JPH0411296B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing cast wheels for light vehicles such as motorcycles.

[Conventional technology]

Conventional wheels for light vehicles can be roughly divided into two types. One type is one in which the entire wheel is made of cast iron, and the other is one in which the entire wheel is made of steel plate.

For wheels to be cast, the separately cast bearing boss and brake drum are placed in a fixed mold attached to a casting machine, and after the movable molds are aligned and clamped, aluminum die casting is poured through a sprue. It is boiled and taken out after cooling. The rim is then tightened and fixed to this integrated body with bolts.

Further, a wheel made of a steel plate is formed by forming each member by press working and integrating them by welding.

[Problem to be solved by the invention]

However, in the case of cast wheels, the bearing boss and the brake drum are molded separately, and they are placed in the mold separately and poured into the mold, but in that case, the pressure of the hot water during pouring Due to this influence and the fact that the cooling rate of the poured aluminum die cast differs in different parts of the mold, misalignment and deflection between the bearing boss and the brake drum often occur. Therefore, after taking out the wheel, it is necessary to mechanically finish the inner and outer diameters of the bearing boss, the inner diameter of the drum, or the portion to which the rim is attached. Therefore, there are problems in that many steps are required, the molding cost increases, and productivity is poor.

In addition, steel plate wheels have a fatal drawback in that the brake drums and other parts are thin, which causes the brake drums to vibrate when the brakes are applied, resulting in so-called brake squeal. .

The present invention was devised in view of these problems, and an object of the present invention is to provide a method for manufacturing a cast wheel for a light vehicle that has good productivity and does not generate brake squeal.

[Means to solve the problem]

As a means for this purpose, first, a hub formed by assembling a steel plate brake drum 2 and a bearing boss 1 and having torque clocks 7, 9, and 10 is fitted into a mold. Thereafter, the spoke portions formed by pouring the metal are welded to the hub by pouring the metal into the mold. Next, after cooling the integrated hub and spoke parts, it was taken out from the mold, and a rim 3 made of a steel plate was assembled to the spoke parts.

[Effect]

By assembling the steel plate brake drum 2 and the bearing boss 1, they are integrated and their mutual positional relationship is maintained in a stable posture. This integrated brake drum 2 and bearing boss 1 is placed in a mold and poured into a mold, but since the two are integrated and their relative positions and postures are stable, their postures will not collapse due to the hot water pressure. Also, it will not warp due to the influence of differences in the degree of cooling of the hot water.

Therefore, troublesome post-processing can be reduced.
Productivity improves.

Further, since the brake drum 2 made of a steel plate is coated with die-casting and has a thick wall, it does not generate brake squeal unlike the conventional brake drum, and the thick wall also increases mechanical strength. Also, brake drum 2
Since it is made of a thin steel plate, which is thinner than the conventional casting, the weight can be reduced by that amount.

In addition, since the rim 3 is made of a steel plate and assembled to the spokes made of cast metal, the mold can be made simpler than the conventional rim made of cast metal.
Therefore, it is advantageous in terms of production.

〔Example〕

FIG. 1, FIG. 1-a, FIG. 1-b, and FIG. 2 show an example of a wheel formed by the method of the present invention.

The brake drum 2 is made of a press-formed steel plate, and a bearing boss 1 formed by finishing the inner and outer diameters of the steel plate material is fitted into the center thereof, and both are welded together at a welding part 6. It forms a hub. The spoke portions 4 are aluminum die-cast. This aluminum die casting is welded to the outer peripheral surface and side end surface of the brake drum 2 and to the peripheral end of the bearing boss 1.

A plurality of torque locks 7, 9, and 10 are formed on the brake drum 2 and the bearing boss 1 to further strengthen the assembly with the aluminum die casting. A torque lock is a so-called anti-slip, and in the case of the brake drum 2 of this embodiment, a plurality of holes are provided at appropriate locations, die-casting is poured into these holes, and the engagement between the two prevents slipping. . This torque lock is not limited to a hole, but any means to prevent slippage, such as a protrusion or unevenness, can be used.

The rim 3 is made of a steel plate, and is press-fitted and fixed to the outer peripheral end of the spoke portion. Various fixing means can be considered, but here we use a fall prevention ring 12 that covers the entire circumference of the wheel (see Figures 1 and 1-a), a plurality of brackets 14 (see Figure 2), and tightening bolts. This has been achieved through 13.

A rim torque clock 11 consisting of countless irregularities is formed on the inner peripheral surface of the rim 3, thereby increasing the frictional force with the outer peripheral ends of the spokes and making the assembly even stronger.

〔Effect of the invention〕

In this way, the present invention involves assembling a brake drum made of a steel plate and a bearing boss, then placing them in a mold, integrally molding the spoke parts by die casting, and assembling a rim made of a steel plate. Therefore, it is possible to reduce the post-processing that was conventionally required and provide a wheel with high productivity.

In addition, there is no brake squeal, and it has excellent mechanical strength.
It exhibits many excellent effects such as being lightweight.

[Brief explanation of drawings]

FIG. 1 is a partial plan view showing an example of a cast wheel manufactured according to the present invention, FIG. a partial perspective view showing a rim provided with;
FIG. 2 is a partial plan view showing another example. Explanation of symbols, 1: Boss, 2: Brake drum,
3: Rim, 6: Welded part, 7, 9, 10: Torque clock, 11: Rim torque clock, 12: Falling prevention ring, 13: Tightening bolt, 14: Bracket.

Claims (1)

[Claims] 1 A torque clock 7 formed by assembling a steel plate brake drum 2 and a bearing boss 1,
After fitting the hub having numbers 9 and 10 into the mold,
Molten metal is poured into the mold, spoke parts formed by the poured metal are welded to the hub, and after cooling, the spoke parts are taken out from the mold, and a rim 3 made of a steel plate is assembled to the spoke parts. A manufacturing method for light vehicle wheels.