JP2517671Y2 - Pipe casting rough material - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting rough material for pipe joints.

[0002]

2. Description of the Related Art When manufacturing a pipe joint, first, a cast rough material having a processing surface for processing an internal thread portion on an inner surface of an end is formed, and then an internal thread portion is processed on the processing surface.

However, in order to produce a cast rough material,
Conventionally, as shown in FIG. 7, a sand mold or the like is used to connect a weir d into which the molten metal flows from the feeder c to the processed surface b of the rough material a.

[0004]

Therefore, in the above-mentioned conventional method, the weir mark e remains on the machined surface b of the rough material a, and the dam mark e is cut with a tap when the female screw portion is machined. Therefore, the tap was damaged, and the formed threaded portion had a screw failure.

In addition, in order to prevent pulling holes, the feeder c
And the cross-sectional area of the weir d was increased.
Therefore, there is a drawback that a large amount of molten metal is required, resulting in a high cost, and a large weir trace and a complicated finishing work.

Therefore, in the present invention, the cross-sectional area of the feeder and the weir can be reduced, and moreover, the tap is not easily damaged,
Moreover, it is an object of the present invention to provide a casting rough material for a pipe joint, in which the formed female screw portion does not have a screw defect.

[0007]

In order to achieve the above object, in the rough material of the pipe joint according to the present invention, the molten metal flows into the cavity of the mold through a weir provided in the mold. And a chamfered portion which is connected to a weir during casting and is not threaded during casting, and which has a nominal diameter of the joint of D When the width dimension of the chamfer is W, W is 2 to 4 mm when D is 1/2 inch, W is 2 to 5 mm when D is 3/4 inch, and D is 1 to 11 / 4 inch, W is 3 to 6 mm, D is 1 1/2 to 2 inch, W is 4 to 7 mm, and D is 21/2 inch, W is 4 to 10 mm. If it is 3 inches, W is 4 ~
12 mm, and if D is 4 inches, W is 4 to 16 mm
It is what

[0008]

Since the die is used, the riser can be made small and the cross-sectional area of the weir can be made small.

Further, the weir traces after casting will be formed on the chamfered portion provided at the inner peripheral edge portion of the opening end, and when forming the female screw portion on the inner peripheral surface of the end portion of this rough material with a tap, It can be performed without being affected by the weir traces.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings showing the embodiments.

FIG. 1 shows a cast rough material of a pipe joint according to the present invention in a cast state, in which the molten metal is melted through a weir 2 provided in a mold 1 of a mold device. It flows into the cavity 4 and is cast.

That is, the mold device used for casting is a mold 1 which is a vertical split mold, and a cavity 4 of the mold 1.
And a collapsible core 5 mounted therein.

The mold 1 is, as shown in FIG.
It is composed of a mold 6 and a second mold 7.

The mating surface 8 of the first die 6 is formed with a vertical main spout forming recess 10a which opens to the upper surface 9 of the first die 6, and a horizontal hot water is formed below the recess 10a. The road forming recesses 11a, 11a are branched left and right.

In addition, throttle portions 12a and 12a for controlling the flow velocity of the molten metal are provided at the branch portions from the main spout forming recess 10a to the runner forming recesses 11a and 11a.

Further, the sprue forming recesses 13a, 13a rise vertically from the recesses 11a, 11a.

Cavity forming recesses 4a for L-shaped pipe joints are formed in two steps at the left and right symmetrical positions of the gate opening forming recess 13a. That is, eight cavity forming recesses 4 a are formed in the first mold 6.

Thus, each cavity forming recess 4a ...
A core 5 is attached to the.

Here, the core 5 is the hole 14 inside the rough material.
(Refer to FIG. 2), and an end forming portion 17 for forming a hole 16 (see FIG. 2) at an end of the rough material.
Further, the outer end of the end forming portion 17 is formed with a taper portion 18 that gradually expands outward, and the inner end of the end forming portion 17 sequentially contracts outward. The tapered portion 19 is formed.

Further, in the recesses 13a, 13a for forming the sprue gate,
The recessed portions 20 are provided, and the recessed portion 20 is communicatively coupled to the weir forming concavity 2a that is communicatively coupled to the cavity forming concavity 4a.

Also, the second mold 7 has a mating surface 21 (see FIG. 2) similar to the first mold, with a main molten metal forming recess, a runner forming recess, and a cavity forming recess. , Is formed,
The recess for forming the gate is not formed.

Therefore, when the first and second molds 6 and 7 are fitted to each other on the mating surfaces 8 and 21, the facing main recess 10 for forming the sprue is formed.
The main sprue 10 is formed at a, the runner 11 is formed at the facing runner forming recess 11a, and the sprue forming recess 13 is formed.
a and the part of the mating surface 21 facing this,
The cavity 4 is formed in the facing cavity forming recess 4a, and the dam 2 is formed by the dam forming concave groove 2a and part of the mating surface 21 facing the dam forming concave groove 2a.
The riser 22 is formed by 0 and a part of the mating surface 21 facing this.

A vent hole (not shown) is provided in the second mold, and the vent hole is opened in the recess 20 and the back surface of the second mold 7.

Then, in this combined state, the main spout 10
If the molten metal is poured into, the molten metal will pass through the runway 11
Then, it enters the cavity 4 from the feeder 22 of the feeder 13 through the weir 2 and the rough material is cast.

That is, in the rough material, the tapered portion 18 and the chamfered portion 23 of the core 5 are formed on the inner peripheral edge of the open end, and the chamfered portion is formed.
Weir 2 is connected to 23.

Therefore, as shown in FIG. 2, the dam trace 24 is formed in the chamfered portion 23, and is not formed in the inner peripheral surface (that is, the processed surface 25) of the hole portion 16 for forming the screw portion.

In this case, in the cast rough material, the width dimension of the chamfered portion 23 and the cross-sectional area of the weir 2 are set as shown in the following Table 1 with respect to the nominal diameter of each joint.

[0028]

[Table 1]

In Table 1, D represents the nominal diameter of the joint,
W indicates the width dimension, and A indicates the weir cross-sectional area. Obey
And setting the relationship between D and W as shown in Table 1
By using the mold 1, the weir cross-sectional area is relatively small.
Can be set to facilitate later finishing work.

The rough material to be formed is an elbow type,
Cheese type and socket. That is, in the embodiment, the case of forming an elbow type rough material is illustrated,
It indicates that it may be a cheese mold or a socket.

However, as described above, in the rough material having the weir traces 24 in a part of the chamfered portion 23, the tapped portion 30 shown in FIGS.

That is, the tap 30 has a shaft portion 32 having a threaded portion 31 on its outer peripheral surface, and cutter portions 34, 34 slidably fitted in the axial grooves 33, 33 on the outer peripheral surface of the shaft portion 32. And elastic members 35, 35 for pressing the cutters 34, 34.

The cutter portion 34 is composed of a substantially rectangular parallelepiped main body portion 34a and an inclined chamfering blade 34b attached to the tip of the main body portion 34a.
Is cut from the chamfer 26.

A cylindrical portion 36 is provided on the outer peripheral side of the shaft portion 32, and an axial concave groove 37 into which the cutter portion 34 is slidably fitted is provided on the inner peripheral surface of the cylindrical portion 36. The cutter portion 34 is held by the concave groove 37 and the concave groove 33 of the shaft portion 32 described above.

Thus, the tap 30 constructed as described above
To form an internal thread on the machined surface 25 by rotating the shaft 32 and inserting it into the hole 16 of the rough material, the threaded part 31 of the shaft 32 forms an internal thread on the machined surface 25. It can be formed, and as shown in FIG. 6, the chamfering blade of the cutter portion 34.
The weir trace 24 can be cut at 34b, and the chamfered portion 26 can be beautifully finished.

Therefore, since the casting rough material constructed as described above is not obstructed by the weir traces 24 when forming the internal thread portion, the tap 30 is not damaged or the thread portion formed is not defective in threading.

Since the rough material is cast in the mold 1,
It has the advantage that it can be rapidly cooled and the cross-sectional area A of the riser 22 and the weir 2 can be reduced.

The present invention is not limited to the above-described embodiment, and the design can be freely changed without departing from the gist of the present invention. For example, as a rough material, the diameter of the opening is different. It may be a cross type or the like.

Further, the number of castings performed once is not limited to eight, but can be freely changed.

[0040]

Since the present invention is constructed as described above, it has the following effects.

Since the weir traces 24 are formed on the chamfered portion 23 that is not threaded , the machined surface 25 is threaded.
There is no damage to the taps 30 and the like to be performed , and no screw failure occurs in the formed female screw portion.

Nominal diameter D and width W of chamfer 23
Set the relationship of as described above and use the mold 1.
This allows the weir traces 24 to be set relatively small.
This facilitates subsequent finishing operations.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a casting state of a casting rough material of a pipe joint according to the present invention.

FIG. 2 is an enlarged sectional view of a main part.

FIG. 3 is a front view.

FIG. 4 is an enlarged cross-sectional view of the tap.

FIG. 5 is an enlarged vertical sectional view of a tap.

FIG. 6 is an enlarged vertical sectional view of a tap.

FIG. 7 is a cross-sectional view of an essential part showing a conventional example.

[Explanation of symbols]

 1 Mold 2 Weir 4 Cavity 23 Chamfer

Claims (1)

(57) [Scope of utility model registration request] 1. A casting raw material which is cast when a molten metal flows into a cavity 4 of a mold 1 through a weir 2 provided in the mold 1 and is cast at an inner peripheral edge of an open end. When the chamfered portion 23 that is connected to the weir 2 and is not threaded is formed, and the nominal diameter of the joint is D and the width dimension of the chamfered portion 23 is W, D is 1/2 If inch, W is 2 to 4 mm, and if D is 3/4 inch, W
Is 2 to 5 mm, W is 3 to 6 mm when D is 1 to 1 1/4 inches, W is 4 to 7 mm when D is 1 1/2 to 2 inches, and D is 2 1/2 If inch, W is 4 to 10 mm, and if D is 3 inch, W is 4 to 10 mm.
12 mm, and if D is 4 inches, W is 4 to 16 mm
The rough casting material for pipe joints characterized by the above.