JP2001205408A - Method for casting pipe having ruggedness on outer periphery of spigot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a pipe having ruggedness on the outer periphery of a spigot by centrifugal casting. SOLUTION: In casting the pipe 3 having the spigot 1 at one end and having a socket 2 at the other end and having the ruggedness 21 on the outer periphery of the spigot 1, centrifugal casting is executed by mounting a sand mold 27 having the shape corresponding to the shape of the outer periphery of the spigot 1 on the inner periphery at a centrifugal casting mold 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for casting a tube having an uneven outer periphery of an insertion opening.

[0002]

2. Description of the Related Art A cast iron tube has an insertion port at one end and a receiving port at the other end, and a pair of pipes is inserted into the receiving port of one adjacent pipe. The joining between the two is performed. Therefore, the receiving port has a larger diameter than the insertion port and the tube body. Such a cast iron tube is generally cast by centrifugal casting.

FIG. 3 shows a schematic configuration of an apparatus for centrifugally casting a cast iron pipe 3 having an insertion port 1 at one end and a receiving port 2 at the other end. Here, reference numeral 4 denotes a metal cylindrical mold, and the shape of the inner surface 5 is formed so as to correspond to the outer shape of the tube 3. Reference numeral 6 denotes an annular receiving core for forming the inner surface of the receiving port 2. The receiving core 6 is formed by hardening molding sand, and its outer peripheral surface 7 is formed so as to correspond to the inner surface shape of the receiving port 2.

When casting a pipe 3 using such a centrifugal casting apparatus, a molten metal is supplied into the mold 4 while rotating the mold 4 having the receiving core 6 around its axis at a high speed. I do. Then, by solidifying the molten metal by cooling, the pipe 3 as shown is cast. After casting,
By clamping the inner surface of the tube 4 and pulling the tube 3 out of the mold 4 from the large-diameter port 2 side, the tube 3 can be released from the mold 4.

On the other hand, a cast iron tube 3 having a projection 8 formed on the outer periphery of the insertion opening 1 as shown in FIG. However, in such a case, when the tube 3 having the projection 8 of the insertion opening 1 is centrifugally cast with the mold 4, the projection 8 is caught by the mold 4 and the cast tube 3 is removed from the mold 4. You can't do that.

Therefore, conventionally, for example, FIG.
As shown in (a), an annular groove 9 is formed by machining on the outer periphery of the insertion port 1 that has been cast and removed from the mold so as to have no protrusion, and a thick ring 10 of another member is formed in the annular groove 9. The ring 10 is fixed to the insertion opening 1 by a welded portion 11 at the end of the ring 10 and integrated to form a projection 8. Also, as shown in FIG.
There is also used one in which a ring 12 is fitted in the insertion opening 1 and the ring 12 is fixed to the insertion opening 1 by a welded portion 13 which melts the ring 12 in the thickness direction, and is integrally formed with the projection 8.

[0007]

That is, in the prior art, the projecting portion 8 on the outer periphery of the insertion port 1 in the cast iron pipe 3 must be formed by welding after casting, which requires a considerable amount of labor. There are issues.

In addition, a cast iron tube having an annular groove or a concave portion on the outer periphery of the insertion opening is often used. The technical problem that such cast iron pipes cannot form an annular groove by centrifugal casting for convenience in demolding, and the annular groove must be formed by machining such as lathe processing after casting. is there.

Accordingly, an object of the present invention is to solve such a problem and to make it possible to manufacture a tube having irregularities on the outer periphery of an insertion port by centrifugal casting.

[0010]

SUMMARY OF THE INVENTION In order to achieve this object, the present invention provides a method for casting a tube having an insertion port at one end, a receiving port at the other end, and an uneven surface around the insertion port.
A sand mold having a shape corresponding to the shape of the outer periphery of the insertion hole on the inner periphery is mounted on a centrifugal casting mold to perform centrifugal casting.

In this case, by using a sand mold,
A tube having irregularities on the outer periphery of the insertion opening can be cast by a centrifugal casting device. After the casting, the tube can be removed from the mold from the receiving side by crushing the sand mold.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 4 denotes a mold, and 3 denotes a cast iron tube which is centrifugally cast by the mold 4. The cast iron tube 3 has an insertion port 1 at one end and a receiving port 2 at the other end. A protrusion 21 is integrally cast on the outer periphery of the tip of the insertion opening 1. A tapered surface 22 is formed on the outer periphery of the distal end of the insertion opening 1 including the projection 21. Reference numeral 23 denotes a tube body between the insertion port 1 and the receiving port 2;
Is formed in a state where its outer diameter is expanded to the outer diameter of the protrusion 21. The inner diameters of the tube body 23 and the insertion opening 1 are formed in their original dimensions. The insertion port 1 is formed over a joining range 24 with a receiving port of another pipe. In the insertion port 1, in a portion other than the portion where the protrusion 21 is formed, the outer diameter D is: It is formed in an original size which is not the expanded size like the tube body 23. That is, the outer diameter D is formed smaller than the outer diameter of the tube body 23. The outer peripheral surfaces of the tube trunk 23 and the insertion opening 1 are connected to each other by a tapered surface 25.

The inner surface 5 of the mold 4 has a size corresponding to such a large-diameter tube body 23. Further, in the mold 4, a large diameter portion 26 having a larger diameter than other portions is formed in a portion forming the insertion opening 1 of the tube 3.
, An annular sand mold 27 for forming the outer surface of the insertion opening 4 is fitted in a fitted state. This sand mold 27 is
The inner peripheral surface 28 corresponding to the outer surface shape of the pipe 3 on the distal end side of the insertion port 1 with respect to the boundary between the pipe body 23 and the tapered surface 25 in FIG. And the projection 21 can be formed.

When the pipe 3 is cast, a receiving core 6 having an outer peripheral surface 7 of a required shape and the above-mentioned sand mold 27 are molded into a mold 4.
And the molten metal is supplied to the inside of the mold 4 while rotating the mold 4 around the axis at a high speed. Then, by solidifying the molten metal by cooling, the pipe 3 as shown is cast. After casting, the inner surface of the tube 4 is clamped, and the tube 3 is pulled out of the mold 4 from the large-diameter port 2 side. Then, the sand mold 27 is crushed by the force at that time, whereby the pipe 3 can be removed from the mold 4. That is, the pipe 3 having the protrusion 21 on the outer periphery of the insertion opening 1 can be manufactured by centrifugal casting.

FIG. 2 shows another embodiment of the present invention. Here, the cast iron tube 3 has an annular groove 29 on the outer periphery of the insertion opening 1.
That is, the insertion opening 1 is configured to have a concave portion on its outer periphery.
In this case, the sand mold 27 has an inner peripheral surface 28 corresponding to the outer surface shape of the insertion opening 1 having the annular groove 29, and is similarly mounted on the large diameter portion 26 of the mold 4.

In this case, similarly, a tube having an annular groove 29 on the outer periphery of the insertion opening 4 can be manufactured by centrifugal casting. When the tube 4 having the protrusion 21 and the annular groove 29 on the outer periphery of the insertion opening 4 is manufactured by centrifugal casting, subsequent welding or lathing is not necessary, and grind processing such as deburring is performed. Will be done. In addition, since it is not necessary to form the tapered surface 22 and the annular groove 29 by machining, there is an advantage that waste of material is eliminated.

[0017]

As described above, according to the present invention, when casting a pipe having an insertion port at one end and a receiving port at the other end and having irregularities on the outer circumference of the insertion port, the shape of the outer circumference of the insertion port can be improved. In order to perform centrifugal casting by attaching a sand mold having a shape corresponding to the inner circumference to the centrifugal casting mold, it is possible to cast a tube having irregularities on the outer periphery of the insertion port, and after casting, by crushing the sand mold The tube can be removed from the mold from the receiving side,
Therefore, a tube having irregularities on the outer periphery of the insertion opening can be manufactured by centrifugal casting.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method for casting a pipe having irregularities on the outer periphery of an insertion opening according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a method of casting a pipe having irregularities on the outer periphery of an insertion opening according to another embodiment of the present invention.

FIG. 3 is a view illustrating a conventional pipe casting method.

FIG. 4 is a view illustrating a conventional method for forming a protrusion on the outer periphery of a tube insertion opening.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion port 2 Reception port 3 Cast iron pipe 4 Mold 21 Projection part 27 Sand mold 29 Ring groove

Claims (1)

[Claims] 1. When casting a tube having an insertion port at one end and a receiving port at the other end and having irregularities on the outer circumference of the insertion port, the inner circumference has a shape corresponding to the shape of the outer circumference of the insertion port. A method for casting a tube having irregularities on the outer periphery of an insertion hole, wherein a sand mold is mounted on a centrifugal casting mold to perform centrifugal casting.