JPH02168109A - Measuring apparatus of bend of pipe end of pipe body - Google Patents

Abstract

PURPOSE:To enable efficient measurement of the amount of bend of the end part of a pipe by measuring the amount of displacement of the bend of a pipe end at two spots of the pipe end part of a pipe body rotated by a mechanism rotating the pipe body, by computing the amount of bend in the circumferential direction in TIR value and by judging whether the TIR value is within a reference value or not. CONSTITUTION:A pipe body supported by a pipe body supporting mechanism 22 is rotated one time by a pipe body rotating mechanism. Meanwhile, two touch rollers 26 being in contact with the outer surface of the pipe end part of the pipe body 21 are moved vertically against the actuating force of actuating devices 27 by the bend of the pipe body 21 respectively, and each image sensor 29 detects the amount of displacement of the pipe body 21 from the movement of a scale 28 in linkage to the roller 26. Next, a TIR value is computed from a measured value in an arithmetic means, and it is judged in a pipe body bend judging means whether or not the computed TIR value is within a reference value set beforehand. In this way, the appropriateness of the amount of the bend of the pipe end part of the pipe body is judged automatically in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a tube end bend n1 determining device for measuring the amount of bend at the end of a steel pipe.

[Conventional technology]

Steel pipes used as oil country tubular goods, which require long supply lines by connecting individual vibrators, require high straightness in the manufacturing process or in the final product. In particular, it is an absolute requirement for the end of a steel pipe to be straight, since a connecting part called a coupling is attached to the end after thread cutting. In the unlikely event that the pipe end is bent, the threaded element will no longer be able to meet the standard tolerances, resulting in a reduction in thread cutting efficiency and yield.In addition, the customer may be required to complain about the material that is threaded at the customer's site. It will cause.

Against this background, the API standard stipulates a method for determining bend n1 using a saddle gauge.

FIG. 5 is an explanatory diagram showing a method for measuring the bending of a tube body using a conventional saddle gauge. This measurement method consists of a support (2) having fork legs (2a) spaced apart on the outer surface of the steel pipe (1).
Rotate the steel pipe (1) once with the dial gauge (3) in contact with the dial gauge, and measure the bend fa (T I R value) of the steel pipe (1) in the circumferential direction using the dial gauge.
1. However, with this method, the steel pipe (1)
Since the bifurcated leg (2a) of the support (2) is positioned on the outer surface of the support body (2) and the amount of bending of the rotating steel pipe (1) is measured using the dial gauge (3), the measurement work is complicated and takes time to get used to. However, there was a problem in that the measurement accuracy was poor due to measurement errors caused by the operator. Furthermore, it is difficult to work efficiently and continuously in a short period of time, and 100% inspection online is impossible.

In order to solve this problem, there is a tube bending measuring device shown in FIG. 6, for example, as described in Japanese Patent Application Laid-Open No. 80-238706. This H1 constant device is the pipe body (1) to be measured.
The two arms (4), (4) extend so as to sandwich the thick part of the tube body (1) while rotating around its axis.
Two detectors (5) attached to one side of the.

(5) detects the bending of the tube (1) as a deviation in the receiving position of the light beam and the magnitude of the received light amount, and the thickness and amount of bending are calculated by the calculator (6) based on the signal from the detector (5). It is something to seek.

In addition, for example, JP-A-61-1 [154f] shown in FIG.
There is an apparatus for measuring the bending of a tube described in Japanese Patent No. 9. This Δ
The Pj determination device measures the length of the pipe body (1) to be measured while the pipe body (1) to be measured is being conveyed in the longitudinal direction of the pipe on a conveyor.
The center position of the tube body (1) is measured from two directions using a plurality of licenser cameras (8) to (15) arranged along the running direction of the tube body (1), and the end edge radius is determined by calculation.

Furthermore, it is shown in FIGS. 8(a) and 8(b). For example, there is a tube bending measuring device described in Japanese Utility Model Application Publication No. 82-7006. This measuring device consists of a gauge plate (18) which rotates on a horizontal skid (17) provided in the middle of an inclined skid (16) for conveyance, and the end of the material to be measured (1) is bent and set to an acceptable reference value. The bending is detected based on whether the end portion of the material to be measured (1) comes into contact or there is no contact due to a gap A, and the bending at the end of the material to be measured (1) is measured based on the contact signal when contact occurs.

[Problems to be Solved by the Invention] In the conventional pipe body bending AP1 determination method shown in FIG. (4) and the detector (5) on one arm (4)
Because of this configuration, the equipment is complicated and large in size, and there are disadvantages such as the measurement range being limited to the vicinity of the pipe end. In addition, in the conventional tube bending measuring device shown in FIG. 7, the tube (1) to be measured is straight on the conveyor! However, in the conventional tubular target measuring device shown in Fig. 8, it is determined whether the end of the material to be measured (1) has touched the gauge plate (18) or not. Fixed material (1)
The problem remains that it is still difficult to accurately measure the amount of curvature because the method only measures that there is a predetermined amount of curvature. Furthermore, in the conventional tube bending All method shown in FIGS. 6 and 8, the amount of bending displacement in one circumferential section is measured, and in the conventional tube bending measurement method shown in FIG. The amount of displacement with respect to the longitudinal center axis of the steel pipe is determined; the amount of displacement of the outer surface of the rotating pipe is measured, and the TIR value according to the API standard generally required by customers for the pipe end edge of the steel pipe is determined. Since the methods are different from each other, there is a problem in that the methods shown in FIGS. 6 to 8 described above cannot be used to determine the TIR value specified by the API standard.

This invention was made to solve this problem, and it measures the amount of bending at the end of a pipe body such as a steel pipe efficiently with high precision online, and calculates the TIR value based on the data. The object of the present invention is to obtain a tube end warp measuring device that can perform calculation judgment.

[Means for Solving the Problems] The tube end edge bending measuring device of the tube body according to the present invention has the following features:
a tube rotation mechanism that rotates the tube to be determined; a tube support mechanism that supports the tube end of the tube; and a tube end that is rotated by the tube rotation mechanism; Two displacement EIIJ instruments each measure the amount of displacement due to pipe end bending at two locations in the longitudinal direction, a calculation means for calculating the TIR value from the two displacement measurement devices, and a TIR value calculated by the calculation means in advance. The apparatus is configured to include a tube object target determination means for determining whether or not the target value is within a set reference upper limit value.

[Function] In this invention, the tube support mechanism supports the tube end portion of the tube body, two displacement maJJ constants are set at a predetermined interval at the tube end portion of the tube body, and the tube support mechanism supports the tube end portion of the tube body. Set the distance between this and the measuring device close to it to be the same as the distance between the two displacement measuring devices, and rotate the tube whose end portion is supported by the tube support mechanism once by the tube rotation mechanism. The amount of radial displacement at the two ends of the tube body is determined multiple times at regular intervals by two displacement measuring devices that are in contact with the outer surface of the tube end portion of the tube body in the meantime, and the calculating means Then, the TIR value is calculated from the measurement value measured by each displacement measuring device, and the TI calculated by the calculation means is calculated by the tube target determination means.
It is determined whether or not the R value is within a preset reference upper limit value to determine whether or not the amount of bending at the end of the tube is acceptable.

[Embodiment] Fig. 1 is a block diagram showing an outline of an embodiment of the present invention.
The figure is a block diagram of the same embodiment, FIG. 3 is a schematic diagram explaining the calculation process of the 1llJ constant value of the two displacement measuring devices, and FIG. 4 is a graph showing the measurement results according to one embodiment of the present invention. . In FIG. 1, (21) is, for example, an outer diameter of 7
The tube to be measured is a specially threaded blank tube with a wall thickness of 3.0 mm and a wall thickness of 7.01 mm, and is rotated by a tube rotation mechanism (not shown). (22) is a tube support mechanism that supports the tube end portion of the tube (21), and (23) is a tube support mechanism (21).
The free roller (24) is the measuring instrument support stand, and the tube body (
21) are installed at a predetermined interval on the pipe end side. (25) is a screw jack that moves the measuring instrument support stand (24) up and down, (2B) is a touch roller that can move up and down, which is installed at the tip of the n1 instrument support stand (24), and a free roller (23 ) is set slightly higher than the pipe axis center level. (27) is a biasing device that is installed on the ilJ stationary support base (24) and always biases the touch roller (2B) upward, and (28) is a scale that is linked to the vertical movement of the touch roller (2B). , (29) is the measuring instrument support stand (24
) is an image sensor that is a displacement measuring device that detects the displacement of the scale (2B).

In Figure 2, (aO) represents each image sensor (29)
(31) is an A/D converter (30) that converts the amount of displacement, which is a measured value detected by
), (32) is a memory that stores the calculated value of the calculation means (3I), and (33) is the TIR calculated by the calculation means (31).
The pipe body (21
) tube target determination means for determining whether or not bending of (3
4) is a tube target display means for displaying the TIR value, which is the pass/fail of bending of the tube body (21) and the amount of bending, from the judgment signal of the tube body target determination means (33).

Next, the operation of the above embodiment will be explained with reference to FIGS. 1 to 4.

In order to calculate and determine the TIR value specified in the API standard, the two measurement supports (24) and (24) are installed so that the distance between them is 304.11 mm, and the tube support mechanism (22 ) and the measuring instrument support stand (24) adjacent thereto are arranged such that the distance between them is 304.8 fins.

Further, the position of the touch roller (26), which is the measurement point of the measuring device support (24) located closest to the tube end, is set within the range of 127 to 152+n from the tube end of the tube body (1). This tube body (1) has an outer diameter of 73.0 mm and a wall thickness of 7.01 mm.
This is a special threaded blank tube and is supported by a tube body support mechanism (2).

Next, the tube body (1
) The height of each measuring instrument support stand (24) is set according to the outer diameter dimension of the measuring instrument support stand (24). Thereafter, the tube (21) is supported by the tube support mechanism (22) by a tube rotation mechanism (not shown).
is rotated once at a circumferential speed of am/sin. In between, the pipe body (
Two touch rollers (2B), (2B) in contact with the outer surface of the tube end of the tube body (21) move up and down against the biasing force of the biasing device (27) due to the bending of the tube body (21), respectively. Each image sensor (29), which is a displacement measuring device, measures the movement of the scale (28) in conjunction with each touch roller (26) with a measurement accuracy of 0.01 mm.During one revolution of the tube body (21), 125 The amount of displacement of the tube body (21) is detected as a measurement value. In this embodiment, a time division method is adopted as a data sampling method for such measurement values, and the pipe body (21
) when measuring time t, t divided into 125 equal parts.
, t, ta..., the amount of displacement a, a, a2゜l a... of the portion of the tube body (21) close to the tube end, and the amount of displacement of the portion far from the tube end, b.

b2. b3...... with two image sensors (29
) (29) respectively, and the measured values are respectively A/
The signal is inputted to the calculation means (31) via the D converter (30). As shown in FIG. 3, the calculation means (31) first calculates the deviation value from these measured values using the following equation.

Here, A1 indicates a deviation value of a portion close to the tube end, and B1 indicates a deviation value of a portion far from the tube end.

Furthermore, from these calculated values, each Δ-j fixed time ti (i-1
The TIR value in 25) is calculated using the following equation.

X -A -2XCXB (i
-1 to 125) The X1 value is stored in the memory (32).

Here, C in the above formula is a correction coefficient, and in the present invention, C-
1, and the number 2 in the above formula is based on the API standard (T
This is a conversion coefficient for correcting the value of B1 in the value of A when calculating the IR value.

As a result, 125 calculated values of the values X 1 , X 2 , . . .

When the measurement of one revolution is completed, the memory (32)
The maximum value X wax and minimum value X win are determined from the 125 calculated values stored in the 125 calculation values, and the actual TIR
Compute values.

TIR value –
It is determined whether the TIR value is within the reference/upper limit value set by the standard, and whether or not the tube body (1) is bent is determined. The tube target display means (34) displays the determination result of the tube target determination means (33) and the TIR value. Further, the determination result and TIR value can also be printed out using a printer (not shown).

The graph in FIG. 4 shows the TIR value measured by the tube end edge Mj determination device of the present invention, and the error due to measurement and calculation is in the range of 0.2 m+s in the range.
It can be seen that the error range is sufficient to make a judgment. Furthermore, the accuracy of the TIR value determined by δ-1 can be improved by changing the correction coefficient C. Furthermore, 1
The cycle time is less than 10 seconds, including the transport time by the walking beam, and can be operated online with front and rear equipment.

The displacement amount sampling method using the image sensor (29) of this embodiment is to determine the sampling time for one rotation of the tube body (21), and sample n pieces of displacement amount data by time division. It goes without saying that the present invention can also be carried out by providing a tube rotation angle detection mechanism and sampling by dividing into equal angles. Further, the number of samples to be sampled varies depending on the outer diameter of the tube body, but whatever sampling method is used, a minimum of 10 or more samples, and approximately 50 to 150 samples is appropriate. Also,
It goes without saying that the larger the number of samplings n, the more accurate the calculation will be, provided that the calculation capacity of the calculation means permits.

Further, in this embodiment, an image sensor (29) is used as a displacement measuring device, but a linear gauge sensor or a differential transformer type may be used.

[Effects of the Invention] As explained above, the present invention rotates the tube whose end portion is supported by the tube support mechanism once by the tube rotation mechanism, and during that time, the outer surface of the tube end of the tube is rotated at a predetermined interval. The displacement in the radial direction at the two ends of the tube body is determined multiple times at regular intervals using two displacement measuring devices that are placed in contact with each other, and the calculation means measures the displacement using a convex bend measuring device. The TIR value is calculated from the measured value, and the tube target determination means determines whether the TIR value calculated by the calculation means is within a preset standard and determines the amount of bending at the end of the tube. Pass/fail judgments are made automatically in a short period of time, and the error of the calculated TIR value is within 0.21, making it possible to make very accurate judgments, improving the quality of tubular products, and improving bend correction feeding It has an excellent industrial effect of being able to sort materials quickly and accurately.

[Brief explanation of the drawing]

FIG. 1 shows a schematic configuration of an embodiment of the present invention. , second
．． ,,Yo. implementation. ,). "t, fjgJ, 1st, □yoyu 艷1" Figure 4 is a schematic diagram illustrating the arithmetic processing of the measured values of the two displacement measuring instruments, respectively, and FIG. 4 is a graph showing the measurement results according to an embodiment of the present invention. The figure is an explanatory diagram showing a conventional method for measuring the bending of a tube body using a saddle gauge, FIG. 6 is a configuration diagram showing another conventional tube bending measuring device, and FIG. 7 is another conventional tube bending measuring device. A configuration diagram showing a measuring device,
FIGS. 348(a) and 348(b) are configuration diagrams showing yet another conventional pipe body bending measuring device. 21... tube body, 22... tube body support mechanism, 29...
Image sensor (displacement measuring device), 31... Calculating means, 33... Pipe body Fig. 2 Bend determination means.

Claims (1)

[Claims] A tube rotation mechanism that rotates the tube to be measured; a tube support mechanism that supports the tube end portion of the tube; and a longitudinal direction of the tube end of the tube rotated by the tube rotation mechanism. two displacement measuring devices that respectively measure the amount of displacement due to bending of the pipe end at two locations, a calculating means that calculates a TIR value from the two displacement measuring devices, and a TIR value calculated by the calculating means.
1. An apparatus for measuring the bending of a tube end of a tube, comprising a tube bending determining means for determining whether an IR value is within a preset reference upper limit value.