JPH07246425A - Method for remedying complete roundness of tube - Google Patents

Abstract

PURPOSE:To easily and inexpensively manufacture a tube part with a branch part with satisfactory roundness. CONSTITUTION:In a method for remedying the branch part 2 of a tube 1 formed by burring to complete roundness by plural spinning rolls 3, when a diameter in the longitudinal direction of the tube of the vertical branch part 2, is formed longer than the diameter in the direction to the longitudinal direction, or when the diameter in the longitudinal direction of the tube of the branch part 2, is formed shorter than the diameter in the vertical direction to the longitudinal direction, the roundness of the branch part is allowed to improve by enlarging or shrinking the tube of the branch part 2 to the diameter in the longitudinal direction of the tube.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe straightening method for straightening a branch portion of a pipe into a perfect circle when manufacturing a machine part.

[0002]

2. Description of the Related Art Pipes are widely used for producing various machine parts. Generally, pipes are often connected and used to form flow paths for oil, gas and the like.
In a pressure vessel or the like, for example, a pipe supplied from a material manufacturer is subjected to secondary processing such as burring to form a branch portion in a part of the pipe, and another pipe is joined to the branch portion by welding or the like. Manufactures assembled structural members.

By the way, a burring method using a press die, a bulging method using hydraulic pressure, a burring method using a rod-shaped rotary tool, etc. are applied as burring processing means for forming a branch portion in a part of a pipe. Has been done.

However, when another pipe is connected to the branch portion of the pipe formed by these processing methods by welding or the like, since the roundness of the branch portion is poor, a worker such as hammering is required in a later step. As a result of work, measures are often taken to correct the roundness of the bifurcation to improve accuracy.

[0005]

As described above, hammering is a work that requires a lot of labor and time, and is not a preferable work in terms of safety and work environment. Therefore, it is conceivable to apply a method of automatically improving the roundness of the pipe branch portion by a mechanical force. For example, it is possible to easily apply a method of expanding a branch portion of a pipe with a spinning roll to correct a perfect circle by applying the principle of drawing using a spinning roll.

However, in the case of straightening a straight pipe, it is possible to certainly improve the roundness by a method using the principle of drawing with a spinning roll. When the rigidity differs along the circumference, the roundness cannot be improved by the method described above.

The present invention has been made to solve the above problems, and provides a pipe roundness correcting method capable of improving the roundness of a pipe part having a branch portion having a good roundness. The purpose is to

[0008]

In order to achieve the above-mentioned object, the present invention is directed to the case where the diverging portion of the pipe formed by burring is straightened by a plurality of spinning rolls to form a perfect circle. When the diameter in the longitudinal direction is formed to be longer than the diameter in the direction perpendicular to the longitudinal direction, the inner surface of the branch portion in the direction orthogonal to the pipe longitudinal direction is pressed by the spinning roll to have a diameter in the pipe longitudinal direction. It is characterized by expanding the pipe.

Further, when straightening the branch portion of the pipe formed by the burring process into a perfect circle by a plurality of spinning rolls, the diameter of the branch portion in the pipe longitudinal direction is larger than the diameter in the direction orthogonal to the longitudinal direction. In the case where it is also formed to be short, the outer surface of the branch portion in the direction orthogonal to the pipe longitudinal direction is pressed by the spinning roll to reduce the diameter to the pipe longitudinal direction.

[0010]

[Function] In such a pipe roundness correcting method,
Since the rigidity of the branch portion in the direction perpendicular to the pipe longitudinal direction is smaller than the rigidity in the pipe longitudinal direction, when the diameter of the branch portion in the pipe longitudinal direction is formed longer than the diameter in the direction perpendicular to the longitudinal direction. , The inner surface of the branching portion is expanded by a spinning roll to expand the pipe, and when the diameter of the branching portion in the pipe longitudinal direction is formed to be shorter than the diameter in the direction perpendicular to the longitudinal direction, the spinning roll By pressurizing the outer surface and contracting the pipe, the diameter of the branch portion in the direction orthogonal to the pipe longitudinal direction can be easily corrected to the diameter of the pipe longitudinal direction, and the roundness of the branch portion can be improved. it can.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pipe straightening method according to the present invention will be described below with reference to the drawings. In FIG.
The pipe 1 is formed with a branching portion 2 by a molding burring process such as a burring process using a press die, a bulging process using hydraulic pressure, and a burring process using a rod-shaped rotary tool.

The branch portion 2 thus formed on the pipe 1.
Is expanded or contracted by rotating the spinning roll 3 as shown in FIG. The spinning roll 3 includes a plurality of (three in this example) rotary arms 6 mounted on the outer periphery of a support column 5 provided on the central axis of the rotating body 4 at equal intervals so as to be expandable and contractible in the radial direction. It is rotatably supported on the tip.

Here, the spinning roll 3 as described above is used.
A case where the roundness of the branch portion 2 of the pipe is corrected by using is described with reference to FIGS. 3 and 4. The branch portion 2 after the burring process in the previous step has a different diameter along the circumference as shown in FIG. 3 or 4, and is greatly deviated from the true circle.

In this case, the diameter of the branch portion 2 is longer than the diameter of the branch portion 2 in the longitudinal direction of the pipe as shown in FIG. 3, or as shown in FIG. In some cases, the diameter of the branch portion 2 in the longitudinal direction of the pipe may be formed to be shorter than the diameter in the direction orthogonal to the longitudinal direction, and each situation differs depending on the processing method and processing conditions in the previous step.

For example, in the burring process using a press die, the diameter of the branch portion 2 in the longitudinal direction of the pipe is formed smaller than the diameter in the direction orthogonal to the longitudinal direction, and in the burring process using a rod-shaped rotary tool, the branch portion 2 is formed. The diameter in the longitudinal direction of the pipe is longer than the diameter in the direction orthogonal to the longitudinal direction.

Here, since the branch portion 2 is formed at a right angle to the cylindrical surface of the pipe, the rigidity differs along the circumference. That is, the rigidity is large in the longitudinal direction of the pipe and small in the direction orthogonal to the longitudinal direction. Therefore, the pipe length direction of the branch portion 2 is not easily deformed.

Therefore, in the case where the diameter of the branch portion 2 in the longitudinal direction of the pipe is formed to be longer than the diameter in the direction orthogonal to the longitudinal direction as shown in FIG. 3, the spinning roll is formed on the inner peripheral surface of the branch portion 2. While contacting 3 and rotating, branching part 2
The circularity can be improved by expanding the pipe from the inside to the diameter in the longitudinal direction of the pipe.

Further, the diameter of the branch portion 2 in the longitudinal direction of the pipe is
As shown in FIG. 4, when the diameter of the pipe is shorter than the diameter in the direction orthogonal to the longitudinal direction, the spin nigr roll 3 is brought into contact with the outer peripheral surface of the branch portion 2 and rotated, and the pipe is drawn from the outside of the branch portion 2. The roundness can be improved by reducing the diameter of the tube in the longitudinal direction.

In this case, the spinning roll 3 is connected to the branch portion 2
2 is moved by a small amount in the radial direction to contact the inner surface of the branch portion 2, and then the branch portion 2 is expanded by a predetermined amount while being fed and moved in the direction of the central axis of the branch portion 2 indicated by the arrow in FIG. The tube is deflated and the roundness of the bifurcation 2 is corrected.

The material to be processed in the present invention is intended for all metal materials, and the roundness correction processing can be carried out on any metal material. Also,
It is preferable to rotate a plurality of spinning rolls 3 at the same time for use. In this case, according to an experiment by the inventor, it was confirmed that the roundness is particularly easily improved when an odd number of spinning rolls 3 are used.

[0021]

As described above, according to the present invention, it is possible to provide a pipe roundness correcting method capable of improving the roundness of a pipe part having a branching portion with good roundness.

[Brief description of drawings]

FIG. 1 is a perspective view of a pipe having a branch portion to which the method of the present invention is applied.

FIG. 2 is a diagram for explaining an embodiment of a roundness correcting method for a pipe according to the present invention.

FIG. 3 is a diagram showing a case where the diameter of the branch portion in the longitudinal direction of the pipe is longer than the diameter in the direction perpendicular to the longitudinal direction.

FIG. 4 is a view showing a case where the diameter of the branch portion in the longitudinal direction of the pipe is shorter than the diameter in the direction perpendicular to the longitudinal direction.

[Explanation of symbols]

1 ... pipe, 2 ... branching part, 3 ... spinning roll.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sada Odawara 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa, Ltd. Hamakawasaki Plant, Toshiba Corporation (72) Takashi Miyatani 33, Isogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Banchi Co., Ltd.Toshiba Production Engineering Laboratory

Claims (2)

[Claims] 1. When straightening a branch portion of a pipe formed by burring to a perfect circle with a plurality of spinning rolls, the diameter of the branch portion in the pipe longitudinal direction is larger than the diameter in the direction perpendicular to the longitudinal direction. A roundness correcting method for a pipe, characterized in that, when it is formed long, the inner surface of the branch portion in the direction orthogonal to the pipe longitudinal direction is pressed by the spinning roll to expand the pipe to a diameter in the pipe longitudinal direction. 2. A straight part of a pipe formed by burring is straightened by a plurality of spinning rolls so that the diameter of the branched part in the longitudinal direction of the pipe is larger than the diameter in the direction orthogonal to the longitudinal direction. If the pipe is also formed to be short, the outer surface of the branch portion in the direction orthogonal to the pipe longitudinal direction is pressed by the spinning roll, and the pipe is contracted to have a diameter in the pipe longitudinal direction. .