JP2882448B2 - Centrifugal casting metal frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal casting frame, and more particularly to a water-cooled centrifugal casting frame used for casting small-diameter cast iron tubes.

[0002]

2. Description of the Related Art As shown in FIG. 3, a water-cooled centrifugal force casting metal frame applied to the casting of a conventional small-diameter pipe has a sleeve 12 fitted on a cylindrical steel metal frame 11, as shown in FIG. And gold frame 1
A water cooling jacket 13 is formed between the sleeve 1 and the sleeve 12. In order to form this water-cooled jacket 13, set bolts 14 are arranged at appropriate intervals in the circumferential direction and axial direction of the sleeve 12, and the set bolts 14 are screwed in the radial direction of the sleeve 12 in a threaded manner. Is brought into contact with the outer peripheral surface of the metal frame 11 so that the sleeve 12
Are held concentrically with respect to the metal frame 11.

[0003]

In such a configuration, after the inner peripheral surface of the metal frame 11 constituting the mold is coated, the molten metal is poured into the metal frame 11 while rotating the metal frame 11 together with the sleeve 12. Casting is performed by heating and cooling and solidifying. By the way, the time from pouring the molten metal into the metal frame 11 until the solidified casting tube can be pulled out is about 20 seconds for a casting tube having a diameter of 200 mm. This time is called the cooling rotation time, and its ratio to the casting cycle time is as large as about 1/4.

[0004] Therefore, if the cooling rotation time is shortened, the productivity of the production of the cast pipe can be increased.
For that purpose, it is necessary to increase the cooling rate. Therefore, it is conceivable to increase the flow rate of the cooling water, but merely increasing the flow rate of the cooling water has little effect on the improvement of the cooling capacity, and increases the cooling speed to shorten the cooling rotation time. Therefore, there was a problem that productivity could not be increased.

In such a configuration, when the casting operation is continued in a running state, the heat capacity of the metal frame may not be able to keep up with the cooling of the metal frame. There is a problem that pinhole defects and the like occur on the outer surface.

SUMMARY OF THE INVENTION The present invention solves such a problem, and can increase the cooling speed of the molten metal to shorten the cooling rotation time, improve the productivity, and generate defects such as pinholes on the outer surface of the casting tube. It is an object of the present invention to provide a metal frame for centrifugal casting that does not have any.

[0007]

According to the present invention, there is provided a centrifugal casting apparatus comprising: a sleeve fitted to a cylindrical metal frame; and a water cooling jacket provided between the metal frame and the sleeve. In the metal frame, at least one of a plurality of concave portions or a plurality of convex portions is formed on an outer peripheral surface of the metal frame vertically and horizontally at intervals in a circumferential direction and an axial direction of the metal frame.

[0008]

According to this structure, the cooling water flowing into the water-cooling jacket is turbulently formed by the concave or convex portions formed on the outer peripheral surface of the metal frame and actively contacts the metal frame, and the cooling water is cooled. Because the contact surface area of water and metal frame increases,
Cooling capacity is improved. As a result, the cooling speed of the molten metal increases, and the cooling rotation time is shortened. Further, even when the casting operation is continued in the running state, the heat of the metal frame is not stored, and the occurrence of pinholes on the outer surface of the casting tube is prevented.

[0009]

FIG. 1 shows a metal frame for centrifugal casting according to an embodiment of the present invention. Here, reference numeral 1 denotes a cylindrical steel frame, a sleeve 2 is fitted on the outside thereof, and a water cooling jacket 3 for passing cooling water is formed between the metal frame 1 and the sleeve 2. .

As shown in FIG. 2, on the outer peripheral surface of the metal frame 1,
The plurality of recesses 4 are formed by peening. For example, the recesses 4 having a diameter d of 15 mm are formed vertically and horizontally in the circumferential direction and the axial direction of the metal frame 1 at a pitch P of 25 mm.
In FIG. 1, these recesses 4 are shown in an enlarged scale.

The set bolts 5 arranged at appropriate intervals in the circumferential direction and the axial direction of the sleeve 2
Are screwed through the wall in the radial direction, and the tip thereof is in contact with the outer peripheral surface of the metal frame 1. Thereby, the sleeve 2 for forming the water cooling jacket 3 is held concentrically with the metal frame 1.

In such a configuration, at the time of manufacturing a cast tube, a mold is applied to the inner peripheral surface of the metal frame 1, and a socket forming core 6 is arranged on the socket 1 a side of the metal frame 1. Insert 1b of frame 1
After disposing the stopper ring 7 on the side, the molten metal 8 is poured into the metal frame 1 while rotating the metal frame 1, and the cooling water 9 flows into the water cooling jacket 3.

In this case, since the plurality of recesses 4 are formed on the outer peripheral surface of the metal frame 1, the cooling water 9 flowing into the water-cooling jacket 3 comes into contact with the recesses 4 to form a turbulent state, which is positive. And the cooling water 9 by the recess 4
The contact surface area between the metal frame 1 and the metal frame 1 increases, and the cooling capacity is improved. As a result, since the heat of the molten metal 8 is effectively removed by the cooling water 9 flowing in the water cooling jacket 3, the molten metal 8 is rapidly cooled and solidified to form a casting tube. The solidified casting tube is subsequently drawn.

Since the molten metal 8 is rapidly cooled and solidified as described above, the cooling rotation time from the pouring of the molten metal 8 into the metal frame 1 until the solidified casting pipe can be pulled out can be shortened. Productivity can be improved.

Further, even when the casting operation is continued in the running state, the heat of the metal frame 1 is not stored, and the occurrence of pinholes on the outer surface of the casting tube is prevented, so that the quality of the casting tube can be improved.

In the above embodiment, the case where a plurality of recesses 4 are formed on the outer peripheral surface of the metal frame 1 has been described. The same effect can be obtained. Also,
In the above embodiment, the case where the recess 4 is formed by peening has been described. However, the present invention is not limited to the formation by peening, and the uneven portion may be formed on the outer peripheral surface of the metal frame 1 by shot blasting or shot peening.
In this case, since the rust can be removed simultaneously with the formation of the uneven portion, there is an advantage that the cooling capacity is further improved.

[0017]

As described above, according to the present invention, at least one of the plurality of concave portions or the plurality of convex portions is formed on the outer peripheral surface of the metal frame vertically and horizontally at intervals in the circumferential direction and the axial direction of the metal frame. As a result, the cooling rate of the molten metal is increased, the cooling rotation time can be significantly reduced, productivity can be improved, and pinholes due to insufficient cooling of the metal frame can be prevented, and the shrinkage of the casting tube also increases. Pull-out becomes easy, and the life of the metal frame can be extended.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a metal frame for centrifugal casting according to one embodiment of the present invention.

FIGS. 2A and 2B are an enlarged plan view and an enlarged longitudinal sectional view of the centrifugal force casting metal frame.

FIG. 3 is a longitudinal sectional view of a conventional centrifugal casting metal frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal frame 2 Sleeve 3 Water cooling jacket 4 Depression 5 Set bolt 9 Cooling water

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B22D 13/10

Claims (1)

(57) [Claims] 1. A sleeve is fitted on a cylindrical metal frame,
A centrifugal casting metal frame provided with a water cooling jacket between the metal frame and the sleeve, wherein at least one of a plurality of concave portions or a plurality of convex portions is formed on the outer peripheral surface of the metal frame. Circumferential direction
And a centrifugal casting metal frame which is formed vertically and horizontally at an interval in the axial direction .