JP2500405B2 - ERW tube manufacturing method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention melts a joint portion of a metal plate bent into a tubular shape, and presses the metal plate from both sides with a pair of welding rolls arranged opposite to each other to join the metal plates. The invention relates to a method for manufacturing an electric resistance welded pipe, in which the distance between a pair of welding rolls is variable, and a preferred apparatus for carrying out the method.

[0002]

2. Description of the Related Art FIG. 3 is a schematic front view of a manufacturing line of a conventionally known electric resistance welded pipe manufacturing apparatus, and FIG. 4 is a perspective view illustrating a welded portion in detail. As shown in FIGS. 3 and 4, a strip 22 of a metal plate unwound from a coil 21 is formed into a tubular shape by a round forming roll 23, and a heating coil 3 using a high frequency oscillator 3a melts a joint portion of the metal plate. , A pair of welding rolls arranged to face each other is pressed from both sides to weld the joint portion 2a of the metal plate. Next, the bead 2a 'formed during welding is cut by a cutter 24 and then formed by a series of rolls 25, and a predetermined electric resistance welded pipe is obtained by a cutting machine 26.

Various structures can be used as the structure of the welded part, and an apparatus for manufacturing an electric resistance welded pipe having a welded part of various structures has been proposed. In the apparatus for manufacturing electric resistance welded pipes disclosed in JP-A-2-211987, as shown in FIGS. 5 and 6, one welding roll 1b of the pair of welding rolls 1a and 1b is a shaft 7b fixed to a fixed holder 6. Is rotatably supported on the other side, and the other welding roll 1a is fixed on the fixed holder 6
Is rotatably supported by a shaft 7a fixed to a slide holder 8 which is slidably arranged. Between the sliding holder 8 and the fixed holder 6, as shown in FIG.
5, a spring 4 for pushing the sliding holder 8 to the right in FIG. 5 and a spring 5 for pushing the sliding holder 8 to the right in FIG. 5 are arranged, and a sensor 9 for detecting the movement of the welding roll 1a through the sliding holder 8 is arranged. To be done. The welding roll 1a and the welding roll 1b are formed by using such a welded portion.
When the distance between and becomes too narrow, the force of F ₂ opposite to the force of F ₁ applied by spring 4 is applied to spring 5
It is possible to control the pressing force of the joint appropriately.

[0004]

In the apparatus for manufacturing an electric resistance welded pipe having a welded portion shown in FIGS. 5 and 6, the sliding holder 8 is arranged in close contact with the fixed holder 6 so that the sliding holder 8 can be moved. On the other hand, there is no backlash. The gap at the boundary surface 11 between the sliding holder 8 and the fixed holder 6 is about several μm. Therefore, frictional resistance is generated at the boundary surface, and the pressing force applied by the springs 4 and 5 is not correctly transmitted to the joint portion of the tubular metal plates. That is, as shown in FIG. 7, when the amount of the molten metal suddenly increases and the sliding holder 8 tries to move to the left due to the force of the spring 4, the frictional force −f in the opposite direction (right side) acts and the pressing force becomes insufficient. , It will result in poor bonding. On the other hand, as shown in FIG. 8, when the amount of molten metal sharply decreases, the frictional force + f on the left side caused by the force of the spring 4 and the sliding holder 8 trying to be pushed back to the right acts. The pressing force becomes excessive and the joint is deformed. Therefore, the conventional known apparatus for manufacturing electric resistance welded pipes shown in FIGS. 5 and 6 cannot cope with a rapid change in the amount of molten metal, resulting in the generation of electric resistance welded pipes with defective joints.

The present invention solves the above-mentioned problems of the conventionally known apparatus for manufacturing electric resistance welded pipes, and is capable of always forming a uniform joint regardless of a rapid change in molten metal. It is an object to provide a manufacturing method and an apparatus thereof.

[0006]

The above objects of the present invention are as follows:
The welded parts of the metal plate are melted and close to each other so that they do not interfere with each other.
From both sides by a pair of welding rolls that have been separated
Bending the metal plate into a tube by pressing
Of the electric resistance welded pipe for welding the welded portion of the metal plate
One of the pair of welding rolls, which is a manufacturing method
Or both welding rolls are welded to each other via a tubular metal plate.
For the contact roll, for the welded part of the metal plate
With the elastic member with the desired pressing force set in advance,
Achieved by a manufacturing method characterized by being pressed
To be done.

If the pair of welding rolls are not interfered with each other, that is, if they are independently moved toward and away from each other, the pressing force between the pair of welding rolls is correctly transmitted to the tubular metal plate by a desired pressing means. As a result, an electric resistance welded tube having a uniform joint can be manufactured.

A preferable apparatus for manufacturing an electric resistance welded pipe for carrying out the method of the present invention is a device for melting a joint portion of a metal plate bent into a tubular shape, a pair of welding rolls arranged to face each other downstream of the device, And an electric resistance welded pipe manufacturing apparatus comprising a pressing joining device having a pressing means for pressing the other welding roll against one of the pair of welding rolls, wherein one of the pair of welding rolls is rotated. A first holder that freely supports and a second holder that rotatably supports the other welding roll are provided on both sides sandwiching the tubular metal plate,
The second holder rotatably supports the welding roll at one end thereof, and is rotatably supported by the manufacturing device at the other end extending along the longitudinal direction of the tubular metal plate.
Thereby, the welding roll on the second holder can swing with respect to the welding roll on the first holder along an arcuate path, which is achieved by an electric resistance welded pipe manufacturing apparatus. The pressing means comprises a first spring means and a second spring means for applying a pressing force to the second holder in a direction in which the second holder swings toward the first holder,
The first spring means is configured to apply the pressing force to the second holder in the entire area of the swinging movement of the second holder, and the second spring means causes the second holder to have a predetermined interval or more. When it comes close to the
It is more preferable that the second holder is provided with a detection unit that is configured not to be applied to the holder and that detects the predetermined interval.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIGS. 1 and 2 showing an example of a preferred manufacturing apparatus for carrying out the method for manufacturing an electric resistance welded pipe of the present invention. FIG. 1 is a plan view showing an example of an electric resistance welded pipe manufacturing apparatus of the present invention, and FIG. 2 is a partial cross-sectional side view showing a bearing mechanism that supports a second holder of the manufacturing apparatus shown in FIG.

In order to clarify the correspondence with the prior art in the present invention, the reference numerals given to the respective members in FIGS. 1 and 2 are the production of the conventionally known electric resistance welded pipes shown in FIGS. The same reference numerals are used for the same members as the device.

As is apparent from the comparison of FIG. 1 with FIG. 6 (prior art), in the present invention, the welding roll 1a is pointed to by the arrow 12 toward the welding roll 1b supported by the fixed first holder 6. As shown, it is swingable. That is, the second holder 13 that rotatably supports the welding roll 1a via a shaft (not shown) has an arm portion 13a extending parallel to the tubular metal plate to be processed, and a bearing is provided at the tip of the arm portion 13a. It is rotatably supported by a machine base 15 of the manufacturing apparatus by 14. Therefore, the approaching / separating movements of the welding roll 1a with respect to the welding roll 1b can be performed independently without interfering with each other, and no frictional resistance is generated between them in the conventional technique. In order to make the swing of the second holder 13 around the bearing 14 smoother, the bearing 14 may be composed of a pair of upper and lower rolling bearings 14a as shown in FIG.

It is preferable that the oscillating motion is performed on the tubular metal plate in a straight line in the vertical direction as much as possible. Therefore, it is preferable to increase the distance between the bearing 14 and the center of rotation of the welding roll 1a. It is set from 150mm to 200mm. If this distance exceeds 200 mm, the mass of the second holder 13 becomes too large and the response of the swinging motion becomes poor, which is not preferable. The position of the bearing 14 is the bearing 1
It is preferable that the line connecting 4 and the center of rotation of the welding roll 1a be parallel to the tubular metal plate.

By making the welding roll 1a swingable by using the second holder 13 having such a structure, the movement resistance of the welding roll 1a with respect to the welding roll 1b is 5 to 30 g.
This value can be kept to a degree, and this value can be greatly reduced compared to 500 to 1000 g in which the second holder is slid with respect to the first holder as shown in FIGS. 5 and 6. Therefore, by using the method and apparatus of the present invention, it is possible to apply an appropriate pressing force to the joint,
High quality ERW pipe can be manufactured.

In the example of the manufacturing apparatus shown in FIG. 1, the welding roll 1b has a fixed structure. However, as shown in FIG. 9, the first holder 6'is mirror-symmetrical to the second holder 13. The welding roll 1b may be swingable similarly to the welding roll 1a. Further, in the example of the manufacturing apparatus shown in FIG. 1, the second holder 13 is formed in a U-shape, and the first spring means and the second spring means are opposite sides of the second holder 13 facing the tubular metal plate. The structure is such that a pressing force is applied to each of the surfaces, but as shown in FIG.
The second holder 13 'is formed in an L shape and the first spring means 4 and the second spring 5 are provided on the outer surface 13b of the arm portion of the second holder 13' opposite to the welding roll 1a when viewed from the shaft 14. You may arrange.

By constructing the welding roll 1a so as to be swingable, in the manufacturing apparatus of the present invention, the pressing means for pressing the welding roll 1a toward the welding roll 1b has a tubular shape of the second holder 13 as shown in FIG. The first spring 4 applies a pressing force to each of the opposite surfaces 13b of the first and second metal plates facing each other.
And a second spring means having a second spring 5. The first spring means is configured to press the welding roll 1a toward the welding roll 1b via the second holder 13 in the entire range of the variation of the distance between the welding roll 1a and the welding roll 1b, and
The spring means is configured not to apply a pressing force to the second holder 13 when the distance between the welding roll 1a and the welding roll 1b is less than a predetermined amount. For that purpose, as shown in FIG. 1, the shaft 4a supporting the first spring 4 may be longer than the shaft 5a supporting the second spring 5. F ₁ spacing between With this arrangement the welding roll 1a and the welding roll 1b is when a predetermined amount greater than the sum of the pressing force F ₂ of the pressing force F ₁ and the second spring 5 of the first spring 4 +
The pressing force of F ₂ can be applied to the tubular metal plate, and when the distance is smaller than a predetermined amount, the pressing force can be only F ₁ , and thereby the pressing force to the joint can be made appropriate. be able to. Reference numeral 9 is a sensor for measuring a minute movement of the welding roll 1a.

[0016]

According to the method and apparatus for manufacturing an electric resistance welded pipe according to the present invention, the pressing of the pair of welding rolls against each other is applied without being affected by the change even when the amount of the molten metal changes rapidly. Therefore, a uniform joint can be always formed.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an example of an electric resistance welded pipe manufacturing apparatus of the present invention.

2 is a partial cross-sectional side view showing a bearing mechanism that supports a second holder of the manufacturing apparatus shown in FIG.

3 to 8 are views for explaining a conventionally known device for manufacturing an electric resistance welded pipe, and FIG. 3 is a schematic front view of a manufacturing line of the device for manufacturing a conventional electric resistance welded pipe.

FIG. 4 is a detailed perspective view of a welding view of the apparatus shown in FIG.

FIG. 5 is a partial sectional front view showing a mechanism for pressing a pair of welding rolls of a conventionally known electric resistance welded pipe manufacturing apparatus.

6 is a plan view of a pressing mechanism of the welding roll shown in FIG.

FIG. 7 is a cross-sectional view schematically showing a state of a joint portion of a tubular metal plate when the amount of molten metal rapidly increases.

FIG. 8 is a cross-sectional view schematically showing a state of a joint portion of a tubular metal plate when the amount of molten metal is sharply reduced.

FIG. 9 is a schematic plan view showing another example of the electric resistance welded pipe manufacturing apparatus of the present invention.

FIG. 10 is a schematic plan view showing still another example of the electric resistance welded pipe manufacturing apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... A pair of welding rolls 1 a ... Movable welding roll 1 b ... Welding roll whose position is fixed 2 ... Tubular metal plate 2 a ... Joint of metal plates 3 ... Heating coil 4, 5 ... Spring 6 ... First holder 7 a , 7b ... Shaft that rotatably supports the welding roll 8 ... Sliding holder 9 ... Sensor 13 ... Second holder 13a ... Second holder arm portion 13b ... Surface contacting pressing means 14 ... Bearing 14a ... Rolling bearing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiro Mitsukawa 1-1, Showa-cho, Kariya city, Aichi Japan Denso Co., Ltd. (56) Reference JP-A-2-211987 (JP, A) JP-A-3 -264170 (JP, A) Actual flat 2-87572 (JP, U)

Claims (6)

(57) [Claims] 1. A welded part of a metal plate is melted and interferes with each other.
Pair of welding rolls that are given a close-and-separate motion
The metal plate by pressing from both sides with
Bending the metal plate and melting the welded part of the metal plate.
A method for manufacturing an electric resistance welded pipe in contact with one another, or one or both of the pair of welding rolls.
Via the tubular metal plate to the other welding roll,
If the desired pressing force is applied to the welded part of the metal plate,
Being pressed by the elastic member that has been set
Method for producing a electric-resistance-welded pipe characterized by. 2. The manufacturing method according to claim 1, wherein at least one of the welding rolls moves toward and away from the other welding roll along an arcuate trajectory. 3. A device for melting a joint portion of a metal plate bent into a tubular shape, a pair of welding rolls arranged to face each other downstream of the device, and one of the pair of welding rolls to the other of the welding rolls. An electric resistance welded pipe manufacturing apparatus including a pressure welding apparatus having at least one pressing means for pressing the welding rolls, the first welding roller rotatably supporting one of the pair of welding rolls.
A holder and a second holder that rotatably supports the other welding roll are provided on both sides sandwiching the tubular metal plate, and the second holder rotatably supports the welding roll at one end thereof and At the other end extending in the longitudinal direction, it is rotatably supported on the manufacturing device so that the welding roll on the second holder can swing relative to the welding roll on the first holder along an arcuate path. An electric resistance welded pipe manufacturing apparatus characterized in that 4. The first spring comprises a first spring means and a second spring means for applying a pressing force to the second holder in a direction in which the second holder swings toward the first holder. Means for applying its pressing force to the second holder in the entire area of the oscillating movement of the second holder, and when the second spring means brings the second holder closer to the first holder more than a predetermined distance. The pressing force is not applied to the second holder,
Further, the detection means for detecting the predetermined interval is the second
The electric resistance welded pipe manufacturing apparatus according to claim 3, wherein the electric resistance welded pipe manufacturing apparatus is provided for the holder. 5. The electric resistance welded pipe manufacturing apparatus according to claim 3, wherein the first holder is fixed to the manufacturing apparatus. 6. The first holder rotatably supports the welding roll at one end thereof, and is rotatably supported by the manufacturing apparatus at the other end extending in the longitudinal direction of the tubular metal plate, whereby the first holder is rotatably supported. 4. The electric resistance welded pipe manufacturing according to claim 3, wherein the welding roll on the first holder and the welding roll on the second holder can swing relative to each other's welding rolls along an arcuate path. apparatus.