JPS595648B2 - Seam tracking control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seam tracking control method, and in particular, to a seam tracking control method that is suitable for use in an annealing process of a seam after welding in an electric resistance welded tube manufacturing process. The present invention relates to a seam tracking control method for causing a head disposed on the downstream side of a conveyance facility to follow the seam tube in the circumferential direction in accordance with the displacement in the circumferential direction of the seam line of the seam tube to be conveyed.

In the manufacture of electric resistance welded pipes, annealing of the seam of the welded part is an important technology in terms of quality.

In particular, as the quality of electric resistance welded pipes has become higher recently, the quality level of annealing required has also become higher.

On the other hand, since the electric resistance welded tube generally twists as it progresses, it is necessary to use some method to make the annealer head follow the displacement of the seam line to maintain a constant relative relationship between the two.

However, in the past, there was no method to automatically detect the displacement of the seam line of the seam tube, so the position of the annealer head was manually controlled by visual inspection by the operator.

That is, the operator is always near the seam tube, visually inspects the seam line position, and drives the annealer head using operation buttons or the like.

However, this method of visually aligning the annealer head to the seam line position requires a worker, and since it is done visually, the seam line position may be incorrectly detected, and furthermore, manual operation may cause problems. There was a problem that operation errors could be made.

Particularly in recent years, speed amplifiers, larger capacities, and larger diameters have been progressing in the manufacturing of ERW pipes, and it has become possible to arrange multiple annealer heads in tandem in the direction of seam pipe movement and to increase the pipe manufacturing speed. Furthermore, in order to prevent the noise generated from the annealer apparatus, the entire annealer apparatus is housed in a soundproof room and is no longer visible from the outside.

Therefore, with the conventional method of visually aligning the annealer head to the seam line position, it has become extremely difficult to quickly respond to high speeds and manually operate a plurality of annealer heads.

In addition, from the viewpoint of quality, as the quality of electric resistance welded pipes increases, it is required to reliably follow the seam part and anneal the pipe.

SUMMARY OF THE INVENTION The present invention has been made to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a seam follow-up control method that can reliably make a head follow the seam line displacement of a seam tube.

The seam tracking control method of the present invention detects the seam deviation amount in the circumferential direction from the seam processing position extension line of the seam line between the seam processing position and the head position, and performs seam processing based on this seam deviation amount. The seam deviation amount at the head position is calculated in proportion to the distance from the seam processing position to the head position relative to the distance from the position to the detection position, and the head is displaced in the circumferential direction of the seam tube using this amount as a target value. That is.

Further, the target value is set to be different between the end of the seam tube and the end of the seam tube, thereby dealing with a peculiar movement of the seam line at the end of the seam tube.

The present invention will be explained in detail below.

Now, as shown in FIG. 1A, the seam tube 10 is seamed at a seam processing position 0 on the upstream side of the conveyance equipment, and a seam deviation amount detection position X is downstream from the seam processing position 0.

The seam processing position extension line A of the seam line A due to twisting of the seam tube 10, etc.

Seam deviation amount M in the circumferential direction from .

, and further detects the seam deviation amount detection position X.

Considering the case where the head 14 disposed at a head position X on the more downstream side follows the seam line displacement of the seam tube 10 in the circumferential direction, the seam deviation amount M1 or M2 at the head position The inventor's experiments have confirmed that, depending on the thickness of the tube 10, the tube diameter, and the conveyance (pipe-making) speed V, the equation (1) or (2) shown below can be approximated.

Here, in the above formula (1), as shown in FIG. 1B, the seam line A1 is the seam processing position extension line A.

This corresponds to the case where the seam tube 10 is displaced almost linearly in the circumferential direction as the seam tube 10 moves, and the coefficient A is O for correcting the translation deviation of the actual seam line from the seam line A1. It is a constant within ~5.

In addition, as shown in FIG. 1C, the above formula (2)
2 is the seam processing position extension line A.

2 with a coefficient B within 0 to 5 is the case where the seam line A is further curved from the seam line A, which has an almost linear relationship to
This is approximated by correction using the next term BX2.

According to the inventor's experiments, the seam deviation amounts M1 and M2 to be selected when the seam tube thickness, tube diameter, and conveyance speed V are varied are as shown in Table 1 below.

In Table 1, vl is the threshold velocity when the seam diameter is 10 to 12 inches, v2 is the threshold velocity when the seam diameter is 12 to 20 inches, and v3 is the threshold velocity when the seam diameter is 20 to 26 inches. It is.

As described above, the seam deviation amount detection position X is determined.

Seam deviation amount M detected in .

The target value is adjusted as appropriate using the above formula (1) or (2), depending on the distance X from the seam processing position 0 to the head position X, the thickness of the seam pipe, the pipe diameter, and the conveyance speed. It is clear that the head 14 may be displaced in the circumferential direction of the seam tube along the seam lines A42 and A2.

Embodiments of the present invention will be described in detail below with reference to the drawings.

In this embodiment, the present invention is applied to continuous annealing equipment for electric resistance welded pipes, and as shown in FIG. ,
On the downstream side of the welding device 20, four annealer heads 22, 24, 2 are arranged in tandem at distances Xs, X2FXs, and X4 from the seam processing position 0, respectively.
6, 28, the seam processing position 0 and the first annealer head position X on the most upstream side
1 intermediate position X.

The seam processing position extension line A of the seam line A, which is placed in the seam line A.

Seam deviation amount M in the circumferential direction from .

The seam deviation amount detector 12 detects the seam deviation amount detector 12, the speed detector 30 detects the conveyance speed V of the seam tube 10 (in this case, the tube manufacturing speed), and the position of the front and rear ends of the seam tube 10.
Seam tube detectors 32 and 34 disposed on the inlet and outlet sides of the annealing equipment, a setting device 36 for setting the plate thickness and outer diameter of the seam tube 10 during pipe production, and the output of the setting device 36, The output of the seam deviation amount detector 12, the speed detector 30
and a digital controller 38 that calculates a target value of the circumferential direction movement amount of each annealer head 22° 24, 26, 28 based on the output of the seam tube detector 32° 340, and based on the output of the digital controller 38, An annealer drive circuit 40 for controlling the circumferential position of each annealer head 22, 24, 26, and 28 is provided.

The seam deviation amount detector 12 is configured as shown in FIG. 3, for example.

In the figure, 16 indicates a seam tube 10 having a seam line A.
The roller 12a for continuously transporting the material in the longitudinal direction is
A detection head 12b detects the position of the seam line A; a drive mechanism 1 that raises or lowers the detection head 12a;
2c is a motor that drives the drive mechanism 12b so that the detection head 12a is located at the same distance from the seam tube 10 according to the outer diameter of the seam tube 10.

Therefore, the seam deviation amount M in the circumferential direction from the seam processing position extension line A of the seam line A of the seam tube 10.

As disclosed by the applicant in JP-A No. 53-131247, the residual heat of the weld zone is continuously measured by scanning it perpendicular to the welding direction using a thermometer with a narrow field of view, and the predetermined temperature and A method of finding the midpoint between two matching positions, or a thermometer that uses the residual heat from welding the seam line to keep these temperatures constant by installing two thermometers at symmetrical positions to the seam line. It is possible to find it by moving .

The action will be explained below.

When the seam pipe 10 is welded at the seam processing position 0 by the welding device 20 and enters the continuous annealing equipment from the right side of the figure, the seam processing position extension line A of the seam line A.

The amount of deviation in the circumferential direction from the seam deviation amount detector 12 is detected by the seam deviation amount detector 12.

Then, the digital controller 38 detects the seam deviation amount M output from the seam deviation amount detector 12.

, the plate thickness and pipe diameter of the seam tube 10 inputted from the setting device 36, the tube forming speed V inputted from the speed detector 30, the arrangement position of each annealer head X1°X2. X3. x
, select the formula (1) or (2) with reference to Table 1, and set the optimal seam deviation amount target value M1 or M2 for each annealer head to the annealer drive circuit 40.
Output to.

Then, the annealer drive circuit 40 drives each annealer head 2.
The following devices are installed every 2.24°26.28,
Arrangement position X of each annealer head 22, 24, 26, 28
1. X2. X3. A target value corresponding to X4 is output, and the annealer head 22, 24, 26° 28 is moved to a position facing the seam line A by the following device.

In addition, the seam tube detectors 32 and 34 arranged before and after the annealer heads 22, 24, 26, and 28 detect the seam tube 1.
If a leading edge or a trailing edge of 0 is detected, the seam displacement target value is the seam displacement amount M instead of the seam displacement target value Ml t M2 calculated by the above equation (1) or (2).

Using the seam deviation target value M3 delayed by the time required to move from the seam detection position to the head position, the abnormal movement of the seam line at the tip or rear end of the seam tube 10 is corrected.

Specifically, this correction is performed as follows.

That is, the seam tube detector 32 on the entry side detects the seam tube 10.
When the tip of the speed detector 3 is detected, the speed detector 3 at that time
From the pipe forming speed V of 0 output, the tip of the seam pipe 10 is located at the seam detection position X according to the following equation.

The time τ required for the head to move from to the head position X is calculated.

Next, the seam deviation amount M stored in the digital controller 38.

From the data, a seam deviation target value M3 is calculated using the following equation and outputted to the annealer drive circuit 40.

Here, MO(-τ) is the pigeon's value τ seconds ago.

Furthermore, when the seam tube 10 advances and its tip is detected by the seam tube detector 34 on the exit side, the correction using the correction calculation formula (4) is stopped and the above-mentioned formula (1) or (2) is used.
) switch to calculation using the formula.

The same applies to the rear end, and the seam tube detector 32 on the entry side
Accordingly, when the rear end of the seam tube is detected, the correction proceeds to the correction calculation formula (4).

According to this example, since the present invention was applied to continuous annealing equipment in which a plurality of annealer heads are arranged in tandem, it is difficult to align each annealer head with the seam position accurately and simultaneously in the conventional method, and the heating position However, according to this embodiment, each annealer head can be accurately aligned with the seam position, and the heating position of each annealer head can be adjusted. The annealing temperature is stabilized.

The scope of application of the present invention is not limited to continuous annealing equipment having annealer heads arranged in tandem, but also continuous annealing equipment having one annealer head, or processing or detection heads that are to follow the seam position of a general seam pipe. It is clear that the same applies to equipment with

As described above, according to the present invention, the head can be made to accurately and reliably follow the seam line position without the intervention of an operator.

Therefore, when used in continuous annealing equipment, it not only allows accurate annealing at the seam line position and eliminates the need for workers, but also has the excellent effect of improving the quality of the welded part.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the seam follow-up control method according to the present invention, and FIG. 2 is a block diagram showing the configuration of continuous annealing equipment to which an embodiment of the seam follow-up control method according to the present invention is applied. , FIG. 3 is a sectional view showing the configuration of a seam detection device in the continuous annealing equipment. 10... seam tube, 12... seam deviation amount detector, 14, 22, 24, 26, 28...
・Head, 16...Roller, 20...
Welding device, 30... Speed detector, 36...
...Setting device, 38...Digital controller,
40... Annealer drive circuit.

Claims (1)

[Claims] 1 One or more heads arranged on the downstream side of the conveying equipment according to the circumferential displacement of the seam line of the seamed pipe to be seamed and conveyed at the seam processing position on the upstream side of the conveying equipment. In the seam tracking control method, a seam deviation amount detector disposed between the seam processing position and the head position detects the seam deviation amount in the circumferential direction from the seam processing position extension line of the seam line, Based on the amount of seam deviation, the seam deviation amount at the head position is calculated in proportion to the distance from the seam processing position to the head position relative to the distance from the seam processing position to the detector, and this amount is set as a target value to calculate the seam deviation amount at the head position. A seam tracking control method characterized in that the seam is displaced in the circumferential direction of the seam tube.