JPS62230444A - Manufacture of cast light alloy wheel - Google Patents

Abstract

PURPOSE:To inexpensively manufacture the wheel with excellent quality and external appearance by forming plural opening parts in a discoid disk part by punching with press working after manufacturing the whole wheel by casting, in case of the manufacture of the light alloy made wheel for auto-bicycles. CONSTITUTION:A rim 2, hub 3 and the disocid disk part in their medium are integrally cast with Al light alloy, in case of manufacturing the light alloy made wheel 1 for auto-bicycles. The rim and hub 3 are thereafter finished in a normal dimension with cutting and one side face 4a of the disk part 4 is subjected to cutting as well. Plural opening parts 5 are punched then by press-working from the cutting face 4a on the disk part 4 and the burr 6 caused at that time is projected to the opposite side face 4b which is not subjected to cutting of the disk part. The wheel 1 in the normal dimension with excellent external appearance is manufactured by removing this burr 6 by cutting in succession.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a cast light alloy wheel for a motorcycle.

[Prior art]

Conventionally, the rim and hub were connected by a disk-shaped part,
In a so-called disc wheel, the rim, hub, and disc part are integrally cast and formed from a light alloy material, and then,
Wheels in which the entire wheel is machined are known.

By the way, in this type of disc wheel, multiple openings are often formed in the disc part, taking into consideration not only the appearance but also the influence of cross winds while driving. The opening is formed by integrally casting out.

[Problem that the invention seeks to solve]

However, when forming the opening by casting,
Since the flow path of the molten metal within the casting mold becomes complicated, casting defects may occur unless the mold is designed with sufficient consideration given to the flow of the molten metal.

1. If the opening is cast out, it is necessary to paint the inner surface of the opening to make the casting surface less noticeable.
This increases the number of man-hours and increases costs.

Additionally, if it became necessary to change the shape or position of the opening due to a change in wheel design, the entire expensive casting mold had to be remade, which was extremely time-consuming. [Means for Solving the Problems] Therefore, in the method of the present invention, when forming a plurality of openings in a disc-shaped disc part, the openings are punched and formed by press working after casting the disc part. It is characterized by

[Effect]

According to the method of the present invention, there is no opening in the disc part at the casting stage, and the disc part is in the shape of a continuous disc, so the hot water flows well and the casting process is carried out smoothly. It is possible to manufacture wheels of good quality with few defects.

Moreover, unlike in the case of conventional casting casting, the inner circumferential surface of the opening does not have a rough casting surface, so a beautiful appearance can be obtained without special painting, and this reduces the number of work steps. This makes it possible to reduce costs.

In addition, the shape and position of the opening can be changed simply by changing the punching die of the press, making it easy to handle changes in wheel design and using expensive casting molds as is. Since it can be used, it is also advantageous in terms of cost.

[Embodiments of the invention]

An embodiment of the method of the present invention will be described below based on drawings in which the method is applied to a wheel for a motorcycle.

The aluminum alloy wheel indicated by reference numeral 1 in the figure has a rim 2,
A hub 3 and a disc-shaped disc part 4 connecting these rims 2 and hub 3 are integrally cast and molded, and the disc part 4 has a plurality of openings 5 at intervals in the circumferential direction. It is formed by

Such a wheel l is manufactured by the procedure described below.

That is, by assembling a casting mold having molding spaces corresponding to the rim 2, hub 3, and disc part 4, and injecting molten metal into this mold, the rim 2, hub 3, and disc part 4 are integrally cast. Shape.

Once the molten metal has solidified, the mold is opened, the product is taken out, and the rim 2 and hub 3 are cut to regular dimensions, and the surface 4a of one side of the disk portion 4 is also cut.

Next, the openings 5 are punched and formed in the disk part 4 by press working, but in this embodiment, the openings 5 are punched from the surface 4a side which has been subjected to the top cutting process, and A burr 6 called a sag produced during molding is made to protrude from the opposite surface 4b of the disk portion 4 which has not been cut, as shown in FIG.

Thereafter, the surface 4b on the opposite side of the disk portion 4 where the burr 6 is present is also subjected to a cutting process to remove the burr 6 and at the same time finish the disk portion 4 to regular dimensions.

According to such an embodiment of the method of the present invention, at the stage of injecting the molten metal into the casting mold, there is no opening 5 in the disk portion 4, and the disk portion 4 is continuous. Since it is shaped like a single disk, the flow path of the molten metal within the disk portion 4 is not complicated. Therefore, the hot water runs well, and a wheel l of good quality with few casting defects can be manufactured.

Moreover, since the inner circumferential surface of the opening 5 does not have a rough casting surface as in conventional casting, a beautiful appearance can be obtained without special painting, which reduces the number of work steps. This makes it possible to reduce costs.

In addition, by changing the punching die of the press, the shape and position of the opening 5 can be arbitrarily changed to Φ as shown by the imaginary line in Figure 1, so it is also possible to change the shape and position of the opening 5. In addition to being easy to deal with, expensive casting molds can be used repeatedly as they are, which has the advantage of being advantageous in terms of cost.

Further, in this embodiment, after cutting the surface 4a on one side of the disk portion 4, punching is performed from the processed surface 4a side to form the opening 5, and then on the opposite side of the disk portion 4. Since the cutting process was applied to the surface 4b,
The burrs 6 generated during the punching and forming process can be removed simultaneously with the cutting of the disk portion 4. This eliminates the need for a dedicated process for removing burrs, which also contributes to cost reduction.

Note that the present invention is not limited to the above-described embodiment, but includes, for example, the surfaces 4a on both sides of the disk portion 4.

4b are cut, the openings 5 are punched and formed, and burrs 6 called sag are actively left in each opening 5.
It may also be incorporated as one of the external appearance elements.

In this case, the direction of the burr 6 is aligned with one side of the wheel 1, so if the brake disc is attached to the end face of the hub 3 facing away from the burr 6,
The brake disc and the burr 6 are weight-balanced, and the ffi amount of the entire wheel 1 can be maintained in a well-balanced manner.

Further, when punching and forming the openings 5, if the punching direction is alternately reversed along the arrangement direction of the openings 5, the burrs 6 are alternately formed on both sides of the disk portion 4. Since the disk portion 4 is disposed in the horizontal direction, the left and right sides of the disk portion 4 are balanced, and the appearance is also convenient.

〔Effect of the invention〕

According to the present invention described in detail above, since the disk portion can be cast without holes, it is possible to obtain a wheel of good quality with good hot water circulation and few casting defects.

Moreover, since the inner circumferential surface of the opening does not have a rough casting surface, a beautiful appearance can be obtained without special painting, and therefore, the number of work steps can be reduced, and costs can be reduced.

In addition, the shape and position of the opening can be changed simply by changing the punching die of the press, making it easy to handle changes in wheel design.
Even expensive casting molds can be used repeatedly, which is advantageous in terms of cost.

[Brief explanation of drawings]

The drawings show an embodiment of the method of the present invention, in which FIG. 1 is a side view of the wheel, FIG. 2 is a sectional view, and FIG. 3 is a sectional view around the opening. ■...Wheel, 2...Rim, 3...Hub, 4...
... Disc part, 5... Opening part. Applicant's agent Patent attorney Takehiko Suzue Procedural amendments Showa Hime 1/1h20

Claims (4)

[Claims] (1) A method for manufacturing a wheel in which a plurality of openings are formed in a disc-shaped portion connecting a rim and a hub, in which the rim, hub, and disk portion are integrally cast and formed from a light alloy material; A method for manufacturing a cast light alloy wheel, characterized in that: a plurality of openings are punched out in the disc portion by press working. (2) After performing cutting on one side of the disk portion, punching and forming the opening portion from the side where this cutting was performed, and then cutting the surface on the opposite side of the disk portion. Claim No. (1) characterized in that
A method for producing a cast light alloy wheel as described in 2. (3) The method for manufacturing a cast light alloy wheel as set forth in claim (1), wherein the opening is punched after cutting both sides of the disc portion. (4) After performing cutting on both sides of the disk portion, when punching and forming the openings, the punching directions of the openings are alternately reversed along the arrangement direction of the openings. A method for manufacturing a cast light alloy wheel according to claim (3).