JP2001239427A - Female screw machining method of pipe, and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for machining a female screw of a pipe capable of improving efficiency and productivity and largely reducing cost. SOLUTION: In the female screw machining method for forming the female screw inside the pipe 1, the pipe 1 is heated to a predetermined temperature by a heating part 2, a recessed/projecting machining part 3 for machining the female screw inside the heated pipe 1 is inserted to be rotated by a rotation mechanism 4, and a female screw thread is formed while the pipe 1 is moved longitudinally by a pipe pressurizing and moving mechanism (rolling roll 5) from the outside of the pipe 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for forming a female screw in a pipe.

[0002]

2. Description of the Related Art Conventionally, in a method for forming a female thread in a pipe, a female thread is formed in a pipe by cold tapping or swaging. First, the tapping is performed by using a tap for threading, and is inserted into a pipe while rotating the tap, and a female screw is formed by shaving a material. In the swaging process, a mandrel having a thread is inserted into a pipe, and the pipe is narrowed while rotating from the outside of the pipe using a rotary aging machine.

[0003]

However, in the method of tapping a pipe according to the female thread, the inside of the pipe is cut, and cutting chips are generated. There was a problem that the work efficiency was poor because it could not be raised. Also,
In the method of deforming pipes by swaging, it is necessary to forcibly plastically deform the hardened metal in the cold state. There is also a problem that the equipment becomes large and the capital investment is costly.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides a method and apparatus for machining a female thread of a pipe which can increase productivity with a high efficiency and can greatly reduce costs. It is.

[0005]

In order to achieve the above object, the present invention provides a method for forming a female screw in a pipe, wherein the pipe is heated to a predetermined temperature by a heating device. Insert a concave / convex portion for female screw processing into the inside of the pipe in a heated state and rotate it by a rotation mechanism, and move the pipe in the longitudinal direction by the pipe pressure moving mechanism from the outside of the pipe while removing the female screw. It is characterized by forming.

Further, the present invention provides a heating section for heating a pipe, a concavo-convex processing section for processing thread-shaped concavo-convex inside the pipe, a rotating mechanism for rotating the concavo-convex processing section, And a pipe pressure moving mechanism for moving in the longitudinal direction while applying more pressure. Furthermore, the pipe pressure moving mechanism is a rolling roll that presses around the pipe.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method and an apparatus for processing a female thread of a pipe according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view showing an internal thread processing apparatus for a pipe according to the present invention, FIG. 2 is a cross-sectional view showing a rolling roll of the internal thread processing apparatus for a pipe shown in FIG. 1, and FIG. FIG.

[0008] An apparatus for processing a female thread of a pipe according to the present invention comprises:
As shown in FIG. 1, a heating unit 2 for heating a pipe 1, an unevenness processing unit 3 for processing a thread-shaped unevenness 1 a inside the pipe 1, and a rotation mechanism unit 4 for rotating the unevenness processing unit 3
And a pipe pressure moving mechanism 5 for moving the pipe 1 in the longitudinal direction while compressing it from the outside.

Further, according to the method for processing a female thread of a pipe according to the present invention, the pipe 1 is heated to a predetermined temperature by the heating unit 2, the unevenness processing unit 3 is inserted into the pipe 1 and rotated by the rotation mechanism unit 4, By moving the pipe 1 in the longitudinal direction while pressing the rolling roll 5 as a pipe pressing and moving mechanism, the thread-shaped unevenness 1a is processed.

The heating section 2 used in the pipe internal thread processing apparatus normally uses a high-frequency coil for performing high-frequency induction heating, but a heating furnace using oil or gas may be used. The heating section 2 softens the pipe 1 by heating it to a predetermined temperature of about 1100 ° C. in the case of an iron material in order to facilitate the processing of the commonly used steel pipe 1. In the case of processing other metals, it is needless to say that the temperature can be controlled to the most appropriate temperature suitable for the material. For this purpose, a temperature sensor and a temperature adjusting function (not shown) are provided.

In addition, the uneven portion 3 for processing the female screw is
It is composed of a processed portion 3a having a male screw unevenness corresponding to the thread-shaped unevenness 1a at the tip, and a shaft portion 3b smaller in diameter than the processed portion 3a. The processing unit 3a
Thread-shaped irregularities 1a are formed inside the pipe 1 which is heated while rotating. The shaft portion 3b is a shaft that transmits a rotational force from the rotation mechanism portion 4 to the processing portion 3a, and is made of a material that is not easily twisted and has little bending. The rear end portion of the shaft portion 3b is formed with a connection portion 3c with the rotation mechanism portion 4 and is connected to the rotation mechanism portion 4 via a rotation stop joint 3d.

A rotation mechanism 4 for rotating the unevenness processing section 3
Is rotatably supported by a rigid casing 4a, and is connected to a shaft portion 3b by a large gear 4b and a small gear 4d meshed with the large gear 4b and attached to the rotating shaft of a motor 4c.
It is composed of The large gear 4b is provided with a position adjusting mechanism (not shown) so that the position of the shaft portion 3b can be adjusted in the axial direction. And the shaft part 3b
The rotation mechanism 4 is connected to the rotation mechanism 3d by a rotation stopping joint 3d, so that the uneven portion 3 having a different size can be connected. With the rotation stop joint 3d, it is possible to easily insert and remove the concave / convex portion 3 at the start of processing and at the end of processing.

A rolling roller 5, which is a pipe pressure moving mechanism, is disposed at the position of the processing portion 3a of the unevenness processing portion 3,
This is for uniformly pressing the pipe 1 from the outside and moving the pipe 1 in the longitudinal direction. This rolling roll 5
As shown in FIG. 2, the contact surface of the pipe 1 is formed in a concave shape so that the pipe 1 can be evenly pressed from the outside, and is constituted by four rolling rolls 5 arranged vertically and horizontally. The pipe 1 is rotated by a drive shaft 5a, and is configured to move the pipe 1 while pressurizing the pipe 1.

Further, a plurality of guide rollers 6, 6,... Are arranged in the female threading apparatus for a pipe, so that the pipe 1 can move smoothly without bending. The guide rollers 6, 6,... Guide the pipe 1 and are appropriately attached to a drive shaft so that the pipe 1 can be fed.

Next, a description will be given of a method of forming a female thread with the female screw processing apparatus for a pipe constructed as described above, with reference to FIG. First, as shown in FIG.
〜12 m) of a pipe 1 is set in a female threading device, and a heating unit 2 composed of a high-frequency coil for high-frequency induction heating is energized, and the heating unit 2 starts heating the pipe 1. Next, as shown in FIG. 3B, after confirming that the temperature of the pipe 1 has reached a predetermined temperature by a temperature sensor or the like (not shown),
The guide roller 6 rotates the concavo-convex processing section 3 by the rotation mechanism section 4 of the pipe 1, and the thread-shaped concavo-convex section 1 a is formed inside the pipe 1.
To form At the same time as the processing of the unevenness processing portion 3 is started, the rolling roll 5 is rotated to roll the pipe 1, and the pipe 1 is pressed from the outside and sent out in the longitudinal direction of the pipe 1.

The pipe 1 processed as described above has a softened material because the pipe 1 is formed in a hot state in the step of forming the thread-shaped unevenness 1a by the unevenness processing part 3, so that the pipe 1 is formed in a cold state. Unlike the cutting process, the pipe 1 is extremely easily deformed.
No shavings are generated even if the unevenness processing part 3 rotates, following the unevenness of the above. Therefore, there is no waste of the material that becomes shavings, the material is effectively used, and the cost can be reduced.

In the pipe internal thread processing apparatus and processing method configured as described above, the pipe 1 is heated by the heating section 2.
Since the pipe 1 is heated to a predetermined temperature and the pipe 1 is processed in a hot state, there is no generation of shavings or the like generated by conventional cutting, and the material can be effectively used. Further, by performing the processing of the pipe hot, the processing is facilitated, and there is no need for an expensive mold that requires a large force, thereby making it possible to reduce equipment costs.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various embodiments can be made within the scope of the claims. For example, although the steel pipe is illustrated in the embodiment in the embodiment, the material of the pipe is not particularly limited as long as it is a metal pipe. Also, in the heating unit, oil or gas other than the high-frequency coil, or may be heated using electrical resistance,
Of course, the heating means most suitable for the material of the pipe can be selected.

[0019]

As described above, according to the present invention, in a method for forming a female screw in a pipe, the pipe is heated to a predetermined temperature by a heating unit.
Insert a concave / convex portion for female screw processing into the inside of the pipe in a heated state and rotate it by a rotation mechanism, and move the pipe in the longitudinal direction by the pipe pressure moving mechanism from the outside of the pipe while removing the female screw. By forming the pipe, the pipe is processed hot, so that there is no generation of shavings and the like generated in the conventional cutting, and an excellent effect that the material can be effectively used can be obtained. Also, since the processing of the pipe is performed hot, the processing becomes easy, there is no need for an expensive mold requiring a large force, and it is possible to reduce the equipment cost, and the cost is greatly reduced. It has the effect of being able to do so.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an apparatus for processing a female thread of a pipe according to the present invention.

FIG. 2 is a cross-sectional view showing a rolling roll of the pipe internal thread processing device of FIG.

FIG. 3 is a process diagram showing a method for machining a female thread of a pipe according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe 1a Thread-shaped unevenness 2 Heating part 3 Unevenness processing part 3a Processing part 3b Shaft part 3c Connecting part 3d Rotation stop joint 4 Rotation mechanism part 4a Casing 4b Large gear 4c Motor 4d Small gear 5 Rolling roll 5a Drive shaft 6 Guide roller

Claims (3)

[Claims] 1. A method according to claim 1, wherein the pipe is heated to a predetermined temperature by a heating unit, and a concave / convex portion for female screw processing is inserted inside the heated pipe. Forming a female screw while rotating the pipe in the longitudinal direction from outside of the pipe by the pipe pressing and moving mechanism. 2. A heating section for heating a pipe, a concavo-convex processing section for processing thread-shaped concavities and convexities inside the pipe, a rotation mechanism for rotating the concavo-convex processing section, and a pipe while pressurizing the pipe from outside. An internal thread processing device for a pipe, comprising: a pipe pressure moving mechanism for moving the pipe in a longitudinal direction. 3. The apparatus according to claim 1, wherein the pipe pressure moving mechanism is a rolling roll that presses around the pipe.