JP2974963B2 - Bicycle wheel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle wheel made of hard synthetic resin or light metal.

[0002]

2. Description of the Related Art A bicycle wheel of this kind is connected to a hub supported by a bicycle axle, a plurality of spokes extending radially outward from the hub, and an outer end of the spoke. In addition, there is an annular rim portion to which a tire including a tube is fitted, which is formed by injection molding of a synthetic resin material. Some conventional spokes are hollow to reduce the weight. These hollows are formed by a blow molding method, or the wheels are divided into left and right parts, and the spokes are formed with concave portions. Then, the left and right sides are adhered to each other so that the recesses are abutted to form a hollow inside of the spoke portion.

[0003]

Among the above-mentioned prior arts, the method of making the spokes hollow by the blow molding method may not be uniform in thickness and may be unstable in strength. In the method of split molding, there is a problem that the number of steps such as a step of bonding the left and right is increased and the manufacturing cost is increased. The present invention has been made in view of the above-described situation, and the object is to facilitate the integral molding of the wheel and to stabilize the strength by making the thickness of the spoke portion uniform. Another object of the present invention is to provide a bicycle wheel that can reduce costs.

[0004]

According to the present invention, the following technical measures have been taken in order to achieve the above object. That is, the present invention provides a hub supported by an axle of a bicycle, a plurality of hollow spokes extending radially outward from the hub, a tube connected to an outer end of the spoke, and including a tube. An annular rim portion to which a tire to be fitted is integrally formed, and a through hole through which each cavity of the hollow spoke portion communicates is formed in the rim portion, and the through hole is connected to a through hole of the tube. A cap is provided to prevent swelling of the cover. In this way, by connecting each cavity of the spoke portion with the through hole provided in the rim portion, it is possible to integrally mold the core by an injection molding method or a casting method such as die casting. And the molding becomes easy. Further, by providing the cap in the through hole, the tube does not swell from the through hole into the cavity, and the deformation and breakage of the tube can be prevented (claim 1).

[0005] The present invention is characterized in that the hub, spokes and rim are integrally formed of a hard synthetic resin, whereby the bicycle having good mass productivity is easily formed by injection molding. Wheel and a lightweight bicycle wheel can be obtained (claim 2). Further, the present invention is characterized in that the hub portion, the spoke portion, and the rim portion are integrally formed of light metal, whereby a bicycle wheel is cast, for example, a cooling strain during forming when the wheel is formed by die casting. , It is possible to obtain a well-balanced wheel, and it is also possible to reduce the thickness of the wheel while maintaining the required strength, and to obtain a wheel with a lighter weight. 3).

The present invention is characterized in that each of the cavities of the spoke portion is formed in a tapered shape such that a cross-sectional area thereof gradually increases outward in a radial direction. The operation of detaching the core mold becomes easy (claim 4). Further, according to the present invention, each cavity of the spoke portion and the through hole are formed in a deformed ellipse having a long axis parallel to the circumferential direction of the rim portion, and the outer peripheral contour of the spoke portion has a streamline shape of a deformed ellipse. As a result, the air resistance associated with the rotation of the wheel is reduced, the running resistance of the bicycle is reduced, and the bicycle can be driven lightly (claim 5).

[0007] The present invention is characterized in that the outer surface of the cap is flush with the inner surface of the rim.
The deformation and damage of the tube in the tire are reliably prevented (claim 6). Further, the present invention is characterized in that a reinforcing rib which fits into the through hole is provided on the inner surface of the cap, whereby the cap is not damaged by the air pressure of the tube, and the through hole is securely provided. And the positioning of the cap with respect to the through hole is facilitated by the reinforcing rib (claim 7).

The reinforcing rib of the cap includes a vertical rib fitted between both ends of the through-hole in the circumferential direction of the rim,
It is characterized by a lateral rib fitted between both ends in the axial direction, so that the positioning of the cap in the circumferential direction and the axial direction with respect to the through hole is ensured (claim 8) .

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 16 show a first embodiment of a bicycle wheel 1 according to the present invention. The wheel 1 includes a hub portion 2 supported by a bicycle axle (not shown), a plurality of (five in this example) hollow spoke portions 3 extending radially outward from the hub portion 2, An annular rim portion 4 is connected to each outer end of the spoke portion 3. The hub portion 2, the hollow spoke portion 3, and the rim portion 4 are formed by an injection molding method using a hard synthetic resin containing a reinforcing material such as glass fiber, carbon fiber, and reinforcing powder, for example, a glass fiber-containing nylon resin, or a light metal. For example, it is integrally formed by a casting method such as die casting using magnesium, aluminum, titanium or an alloy thereof.

[0010] When mass production is performed by a die casting method using a light metal as a magnesium alloy, (Mg) 9
0.4% by weight, (Al) 8.7% by weight, (Zn) 0.7
It is preferable to use a die casting alloy of 0.2% by weight and (Mn) 0.2% by weight. The hub 2 includes an inner cylinder 5 that is externally fitted to the axle, an outer cylinder 6 that concentrically surrounds the inner cylinder 5 and connects the spokes 3, and an inner / outer cylinder 5, A plurality (five in this example) of connecting bodies 7 are arranged radially between the two cylindrical bodies 5 and 6 so as to connect them in the radial direction. In the case where the wheel 1 is formed of a synthetic resin, a hub shaft (not shown) serving as a mounting portion on the bicycle side is insert-molded inside the inner cylinder 5.

The spoke portion 3 has a wheel rotation direction R
Of the front edge 3A of the hub portion 2 coincides with the tangent of the outer cylindrical body 6 of the hub portion 2, and the rear edge 3B of the wheel rotation direction R coincides with a straight line passing through the center of the hub portion 2. The cross-sectional area (the area of the cross section orthogonal to the radial direction of the spoke portion 3) extending from the outer cylindrical body 6 in each cavity 8 is sequentially increased radially (radially) outward. I have. The end of each cavity 8 on the center side of the wheel 1 communicates with a through hole 9 provided in the outer cylindrical body 6 of the hub portion 2 between the connecting bodies 7 and provided in a radially penetrating manner (FIG. 2, FIG. 4, FIG. 5).

The spoke 3 has a transverse cross-sectional shape of:
As shown in FIGS. 6 to 8, a deformed elliptical shape whose axial direction dimension is smaller than the circumferential dimension (the major axis is parallel to the circumferential direction) and the outer peripheral contour is tapered on the leading side with respect to the wheel rotation direction R. It is streamlined so that the air resistance during rotation of the wheel 1 is reduced. And
Ribs 1 are provided on both sides in the axial direction of the base of the spoke portion 3 on the hub 2 side.
0 is provided respectively. The rim portion 4 is shown in FIGS.
As shown in FIG. 5, a peripheral groove 11 having a substantially U-shaped cross section is provided.
The outer ends of the spokes 3 are integrally connected to the inner peripheral side of the peripheral groove bottom 11A, and a tire (not shown) is fitted between the flanges 11B on both axial sides. A tire tube (also not shown) is included in the vehicle.

[0013] The peripheral groove bottom 11A of the rim portion 4 has
A through hole 12 communicating with the cavity 8 of each spoke portion 3 is provided. The through hole 12 and the through hole 9 of the hub portion 2
Is a tapered surface that is flush with the inner surface of the cavity 8 of the spoke portion 3 in the radial direction of the wheel 1, so that the cavity forming core (described later) at the time of molding the wheel 1 easily moves radially outward. It can be extracted to. Further, as shown in FIG. 3, a deformed elliptical concave portion 13 with a cap fitted therein is provided on the inner surface of the peripheral groove bottom 11A of the rim portion 4 on the outer peripheral side of the through hole 12.
Are formed in the recess 13 at both sides of the rim portion 4 of the through hole 12 in the circumferential direction, respectively, and cap locking holes 14 are provided (see FIGS. 3, 10, and 11). After the wheel 1 is formed, a tube support cap 15 for preventing a tire tube (not shown) from bulging into the through hole 12 is fitted into the recess 13.

The cap 15 has the shape shown in FIGS. 12 to 16 and is made of the same material as the wheel 1 (hard synthetic resin, light metal, etc.). The outer surface is a concave curved surface 15A which is flush with the inner surface of the circumferential groove bottom 11A. On the inner side surface 15B of the cap 15 (the center side of the wheel 1), locking projections 16 that fit into the holes 14 are provided at both ends in the longitudinal direction corresponding to the cap locking holes 14, respectively. A substantially cross-shaped rib 17 protrudes in the longitudinal direction of the cap 15 and in a direction perpendicular to the longitudinal direction.

The ribs 17 are composed of vertical ribs 17A which are parallel to the circumferential direction of the wheel and horizontal ribs 17B which are parallel to the axial direction. The outer ends of the vertical and horizontal ribs 17A and B are respectively connected to the circumferential groove bottom 11A. Contacting the inner surfaces of both ends in the circumferential direction and both ends in the axial direction of the through hole 12, and exerting the positioning function of the cap 15, and the pressure of the air sealed in the tube is reduced by the ribs 17 </ b> A, B. The force is transmitted to the circumferential groove bottom 11A via the circumferential surface, and the strength is sufficient to support the air pressure in the tube . FIG.
Indicates a half of a cross section of a molding die for injection molding or casting employed in the method of manufacturing the wheel 1 according to the first embodiment , and a die 18 includes an upper die 19, a lower die 20, A plurality of divided molds 21 divided in the circumferential direction forming the outer peripheral end portion of the flange 11B of the rim portion 4 and the circumferential groove 11, and a plurality of cavities 8 and through holes 9, 12 of the spoke portion 3 formed in a communicating manner. And a core 22.

Each core mold 22 has a mold space side end 22A (wheel radial direction inner end) forming the hub portion 2.
Are formed between the inner and outer cylindrical bodies 5 and 6 forming spaces 23 and 24 forming the hub portion 2 of the upper and lower dies 19 and 20, that is, the arc-shaped projections 2.
5, 26, the wheel radial outer end 22B
Is penetrated through the space 27 forming the rim portion 4 and is supported by each of the split molds 21. The taper whose cross-sectional area sequentially increases from the radially inner end 22A to the outer end 22B is formed. Has been granted. When the molding material flows into the molding space (cavity) of the mold 1, that is, injection or injection of a reinforcing material-containing nylon or the like, or press-fitting of a magnesium alloy or the like is completed, and the cooling and solidification of the molding material is completed. 22 is extracted radially outward of the wheel 1, and each split mold 21 is separated radially outward.
By separating and opening the lower dies 19 and 20, the wheel 1 is integrally formed, the cavity 8 of the hollow spoke portion 3 and the through holes 9 and 12 are formed in communication, and the thickness of the spoke portion 3 is reduced. Become uniform.

Since the core mold 22 is accurately positioned and supported by the upper and lower dies 19, 20 and the split mold 21, when the molding material flows into the mold cavity, the core mold 22 is moved by the molding material. Therefore, the thickness of the hollow spoke portion 3 becomes uniform as designed, and the wheel 1 of good quality can be integrally formed by injection molding. When the wheel 1 is molded from light metal, dimensional distortion or the like due to cooling or the like is less likely to occur during molding after casting than in the case where the wheel 1 is molded from a hard synthetic resin. In addition to being able to form a wheel without any of them, it has an advantage that it can be made thinner while maintaining necessary strength, so that it is possible to further reduce the weight.

In the above embodiment, the molding die 1
By making the number of divisions of the eight divided molds 21 equal to the number of the core molds 22, the divided molds 21 and the core mold 22 can be simultaneously separated. FIGS. 18 to 21 show a second embodiment of the bicycle wheel 1 according to the present invention. The difference from the first embodiment is that the center of the spoke 3 is a straight line passing through the axis of the hub 2. The spokes 3 are radially provided so as to coincide with each other, the spokes 3 have a true elliptical cross-sectional shape, and the cap 15 has no ribs and bulges radially outward of the wheel 1. The same operation and effect as the embodiment can be expected. Therefore, FIG.
The reference numerals in FIG. 21 are the same as those in FIGS.
Detailed description is omitted.

It should be noted that the cap 15 in the second embodiment
Is designed to be deformed by the air pressure of the tire tube fitted to the rim portion 4 and to be flush with the inner surface of the circumferential groove bottom portion 11A, so that the tire tube maintains an appropriate shape. Reference numeral 28 in FIG. 18 denotes an air valve mounting hole.
Further, the wheel 1 of the second embodiment is integrally formed by the above-described method , similarly to the first embodiment. The present invention
The present invention is not limited to the above embodiment, and the design can be appropriately changed.

[0020]

As described above, the bicycle wheel according to the present invention comprises a hub portion supported by a bicycle axle, a plurality of hollow spoke portions extending radially outward from the hub portion, and An annular rim portion, which is connected to the outer end of the spoke portion and in which the tire containing the tube is fitted, is integrally formed, and a through hole is formed in the rim portion, through which each cavity of the hollow spoke portion communicates. Since the cap is provided in the through hole to prevent the tube from bulging into the through hole, a hollow spoke portion having a uniform thickness can be integrally formed by injection molding or casting, and the strength is stable. In addition, the quality can be improved and the manufacturing cost can be reduced. Further, by providing the cap in the through hole, the tube does not swell from the through hole into the cavity, and the deformation and breakage of the tube can be prevented (claim 1).

According to the second aspect of the present invention,
Since the hub, spokes and rim are integrally formed of a hard synthetic resin, it is possible to obtain a mass-produced bicycle wheel and a lightweight bicycle wheel which are easily integrally formed by injection molding. According to the third aspect of the present invention, since the hub, the spokes and the rim are integrally formed of light metal, there is little cooling distortion during forming when the wheel is formed by casting such as die casting. As a result, it is possible to obtain a well-balanced wheel, and it is also possible to reduce the thickness of the wheel while maintaining the required strength, thereby obtaining a wheel that is further reduced in weight.

According to the fourth aspect of the present invention, each of the cavities and the through-holes of the spoke portion is formed in a tapered shape such that the cross-sectional area thereof gradually increases outward in the radial direction. This facilitates the operation of removing the core mold during molding. According to the invention described in claim 5, each cavity and the through hole of the spoke portion are formed in a deformed elliptical shape having a long axis parallel to the circumferential direction of the rim portion, and the outer contour of the spoke portion is Due to the streamline shape of the deformed ellipse, the air resistance associated with the rotation of the wheel decreases,
The running resistance of the bicycle is reduced, and the bicycle can be driven lightly.

Further, according to the invention described in claim 6,
Since the outer surface of the cap is flush with the inner surface of the rim portion, the deformation and damage of the tube in the tire are reliably prevented. Further, according to the invention as set forth in claim 7, since the reinforcing rib which fits into the through hole is provided on the inner surface of the cap, the cap is not damaged by the air pressure of the tube. The through hole can be reliably closed, and the positioning of the cap with respect to the through hole is facilitated by the reinforcing rib.

According to the eighth aspect of the present invention,
Since the reinforcing ribs of the cap are composed of vertical ribs fitted between both ends in the circumferential direction of the rim portion of the through hole and horizontal ribs fitted between both ends in the axial direction, the circumferential direction and the axial direction with respect to the through hole are provided. The positioning of the cap with respect to is ensured .

[Brief description of the drawings]

FIG. 1 is a front view showing a first embodiment of a wheel of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view as viewed in the direction of arrow B in FIG. 1;

FIG. 4 is an enlarged front view of the hub portion of the embodiment.

FIG. 5 is a sectional view taken along line CC of FIG. 4;

FIG. 6 is an enlarged cross-sectional view taken along line DD of FIG. 1;

FIG. 7 is an enlarged cross-sectional view taken along the line EE of FIG. 1;

FIG. 8 is an enlarged sectional view taken along line FF of FIG. 1;

FIG. 9 is an enlarged cross-sectional view taken along line GG of FIG. 1;

FIG. 10 is a sectional view taken along line HH of FIG. 3;

FIG. 11 is a sectional view taken along line II of FIG. 10;

FIG. 12 is a plan view of the cap according to the first embodiment.

FIG. 13 is a front view of FIG.

FIG. 14 is a rear view of FIG.

FIG. 15 is a right side view of FIG.

FIG. 16 is a sectional view taken along line JJ of FIG. 13;

FIG. 17 is a partial sectional view of a molding die .

FIG. 18 is a partially broken front view showing a second embodiment of the wheel of the present invention.

FIG. 19 is a sectional view taken along line LL of FIG. 18;

20 is an enlarged view of a portion K in FIG. 18;

FIG. 21 is a sectional view taken along line MM of FIG. 19;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bicycle wheel 2 Hub part 3 Spoke part 4 Rim part 5 Inner cylinder 6 Outer cylinder 7 Connecting body 8 Cavity 9 Through hole 12 Through hole 15 Cap 17 Rib 18 Molding mold 19 Upper mold 20 Lower mold 21 Split mold 22 core type 22A core inner end side 22B core outer end side 23 inner cylindrical body forming space 24 outer cylindrical body forming space

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B60B 1/00-5/02 B60B 21/00-21/12

Claims (8)

(57) [Claims] 1. A hub supported by a bicycle axle, a plurality of hollow spokes extending radially outward from the hub, and a tube connected to an outer end of the spoke and enclosing a tube. An annular rim portion to which the tire is fitted is formed integrally, and a through hole is formed in the rim portion to communicate with each cavity of the hollow spoke portion.
A bicycle wheel, wherein a cap is provided to prevent the tube from bulging into a through hole. 2. The bicycle wheel according to claim 1, wherein the hub, the spoke, and the rim are integrally formed of a hard synthetic resin. 3. The bicycle wheel according to claim 1, wherein the hub, the spoke, and the rim are integrally formed of light metal. 4. The spoke according to claim 1, wherein each of the cavities of the spoke portion is formed in a tapered shape such that a cross-sectional area thereof gradually increases outward in a radial direction. Bicycle wheel. 5. Each of the cavities of the spoke portion and the through hole are formed in a deformed elliptical shape having a major axis parallel to the circumferential direction of the rim portion, and the outer peripheral contour of the spoke portion is streamlined. The bicycle wheel according to any one of claims 1 to 4, wherein 6. The bicycle wheel according to claim 1, wherein an outer surface of the cap is flush with an inner surface of the rim portion. 7. The bicycle wheel according to claim 1, wherein a reinforcing rib fitted into the through hole is provided on an inner surface of the cap. 8. The reinforcing rib of the cap comprises a vertical rib fitted between both ends of the through-hole in the circumferential direction of the rim, and a horizontal rib fitted between both ends in the axial direction. A bicycle wheel according to claim 7.