JPH06238414A - Metallic mold for centrifugal casting - Google Patents

Abstract

PURPOSE:To provide a metallic mold for centrifugal casting which hardly generate the difference in the quality of a cast product between the opening hole part side for casting molten metal and the other end part side. CONSTITUTION:In the metallic mold 1 for centrifugal casting, the whole is formed as a cylindrical shape and a molten metal casting space 3 is provided in the inner part and the opening hole part 5 for casting the molten metal into the molten metal casting space 3 while rotating the mold around the axis C thereof is arranged at the one end in the axial C direction and, an insulating part A is arranged at the other end part 6 opposite the opening hole part 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is formed into a tubular shape as a whole, has a molten metal pouring space therein, and an opening for pouring into the molten metal pouring space in a state of being rotated around its axis. The present invention relates to a centrifugal casting mold having a part provided at one end in the axial direction.

[0002]

2. Description of the Related Art Heretofore, this type of centrifugal casting mold has been formed into a cylindrical shape having a substantially uniform thickness over the entire length thereof, and the heat absorption and heat dissipation at the same temperature have been substantially equal.

[0003]

According to the above-mentioned conventional centrifugal casting mold, in the process in which the molten metal is cast into the centrifugal casting mold, the molten metal flows from the opening side at one end to the other end side. When flowing, the heat of the molten metal is drawn to the centrifugal casting mold and the molten metal pouring space, so that when the molten metal reaches the other end side, the temperature of the molten metal greatly decreases, and the opening side and the A large temperature difference occurs between the other end side and the molten metal solidifies quickly on the other end side. In an extreme case, the molten metal solidifies by the time it reaches the other end side. It is possible that molten metal is not supplied to all parts. Moreover, the speed at which the molten metal solidifies greatly differs between the opening side and the other end side, and there is a difference in quality in the axial direction of the cast product. There is a defect that defects such as pinholes, cavities inside, and so-called "shrinkage cavities" may occur, resulting in deterioration of quality.

Therefore, in view of the above-mentioned drawbacks, an object of the present invention is to provide a centrifugal casting mold in which difference in quality of cast products between the opening side for molten metal casting and the other end side hardly occurs. It is in.

[0005]

A characteristic feature of the present invention for achieving this object is that a heat retaining portion is provided at the other end of the centrifugal casting mold opposite to the opening, Further, the heat retaining portion may be formed such that the heat retaining degree increases as the distance from the opening portion increases, and the function and effect thereof are as follows.

[0006]

In other words, since a heat retaining portion is provided at the other end of the centrifugal casting mold (hereinafter abbreviated as a mold) opposite to the opening, the molten metal is poured into the mold. When the molten metal flows from the pouring opening to the other end, the heat retaining portion suppresses the amount of heat of the molten metal taken through the mold, so even if the molten metal flows to the other end, the heat of the molten metal Is less likely to be deprived by the mold, and it is possible to suppress the temperature of the molten metal from decreasing at the other end side of the mold earlier than that at the opening side. Under similar conditions, it became easier to solidify the melt.

Furthermore, if the heat retaining portion is formed so that the degree of heat retaining increases as the distance from the opening increases, it becomes possible to maintain the temperature of the molten metal substantially the same over the entire length of the die. It became possible to solidify the molten metal under almost the same conditions over the entire length.

[0008]

Therefore, the temperature of the molten metal does not significantly differ between the two ends inside the mold, and the molten metal can be solidified under the same solidification conditions at the opening and the other end. Side and the other end side do not have a large difference in quality, and pinholes and shrinkage cavities are less likely to occur at the other end, and there is a risk of product defects or deterioration of quality. It dropped significantly. As a result, it has become possible to reliably provide high-quality cast products.

[0009]

EXAMPLE A centrifugal casting mold of the present invention (hereinafter referred to as mold 1)
(Abbreviated as "), an embodiment of the mold 1 used for manufacturing a long pipe will be described with reference to the drawings.

As shown in FIG. 1, the mold 1 of the present invention is a cylindrical body having an outer shape of a truncated cone and a cylindrical molten metal pouring space 3 formed therein, and having both ends opened. It is made of heat-resistant steel.

Further, on the outer peripheral portion of the die 1, there are two enlarged diameter portions 2 having a larger diameter than the other portions at two locations spaced apart in the axial direction thereof.
Is provided over the entire circumference, and each expanded diameter portion 2 is formed in an annular shape having the same diameter. Further, when ring-shaped ring members 4 are fixedly provided in the openings at both ends in an internally fitted state, and the molten metal B is cast into the molten metal casting space 3,
It is possible to prevent the molten metal B, which spreads on the inner wall of the mold of the molten metal casting space 3 from leaking from the both ends of the mold 1 to the outside by the centrifugal force. The molten metal B is cast from the opening of the small-diameter side end portion of the mold 1, and the end portion on the molten metal B casting side is hereinafter referred to as the opening portion 5 and the other end is referred to as the other end portion 6. To do.

Within the wall thickness of the large-diameter other end portion 6 side of the die 1, a large number of hollow cavity chambers 7 are provided in a line in the axial direction to form a heat retaining portion A. .

At the bottom of the mold 1, there is provided a support roller 8 which is operably linked to a rotation driving device. The mold 1 contacts the expanded diameter portion 2 with the support roller 8. By doing so, the rotational driving force of the support roller 8 is transmitted to the mold 1, and the rotating force causes the mold 1 to move along the axis C.
It is rotatably mounted on the support roller 8 so as to be rotated around.

A flange portion 8a is continuously provided at one end of the support roller 8, and the flange portion 8a is provided on the side surface of the expanded diameter portion 2 of the die 1 placed on the support roller 8. By abutting against each other, the structure prevents the die 1 from moving in the direction of the axis C.

According to the mold 1 of this embodiment, after the inner wall surface of the molten metal pouring space 3 surrounded by the mold 1 and the ring member 4 is covered with the coating agent 9, the mold is made around the axis C. When the molten metal B is poured from the opening 5 into the molten metal pouring space 3 in a state where the liquid 1 is rotated, the molten metal B spreads along the inner peripheral surface of the mold coating agent 9 from the opening 5 to the other end 6 side. The molten metal B flows, but at this time, the temperature of the molten metal B is supplied to the inner surface of the molten metal pouring space 3 in a state where the temperature of the molten metal B is suppressed from being greatly reduced, and then the entire molten metal B starts to solidify. The molten metal B as a whole solidified under substantially the same conditions, and the cast product was manufactured substantially uniformly over the longitudinal direction.

[Other Embodiments] In this embodiment, the heat retaining portion A was formed by a large number of hollow chambers 7 provided within the thickness of the mold 1. However, as shown in FIG. It may be formed in a tubular shape having various thicknesses, and the heat insulating material 10 may be coated on the other end 6 side to form the heat insulating portion A. Even in this case, since the other end portion 6 where the heat of the molten metal B is most easily deprived of heat is kept warm to suppress the temperature decrease, the mold 1
The temperature difference of the molten metal B becomes small at both end portions, and the purpose can be achieved by a simple modification of the conventional mold 1.

Further, in this embodiment, the ring member 4 is
Although formed into an annular shape and fitted into the inner walls of both ends of the molten metal pouring space 3, the other end 6 side may be closed by using a disc-shaped lid member (not shown). It suffices if the portion is opened as an opening 5 for casting molten metal.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a view showing a mold for centrifugal casting according to an embodiment of the present invention.

FIG. 2 is a view showing a mold for centrifugal casting according to another embodiment of the present invention.

[Explanation of symbols]

 3 Molten metal casting space 5 Opening 6 Other end A Heat insulation C C axis

Claims (2)

[Claims] 1. The whole is formed into a tubular shape, and a molten metal pouring space (3) is provided inside, and the molten metal pouring space (3) is cast while being rotated around its axis (C). Is a mold for centrifugal casting provided with an opening (5) at one end in the direction of the axis (C), and heat insulation is provided at the other end (6) opposite to the opening (5). A mold for centrifugal casting provided with a part (A). 2. The mold for centrifugal casting according to claim 1, wherein the heat retaining portion (A) is formed such that the degree of heat retaining increases as the distance from the opening (5) increases.