JP2012078308A - Hydraulic tester of steel pipe and method for measuring pipe length after steel pipe hydraulic test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reflect a hydraulic tester on optimization of the next process condition by adding a scaling function to a series of test processes of the hydraulic tester.SOLUTION: Migration length of both head parts 1, 2 in a hydraulic test are measured by a pulse generator system, laser type position sensors 4, 4for detecting pipe end positions of a steel pipe are installed at the respective head parts, the respective head parts are moved to match laser optical paths of the laser type position sensors to a predetermined origin before setting of the steel pipe 3, pieces of the migration length of the respective head parts are measured from a point of time when the laser optical paths are matched to the predetermined origin to a point of time when the respective laser type position sensors detect the pipe end positions of the steel pipe when the respective head parts are separated from the steel pipe via the hydraulic test, and pipe length of the steel pipe is calculated by using this measurement result.

Description

  TECHNICAL FIELD The present invention relates to a steel pipe water pressure tester and a pipe length measurement method after a steel pipe water pressure test. The present invention relates to a test machine and a pipe length measurement method after a steel pipe water pressure test. The obtained pipe length is used for optimizing the operating conditions of the next process such as intermediate cutting and chamfering of steel pipes.

  In a water tester for steel pipes, a steel pipe (hereinafter also simply referred to as a pipe) for use in a water pressure test is fixed, sealed at both ends with a closure lid, and then tested by injecting test water into the pipe and applying pressure. Do. Depending on the standard, in order to raise the applied water pressure to near the yield point, the tube length changes in addition to the change in the roundness of the tube. Therefore, the dimensional change after water pressure is an important quality control item regardless of the process sequence.

  For example, Patent Document 1 proposes a method for measuring the length of a material to be transported such as a moving steel pipe using a pulse measuring facility and a laser unit as a conventional technique related to a steel pipe measuring scale (synonymous with pipe length measurement). .

JP-A-4-166704

  In the conventional technology, when the water pressure tester and the pipe length measuring machine are separated, or when it is difficult to improve the cutting accuracy of the steel pipe, the final pipe length does not fall within the pipe length tolerance because the pipe length accuracy is poor and the process such as chamfering is entered. There was a problem that there was a case. Since the tube length is difficult to visually inspect, the tube length measurement is not revealed until the tube length measurement process, which is the final process after finishing as a product, and the efficiency is greatly reduced, such as remanufacturing defective products.

  To solve this problem, there is a plan to add a pipe length measuring machine and add a pipe length measuring process. However, there is a disadvantage that an increase in manufacturing time and an increase in equipment cost are inevitable due to the additional process. Met. An object of the present invention is to solve the above-mentioned problems by adding a measuring function to a series of test processes of a hydraulic pressure tester, and to reflect the results in optimization of the next process condition.

The present invention has been made to solve the above problems, and the gist of the present invention is as follows.
(1) In a water tester for steel pipes, in which both ends of the steel pipe are held and sealed with both head parts movable in directions facing each other and water pressure can be applied to the pipe of the steel pipe, the moving distance of each head part A water pressure tester for steel pipes, characterized in that a laser-type position sensor for detecting the pipe end position of the steel pipe is installed in each head part.
(2) Using the water tester for steel pipes described in (1) above, each head part is moved before setting the steel pipes so that the laser beam path of the laser type position sensor coincides with a predetermined origin, and from that time point Then, when moving each head part away from the steel pipe through the water pressure test, the moving distance of each head part is measured until each laser type position sensor detects the pipe end position of the steel pipe. A pipe length measurement method after a steel pipe hydraulic test, characterized in that the pipe length is calculated.

  According to the present invention, it is possible to measure the pipe length immediately after the water pressure test of the steel pipe without reducing the processing efficiency of the steel pipe refining process and without adding a pipe length measuring machine. As a result, pipe length defects can be found immediately after the water pressure test, enabling optimization of the operating conditions online after the next process, which contributes to improving the production efficiency of the entire factory.

3D view showing an example of an embodiment of the present invention The side view which shows an example of embodiment of this invention

1 and 2 are a three-dimensional view and a side view, respectively, showing an example of an embodiment of the present invention. As shown in the figure, the hydraulic pressure testing machine has two head portions 1 and 2 that are movable in directions opposite to each other, and these hold and seal one end portion and the other end portion of the steel pipe 3 respectively. It is possible to apply water pressure in the three tubes.
Laser-type position sensors 4 ₁ and 4 ₂ for detecting the positions of the pipe ends (one end and the other end) of the steel pipe 3 are installed in the head portions 1 and 2, respectively. The laser type position sensors 4 ₁ and 4 ₂ each have a laser beam transmission path (laser beam paths L 1 and L 2) from the light projecting unit A to the light receiving unit B. In this example, the positions of the laser light paths L1 and L2 are made to coincide with the positions of the steel pipe end loading / unloading positions of the head portions 1 and 2, respectively. You may shift to the position outside a head part.

When the laser type position sensors 4 ₁ and 4 ₂ move together with the head units 1 and 2 on the side where the laser type position sensors 4 ₁ and 4 ₂ are installed, the light receiving unit B at the moment when the respective laser beam paths L 1 and L 2 pass through the tube end of the steel pipe 3. The pipe end position of the steel pipe 3 is detected by rapidly increasing the amount of received light. The laser light paths L1 and L2 are preferably along a horizontal line passing through the center of the tube in a plane orthogonal to the tube axis of the steel tube 3.
The water pressure tester can measure the moving distance of each head portion by a pulse generator method.

  The pulse generator system used here starts counting a pulse from the pulse generator set to generate one pulse for each of the two head units by a predetermined unit distance. This is a method of sequentially counting from a point in time (the number of accumulated pulses is zero) to a predetermined count end point and converting the counted number of accumulated pulses into a moving distance. The conversion formula is moving distance = accumulated pulse number × predetermined unit distance. The predetermined unit distance shall be within the pipe length tolerance of the steel pipe. For each head part, if the movement is forward (movement toward the opposite party), the pulse is counted negative, and if it is backward (movement away from the opposite party), the pulse is positive. Be counted.

In the present invention, the above-described water pressure tester is used to move each head part before setting the steel pipe so that the laser optical path of the laser type position sensor coincides with a predetermined origin, and from that point on, each head part undergoes a water pressure test. The distance of movement of each head part is measured until each laser type position sensor detects the end position of the steel pipe when separating the steel pipe from the steel pipe, and the pipe length of the steel pipe is calculated using this measurement result. A specific procedure will be described below.
(1) First, before setting the steel pipe 3, the heads 1 and 2 are moved so that the laser light paths L1 and L2 coincide with a predetermined origin. The origin is not particularly limited, but may be, for example, the midpoint of the maximum allowable interval between head units 1 and 2 (determined from the equipment specifications of the hydraulic pressure tester). When the laser light paths L1 and L2 coincide with the origin, the pulse counter is initialized (the number of accumulated pulses is cleared to zero). The pulse generator is started before the pulse counter is initialized, but may be always operated.
(2) As usual, the steel pipe 3 is set in a water pressure tester and a water pressure test is performed. During the time from the steel pipe set to the water pressure test, the pulse generator on the head side emits pulses as described above in response to the movement of each head, which is sequentially counted and accumulated by the pulse counter, and the accumulated number of pulses is stored. Is done.
(3) In the state (FIGS. 1 (a) and 2 (a)) immediately before the heads 1 and 2 are retracted, the heads 1 and 2 are separated from the steel pipe 3 after the water pressure test. Record the cumulative number of pulses for 1 and 2 (referred to as n1 and n2). When a predetermined unit distance corresponding to one pulse is represented by Δx, the interval C between the two laser light paths L1 and L2 is C = (n1 + n2) × Δx, and C is obtained by calculating this equation.
(4) The pulse counter is reinitialized, and the head units 1 and 2 are moved backward as usual. At this time, the hydraulic pressure tester shifts from the state shown in FIGS. 1A and 2A to the state shown in FIG. 2C, but in the middle of the state shown in FIGS. 1B and 2B. Take. That is, the laser optical paths L1 and L2 pass through one end and the other end of the steel pipe 3, respectively, and the laser type position sensors 4 ₁ and 4 ₂ detect the pipe end position of the steel pipe 3. Therefore, the number of accumulated pulses at the time of tube end position detection (which are referred to as m1 and m2) is recorded. At this time, the movement distances a and b of the head units 1 and 2 from the re-initialization time of the pulse counter (head portion retraction start time) to the tube end position detection time are a = m1 × Δx, b, respectively. = M2 × Δx. Therefore, this expression is calculated to obtain a and b.
(5) Obviously, the tube length is represented by C + a + b, and this equation is calculated to obtain the tube length.

In the above procedure, the re-initialization of the pulse counter (4) can be omitted. In that case, the tube length can be obtained by calculating the tube length = (N1 + N2) × Δx using the cumulative number of pulses at the time of detection of the tube end position (referred to as N1 and N2).
In the above-described example, one origin common to both head portions is provided. However, the origin may be individually provided between each head portion and the midpoint of the maximum allowable interval. In this case, assuming that the distance between these two origins is a known amount L0, the tube length can be obtained by adding L0 to the calculation result of C + a + b or (N1 + N2) × Δx obtained in the above procedure. .

  In addition, when the pipe end position of a steel pipe is detected by a laser type position sensor as in the present invention, the pipe end position may be erroneously detected if the steel pipe has an end shape irregularity such as a pipe end tilt or a pipe end burr. There is. In order to reduce the frequency of troubles due to misreporting of tube length measurement values in subsequent processes due to such false detection, the contact position sensor should be brought into contact with the outer circumference of the steel pipe at the same position as the laser beam path of the laser position sensor. If the pipe end position is detected by both laser and contact sensors, and the time difference between the pipe end position detection points is too large between the two sensors, An alert should be issued.

DESCRIPTION OF SYMBOLS 1 Head part of both head parts 2 Other head part of both head parts 3 Steel pipes 4 ₁ and 4 ₂ Laser type position sensors L1 and L2 Laser optical path

Claims (2)

  In a hydraulic testing machine for steel pipes, both ends of the steel pipe can be held and sealed with both head parts movable in directions opposite to each other, and water pressure can be applied to the pipe of the steel pipe. A water pressure tester for a steel pipe, characterized in that a laser-type position sensor for detecting the pipe end position of the steel pipe is installed in each head part.   Using the water tester for steel pipes according to claim 1, each head part is moved before setting the steel pipes so that the laser beam path of the laser type position sensor coincides with a predetermined origin, and from that time, the water pressure test is performed. After that, when each head part is separated from the steel pipe, the movement distance of each head part is measured until each laser type position sensor detects the end position of the steel pipe, and the pipe length of the steel pipe is calculated using this measurement result. The pipe length measuring method after the steel pipe water pressure test characterized by the above-mentioned.

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