JPS62130767A - Casting method for hollow aluminum wheel - Google Patents

Abstract

PURPOSE:To improve the strength in the hollow parts of an aluminum wheel by quick inside and outside cooling and to permit the reduction of the thickness and weight of the product by preliminarily casting thin-walled hollow bodies enclosing the hollow parts of the aluminum wheel, disposing such bodies in the parts corresponding to the hollow parts of a metallic mold and subjecting the same to insert casting with a molten metal. CONSTITUTION:The hollow spoke parts of the aluminum wheel are cast to the thin-walled hollow bodies by the metallic mold and core sand. The core sand is discharged and the hollow bodies 10 are hermetically sealed. Such hollow bodies 10 are disposed into the parts of the metallic mold 3 for the aluminum wheel corresponding to the hollow parts and molten aluminum is poured into the mold to make casting so as to insert-cast said bodies. The spoke parts are quickly cooled from the inside and outside and the strength thereof is improved as compared to the conventional case of putting the cores into the hollow parts and executing casting. The wall thickness of the spoke parts is thus made smaller and the entire part of the aluminum wheel 2 is made lighter in weight. Since the hollow parts are preliminarly cast, the shape thereof is made free.

Description

Detailed Description of the Invention (Field of Application and Summary of the Invention) The present invention relates to a method for casting a hollow wheel, particularly a method for casting a hollow aluminum wheel. By directly casting the
This makes it possible to cast products with complex hollow shapes, and also reduces the weight of aluminum wheels.

(Prior art and its problems) Aluminum wheels with hollow spokes have conventionally been cast using a core (1) that corresponds to the hollow part (see Figure 5), or a method that uses slide pins that correspond to the hollow part. It is manufactured by a casting method using a movable metal core such as. Recently, casting using molds has become mainstream,
In any of the above methods, a movable metal core such as a core Tl) or a slide bottle is combined with an outer mold having an inner shape that matches the outer shape.

In the above-mentioned two methods, in the former method using a normal core, the core (1) is made of a fragile material, so after casting, the core is broken down into powder and released from the product. Complex hollow shapes can also be cast, as long as they can be taken out and a core (1) can be formed.

However, in this method, the material used for the core (1) is clay-based casting #1 or oil sand, both of which have poor thermal conductivity.

Therefore, during casting, the part corresponding to the outer surface of the product comes into contact with the mold surface, and the molten metal is rapidly cooled to form a sufficiently strong aluminum layer, but the part that comes into contact with the core (1) , the molten metal is slowly cooled, and the aluminum structure in this part after casting becomes a layer with poor strength. Therefore, even if the weight of an aluminum wheel is reduced by providing a hollow part, the thickness of the outer periphery of the hollow part must be set within the thickness because the strength of the next casting layer is insufficient because it is in contact with the core. However, it is not possible to reduce the weight of aluminum wheels sufficiently.

On the other hand, in the latter casting method using a metal core, since the core is made of metal, there is no problem as described above, and the weight of the aluminum wheel can be sufficiently reduced. However, in this method, the metal core is pulled out of the product after the casting is completed, so the metal core has a straight line.
Casting is limited to specific shapes such as arcuate shapes, and products with hollow parts of complex shapes cannot be cast.

An object of the present invention is to enable even aluminum wheels with complicated hollow parts to be cast, and to reduce the weight of the entire wheel.

(Means) The technical means of the present invention taken to achieve the above object is to pre-cast a thin-walled hollow body QG that envelops the hollow part of the aluminum wheel (2), and to cast this thin-walled hollow body (llf
The hollow holes f[)11 and 211 in the aluminum wheel are disposed correspondingly to each other and cast.

(Function) The above technical means of the present invention functions as follows.Since the thin-walled hollow body αG is set to be thinner than the wall thickness of the hollow cross section in the completed state, the cooling effect by the mold during casting is The structure of the thin-walled hollow body aJ is formed by rapid cooling casting and has a high strength. Moreover, since the thin-walled hollow body αI is cast as a single unit, there are no major restrictions on its finished shape, and a thin-walled hollow body Ql with a complicated shape can also be cast.

When the thin-walled hollow body αG formed as described above is placed in a position corresponding to the hollow part QD of the aluminum wheel (2) and cast, the hollow part C11l is shaped into the desired shape. The wheels (2) are arranged flatly. In this casting process, the inner circumferential side of the molten metal corresponding to the hollow part of the aluminum wheel (2) is in contact with the thin-walled hollow body ttn, and the outer circumference l1
11J comes into contact with the outer mold. Therefore, the hollow part l2
Both the inner and outer layers of the cross section of Il become rapidly cooled cast layers, improving the strength of this cross section.

(Effects) Since the present invention has the above configuration, it has a first-order unique effect.

Since the overall strength of the cross section of the aluminum wheel is improved from the inner surface to the outer surface of the hollow section, the strength of the aluminum wheel having a hollow cross section is increased, and the diameter of the aluminum wheel can be increased.

In addition, since the part corresponding to the inner surface of the hollow part is formed as a thin-walled hollow body, there are few restrictions on the shape of the hollow part, and the hollow part can have a variety of shapes. - Allows for significant design leeway in shape.

(Example) An example of the present invention will be described below based on FIGS. 1 to 4.

This embodiment was adopted when casting an aluminum wheel having a shape as shown in FIG. 2, and each spoke part has a hollow part +211 and @.

Thin-walled hollow body α [
Each of them has a shape as shown in Fig. 3, and each thin-walled hollow body has an outer mold made of gold 14 as shown in Fig. 4.

It is cast into a hollow shape by combining cores such as cell cores.

Note that since a normal core is used here, it is desirable that the thickness of the thin hollow body be set as thin as possible for casting.

Each of the thin-walled hollow bodies cast as described above is placed in a metal outer mold (31, (3) for casting an aluminum wheel, as shown in the figure).
) and cast, it becomes an aluminum wheel (2) in which the hollow parts are arranged as desired.

[Brief explanation of drawings]

Fig. 1 is a diagram #1 of the casting state of the embodiment of the present invention, Fig. 2 is a front view of the completed aluminum wheel, Fig. 3 is an explanatory diagram of the thin-walled hollow body 0α, and Fig. 4 is the illustration of this thin-walled hollow body. FIG. 5 is an explanatory diagram of a conventional example of casting, and is part of the diagram. 0Q...Thin-walled hollow body (2)...Aluminum wheel (21)...Hollow part...
...Cavity Department Agent Patent Attorney Yoshi Sakagami Hiroshi 4151 Figure 3 Outer mold s 5 Figure 0Q

Claims (1)

[Claims] A thin-walled hollow body (10) that surrounds the hollow part of the aluminum wheel (2) is cast in advance, and this thin-walled hollow body (10)
) in the hollow part (21), (21) of the aluminum wheel
A casting method for hollow aluminum wheels that is placed and cast in accordance with the following.