JPH0629754U - Centrifugal casting metal frame - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the productivity by increasing the cooling rate of the molten metal poured into the metal frame to shorten the cooling rotation period. [Structure] The sleeve 2 is externally fitted to the cylindrical metal frame 1,
A water cooling jacket 3 is provided between the metal frame 1 and the sleeve 2. The metal frame 1 is composed of a steel layer 4 on the inner peripheral side and a copper layer 5 formed on the outer peripheral side of the steel layer 4 and having a higher thermal conductivity than the steel layer 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a centrifugal force casting metal frame, and more particularly to a water-cooled centrifugal force casting metal frame used for casting small diameter cast iron pipes.

[0002]

[Prior art]

 As shown in FIG. 2, a conventional water-cooled centrifugal casting metal frame applied to the casting of small-diameter pipes has a cylindrical steel metal frame 11 with a sleeve 12 fitted externally to form a metal frame. A water cooling jacket 13 is formed between 11 and the sleeve 12. In order to form the water cooling jacket 13, set bolts 14 are arranged at appropriate intervals in the circumferential direction and the axial center direction of the sleeve 12, and the set bolts 14 are threadedly fitted in the radial direction of the sleeve 12 and the tip thereof is inserted. The sleeve 12 is held concentrically with the metal frame 11 by bringing the sleeve 12 into contact with the outer peripheral surface of the metal frame 11.

[0003]

[Problems to be solved by the device]

 According to such a configuration, after the inner peripheral surface of the metal frame 11 constituting the mold is coated, the metal frame 11 is rotated together with the sleeve 12 to pour the molten metal into the inside of the metal frame 11 for cooling and solidification. As a result, casting is performed. By the way, the time from pouring the molten metal into the metal frame 11 until the solidified casting pipe can be pulled out is about 20 seconds with a casting pipe having a diameter of 200 mm. This time is called the cooling rotation time, and it accounts for about 1/4 of the casting cycle time.

Therefore, if the cooling rotation time is shortened, the productivity of manufacturing the cast pipe can be improved, but 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 since the steel metal frame 11 has a low thermal conductivity, it has little effect on improving the cooling capacity, and the cooling speed is increased to increase the cooling rotation time. There is a problem that productivity cannot be improved by shortening

Therefore, the present invention has as an object to solve the above problems and to provide a metal frame for centrifugal casting, which can increase the cooling rate of the molten metal to shorten the cooling rotation time and improve the productivity.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a centrifugal casting metal frame in which a sleeve is fitted on a cylindrical metal frame and a water cooling jacket is provided between the metal frame and the sleeve. A steel layer on the inner peripheral side and a metal layer formed on the outer peripheral side of the steel layer and having a higher thermal conductivity than the steel layer.

[0007]

[Action]

 With such a structure, the metal frame is composed of a steel layer on the inner peripheral side and a metal layer having a higher heat conductivity than the steel layer on the outer peripheral side. The cooling rate of the molten metal is higher than that of the structure, and the cooling rotation time is shortened.

[0008]

【Example】

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

The metal frame 1 is composed of a steel layer 4 on the inner peripheral side and a copper layer 5 on the outer peripheral side. The copper layer 5 is formed on the outer peripheral surface of the steel layer 4 and has a higher thermal conductivity than that of steel. It is formed by overlay welding and machining. If the thickness of the conventional steel metal frame is, for example, about 30 mm, correspondingly, the thickness of the steel layer 4 is set to about 10 mm, and the thickness of the copper layer 5 on the outer periphery thereof is set to about 10 mm. It is preferably about 20 mm.

The thermal conductivity of the steel constituting the steel layer 4 is about 0.18 cal / cm · s · ° C., whereas the thermal conductivity of the copper constituting the copper layer 5 is 0.941 cal / cm · s.・ C, and the thermal conductivity of copper is about 5 times that of steel. For this reason, the thermal conductivity of the metal frame 1 is significantly improved as compared with the conventional one.

Set bolts 6 arranged at appropriate intervals in the circumferential direction and the axial center direction of the sleeve 2 are threadedly fitted through the wall of the sleeve 2 in the radial direction, and the tips of the set bolts 6 are made of the copper layer 5. It is in contact with a steel protection ring 7 provided on the outer periphery. Thus, the copper layer 5 is prevented from being damaged by the pressing of the set bolt 6, and the sleeve 2 for forming the water cooling jacket 3 is held concentrically with the metal frame 1.

With such a configuration, at the time of manufacturing the cast pipe, a coating mold is applied to the inner peripheral surface of the metal frame 1, and the socket forming core 8 is arranged on the socket portion 1a side of the metal frame 1. After arranging the stopper ring 9 on the insertion opening 1b side of the frame 1, the molten metal 10 is poured into the metal frame 1 while rotating the metal frame 1. Then, the heat of the molten metal 10 is efficiently conducted between the thin steel layer 4 and the copper layer 5 on the outer side thereof, and is taken away by the cooling water flowing in the water cooling jacket 3, so that the molten metal 10 is rapidly cooled and solidified. Then, a cast pipe is formed. This solidified cast tube is then withdrawn.

Since the molten metal 10 is rapidly cooled and solidified in this manner, the cooling rotation time from pouring the molten metal 10 into the metal frame 1 until the solidified casting pipe can be pulled out is, for example, 200 mm in diameter. The casting tube can be shortened to about 1/3, which is about 7 seconds, and the productivity of the casting tube can be improved.

[0014]

[Effect of device]

 As described above, according to the present invention, since the metal frame is composed of the steel layer on the inner peripheral side and the metal layer having higher thermal conductivity than the steel layer on the outer peripheral side, the cooling rate of the molten metal can be increased. Therefore, the cooling rotation time can be greatly shortened, productivity can be improved, pinholes can be prevented from occurring due to insufficient cooling of the metal frame, and the shrinkage amount of the casting pipe will be large, so that it can be easily pulled out. Further, the life of the metal frame can be extended.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a centrifugal casting metal frame according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a conventional centrifugal casting metal frame.

[Explanation of symbols]

 1 Gold frame 2 Sleeve 3 Water cooling jacket 4 Steel layer 5 Copper layer

Claims (1)

[Scope of utility model registration request] 1. A sleeve is fitted on a cylindrical metal frame,
A centrifugal casting metal frame having a water-cooling jacket between the metal frame and the sleeve, wherein the metal frame is formed on a steel layer on the inner peripheral side and on the outer peripheral side of the steel layer. A metal frame for centrifugal force casting, comprising a metal layer having a thermal conductivity higher than that of the layer.