JPH0451041Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a cast wheel for a motorcycle or the like, which is formed by integrally casting a hub, a rim, and spokes.

Prior Art Spoke wheels are generally used as wheels for motorcycles, and one of them is
There is a light alloy cast wheel in which a hub part supported by an axle, a rim part on which a tire is mounted, and a plurality of spoke parts connecting these parts are integrally formed by casting. In such a cast wheel, the spokes have a substantially H-shaped cross section and are connected to the rim at the center in the width direction.

Problems that the invention aims to solve: In the conventional cast wheels mentioned above, as the width of the rim increases, the width of the spokes must also increase accordingly to maintain the lateral rigidity of the rim and the entire wheel. However, as the width of the spokes increased, the weight of the wheel tended to increase.

Therefore, an object of the present invention is to provide a cast wheel that can provide sufficient lateral rigidity even to a wide rim portion and can also reduce the weight of the wheel.

Means and Effects for Solving the Problems Therefore, in the present invention, in a cast wheel in which a hub part supported by an axle, a rim part to which a tire is attached, and a plurality of spoke parts connecting these parts are integrally molded, The cross-sectional shape of each spoke part is such that, from the hub part to the rim part, two linear parts extending in the width direction of the rim part are connected on one side via a curved part and the other side is an opening. The spokes are formed in a U-shape, and the openings of the spokes are alternately opened toward the left and right sides of the wheel, and the centerlines of the adjacent spokes in the wheel width direction are aligned such that the curved portion side is aligned with the rim portion. They are arranged so as to be alternately offset to the left and right by an equal amount with respect to the central cross section so as to move away from the central cross section in the width direction.

According to the present invention, since the adjacent spokes are arranged so as to be offset by an equal amount alternately to the left and right with respect to the center cross section in the width direction of the rim, the rim is placed closer to the spokes than the width of the individual spokes. Since it is supported symmetrically over a wide width and in relation to the center cross section in the width direction, and the outermost part is supported by the highly rigid curved part of the spoke part, the lateral rigidity of the rim and the entire wheel is improved. Increase. Therefore, even if the width of the rim portion becomes wider, the rim portion will not fall or stress concentration will occur with respect to the spoke portions.

In addition, in this invention, the cross-sectional shape of the spokes is not H-shaped like in the past, but U-shaped, and the width can be made relatively narrow as described above, which reduces the weight of the entire wheel. .

Embodiments Hereinafter, the present invention will be described with reference to illustrated embodiments. FIG. 1 is a side view of a cast wheel 1 according to the present invention. This cast wheel 1 is made of light alloy, and has a rim portion 2, a hub portion 3, and six spoke portions 4 connecting these portions that are integrally molded. Each spoke part 4 is arranged to be inclined with respect to the radial direction of the cast wheel 1, and the connection part with the hub part 3 is located forward in the rotation direction R from the connection part with the rim part 2. There is. 5 is a brake disk fixed to the side of the cast wheel 1.

As best shown in FIG. It is arranged toward the side and the other side. That is, the three spoke parts indicated by 4 in FIG. The three spoke parts 4 are arranged with the curved part 6 facing the right side, that is, the opening 7 facing the left side,
Overall, six spoke portions 4 are arranged in a well-balanced manner.

Further, as shown in FIGS. 2 and 3, these spoke portions 4 are arranged so as to be alternately shifted to the left and right by the same amount with respect to the central cross section M in the width direction of the rim portion 2. Fig. 2 shows the rim part 2 and the hub part 3 in a cross section that includes the rotational axis of the cast wheel 1, and shows overlapping outlines of two adjacent spoke parts 4, 4 arranged between them. FIG. 3 is a drawing showing the arrangement positions of the spoke parts 4, 4 along the inner circumferential surface of the rim part 2. In FIG. 3, m is the center line of the spoke part 4 in the wheel width direction, and m is a similar center line of the spoke part 4, but the center line m is a distance a to the right from the central cross section M.
The center line m is offset to the left by the same distance a from the center cross section M. As a result, the rim portion 2 has a relatively narrow line between the line connecting the tips of the curved portions 6 extending to the right of the spoke portions 4 and the line connecting the tips of the curved portions 6 extending to the left of the spoke portions 4. It is supported by the spoke part over a wide width A. Assuming that each spoke portion 4 is arranged linearly along the central cross section M as shown by the chain line 4a in FIG.
The support width for the rim portion 2 is B, which is smaller than the support width A in this embodiment. This increase in support width increases the resistance moment when the rim part 2 tries to fall against the spoke parts 4, and the outermost part, where the largest moment acts, is supported by the highly rigid curved part 6 of the spoke part 4. Therefore, the lateral rigidity of the rim portion 2 is increased, and the stress generated in the curved portion 6 of each spoke portion 4 is also reduced. The above also applies to the connecting portion between the spoke portion 4 and the hub portion 3, and the lateral rigidity of the entire wheel increases.

In this way, it is not necessary to increase the width of each spoke part 4 correspondingly to the wide rim part 2, so that, together with the U-shaped cross section of the spoke part 4, the width of the cast wheel 1 This greatly contributes to weight reduction.

Effects of the invention As described above, in the present invention, in a cast wheel in which a hub part supported by an axle, a rim part on which a tire is mounted, and a plurality of spoke parts connecting these parts are integrally molded, the cross section of each spoke part is The shape is formed into a U-shape in which two linear parts extending in the width direction of the rim part from the hub part to the rim part are connected via a curved part on one side and an opening on the other side, The openings of these spoke portions are alternately opened toward the left and right sides of the wheel, and the center lines of adjacent spoke portions in the width direction of the wheel are such that the curved portion side moves away from the center cross section in the width direction of the rim portion. As for the central cross-section, they are arranged alternately on the left and right by an equal amount, so that
Even if the width of the rim portion is wide, sufficient lateral rigidity can be imparted to the wheel without increasing the width of the spoke portions accordingly, and the weight of the wheel can be reduced.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is a sectional view showing the relative position of the spoke parts with respect to the rim part and the hub part, and FIG. 3 is a drawing showing the arrangement of the spoke parts along the inner peripheral surface of the rim part. 1...Cast wheel, 2...Rim part, 3...
...Hub part, 4...Spoke part, 5...Brake disc, 6...Curved part, 7...Opening part.

Claims (1)

[Scope of utility model registration request] In a cast wheel in which a hub part supported by an axle, a rim part on which a tire is attached, and a plurality of spoke parts connecting these parts are integrally formed, the cross-sectional shape of each spoke part extends from the hub part to the rim part. 2 extending in the width direction of the rim portion up to
Two straight parts are connected via a curved part on one side and are formed into a U-shape with an opening on the other side, and these spoke parts are opened so that the openings alternately open toward the left and right sides of the wheel. , and the center lines of adjacent spoke portions in the wheel width direction are arranged so that the curved portion side is shifted away from the center cross section in the width direction of the rim portion by an equal amount alternately to the left and right with respect to the center cross section. cast wheel.