JPS59209486A - Production of metallic pipe - Google Patents

Abstract

PURPOSE:To obtain a metallic pipe having high quality by detecting the seam of a metallic tape formed into a pipe shape by means of a sensor and rising and descending the forming roll in accordance with the detection signal thereby correcting automatically the circumferential deviation of the seam and stabilizing welding of the seam. CONSTITUTION:A metallic tape 1' is formed to a pipe shape by using forming rolls 7A, 7B, 8, 4A, 4B. The position of the seam 2 of the tape 1' is detected with a photoelectric sensor 9 just before forming rolls 4A, 4B and the signal thereof is fed to a controller 11. The signal from the controller 11 is applied to a motor 17 of a roll lifting mechanism 13 to run forward or backward the motor 17 thereby rising or descending at least one roll, for example, 4A and correcting automatically the deviation of a seam 2. The seam 2 is thus always positioned opposite to the electrode of a welding machine 3 and stable seam welding is accomplished. Generation of a defective welded point with the metallic pipe 1 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a metal tube by forming a metal tape into a pipe and welding the seams thereof.

(Prior Art) As a method for forming a metal tape into a pipe, there are the Rolf and E-Mink methods. According to this roll forming method,
Since the forming rolls are rotationally driven, there is an advantage that almost no tension acts on the metal tape or the metal tube made from it.

The metal tape is sequentially formed from a flat shape to a circular shape by forming the metal tape into a circular shape, and then, as shown in FIG. ing.

In such a roll forming method, stabilizing seam welding over a long period of time is a key point in ensuring the stability of the equipment. If the device is operated continuously for a long time, the seam 2 of the metal tape f may shift in the circumferential direction due to differences in the surface condition of the forming rolls or thermal expansion due to welding, etc., causing the welding machine 3
It may become impossible to face the electrode 3A, and it may become impossible to seam weld the seam 2. In such cases, conventionally, workers had to spend considerable time adjusting the forming rolls using measuring instruments such as micro gauges and calipers.In order to adjust the forming rolls, a small diameter metal tube was used to adjust the forming rolls. This is particularly important when manufacturing. That is, in the case of small-diameter metal tubes, the arc is constricted at the welding part, so a slight deviation of the seam 2 will have a large effect on the welding.

(Object of the Invention) The object of the present invention is to provide a metal pipe manufacturing method that can automatically correct deviations in the circumferential position of joints of pipe-formed metal tapes and stabilize seam welding work. It is on offer.

(Structure of the Invention) In the present invention, as shown in FIG. 2, the metal tape When the seam 2 of r is shifted to the left side (forming roll 4B side) in the drawing, when the forming roll 4A is moved upward as indicated by arrow 5A, seam 2 moves in the direction of arrow 6B (forming roll 4A side), On the other hand, note that when the seam 2 shifts to the right side (forming roll 4A side), when the forming roll 4A is moved downward as indicated by arrow 5B, seam 2 moves in the direction of arrow 6A (forming roll 4B side). Then, the position of the seam is detected by a sensor and driven, at least one of the forming rolls on both sides of the seam is raised and lowered, the position of the seam is automatically corrected, and then the seam welding of the seam is performed. It is characterized by:

(Example) Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 3 and 4. Gold of this example as shown.

In the pipe manufacturing apparatus, vertical forming rolls 7A and 7B, horizontal forming roll 8 (the lower forming roll is not shown), and vertical forming roll 4A are used along the production line.
, 4 B, etc. are arranged in multiple stages.

A photoelectric sensor 9 is disposed between the forming roll 8 and the forming rolls 4A and 4B. The photoelectric sensor 9 of this embodiment is composed of photoelectric conversion elements 9A and 9B arranged adjacent to each other, and an image 2' of the alignment 2 is projected onto the light receiving surface of these photoelectric conversion elements 9A and 9B. The image is the photoelectric conversion element 9A.

Pixel element 9A when biased to either side of 9B.

The balance in the magnitude of the signal output from 9B is disrupted, and it is possible to detect that the position of seam 2 has shifted due to this, and to which side it has shifted.

The detection signal from the photoelectric sensor 9 is inputted to the controller 11 via the cable 10, and thereby the control signal is given from the controller 11 to the roll lifting mechanism 13 via the cable 12.・Roll lifting mechanism 13 as,
In this embodiment, a rack and pinion type is used for convenience of explanation. That is, this roll lifting mechanism 13 is provided with a rack 15 on a roll shaft 14 that rotatably supports the forming roll 4A through bearings, and a pinion 1 on this rack 15.
6 is engaged and the pinion 16 is rotated in forward and reverse directions by a motor 17, thereby raising and lowering the forming roll 4A. A head portion of a welding machine 3 is disposed behind the forming rolls 4A and 4B so as to face the seam 2.

Therefore, in the metal tube manufacturing method of this embodiment, the metal tape 1'
Forming rolls 7A and 7B are arranged in multiple stages.

8. Forming roll 4 while performing tube forming using 4A, 4B, etc.
A, 4. A photoelectric sensor 9 detects the position of the seam 2 of this metal tip in front of B, and sends the detection signal to the controller 11, which sends the control signal to the motor of the roll lifting mechanism 13. 17, and if the seam 2 shifts to the left in FIG. If the seam 2 deviates to the right in Fig. 4, the motor 17 is reversed to lower the forming roll 4A, and the seam 2 is automatically corrected to move to the left, controlling the amount of deviation to be zero. . In this way, seam welding can be stably performed with the seam always facing the electrode of the welding machine 3, and it is possible to prevent welding defects from occurring in the resulting metal tube 1.

Example Metal tube: Outer diameter 5 adjustment φ, length 1500771 Metal tube material: At1050 Line speed - 4 to 6 m 1 minute adjustment forming roll diameter near 0 mφ Motor: Stepping motor Lifting amount: 1 fall/1 rotation Nao , roll lifting/lowering (Z structure 13 is not limited to a rack and pinion type, but can be appropriately used such as a scree set).

(Effects of the Invention) As explained above, in the metal tube manufacturing method according to the present invention, a sensor detects the seam of a metal tape formed into a tube, and the forming roll is raised and lowered based on the detection signal. Since the deviation in the circumferential direction of the horizontal seam is automatically corrected, welding of the seam can be performed stably, and welding defects can be prevented from occurring. Therefore, according to the present invention, it is possible to easily continuously produce metal tubes with excellent quality.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the welded state of the seams of metal tape formed into pipes, and Fig. 2 is a cross-sectional view showing the relationship between pipe-forming metal, metal tape, and forming rolls for detailed explanation of the present invention. , FIG. 3 is a plan view showing an example of the arrangement of devices for carrying out the method of the present invention, FIG. 4 is a partial cross-sectional system diagram showing the configuration of main parts of the device for carrying out the method of the present invention, and FIG. 5 FIG. 2 is a front view showing an example of a sensor. f... Metal tape, 1... Metal tube, 2... Seam, 3... Welding machine, 4A, 4B, 7A, 7B, 8...
Forming roll, 9...Photoelectric sensor, 9A,, 9B...
... Photoelectric conversion element, 11 ... Controller, 13 ... Roll lifting mechanism, 14 ... Roll axis, 15 ... Rack,
16... Binion, 17... Motor. Agent Patent Attorney Hidetoshi Matsumoto

Claims (1)

[Claims] In a method for manufacturing a metal tube in which a metal tube is formed by passing a metal tape through forming rolls arranged in multiple stages and seam welding the seam while forming the pipe, the position of the seam before welding is detected by a sensor, A method for manufacturing a metal tube, characterized in that the position of the seam is automatically corrected by raising and lowering at least one of the forming rolls present on both sides of the seam based on the detection signal.