JPS5919783B2 - Manufacturing method of hollow balls for grinding mills - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing hollow balls for a grinding mill, and in particular, a spherical core is set in a main mold, a riser is provided on the upper part of the main mold, and the main mold and the spherical core are assembled together. The present invention relates to a method of manufacturing a hollow ball corresponding to the hollow ball-shaped gap by pouring molten metal into the hollow ball-shaped gap to be formed.

Conventionally, hollow balls for grinding mills are manufactured by setting a completely spherical core 1 in a main mold via a core 2, as shown in FIG.
A hollow ball 4 of equal thickness is manufactured by pouring molten metal into a gap formed by a core 1 and a main mold 3 (not particularly shown, but refers to the outer periphery of the hatching part).

At this time, the hollow ball 4 of equal wall thickness has two or four casting holes, and in order to ensure the internal quality of the hollow ball 4, the main mold 3
A method is adopted in which two feeders 5 are provided at the upper part of the feeder.

In other words, in this method, in order to solidify the molten metal directionally, the internal quality of the hollow ball 4 cannot be ensured, and the amount of feeder cannot be ensured unless a large amount of waste is added to the upper part of the main body of the hollow ball 4 and cast. There will be more.

As a result, there is a drawback that a considerable number of man-hours are required to remove the waste material attached to the hollow ball 4 after casting.

An object of the present invention is to provide a method for manufacturing hollow balls for a grinding mill, which eliminates the drawbacks of the prior art described above, reduces the amount of feeder, reduces the amount of waste, and shortens the finishing process. be.

In view of the fact that directional solidification of the molten metal can be obtained by smoothing the supply of the molten metal from the feeder, the present invention makes the inner diameter center of the hollow ball to be manufactured eccentric to the outer diameter center, A spherical core is set in the main mold so that the wall thickness of the ball increases as it approaches the feeder.

As a means for this purpose, the present invention makes the center of the core (point A in FIG. 2) eccentric with respect to the outer diameter center of the hollow ball-shaped gap formed by the main mold and the spherical core, and The core is characterized in that the radius of curvature becomes smaller toward the feeder side.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a schematic configuration diagram showing an example of the present invention.

In FIG. 2, the outer diameter surface (working surface) of the hollow ball 6 determined by the shape of the main die 3 is a spherical surface with a spherical center B and a radius D1.

The radial side of the core 7 facing the feeder 8 side forms a hemispherical surface with a radius R1 centered at A, and the hemispherical side facing the feeder 8 is eccentric with respect to the feeder 8 side, so that the radius of curvature is It forms a hemispherical surface that gradually becomes smaller.

That is, in FIG. 2, the hemispherical side of the core on the riser 8 side is
It has a hemispherical surface with centers C, D, and E and radii R2, R3, and R4, and each radius has a relationship of R,>R2>R3> R4.

With this configuration, it is possible to reduce uneven wear when the hollow balls are used in a grinding mill.

Furthermore, the diameter of the inscribed circle of the thick wall portion of the hollow ball 6 is
The thickness gradually becomes smaller as the thicker part faces the riser 8 side.

That is, in FIG. 2, the diameter of the inscribed circle of the thick portion of the hollow ball 6 has a relationship of D2<D3<D4.

In the figure, 10 is a book.

According to the method described above, since the effect of the feeder is promoted, the number of feeders can be reduced to one and the amount of feeder can be reduced, and the amount of meat added to the hollow ball can be reduced. can.

Therefore, compared to conventional manufacturing methods, the yield is improved and the number of man-hours such as removing waste material is significantly reduced, productivity is improved, and molten metal is sufficiently replenished from the riser, resulting in directional solidification. It is possible to produce sound castings.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing a conventional method for manufacturing hollow balls for a grinding mill, and FIG. 2 is a schematic block diagram showing an example of the present invention. 1.7...Nakako, 2,10...Nakamoto,
3...Main mold, 4,6...Hollow ball,
5, 8...Rise bath.

Claims (1)

[Claims] 1. A hollow grinding mill for use in a grinding mill, which includes the process of setting a spherical core in a main mold, providing a riser at the top of the main mold, and pouring molten metal into a hollow ball-shaped gap formed by the main mold and the spherical core. In the method for manufacturing a ball, the center of the core is eccentric to the lower side with respect to the outer diameter center of the cavity, and the radius of curvature of the hemispherical surface of the core on the feeder side becomes smaller toward the feeder. A method for manufacturing a hollow ball for a grinding mill, characterized by manufacturing a hollow ball whose wall thickness increases toward the feeder side.