JPH10286621A - Manufacture of electric resistance welded tube with inner surface groove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the formation of a for with the good groove even when the groove is formed into the one way sloping shape under high reduction ratio at the time of working the groove by forming a recessed part in the axial direction of the peripheral surface of a roll for forming the groove according to the width of the bar with groove to form the groove at the bottom of the recessed part and restricting the edge surface in the width direction of the bar with groove. SOLUTION: The recessed part 2b is formed according to the width of the bar 7 with groove in the axial direction of the peripheral surface of the roll 2 for forming the groove to form the groove 2b on the bottom of the recessed part 2b. The flat bar supplied to the rolling mill from an uncoiler is introduced into a frame formed by the recessed part 2b of the roll 2 for forming the groove and a flat roll 3 to form the bar 7 with the groove forming the groove on the one side surface by rolling while receiving the restriction in the width direction. Since the width of the flat bar is different in each part, the rolling is executed while adjusting so that the width of the far 7 with groove becomes constant by adjusting the rolling reduction force of the rolling mill, front tension and back tension.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an electric resistance welded pipe with an inner groove, and more particularly to a method of manufacturing an electric resistance welded pipe with an inner groove using a groove.

[0002]

2. Description of the Related Art As shown in FIG.
With the grooved surface (not shown) of the grooved strip 17 inside,
There is an inner grooved electric resistance welded tube 10 in which spirally wound tightly wound without an overlapping portion is electrically stitched (welded) by a high frequency welding method or the like.

[0003] Fig. 2 is a schematic view of a rolling mill for producing a grooved strip for an electric resistance welded pipe with an inner surface groove. The same members as those in FIG. 5 are denoted by the same reference numerals.

[0004] As shown in FIG. 2, the smooth strip 6 supplied from the uncoiler section 1 on which the smooth strip 6 is wound is supplied to a roll mill 4 for forming a groove on one side thereof. At 4, a groove is formed to form a grooved strip 17, and then wound around the recoiler section 5.

[0005] The roll rolling machine 4 comprises a grooving roll 12 and a flat roll 3, and as shown in FIG. 3, a partially enlarged perspective view of FIG. 2, an uncoiler section (not shown).
The grooved roll 12 and the flat roll 3 rotating in the direction of the arrow in FIG.
To form a grooved strip 17 having a groove formed on one side. At this time, the grooved strip 17 is extended in the width direction and the longitudinal direction (the direction of arrow S in the figure).

In order to form a good electric resistance welded pipe with an inner groove, it is necessary to perform high-frequency welding satisfactorily. However, in order to perform high-frequency welding satisfactorily using the grooved strip 17 obtained by roll rolling. It is important that the edge of the grooved strip 17 after the groove processing is vertical and that the grooved strip 17 does not meander in the longitudinal direction.

Conventionally, the reduction (reduction rate) is reduced so that the grooved strip 17 is not deformed,
The groove processing was performed using a large-diameter flat roll 3.

[0008]

However, when a large-diameter roll is used, the production cost of the large-diameter roll is increased, which leads to an increase in the cost of the grooved groove. To reduce the cost of the grooved strip, it is necessary to use a small-diameter roll. However, if grooving is performed using a small-diameter roll, the reduction becomes high. Therefore, as shown in FIG.
Had an oblique (trapezoidal) edge surface shape.

In addition, since the grooved strip 17 extends greatly in the width direction, the metal material hardly flows into the groove 12a of the groove forming roll 12 near the edge of the grooved strip 17, and the grooved strip 17 has a large diameter. The groove shape was not very good.

Furthermore, when the groove shape of the grooved strip 17 is one-way, there is a problem that the grooved strip 17 meanders.

Therefore, the present invention solves the above-mentioned problems, and achieves high reduction at the time of grooving using a small-diameter roll, and
It is an object of the present invention to provide a method for manufacturing an inner grooved electric resistance welded tube capable of obtaining a good grooved groove even if the groove shape is set to a single flow.

[0012]

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide an electric resistance welded pipe with an inner surface groove in which a smooth strip forming an electric resistance welded pipe is rolled by a groove processing roll to form a groove on one side. In the manufacturing method, the edge in the width direction of the groove is restrained.

According to a second aspect of the present invention, a recess is formed in the axial direction of the circumferential surface of the groove forming roll in accordance with the width of the groove to restrain the edge in the width direction of the groove. 2. The method according to claim 1, wherein a groove is formed at a bottom of the recess.

According to a third aspect of the present invention, there is provided the method of manufacturing an electric resistance welded tube with an inner surface groove according to the first aspect, wherein rolling is performed by a four-direction roll in order to restrain an edge surface in a width direction of the grooved stripe.

According to the above construction, in the method of manufacturing an inner grooved electric resistance welded tube in which a groove is formed on one side by rolling a smooth line forming an electric resistance welded tube with a groove forming roll, the smooth line is rolled to form a groove. When forming the ridge, to reduce the width direction edge surface of the ridge, the reduction at the time of grooving using a small-diameter roll is high, and even if the groove shape is one-sided, a good ridge is provided. Can be obtained.

[0016]

Embodiments of the present invention will be described below.

According to the method for manufacturing an inner grooved electric resistance welded pipe of the present invention, when the flat strip forming the inner grooved electric resistance welded pipe is roll-rolled to form the grooved strip, the widthwise edge of the grooved strip is formed. It restrains the surface.

FIG. 1 shows a cross-sectional view of a grooved strip for rolling the electric-resistance-welded tube of the present invention at the time of rolling. The same members as those in FIG. 4 are denoted by the same reference numerals.

More specifically, as shown in FIG.
A recess 2b is formed in the axial direction (the left-right direction in the figure) of the peripheral surface of the groove processing roll 2 according to the width of the groove 7, and a groove 2a is formed at the bottom of the recess 2b.

The smooth strip (not shown) supplied from the uncoiler section (not shown) to the roll mill (not shown)
The grooved groove 7 is introduced into a frame (not shown) formed by the concave portion 2b of the grooved roll 2 and the flat roll 3 and rolled while restraining in the width direction to form a grooved groove 7 having a groove formed on one surface. Form.

At this time, since the width of the smooth strip is different in each part, the width of the grooved strip 7 is adjusted to be constant by adjusting the rolling force, the front tension and the back tension of the rolling mill. While performing roll rolling.

The shape of the concave portion is not particularly limited to a rectangle. For example, by making the shape of the concave portion a parallelogram, the widthwise edge surface of the grooved strip can be formed obliquely. Spiral winding during tube production is facilitated.

In other words, according to the method of manufacturing an electric resistance welded pipe with an inner surface groove of the present invention, the groove formed by the concave portion of the groove forming roll and the flat roll is used to suppress the extension of the grooved groove in the width direction. The flow of the metal material into the groove of the grooving roll near the edge of the ridge is improved, so that even with a small-diameter grooving roll, a good groove shape and a straight groove can be obtained.

Further, even if a large-diameter roll is used, even if the grooved shape of the grooved groove is not very good (for example, a smooth line made of a soft metal or alloy), the grooved shape is good. Articles can be obtained.

Further, since good roll rolling can be performed with a small-diameter roll, the manufacturing cost of the grooved groove can be suppressed.

In the present invention, the recess is formed in the groove processing roll. However, it goes without saying that the recess may be formed in the flat roll.

Next, another embodiment of the present invention will be described.

In the present invention, the width direction edge surface of the grooved strip is restricted by forming a concave portion on either the groove processing roll or the flat roll.
Rolling is performed by a directional roll.

Specifically, a four-way roll is provided in which a twin roll whose axial direction is the thickness direction of the grooved strip is disposed in a gap between the groove forming roll and the flat roll. The widthwise edge surface of the grooved strip is constrained by the frame formed in step (1).

It goes without saying that the present embodiment also exhibits the same operation and effect as the present invention.

[0031]

In summary, according to the present invention, the following excellent effects are exhibited.

(1) The groove formed by the concave portion of the grooving roll and the frame formed by the flat roll suppresses the extension of the grooving strip in the width direction, so that the grooving roll enters the groove near the edge portion of the grooving roll. The flow of the metal material is improved, and even if a small-diameter groove processing roll is used, a good groove shape and a straight groove can be obtained.

(2) Even if a large diameter roll is used, even if the grooved shape of the grooved groove is not so good (for example, a smooth line made of a soft metal or alloy), the groove has a good groove shape. Appendices can be obtained.

(3) Since good roll rolling can be performed with a small-diameter roll, the manufacturing cost of grooved strips can be reduced.

[Brief description of the drawings]

FIG. 1 is a transverse cross-sectional view of a grooved strip for producing an inner grooved electric resistance welded pipe of the present invention at the time of rolling.

FIG. 2 is a schematic view of a rolling mill for producing a conventional grooved strip for an electric resistance welded pipe with an internal groove.

FIG. 3 is a partially enlarged perspective view of FIG. 2;

FIG. 4 is a cross-sectional view of a grooved strip for producing a conventional inner grooved electric resistance welded tube at the time of rolling.

FIG. 5 is a schematic view of a conventional electric resistance welded tube with an inner surface groove.

[Explanation of symbols]

 2 Grooving roll 2a Groove 2b Recess 7 Groove

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hideo Murayama 3550 Kida Yomachi, Tsuchiura City, Ibaraki Prefecture Within the Tsuchiura Plant of Hitachi Cable Co., Ltd. Tsuchiura Plant (72) Inventor Kazuo Ishida 3550 Kida Yomachi, Tsuchiura City, Ibaraki Prefecture Hitachi Cable Tsuchiura Plant

Claims (3)

[Claims] 1. A method of manufacturing an inner grooved electric resistance welded tube in which a flat strip forming an electric resistance welded pipe is rolled by a groove forming roll to form a groove on one side, wherein the smooth strip is rolled to form a grooved strip. At this time, a method for manufacturing an inner grooved electric resistance welded tube, wherein an edge surface in a width direction of the grooved groove is restrained. 2. A groove is formed in an axial direction of a peripheral surface of the groove forming roll in accordance with a width of the groove to restrict an edge surface in a width direction of the groove, and a groove is formed at a bottom of the groove. The method for manufacturing an electric resistance welded pipe with an inner surface groove according to claim 1, wherein: 3. The method according to claim 1, wherein rolling is performed by a four-way roll to restrain the widthwise edge surface of the grooved strip.