and two-piece wheels in which the rim part 1 and disc part 2 are molded independently and then connected with metal bolts. It is broadly divided into two-piece wheels that are joined together and integrated. Two-piece wheels have a great advantage over one-piece wheels in that by changing the design of the disc part 2 while keeping the rim part 1 the same, it is possible to provide wheels with a variety of combinations. . On the other hand, in order to join the rim part 1 and the disc part 2, it is necessary to provide an overlapping part between them, and furthermore, this part is joined with metal bolts, which has the disadvantage that it is heavier than a one-piece wheel.

[0009] On the other hand, since a resin wheel naturally has its light weight as a major selling point, configurations that increase weight can be avoided as much as possible. For this reason, conventional commercially available resin wheels are currently developed on the premise that they will be made into one-piece wheels by compression molding thermosetting resin.

0010

[Problems to be Solved by the Invention] Among the conventional molding methods for resin wheels, wheels manufactured by compression molding are superior in terms of rigidity, strength, etc. because fiber damage during molding is relatively slight. . Moreover, since the resin used is mainly a thermosetting resin, the heat resistance and creep resistance are also good. However, it is unsuitable for molding complex-shaped objects (for example, those with significant changes in wall thickness), and has the disadvantage of poor productivity due to the long molding cycle.

In contrast, the injection molding method has extremely high productivity and is superior in terms of production costs, but the drawback is that injection molded products generally have a lower strength of 1/3 to 1/5 than compression molded products. There is. This is caused by the breakage of fibers during resin kneading and flow, the orientation of fibers and molecules caused by flow, and
In particular, when a hole or the like exists in the product, weld lines occur at the resin confluence point, which causes the physical properties of the material constituting the molded product to become uneven or deteriorate, resulting in a decrease in strength. Particularly in the case of wheels, as shown in Fig. 7, many decorative holes 5 are provided in the disc part 2 for design reasons and to increase the air cooling effect during rotation, and the brake drum of the car body is also provided with many decorative holes 5. Since there are bolt holes 4 for fastening, etc., the shape has many weld lines. Therefore, to date, no resin wheel made by injection molding using thermoplastic resin has been completed and commercially available.

[0012] The present invention solves the above conventional problems by eliminating decorative holes in the disk portion, and improves bending strength, rigidity,
The objective is to provide a resin wheel that has excellent mechanical properties such as impact strength, heat resistance, fatigue resistance, and creep resistance, and that can be mass-produced at low cost.

[0013]

[Means for Solving the Problems] The resin wheel of claim 1 is a one-piece wheel in which a rim portion and a disk portion are integrally molded, and a blind plate-like space is provided between the axle hole of the disk portion and the rim portion. It is characterized by being non-porous and being obtained by injection molding or injection compression molding of fiber-reinforced thermoplastic resin.

[0014] The resin wheel according to the second aspect of the present invention is a one-piece wheel in which a rim part and a disc part are integrally molded, in which only bolt holes are formed between the axle hole of the disc part and the rim part, and other parts are formed. It is characterized by being non-porous in the form of a blind plate, and being obtained by injection molding or injection compression molding of a fiber-reinforced thermoplastic resin.

[0015]

[Function] The resin wheel of the present invention is an integrally molded product obtained by injection molding or injection compression molding using fiber-reinforced thermoplastic resin. This structure does not include decorative holes. Although the resin wheel of the present invention without decorative holes is an injection molded or injection compression molded product using fiber-reinforced thermoplastic resin, it has excellent strength. It has the advantages of an integrally molded plastic resin product: low cost, recyclability, light weight, and mass production.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the drawings. 1 to 5 are cross-sectional views showing one embodiment of the present invention. The resin wheel of the present invention has a blind plate-like gap between the axle hole of the disk part and the rim part, or
Only bolt holes are formed between the axle hole of the disk part and the rim part, and the other parts are blind plate-like and have no holes. That is, the resin wheel of the present invention does not have decorative holes.

[0017] Since the resin wheel of the present invention does not have decorative holes, it is conceivable that the air cooling effect of the rotating shaft is reduced. Therefore, in the resin wheel of the present invention, it is preferable to improve this point by implementing the following measures.

For example, wheels are typically attached via hub bolts to a disc adjacent to a brake drum or brake disc. Therefore, the area around the hub bolt hole is directly affected by brake heat generation, and during long-term use, stress relaxation occurs as the resin softens and creeps.
The hub nut becomes loose. In order to solve this problem, for example, Fig. 1 (cross-sectional view near the hub part) and Fig. 2 (
As shown in FIG. 1 (enlarged view of section ■ in FIG. 1) and FIG. 3 (cross-sectional view taken along the line ■-■ in FIG. It is preferable to have a structure in which a member 20 having both the above-mentioned characteristics and the above-mentioned properties is fitted together, and the tightening force of the hub nut 22 is transmitted to the brake drum 24 through this fitted member. (In the figure, 25 is a tire.)
In this case, optimal materials for the fitting member 20 include metal, heat-resistant plastic, FRP thereof, carbon fiber-reinforced carbon composite, and ceramic.

[0019] Furthermore, in order to cut off heat from the brake drum, a method of insert molding a heat insulating material on the surfaces of the disc portion and the rim portion on the brake drum side may be considered. In this case, such improvements may be made, for example, as shown in FIG. Even if the entire surface is 33, the entire surface on the brake drum side (i.e. surface 3
1, 32 and 33). Examples of heat insulating materials to be used include plates made of heat-resistant plastics, ceramics, inorganic materials, and their reinforcements, and slate boards made of asbestos, etc., but any material with heat insulating properties and strength can be used. is also available.

[0020] In the present invention, the reinforcing fibers added to the synthetic resin include glass, carbon, graphite,
Aramid, polyethylene, ceramic (SiC, Al2
Examples include fibers of metals (boron, stainless steel, etc.). Among these, carbon and glass are particularly effective. If the diameter of such reinforcing fibers is too small, a sufficient reinforcing effect cannot be obtained, whereas if it is too large, injection compression molding becomes difficult and moldability deteriorates. Therefore, the diameter of the reinforcing fibers is 0.1 to 100 μm, especially 0.5 to 100 μm.
A range of 50 μm is preferable.

[0021] If the amount of such reinforcing fibers is too small, a sufficient reinforcing effect cannot be obtained, whereas if it is too large, there will be a shortage of matrix resin, resulting in poor moldability. For this reason, the blending amount of reinforcing fibers is preferably 5 to 70% by volume, particularly preferably 10 to 60% by volume, relative to the molding material.

[0022] In the present invention, a particularly preferable molding material is a granular body obtained by cutting a rod-shaped body having a diameter of 2.5 to 3 mm into lengths of, for example, 10 mm, which are formed by pultrusion using continuous fibers and a thermoplastic resin. Can be mentioned. in this case,
As mentioned above, the length of the reinforcing fibers contained can be arbitrarily adjusted by changing the cutting length. Furthermore, since it is formed by pultrusion molding, resin impregnation between the fibers is sufficient despite the long fibers. Furthermore, as mentioned above, although the mechanical properties of this type of long fiber reinforced resin are significantly improved compared to ordinary short fiber reinforced resin, there is almost no loss in moldability or processability, and the same level of Good moldability and workability can be obtained. In addition,
In order to improve the processability of these long fiber reinforcements,
It is extremely effective to mix and use ordinary short fiber reinforced resins. In this case, the mixing ratio of the short fiber reinforced resin is preferably 70% or less, preferably 60% or less of the total weight.

The resin wheel of the present invention can be easily manufactured by integrally molding such a fiber-reinforced thermoplastic resin by injection molding or injection compression.

[0024] The injection compression molding method described in the present invention means that the mold is opened slightly in advance or the mold is closed with a weak mold clamping force, and after the material is injected into the mold, the mold clamping force is applied. This is a method of compression molding by increasing the In particular, the injection compression molding method described in the present invention involves injecting molten resin into upper and lower molds installed between presses using an injection cylinder or an extruder. A molding method in which the mold is closed is preferred.

Incidentally, in recent years, energy conservation has been avoided due to social and environmental demands, and as mentioned above, there is a desire to reduce the weight of automobile parts. In particular, unsprung members are highly effective and are required to be lightweight from the viewpoint of maneuverability.

The thermoplastic resin constituting the resin wheel of the present invention includes various polyamide resins, specifically, nylon 6, 6, 6, 4, 6, 6, 10, 10, 11, 12.
Aromatic polyamide, etc., polybutylene terephthalate (P
BT), polyphenylene sulfide (PPS), acetal resin (POM), polycarbonate (PC), polyethylene terephthalate (PET), polypropylene (
PP), polyether sulfone (PES), polysulfone (PSF), polyether ether ketone (PEEK)
), polyphenylene oxide (PPO), polyamideimide (PAI), polyimide (PI), polyester, various liquid crystal polymers, etc. can be used. Among these, various polyamide resins, PBT, PPS, POM,
Preferred are PC, PES, PI, PAI, PEEK, polyester, various liquid crystal polymers, and the like. These thermoplastic resins may be used alone or as a mixture of two or more.

These synthetic resins have weather resistance, heat resistance,
Mixing necessary amounts of various fillers, anti-aging agents, cross-linking agents, oils, plasticizers, oligomers, nilastomers, etc. for the purpose of improving wear resistance, fluidity, thermal expansion, flame retardance, chemical resistance, etc. It is also possible to do so.

[0028] For this reason, it is preferable that the wheel is combined with a reinforcing structure to further improve strength and a lightweight structure. The parts to which these structures are introduced may be the entire wheel, only the rim part, only the disc part, or can be used in other necessary parts as appropriate.

As a reinforcing structure, for example, as shown in FIG. 5, a certain type of reinforcing layer, specifically a layer with an increased amount of reinforcing fibers, or a reinforcing member, etc., is used as the intermediate layer 18 of the wheel body 17. Alternatively, a structure introduced as the surface layer 19 can be adopted. (In addition, in FIG. 5, the boundary line of each divided molded body is omitted from illustration.) In this case, the materials used for the reinforcing layer include glass, carbon, graphite, aramid, ceramic (SiC, Al2O3
etc.), metals (boron, stainless steel, etc.), and their forms include unidirectional long fibers such as roving, cloth, braid, stranded wire, net, and linear structures made by arranging these and hardening them with resin. Alternatively, plate-like materials (FRP), three-dimensional fabrics, etc. are optimal. When filling and arranging a reinforcing layer in a wheel, insert molding is advantageous, in which a filler having a predetermined shape is preformed, and the filler is placed in a predetermined position in a mold and then injection molded.

The resin wheel of the present invention also has the advantage that a device with another function can be embedded in the wheel and integrally molded. For example, by embedding and integrally molding an abnormality warning device such as a tire puncture warning device into a wheel, a safe automobile suspension component in which the wheel and tire are integrated can be provided. It is also easy to integrally mold a fail-safe mechanism, such as a rib on the rim of the wheel, with the wheel.

If the resin wheel of the present invention requires a decorative hole, the decorative hole can be provided by post-processing such as cutting after molding. By doing so, it is possible to avoid a decrease in strength due to welding.

[0032]

[Effects of the Invention] As detailed above, the resin wheel of the present invention is lightweight and has high strength, especially bending strength, impact strength,
Excellent properties such as rigidity, heat resistance, fatigue resistance, and creep resistance. ■ Excellent uniformity, with almost no variation in product quality. ■ Excellent in mass production, reducing product costs. This is a resin wheel with an extremely lightweight and reinforced structure that has the following effects. According to the present invention, a highly practical resin wheel is provided.

The resin wheel of the present invention can be used not only as a wheel for automobiles in a narrow sense such as passenger cars, buses, and trucks, but also for railway vehicles, subway vehicles, linear motor cars, aircraft, motorcycles, bicycles, golf and amusement parks. It is also suitable as a wheel for a wide range of automobiles, such as go-karts for recreational purposes such as land use.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a resin wheel of the present invention.

FIG. 2 is an enlarged view of section 2 in FIG. 1;

3] FIG. 3 is a sectional view taken along the line ■-■ in FIG. 2.

FIG. 4 is a sectional view showing another embodiment of the resin wheel of the present invention.

FIG. 5 is a sectional view showing another embodiment of the resin wheel of the present invention.

FIG. 6 is a sectional view of a conventional resin wheel.

FIG. 7 is a perspective view of a conventional resin wheel.

[Explanation of symbols]

1 Rim part 2 Disc part 3 Axle hole 4 Bolt hole 10 Resin wheel

Claims (2)

[Claims] Claim 1: A one-piece wheel in which a rim part and a disc part are integrally molded, wherein the space between the axle hole of the disc part and the rim part is a blind plate-like non-porous part, and a fiber-reinforced thermal A resin wheel characterized in that it is obtained by injection molding or injection compression molding of a plastic resin. Claim 2: A one-piece wheel in which a rim part and a disc part are integrally molded, in which only bolt holes are formed between the axle hole of the disc part and the rim part, and the other parts are blind plate-like blanks. 1. A resin wheel, which has holes and is obtained by injection molding or injection compression molding of a fiber-reinforced thermoplastic resin.