JPS5929354B2 - centrifugal casting equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to processing equipment for casting articles, and more particularly to centrifugal casting equipment.

The invention can be most advantageously used in machine manufacturing and other industrial fields in which articles are centrifugally cast from ferrous, non-ferrous metals, glass, plastics and ceramics. Although centrifugal casting has been known and widely used for a long time, there are still difficulties in filling the mold with metal and in proportioning the metal. The solution to this problem currently appears to be urgent in view of the fact that a number of patents relating to improvements in centrifugal casting equipment have been granted in several countries. Some companies still fill the molds with melt by hand, by pouring the melt from above using a diamond, which is useful as a batch meter. This method allows accurate measurement of melt batches without the need for special equipment, and also eliminates the problem of crust formation on the outside surface of the mold.
) generation can be prevented. However, this method cannot increase manufacturing efficiency and consumes a large amount of labor. Apparatus is known in the art that can mechanize and to some extent automate the process of dispensing melt and filling molds.

In particular, a centrifugal casting device is known (FR 15871
87, International Classification 2B22D13/00). A siphon pipe extending from the sprue connects the sprue directly to the melt in the pool. The melt is conveyed into the mold through a siphon tube by an electromagnetic or vacuum pump. Once the mold is filled with melt, the melt begins to solidify around it, and at the same time a portion of the melt in the siphon tube is dispensed.

Due to the large diameter of the siphon tube and due to the presence of the thermally insulating material, this part of the metal melt finally solidifies and forms a contracted head. This shrinking head must of course be removed when obtaining the finished product, which requires additional raw material consumption and is accompanied by large losses. Additionally, electromagnetic pumps cannot be used when casting plastics, glass, and ceramics, while vacuum pumps are inefficient when casting dense materials. Also, Soviet Patent No. 5201
Centrifugal foundry apparatus, which convey the melt to the mold by centrifugal force, are known in the art, as described in International Classification No. 81, International Classification 2B22D13/10.

The device consists of a mold which is mounted for rotation about a vertical axis and has a bottom portion provided with an axial opening therethrough. The opening in the bottom is provided with means partially immersed in the melt and supplying the mold with the melt. This means is made in the form of a collet which is fixed to the bottom of the mold and has an upwardly extending groove. The mold and collet are connected to a rotational drive and a vertical motion drive. By lowering the rotating mold,
A collet is immersed in the melt and under the action of centrifugal force the melt is directed through the grooves of the collet into the mold. The mold and collet assembly is then lifted, with most of the melt pouring out of the collet into the distribution pool. However, some of the melt inevitably remains in the collection, which impairs the accuracy of the quantification and forms a shrinkage head. As will be appreciated, removing the shrink head requires additional raw material consumption and is associated with significant losses. Furthermore, the device described above has the disadvantage that slag inevitably enters the mold, thereby having an adverse effect on the quality of the casting. It is an object of the present invention to provide a centrifugal casting apparatus in which the means for supplying the melt to the mold are configured to prevent the formation of shrinkage heads and the fouling of the mold by slag.

The object of the present invention is achieved in the following device.

namely, a mold having a bottom portion arranged to rotate about a vertical axis and provided with an axial opening therethrough; means for supplying the conditioned melt into the mold; a rotary drive connected to the mold and said means;
A centrifugal casting apparatus comprising a mold and a vertical movement drive for vertically moving said means, wherein means for supplying the melt to the mold have a helical surface and are arranged axially in said bottom opening. , and a lower part extending from the opening below the bottom of the mold. In the device described above, the inner surface of the opening at the bottom is configured vertically, so that when the mold is pulled up, the melt does not remain on the vertical surface of the opening, thus preventing the formation of shrinkage heads.

Also, during the lowering of the mold, the lower part of the member comes into contact with the melt, and the rotation of the member dissipates the slag, thereby making it possible to remove it from the surface of the opening. In this method, mold contamination caused by slag is actually removed and the quality of the produced castings is improved. Advantageously, the member with a helical surface is made in the form of a screw.

Best results are obtained when the ratio between the diameter of the screw and the diameter of the bottom opening is between 0.1 and 1.

A variant of the centrifugal casting apparatus in which the above-mentioned member is made in the form of a helical plate, essentially a screw, is the simplest in construction.

If the mold is fairly tall, it is desirable to have the length of the screw equal to the height of the mold.

This is because, with this arrangement, the molten liquid filling the mold is uniformly distributed over the entire inner surface of the mold. The filling of the mold with melt is accelerated by a modification of the centrifugal casting apparatus in which the screw blades are made in the form of a tube with an open lower end and an open upper end.

A highly efficient centrifugal casting process is provided by a modification of the apparatus in which the screw 1 is a multi-start screw 1.

It has been found that the number of blades in the screw preferably corresponds to 2 to 6 threads. Advantageously, the screw is hollow and filled with coolant.

Such a configuration makes it possible to equalize the temperature of the screw over its entire length, thereby preventing deformation and damage of the screw caused by thermal strain. Furthermore, with this configuration, the screw 1 can be made from inexpensive structural steel and can be used in steel casting. It has been found that no segregation occurs in the casting when the mold and screw rotate at different speeds. Therefore, it is desirable that the screw and mold be differentially connected to the rotary drive. In particular, it is desirable that the screw and the mold be attached to the end of a coaxially arranged output shaft of the differential gear, and the input shaft of the differential gear is connected to the rotary drive body.

Best results are obtained when the differential gear has a gear ratio that allows the ratio of the angular velocity of the screw to the angular velocity of the mold to be kept within a range of 1 to 2.

A variant of the centrifugal casting apparatus in which the above-mentioned member with a helical surface is in a rigid connection with the mold is of simple construction. A modification of the centrifugal casting apparatus is also possible, in which the above-mentioned elements are made in the form of helically arranged protrusions on the inner surface of the opening in the bottom of the mold.

The element can also be made in the form of an impeller, the blades of which are fixed to the mold bottom. The last two modifications of the centrifugal casting apparatus are useful for casting products from glass and ceramics. Next, specific examples of the present invention will be described in detail with reference to the accompanying drawings.

The centrifugal casting apparatus shown in FIG. 1 consists of a mold 1 having a bottom part 2 mounted for rotation about a vertical axis and provided with an axial opening therethrough.

The mold 1 also has a removable cover 3. Mold 1
A distribution basin 4 containing the melt is provided below. Means for feeding the melt into the mold 1 are provided at the entrance to the opening in the bottom 2 of the mold 1. According to the invention, said means for feeding the melt into the mold 1 is a member 5 having a helical surface 6 . This member 5 is mounted axially within an opening in the bottom 2 and extends from the opening into the bottom 2 of the mold 1.
and has a lower portion extending below and adapted to be immersed in the melt. The member 5 is operatively connected to a rotary drive 7 (the operative connection is indicated by a dotted line 8).

Further, the mold is interlocked and connected to the rotary drive body 7 by a shaft 9,
This shaft is fixed to the cover 3 and is arranged inside the guide 10. The rotary drive 7 is connected in conjunction with a vertical movement drive 11, which is made in the form of an operating cylinder, the rod 12 of which is connected to the rotary drive 7.

FIG. 2 of the accompanying drawings shows another embodiment of the invention,
Here, a member 5 with a helical surface 6 is made in the form of a screw 13 according to the invention.

The ratio between the diameter of the screw 13 and the diameter of the opening in the bottom part 2 is preferably between 0.1 and 1. FIG. 3 of the accompanying drawings shows another embodiment of the invention, in which the member 5 with a helical surface 6 is formed according to the invention into a helical plate 14 which is essentially a single thread. It is made in FIG. 4 of the accompanying drawings shows another embodiment of the invention, in which the length of the screw 13 is equal to the height of the mold 1 according to the invention.

In this case, the screw 13 is firmly fixed to the cover 3 of the mold 1. FIG. 5 of the accompanying drawings shows another embodiment of the invention, in which the vanes of the screw 13 are made in accordance with the invention in the form of a tube 15, which tube has an open lower end 1.
6 and an open upper end 17.

FIG. 6 of the accompanying drawings shows another embodiment of the invention,
Here, the screw 13 is constructed according to the invention as a multi-thread screw (in this case two-thread). The most preferred variant of the multi-strip screw 13 is provided with a large number of blades corresponding to 2 to 6 threads. FIG. 7 of the accompanying drawings shows another embodiment of the invention in which the screw 13 is made hollow and filled with a coolant, such as sodium, in accordance with the invention.

FIG. 8 of the accompanying drawings shows another embodiment of the present invention,
Here, according to the present invention, the screw 13 and the mold 1 are differentially connected to the rotary drive body 7, and the screw 13 and the mold 1 are connected to an output shaft 18 coaxially disposed on the differential gear 20.
and 19, respectively.

Output shafts 18 and 19 are arranged within guide 10. The input shaft 21 of the differential gear 20 is connected to a rotary drive 7, which in turn is connected by a rod 12 to a vertical movement drive 11. The differential gear according to the invention preferably has a gear ratio that makes it possible to maintain the ratio between the angular velocity of the screw 13 and the angular velocity of the mold 1 within a range of 1 to 2. FIG. 9 of the accompanying drawings shows another embodiment of the invention, in which a member 5 having a helical surface 6 is shown.
are made in the form of helically arranged protrusions 22 inside the opening in the bottom 2 of the mold 1.

The bottom 2 of the mold 1 has a projection 23 which is arranged in coaxial relation with the mold and is immersed in the melt. Furthermore, a vane 24 is fixed to the outer surface of the protrusion 23. FIG. 10 of the accompanying drawings shows another embodiment of the invention, in which a member 5 with a helical surface 6 is made in the form of an impeller 25, the blades 26 of which are located at the bottom of the mold 1. is fixed to.

The bottom part 2 has a projection 23 which is arranged in coaxial relation with the mold and is immersed in the melt. The vanes 24 are fixed to the outer surface of the protrusion 23. In the embodiment of the invention shown in FIGS. 4, 9 and 10 of the accompanying drawings, a member 5 with a helical surface 6 is rigidly connected to the mold 1 according to the invention. . The centrifugal casting apparatus of the present invention operates in the following manner.

A driver 7 (FIG. 1 of the accompanying drawings) imparts rotation to the mold 1 and to the member 5 having a helical surface 6. The driver 11 lowers the mold 1 and the member 5. When this element 5 comes into contact with the molten slag covering the surface of the melt of the material to be treated, it scatters this slag and thereby cleans the surface of the melt of the material to be treated below the mold 1 . When the bottom 2 of the mold 1 comes into contact with the surface of the melt, the drive 11 stops. The member 5 conveys the melt through the opening in the bottom 2 into the mold 1 by rotation.

Under the action of centrifugal force, the melt is forced against the walls of the mold 1, thereby forming a continuously increasing layer. The internal diameter of the casting is determined by the diameter of the opening in the mold bottom 2.
Once the mold 1 has been filled, the excess melt flows down the vertically extending face of the opening into the distribution sump 4. At this time, the driver 11 begins to raise the mold 1 and the member 5. When the melt solidifies, the drive body 7 stops operating, thereby stopping the rotation of the mold 1 and the member 5. Cover 3 was removed from mold 1 without removing the finished molded product. The embodiments of the invention illustrated in FIGS. 2, 3, 4, and 6 operate in a manner similar to that described above.

According to an embodiment of the invention shown in FIG. 5 of the accompanying drawings:
The melt is conveyed into the mold through tubes 15, which act like the blades of screw 13.

The melt is captured by the open lower end 16 of the tube 15;
It is force fed into the mold 1 through the open upper end 17. The embodiment of the invention shown in FIG. 7 of the accompanying drawings operates substantially as described above.

However, in this case, the internal space of the screw 13 is filled with a liquid coolant such as molten sodium.
This coolant circulates to equalize the temperature over the entire height of the screw 13. The embodiment of the invention illustrated in FIG. 8 of the accompanying drawings operates in the following manner.

The driver 7 applies rotation to the input shaft 21 of the differential gear 20 .
The outer output shaft 19 rotates the mold 1, while the inner output shaft 1
8 rotates the screw 13. said shafts 18 and 1
9 rotates at different angular velocities. The embodiment of the invention shown in FIG. 9 of the accompanying drawings operates in the following manner.

Claims (1)

[Scope of Claims] 1. A mold 1 having a bottom part 2, which is arranged to rotate around a vertical axis and is provided with a through-axial opening; a rotary drive body 7 connected to the mold 1 and the supply means; and a rotary drive body 7 for vertically moving the mold 1 and the supply means; In a centrifugal casting apparatus, the means for supplying the melt into the mold 1 comprises a member 5 having a helical surface 6 and a vertical movement drive 11 that extends axially into the mold 1. A centrifugal casting apparatus characterized in that it has a lower portion extending outwardly from an axial opening arranged and having vertical walls. 2 The member 5 having the helical surface 6 is connected to the screw 13
The centrifugal casting apparatus according to claim 1, characterized in that it is made in the shape of. 3. The centrifugal casting apparatus according to claim 2, characterized in that the ratio between the diameter of the screw 13 and the diameter of the opening of the bottom part 2 is between 0.1 and 1. 4. Centrifugal casting device according to claim 2, characterized in that said member 5 is made in the form of a helical plate 14, which is essentially a screw. 5. The centrifugal casting apparatus according to claim 2, wherein the length of the screw 13 is equal to the height of the mold 1. 6. Centrifugal casting device according to claim 2, characterized in that the vanes of the screw (13) are made in the form of a tube (15) with an open lower end (16) and an open upper end (17). 7. The centrifugal casting apparatus according to claim 2, wherein the screw 13 is a multi-thread screw. 8 Claim 7, characterized in that the screw 13 is provided with a large number of blades corresponding to 2 to 6 threads.
Centrifugal casting equipment as described in Section 1. 9. The centrifugal casting apparatus according to claim 2, wherein the screw 13 is hollow and filled with a coolant. 10. The centrifugal casting apparatus according to claim 2, wherein the screw 13 and the mold 1 are differentially connected to the rotary drive body. 11 The screw 13 and the mold 1 are arranged at the ends of the coaxially arranged output shafts 18 and 19 of the differential gear 20, and the input shaft 21 of the differential gear is connected to the rotary drive body 7. The centrifugal casting apparatus according to claim 10, characterized in that: 12. Claim 11, characterized in that the differential gear 20 has a gear ratio that can maintain the ratio between the angular velocity of the screw 13 and the angular velocity of the mold 1 within a range of 1 to 2. The described centrifugal casting apparatus. 13. Claim 1, characterized in that said member 5 with a helical surface 6 is rigidly connected to the mold 1.
Centrifugal casting equipment as described in Section 1. 14. Claim 13, characterized in that said element 5 with a helical surface 6 is made in the form of a helically arranged projection 22 on the inner surface of the opening in the bottom 2 of the mold 1 Centrifugal casting equipment as described in Section 1. 15. Centrifugal casting apparatus according to claim 13, characterized in that the element (5) is made in the form of an impeller (25), the blades (26) of which are fixed to the mold bottom (2).