JPH05329542A - Operating method for spiral looper of strip - Google Patents

Abstract

PURPOSE:To exactly detect buckling of a strip in an early stage by executing rotated speed control of a tower pinch roller, based on a detected strip displacement or/and speed difference. CONSTITUTION:Based on a plate speed of a strip 6 measured by a plate speed detector, a speed difference between its plate speed and a peripheral speed of a tower pinch roller is derived by an arithmetic circuit. In the case displacement of the strip exceeding a reference value is detected in an inlet of a guide device 7 by a non-contact type displacement sensor 11, or the speed difference exceeds the reference value, a buckling alarm of the strip is raised. Also, based on a detecting signal, rotating speed control (rotating speed correction) of the tower pinch roller is executed. In such a way, prevention of buckling and stabilization of a plate winding form of a loop coil can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating a strip spiral looper applicable to a manufacturing facility for electric resistance welded pipes.

[0002]

2. Description of the Related Art Conventionally, strip spiral loopers have been used on the entry side of electric resistance welded pipe manufacturing equipment. Generally, this spiral looper includes a rotatable cylindrical loop tower, a first annular roller table and a second annular roller table arranged in two stages above and below the loop tower, and a strip on the first annular roller table. For guiding the tower, the tower pinch roller for ejecting the strip from the second annular roller table, and the S-loop for guiding the strip from the first annular roller table to the second annular roller table. In order to do so, it is composed of a tower pinch roller, an S-shaped roller table, a guide device and the like provided in the loop tower.

FIG. 4 schematically shows the action of the spiral looper, and the loop coils 4 and 5 formed in the upper and lower two stages in the loop tower are shown at different positions for easy understanding. .. The strip 6 guided by the tower entrance side pinch roller 1 forms the first loop coil 4 on the first annular roller table, and then the strip 6 in the innermost layer of the loop coil 4 is inside the loop tower (S-shaped). (Roller table). This strip 6 is guided by a tower pinch roller 3 and a guide device (not shown) to form an S-shaped loop and is sent to a second annular roller table, where a second loop coil 5 is formed. Further, the strip 6 is delivered from the outermost layer side by the tower delivery side pinch roller 2.

In this apparatus, when the loop tower rotates in one direction, the strip payout speed increases and the number of turns of the loop coils 4 and 5 decreases, and when the loop tower rotates in the opposite direction, the strip payout speed decreases. As a result, the number of turns of the loop coils 4 and 5 increases.

[0005]

In such a spiral looper, when the loop tower is rotated in the payout direction of the strip 6, the first loop coil 4 is guided to the second loop coil 5 in an S-shape. The strip 6 swells greatly at the guide device entrance on the S-loop entry side,
There is a problem that so-called buckling occurs and the stable running of the strip is impaired. FIG. 5 shows the occurrence of this buckling phenomenon, and 7 is an S-shaped loop guide device. In (a) of the figure, only the strip 6 travels, and the loop tower is in a non-rotating state. From this state, as shown in (b), the loop tower starts rotating in the strip payout direction, and further ( When the rotation is continued as shown in c), the strip speed at the entrance side of the tower pinch roller 3 decreases at a certain time, and as a result, the strip to form the S-shaped loop swells greatly at the entrance of the guide device 7, and Ring occurs.

[0006] Conventionally, as a technique for preventing strip buckling in a spiral looper, Japanese Patent Laid-Open No. 60-17
No. 8150, a looping device has been proposed, but this device is mainly intended to prevent the wavy deformation of the strip in the loop coil, and the buckling at the S-shaped loop entrance side as described above. It cannot be an effective means of prevention.

Further, when the loop tower is rotated in the payout direction of the strip 6, a slip occurs between the tower pinch roller 3 and the strip 6, and the tower pinch roller 3 is moved at a speed calculated from the rotation amount of the loop tower. Even if you rotate
There is a problem in that the calculated plate feed amount does not match the actual plate feed amount, and the strip storage amounts in the first loop coil 4 and the second loop coil 5 become unbalanced. For this reason, the expansion phenomenon occurs in the first loop coil 4 and the contraction phenomenon occurs in the second loop coil 5, and the plate winding shape of the coil becomes unstable. This problem is particularly noticeable in pickling plates and rust-preventing oil plates and the like, and it is not possible to sufficiently deal with it only by pretreatment or adjusting the tower pinch roller pressure.

The present invention has been made in view of such conventional problems, and a first object thereof is a method capable of accurately detecting the buckling of the strip on the S-loop entry side of the spiral looper in an early stage. To provide. A second object of the present invention is to provide a method capable of preventing the occurrence of buckling and stabilizing the plate winding shape without causing the expansion / contraction phenomenon of the loop coil.

[0009]

To achieve these objects, the present invention provides a rotatable cylindrical loop tower,
A first annular roller table and a second annular roller table arranged in two stages above and below the loop tower, a tower entry side pinch roller for guiding the strip to the first annular roller table, and a second annular roller table. And a tower pinch roller provided on the loop tower for guiding the strip in an S-shaped loop from the first annular roller table to the second annular roller table. The method of operating the spiral looper has the following configuration.

(1) The following (a) and / or (b) are detected, and (b) the displacement of the strip is detected by the non-contact type displacement sensor on the S-loop entry side of the strip. (B) The strip plate speed detector measures the strip plate speed in the vicinity of the tower pinch roller, and the speed difference between this strip plate speed and the tower pinch roller peripheral speed is detected. A method of operating a spiral looper for detecting buckling of a strip based on the detected strip displacement or / and the speed difference.

(2) The following (a) and / or (b) are detected, and (a) the displacement of the strip is detected by the non-contact type displacement sensor on the S-shaped loop entrance side of the strip. (B) The strip plate speed detector measures the strip plate speed in the vicinity of the tower pinch roller, and the speed difference between this strip plate speed and the tower pinch roller peripheral speed is detected. A method for operating a spiral looper, which controls the rotation speed of a tower pinch roller based on the detected strip displacement and / or the speed difference.

(3) A method of operating the spiral looper in the method of (2) above, which controls the reduction of the tower pinch roller based on the detected strip displacement or / and the speed difference.

[0013]

[Function] The buckling of the strip with the S-shaped loop is
It has been confirmed that this occurs only when the loop tower rotates in the strip payout direction, and the cause of the occurrence is estimated as follows from such a buckling occurrence situation.

First, when the loop tower starts rotating in the strip payout direction, the guide rollers 8 of the S-shaped loop entrance side and exit side guide devices 7 come into contact with the strip 6 as shown in FIG. 6A. As shown in FIG. 6B, when the guide roller 8 further swivels in the direction of pushing the strip 6, the guide roller 8 bends the strip 6, and a resistance force is generated between the strip 6 and the guide roller 8. To do. Due to this resistance force, the roller peripheral speed of the tower pinch roller 3 and the strip plate speed do not match (plate speed <roller peripheral speed), slippage occurs between the strip 6 and the tower pinch roller 3, and as a result, the S-shaped loop entrance side plate Speed> S-loop inner plate speed, and the strip 6 swells greatly at the entrance of the guide device 7 on the S-loop entry side, causing buckling.

If the displacement of the strip at the entrance of the guide device on the S-loop entry side is detected based on the presumed cause of buckling, the occurrence of buckling or its sign can be known at an early stage. You can do it. Buckling occurs because the roller peripheral speed of the tower pinch roller 3 is higher than the strip plate speed. Therefore, the strip plate speed in the vicinity of the tower pinch roller 3 is measured, and this speed and the tower pinch speed are measured. The occurrence of buckling or its sign can be known by comparing the roller peripheral speed with the speed difference.

Therefore, the non-contact displacement sensor is used to detect the displacement of the strip on the S-loop entrance side of the strip, or the strip plate speed near the tower pinch roller is measured by the plate speed detector to determine the tower pinch roller. If the speed difference from the peripheral speed is detected, the occurrence of buckling of the strip can be detected early based on these detection results.

By controlling the rotation speed of the tower pinch roller based on the strip displacement or / and the speed difference, it is possible to prevent the occurrence of buckling, and in particular, the strip plate speed and the tower pinch roller peripheral speed. By controlling the rotation speed of the tower pinch roller based on the speed difference between the two, and compensating for the actual plate feed amount due to the plate slip on the tower pinch roller, the expansion and contraction of the upper and lower loop coils due to the plate slip on the tower pinch roller can be suppressed. , Loop coil plate winding figure is always stabilized. Further, by controlling the reduction of the tower pinch roller based on the strip displacement or / and the speed difference, the plate slippage itself on the tower pinch roller is prevented.

[0018]

1 and 2 show an embodiment of the method of the present invention. FIG. 1 shows the state of strip displacement detection on the S-loop entry side, and FIG. 2 shows the vicinity of the tower pinch roller (entry side). Fig. 4 shows the measurement conditions of the strip plate speed at. In FIG. 1, reference numeral 7 denotes a guide device on the S-shaped loop entrance side. The guide device 7 includes two guide bodies 9a and 9b forming a guide part of the strip between them and the tip of each guide body (strip entrance side). ) Is provided with the guide roller 8. Since each of the guide bodies 9a and 9b forms a curved guide portion 10 for guiding the strip in an S shape,
It is curved in the radial direction of the loop tower.

A non-contact displacement sensor 11 is provided on the guide body 9a located inside the curved guide portion 10 to detect the displacement of the strip (displacement from the regular loop forming position). There is. In the guide device 7 on the S-loop entry side, buckling of the strip 6 occurs as shown by the chain line in the figure, and therefore the non-contact displacement sensor 11 is located outside the curved guide portion 10. The guide body 9b is attached to the guide body 9a so as to detect the displacement of the strip at a position slightly upstream of the guide roller 8 in the loop. An ultrasonic sensor is usually used as the non-contact displacement sensor 11, and the sensor is attached to a mounting hole provided in the guide body 9a.

In FIG. 2, a strip plate speed detector 12 is provided on the entrance side of the tower pinch roller 3 to measure the plate speed of the strip 6. In this embodiment, a roller encoder 13 is used as the plate speed detector 12. The roller encoder 13 is pressed against the strip 6 by the spring mechanism 14, and the plate speed thereof is continuously measured.

FIG. 3 shows an example of a processing flow of these detection data. Based on the plate speed of the strip 6 measured by the plate speed detector 12, the plate speed and the peripheral speed of the tower pinch roller 3 are calculated by an arithmetic circuit. And the speed difference is required. The non-contact displacement sensor 11 detects the displacement of the strip that exceeds the reference value (for example, the distance l to the guide roller 8 shown in FIG. 1) at the entrance of the guide device 7, or the speed difference exceeds the reference value. A strip buckling alarm is issued. Further, the rotation speed of the tower pinch roller is controlled (rotation speed correction) based on the detection signal.

In this embodiment, the plate speed detector 12 is constituted by a contact type roller encoder. However, from the viewpoint of accurately measuring the plate speed, it may be affected by plate fluctuations (flapping, rising, etc.). Fewer non-contact speedometers (eg laser Doppler speedometer) can be used,
Similarly, speed measurement can be performed at several points in order to improve the accuracy of plate speed measurement. Further, the non-contact type displacement sensor 11 may be provided at several positions on the S-shaped loop entrance side to detect the displacement of the strip.

FIG. 7 shows another embodiment of the present invention.
The non-contact displacement sensor 11 detects the displacement of the strip 6 on the S-loop entrance side, and the non-contact plate speed detector 12 detects the strip 6 on the exit side of the tower pinch roller 3.
Is measuring the plate speed. These detection signals are sent to the discrimination / control circuit, and the plate speed is calculated as a speed difference from the tower pinch roller peripheral speed. Then, based on the speed difference and / or the strip displacement, the rotation speed control (rotation speed correction) of the tower pinch roller 3 is performed. In addition to this speed correction, rotation of the loop tower, rotation speed correction of the upper roller table and the lower roller table,
Further, the reduction of the tower pinch roller 3 is corrected based on the speed difference.

FIG. 8 shows another embodiment of the present invention.
In this embodiment, plate speed detectors 12 are provided on the inlet side and the outlet side of the tower pinch roller 3, and the plate speed of the strip 6 is measured. FIG. 9 shows a control flow based on the detection of the plate speed. The strip plate speed measured by the plate speed detector 12 is compared with the peripheral speed of the tower pinch roller 3 to calculate the speed difference. The average speed reference of the tower entrance side pinch roller 1 and the tower exit side pinch roller 2 is corrected based on a position detection signal from a potentiometer (not shown) arranged inside each loop coil, and the strip plate It is corrected based on the speed difference between the speed and the peripheral speed of the tower pinch roller, and this is used as the speed command value of the tower pinch roller to control the rotation speed of the tower pinch roller.

[0025]

According to the present invention described above, the displacement of the strip detected at the S-loop entrance side of the strip or the speed difference between the strip plate speed and the tower pinch roller peripheral speed in the S-loop, or Based on both of them, it is possible to accurately detect the buckling of the strip, and
By controlling the rotation speed of the tower pinch roller based on these detection signals, it is possible to prevent buckling and stabilize the plate winding form of the loop coil.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a strip displacement detection state on an S-shaped loop entry side in one embodiment of the method of the present invention.

FIG. 2 is an explanatory diagram showing a strip plate speed detection state on the entrance side of a tower pinch roller in one embodiment of the method of the present invention.

FIG. 3 is an explanatory diagram showing a processing flow of detection data in one embodiment of the method of the present invention.

FIG. 4 is an explanatory view schematically showing the action of the spiral looper.

FIG. 5 is an explanatory view showing the occurrence of buckling of the strip over time.

FIG. 6 is an explanatory diagram showing a cause of occurrence of a buckling phenomenon.

FIG. 7 is an explanatory view showing another embodiment of the present invention.

FIG. 8 is an explanatory view showing another embodiment of the present invention.

9 is an explanatory diagram showing a control flow in the embodiment shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input side pinch roller, 2 ... Output side pinch roller, 3 ... Tower pinch roller, 4, 5 ... Loop coil, 6 ... Strip, 7 ... Guide device, 8 guide roller, 11 ... Non-contact displacement sensor, 12 ... Plate speed detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Izumi Terada 1-2 1-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Tube Co., Ltd. (72) 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Inventor Katsuhiro Honbo 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Gaiji Miyata 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Japan Steel Pipe Co., Ltd. (72) Inventor Akira Iwatani 1-2-2 Marunouchi, Chiyoda-ku, Tokyo Nihon Steel Pipe Co., Ltd. (72) Inventor Ichiro Kasahara 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Nihon Inside Steel Pipe Co., Ltd.

Claims (3)

[Claims] 1. A rotatable cylindrical loop tower, a first annular roller table and a second annular roller table which are vertically arranged on the loop tower, and a strip on the first annular roller table. A tower entrance side pinch roller for guiding, a tower exit side pinch roller for ejecting the strip from the second annular roller table, and an S-shaped loop for guiding the strip from the first annular roller table to the second annular roller table. In order to operate a spiral looper equipped with a tower pinch roller and a guide device, which are provided in a loop tower, the following (a) or /
And (b) are detected, and (a) the displacement of the strip is detected by the non-contact displacement sensor on the S-loop input side of the strip. (B) The strip plate speed detector measures the strip plate speed in the vicinity of the tower pinch roller, and the speed difference between this strip plate speed and the tower pinch roller peripheral speed is detected. A method of operating a spiral looper, characterized in that buckling of a strip is detected based on the detected strip displacement and / or the speed difference. 2. A rotatable cylindrical loop tower, a first annular roller table and a second annular roller table which are vertically arranged on the loop tower, and a strip on the first annular roller table. A tower entrance side pinch roller for guiding, a tower exit side pinch roller for discharging the strip from the second annular roller table, and an S-shaped loop for guiding the strip from the first annular roller table to the second annular roller table. In order to operate a spiral looper equipped with a tower pinch roller and a guide device, which are provided in a loop tower, the following (a) or /
And (b) are detected, and (a) the displacement of the strip is detected by the non-contact displacement sensor on the S-loop input side of the strip. (B) The strip plate speed detector measures the strip plate speed in the vicinity of the tower pinch roller, and the speed difference between this strip plate speed and the tower pinch roller peripheral speed is detected. A method for operating a spiral looper, characterized in that the rotational speed of a tower pinch roller is controlled based on the detected strip displacement and / or the speed difference. 3. The method of operating a spiral looper according to claim 2, wherein the roll-down control of the tower pinch roller is performed based on the detected strip displacement or / and the speed difference.