JP6557293B2 - ERW steel pipe length measuring device in ERW steel pipe production line - Google Patents

Description

  The present invention relates to an ERW steel pipe length measuring device in an ERW steel pipe production line.

Regarding a method of measuring the length of a long strip material such as an electric resistance welded steel pipe being transported on a transport line, there is an invention of a strip material length measuring method disclosed in Patent Document 1, for example.
The length measurement method for this strip is as follows: “A single reflection type laser rangefinder is used to transport one strip from a state in which a plurality of strips including one strip are arranged in parallel, Search for the leading edge of the strip in the transport direction, search for the rear of the strip in the transport direction with another reflective laser rangefinder, and use one reflective laser rangefinder and another reflective laser rangefinder The first step is the direction in which the search direction is detected by overlapping with a plurality of other strips, and the other reflection type after one reflective laser rangefinder detects the leading end of the transport direction of one strip. The second step of measuring the number of pulses until the laser distance meter no longer detects one strip, the transport distance per pulse of the transport device and this number of pulses are multiplied to calculate the passage length L2, This interval length L1 is determined by one reflective laser rangefinder and another reflective laser rangefinder. By adding the length L2, comprising a third step of calculating the length of the elongated member, the "is intended (see claim 1 of Patent Document 1).
And in patent document 1, it is made to measure the conveyance distance by detecting the pulse number per rotation of a roller.

  Moreover, regarding the length measurement of the moving strip material, there is an invention of a “moving object length measuring device” disclosed in Patent Document 2 as one using a speedometer utilizing a laser Doppler effect.

JP 2008-304286 A JP 7-270436 A

In order to accurately measure the length of the strip by the method of Patent Document 1, it is necessary to accurately detect the front end and the rear end of the transported strip and to accurately detect the number of pulses required for passage. is there.
In this respect, the ERW steel pipe transported through the ERW steel pipe production line which is the subject of length measurement according to the present invention has a specific problem that it is difficult to accurately detect these. Hereinafter, this point will be described.

  The production of ERW steel pipes is a process of forming a steel sheet into a tubular shape by a forming roll, a process of welding the upper surface by high frequency welding, a process of grinding the outer and inner weld beads of the welded part, and cutting the steel pipe to a predetermined length. And a step of measuring the length of the cut steel pipe. In addition, ERW steel pipes are mounted on a number of rotating transport rollers and transported. However, the shape of the pipe is not limited to a circle, and there are also square ones. In some cases, there is a case where a dual-purpose transport line is provided. However, in many cases, a common transport line is used for the purpose of saving equipment cost and site area.

Due to such a manufacturing process, there are the following problems during length measurement.
First, in the case of a circular and square conveying line, rolls are likely to occur when conveying a circular steel pipe.
Therefore, in the method of measuring the transport distance from the number of pulses per rotation of the roller as disclosed in Patent Document 1, an error is likely to occur. For this reason, it is conceivable to use a Doppler type speedometer as disclosed in Patent Document 2.

However, since the laser Doppler type speedometer has a narrow allowable range of distance to the measurement object, as shown in FIG. 6, when the electric resistance welded steel pipe 31 being rolled is being measured, Since there is less vibration in the vertical direction, it is conceivable to install the speedometer 33 above the ERW steel pipe 31.
However, as shown in FIG. 7, there is a weld bead grinding portion 35 obtained by grinding the weld bead on the outer surface of the upper surface of the ERW steel pipe 31, and when irradiated with laser light from above, There is a problem that a measurement error occurs due to irregular reflection of the hit laser beam.

  Further, as shown in FIG. 8, the bead 39 after cutting when the inner surface side of the welded portion is ground is projected like a tail from the end of the pipe, or white smoke 37 of steam is generated by water cooling after welding. May have occurred. Therefore, if a detector having a light projecting unit 41 and a light receiving unit 43 as shown in FIG. 8 is used for detecting the tube end, for example, white smoke 37 or a post-cutting bead 39 protruding from the tube is detected. There is also a problem that a measurement error occurs due to detection.

  What is the subject of length measurement in Patent Document 1 is a billet manufactured by obtaining processes such as refining, ingot making, and ingot rolling, and what is subject to measurement in Patent Document 2 is a section steel, There is no problem peculiar to the ERW steel pipe as described above. Therefore, Patent Documents 1 and 2 do not touch on the solution of these problems. It is not possible to accurately measure the length of the ERW pipe being transported through the line.

  The present invention has been made to solve such a problem, and the length of the ERW steel pipe transported through the ERW steel pipe production line can be accurately measured. The object is to provide a length measuring device.

(1) An apparatus for measuring the length of an electric resistance welded steel pipe according to the present invention has a weld bead grinding portion obtained by grinding a weld bead, and a roller for conveying an electric resistance welded steel pipe production line so that the weld bead grinding portion becomes an upper surface. An apparatus for measuring the length of an ERW steel pipe conveyed by
The conveyance roller is a common type that can convey a round steel pipe or a square steel pipe having different shapes, or a round steel pipe having a different outer shape,
A tip detection sensor for detecting the tip of the electric resistance welded steel pipe conveyed on the conveyance roller;
A rear end detection sensor for detecting a rear end of the electric resistance welded steel pipe conveyed on the conveyance roller;
A laser Doppler type speedometer provided on the side of the ERW steel pipe ;
A distance meter for measuring a distance between the speedometer and the ERW steel pipe; and an actuator for adjusting a distance of the speedometer to the ERW steel pipe to a predetermined distance, and the speed based on a measurement value of the distance meter. A position control device that controls the position of the speedometer so that a gauge is held at a predetermined distance from the ERW steel pipe;
The detection information of the speedometer, the front end detection sensor and the rear end detection sensor is input, the distance from the detection of the front end by the front end detection sensor to the detection of the rear end, the front end detection sensor, and the A calculation unit that calculates the length of the ERW steel pipe from the distance from the rear end detection sensor.

(2) Further, in the above-described (1), the leading edge detection sensor and the trailing edge detection sensor detect the presence or absence of an object by irradiating the object with light and receiving reflected light. And a purge means for purging a portion irradiated with light from the front end detection sensor and the rear end detection sensor. It is characterized by this.

(3) Further, in the above-described (1) or (2), a protective plate is provided to prevent a rolled electric resistance steel pipe from coming into contact with the speedometer.

  In the present invention, a tip detection sensor that detects a tip of the electric resistance welded steel pipe conveyed on the conveyance roller, a rear end detection sensor that detects a rear end of the electric resistance welded steel pipe conveyed on the conveyance roller, and a laser The distance from the detection of the leading edge to the detection of the trailing edge by inputting the detection information of the Doppler type speedometer and the speedometer, the leading edge detection sensor and the trailing edge detection sensor. And a calculation unit that calculates the length of the ERW steel pipe from the distance between the front end detection sensor and the rear end detection sensor, and the speedometer is located on the side of the ERW steel pipe and on the ERW steel pipe. The distance between the speedometer and the ERW steel pipe is measured so that the speedometer can move in a direction toward and away from the ERW steel pipe. Position of the speedometer to hold at a distance With the position control device to control, there is a grinding part of the weld bead on the outer surface, and despite the special circumstances of the ERW steel pipe transfer line that the roll tends to occur during transfer, the accuracy is Length measurement can be performed well.

It is explanatory drawing of the length measuring apparatus of the ERW steel pipe in the ERW steel pipe manufacturing line which concerns on one embodiment of this invention. It is explanatory drawing of the conditions which the speedometer shown in FIG. 1 should satisfy | fill. It is explanatory drawing explaining a part of apparatus shown in FIG. It is explanatory drawing of an effect | action of the length measuring apparatus of the ERW steel pipe shown in FIG. It is explanatory drawing of the length measuring method of the ERW steel pipe by the length measuring apparatus of the ERW steel pipe shown in FIG. It is explanatory drawing of the subject which this invention tends to solve (the 1). It is explanatory drawing of the subject which this invention tends to solve (the 2). It is explanatory drawing of the subject which this invention tends to solve (the 3).

As shown in FIG. 1, the length measuring device 1 for an electric resistance steel pipe according to an embodiment of the present invention continuously measures the length of the electric resistance steel pipe 5 conveyed on the conveying roller 3. A front end detection sensor 7, a rear end detection sensor 9, a laser Doppler type speedometer 11, a position control device 13 for controlling the distance of the speedometer 11 to the electric resistance welded steel pipe 5 to a predetermined position, A calculation unit 15 is provided that inputs information on the front end detection sensor 7, the rear end detection sensor 9, and the speedometer 11 and calculates the length of the ERW steel pipe 5.
Hereinafter, each component device will be described in detail.

<Conveying roller>
The conveyance roller 3 includes a drive conveyance roller 3a that is driven by itself and a non-drive conveyance roller 3b that is not driven by itself. This conveyance roller 3 is of a common type that can convey different shapes such as a circular steel tube and a square steel tube, or a circular steel tube having a different outer shape, due to the particularity of the ERW steel tube production line.
In addition, since the conveyance roller 3 is shared, since the electric resistance welded steel pipe 5 is not held, it is assumed that the electric resistance welded steel pipe 5 rolls during the conveyance. Therefore, as shown in FIG. 1, it is preferable to provide a protective plate 17 that restricts the movement of the ERW steel pipe 5 so that the rolled ERW steel pipe 5 does not collide with the speedometer 11.

<Tip detection sensor>
The tip detection sensor 7 is for detecting that the tip of the electric resistance welded steel pipe 5 being conveyed by the conveyance roller 3 has passed.
In the present invention, the tip detection sensor 7 is of a reflective type, and the laser light emitted from the tip detection sensor 7 is reflected by the ERW steel tube 5 and is incident on the tip detection sensor 7 again. Detect the tip. The tip detection sensor 7 can set a detectable range (distance) in advance, and sets this measurable range based on the outer diameter and the rolling range of the electric resistance welded steel pipe 5 being conveyed. By doing in this way, even if it is a case where the ERW steel pipe 5 conveyed rolls or the outer diameter of the ERW steel pipe 5 changes, it becomes possible to detect a front-end | tip.
On the other hand, since the post-cutting bead 19 is normally located at the middle position in the radial direction of the ERW steel pipe 5, it is out of the measurable range, so the post-cutting bead 19 is not detected (see FIG. 2). . The range indicated by the arrow in FIG. 2 indicates the measurable range of the tip detection sensor 7.

  As described above, white smoke may be generated in the ERW steel pipe 5 due to evaporation of the cooling water. In order to prevent erroneous detection due to the white smoke, in the present embodiment, FIG. As shown in FIG. 2, purge means 21 for injecting purge gas to the measurement point is provided. As a result, erroneous detection due to white smoke can be effectively prevented.

  In the case of the transmission type sensor as shown in FIG. 8, it is necessary to purge the entire range from the light emitting side to the light receiving side, and the purge range becomes wide. As described above, by adopting the reflection type, it is sufficient to purge a very narrow range of only the measurement points, so that the apparatus configuration of the purge means 21 can be simplified.

<Rear end detection sensor>
The rear end detection sensor 9 is for detecting that the rear end of the ERW steel pipe 5 being conveyed by the conveyance roller 3 has passed.
In the present invention, the rear end detection sensor 9 is of a reflective type like the front end detection sensor 7, and the laser light emitted from the rear end detection sensor 9 is reflected by the ERW steel pipe 5 and is again applied to the front end detection sensor 7. The rear end of the ERW steel pipe 5 is detected by changing from the incident state to the non-incident state.

<Speedometer>
The speedometer 11 is composed of a laser Doppler type speedometer 11 that applies the laser Doppler principle and measures the actual transport speed from the reflected light of the laser irradiated to the measurement target being transported. About the measured conveyance speed, it is made into a steel pipe length by integral calculation, and length is counted by making the steel pipe length 0.1mm into 1 pulse.

<Position control device>
The position control device 13 controls the position of the speedometer 11 with respect to the electric resistance welded steel pipe 5 at a predetermined position. The distance control device 13 measures the distance between the speedometer 11 and the electric resistance welded steel pipe 5, and the distance meter 23. And an actuator 25 that adjusts the distance of the speedometer 11 relative to the electric resistance welded steel pipe 5 to a predetermined distance.
The distance of the speedometer 11 to the object to be measured is a predetermined distance, for example, ± 7.5 mm with respect to 200 mm. Therefore, even if the ERW steel pipe 5 rolls during transportation, the position of the speedometer 11 is adjusted to follow the above. To be in the range.

  FIG. 4 schematically shows this point, and FIG. 4A shows the distance between the speedometer 11 and the ERW steel pipe 5 when the position of the speedometer 11 is not controlled. Although it may deviate from the allowable range, FIG. 4B shows a case where the position control is performed, which indicates that the distance is within the allowable range.

  Thus, by using the position control device 13, even when the ERW steel pipe 5 rolls, the measurement with the speedometer 11 can be accurately performed. In other words, in the conveyance line in the production line of the ERW steel pipe 5, the common conveyance roller 3 is used to convey the steel pipes of various shapes and diameters. Even in such a case, the length is accurately measured. It means you can do it.

<Calculation unit>
The calculating part 15 inputs the signal of the front-end | tip detection sensor 7, the rear end detection sensor 9, and the speedometer 11, and calculates the length of the ERW steel pipe 5 currently conveyed. Specifically, the rear end detection sensor 9 starts the rear end of the ERW steel pipe 5 from the time when the front end detection sensor 7 inputs that the front end of the ERW steel pipe 5 being detected is input (FIG. 5A). The speed by the speedometer 11 up to the point of time when (a) is detected (FIG. 5B) is detected, and the length L2 is calculated from the speed. The distance (L1 + L2) obtained by adding the distances L1 and L2 between the leading end detection sensor 7 and the trailing end detection sensor 9 is defined as the distance of the ERW steel pipe 5.
In order to display the measured distance, it is preferable to provide a display 27 as shown in FIG. In addition, it is preferable to provide a touch panel 29 for performing setting / operation on the arithmetic unit 15.

An outline of the method for measuring the length of the electric resistance welded steel pipe 5 using the length measuring device 1 of the electric resistance welded steel pipe 5 of the present embodiment configured as described above is as follows.
The electric resistance welded steel pipe 5 cut on the conveying roller 3 is conveyed, and during the conveyance, the portions of the electric resistance welded pipe 5 irradiated with light from the leading end detection sensor 7 and the trailing end detection sensor 9 are purged by the purge means 21. Yes. As a result, even when white smoke is generated, detection by the front end detection sensor 7 and the rear end detection sensor 9 is not hindered (see FIG. 1).

  When the electric-welded steel pipe 5 being conveyed passes the position of the tip detection sensor 7, the tip is detected by the tip detection sensor 7, and this detection information is input to the calculation unit 15. At this time, the rear end detection sensor 9 is in a state where the reflected light from the ERW steel pipe 5 is incident. When the ERW steel pipe 5 advances forward and passes the position of the rear end detection sensor 9, the rear end detection sensor 9 reflects the reflected light. This information is input to the calculation unit 15. In the speedometer 11, the transport speed is accurately measured by irradiating the transported ERW steel pipe 5 with laser light, and this speed information is input to the calculation unit 15.

Although the electric resistance welded steel pipe 5 may roll, the speedometer 11 is position-controlled by the position control device 13 so that the distance from the electric resistance welded steel pipe 5 is within a predetermined range, and is always within the measurable range. Because there is, accurate speed measurement is possible.
In the calculation unit 15, the time from the time when the front end of the ERW steel pipe 5 is detected based on the information of the front end detection sensor 7 and the rear end detection sensor 9 to the time when the rear end detection sensor 9 detects the rear end, the speed The length L2 shown in FIG. 5 is calculated based on the speed at the time by the total 11.
And the distance (L1 + L2) which added the distance L1 and L2 of the front-end | tip detection sensor 7 and the rear-end detection sensor 9 is calculated | required, and this is displayed as a length of the ERW steel pipe 5 on a display part.

  As described above, according to the length measuring device 1 of the electric resistance welded steel pipe 5 of the present embodiment, rolling occurs during conveyance, white smoke is generated, or the beads 19 are attached after cutting. Even if the special circumstances of the electric resistance welded steel pipe 5 occur, accurate length measurement can be performed without erroneous detection.

  In addition, in order to confirm the measurement accuracy of the ERW steel pipe length measuring device 1 according to the present embodiment, the measured value and the actual measurement value of ERW steel pipe of φ165 × 5.0t × 4012 mm (target cutting length) Compared. The results of comparison are shown in Table 1.

  Looking at Table 1, it is proved that there is almost no difference between the measured value and the actually measured value, and that the length can be measured with extremely high accuracy.

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 3 Conveyance roller 3a Drive conveyance roller 3b Non-drive conveyance roller 5 Electric-resistance-welded steel pipe 7 Front end detection sensor 9 Rear end detection sensor 11 Speedometer 13 Position control device 15 Calculation unit 17 Protection plate 19 Post-cutting bead 21 Purge means 23 Distance Total 25 Actuators 27 Indicators 29 Touch panel <Devices explaining the problem>
31 ERW Steel Pipe 33 Speedometer 35 Weld Bead Grinding Section 37 White Smoke 39 Bead after Cutting 41 Light Emitting Section 43 Light Receiving Section

Claims (3)

An apparatus for measuring the length of an electric resistance welded steel pipe having a weld bead grinding part obtained by grinding a weld bead, and the electric welded steel pipe production line being conveyed by a conveying roller so that the weld bead grinding part becomes an upper surface ,
The conveyance roller is a common type that can convey a round steel pipe or a square steel pipe having different shapes, or a round steel pipe having a different outer shape,
A tip detection sensor for detecting the tip of the electric resistance welded steel pipe conveyed on the conveyance roller;
A rear end detection sensor for detecting a rear end of the electric resistance welded steel pipe conveyed on the conveyance roller;
A laser Doppler type speedometer provided on the side of the ERW steel pipe ;
A distance meter for measuring a distance between the speedometer and the ERW steel pipe; and an actuator for adjusting a distance of the speedometer to the ERW steel pipe to a predetermined distance, and the speed based on a measurement value of the distance meter. A position control device that controls the position of the speedometer so that a gauge is held at a predetermined distance from the ERW steel pipe;
The detection information of the speedometer, the front end detection sensor and the rear end detection sensor is input, the distance from the detection of the front end by the front end detection sensor to the detection of the rear end, the front end detection sensor, and the A calculation unit for calculating the length of the ERW steel pipe from the distance to the rear end detection sensor;
An apparatus for measuring the length of an ERW steel pipe, comprising:   The leading edge detection sensor and the trailing edge detection sensor are reflective sensors that detect the presence or absence of an object by irradiating the object with light and receiving reflected light. 2. The electric resistance welded steel pipe according to claim 1, further comprising a purge unit that purges a portion irradiated with light from the leading end detection sensor and the trailing end detection sensor. Length measuring device.   The length measuring device of the ERW steel pipe according to claim 1 or 2 provided with the protection board which prevents a rolled ERW steel pipe from contacting the speedometer.

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