JPS60171409A - Thickness measuring apparatus for tube thread part - Google Patents

Abstract

PURPOSE:To achieve an automatic measurement in parallel with machining by measuring the thickness based on measured values with a displacement meter which can be fixed at a specified distance with respect to a thread cutting tool and measures the position of the surface of a tube opposite to a thread cutting surface thereof. CONSTITUTION:When a frame 24 is moved following a taper guide 22 to perform a thread cutting at the end of a tube 20, a displacement meter 30 is retreated with a feed mechanism 32 before the displacement meter 30 mounted at the tip 28 of the frame 24 moves into the tube 20 and then, the meter 30 is fed to a specified projection position when almost entering the tube 20. At this point, a measuring element 30A abuts on the inner surface 20A of the tube 20 and the output of the displacement meter 30 gives the thickness of the thread section. Thus, the thickness at various points can be learned by reading the output of the displacement meter 30 at any time during the cutting to the end thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a pipe thread thickness measuring device for measuring the wall thickness of a threaded part formed in a pipe g section.

As shown in the partial cross-sectional view of FIG. 1, a steel pipe used as a conventional oil country tubular goods has a thread on the outer circumferential surface of its end 10 to be threadedly connected to a joint 12 for connection with another steel pipe. Part 1
4 is formed. The strength of this threaded part is extremely important for oil country tubular goods, which are used in conjunction with hundreds of pipes, and for this reason, thread elements such as taper, lead, hide, etc. are measured to find out that they do not meet the standards, and to check the thread surface. It is required that there are no defects.

In addition, for pipes without upsets, the thickness of the threaded portion is important. That is, as can be seen from FIG. 1, the threaded portion cut into the tube without upset has a thinner wall thickness. The part of the threaded part 14 having a length La that is threaded with the joint 12 and has a length Lb is reinforced by the joint 12, whereas the part of the threaded part 14 having a length La that is not threaded with the joint 12 is reinforced by the joint 12. The portion is weaker than other portions, and the stress of the connection portion is concentrated at that portion. Therefore, the insufficient thickness of the threaded portion 14 causes a buckling accident to occur at the portion of length Lc.

Therefore, API (American Petroleum)
In the standard, the length La from the tube end to the thread reduction point A and the length Lb from the tube end to the limit point B at which the fitting is screwed are determined. During thread cutting, it is necessary for the strength of the threaded part that the thicknesses Ta and Tb of the threaded part at those points A and B be at least the minimum standard values, respectively.

However, in the conventional wall thickness inspection of the threaded part of a pipe end, a tuning fork-shaped gauge 16 is inserted from the end of the pipe 10 so as to sandwich the pipe wall part, as shown in FIG. If the insertion amount p into the threaded portion 14 formed with a taper such that In other words, the wall thickness itself was not measured, and moreover, it was a manual inspection, so some kind of improvement is desired.

In light of such circumstances, the present applicant has filed the
Patent application published in 1984 as Publication No. 171613
No. 54402, we proposed a method and device for measuring wall thickness of pipe threads.

The method for measuring the wall thickness of a pipe thread part according to Japanese Patent Application Laid-Open No. 58-1716 No. 3 measures the distance from a reference position on the outside of the pipe to the outer peripheral surface of the pipe thread, and separately measures the distance from a reference position on the inside of the pipe. The wall thickness of the threaded portion of the pipe is measured by measuring the distance from to the inner circumferential surface of the pipe and subtracting the sum of the two measured distances from the distance between both reference positions.

As is clear from the following, in the method of Publication No.-1-, the thickness of the threaded portion must be measured independently of the cutting process of the thread. Furthermore, the measurement operation itself is complicated because two measurements have to be taken, one on the inside and one on the outside of the tube. Furthermore, two distance or length measuring means are required, and the device configuration is complicated.

The device disclosed in Publication No. 1 uses an optical laser beam to measure the outer circumferential surface of a pipe thread, and when measuring the thread thickness, it is necessary to calculate the bottom and peak of the thread from profile data. .

OBJECT OF THE INVENTION Therefore, the first object of the present invention is to measure the thickness of a thread part almost in parallel with the thread cutting process, and to automatically quantify the wall thickness of a thread part using a single measuring means without the need for calculations from profile data. It is an object of the present invention to provide a pipe thread wall thickness measuring device with a simple configuration that enables accurate measurement.

A second object of the present invention is to provide a pipe thread wall thickness measuring device similar to item 1, which can easily measure the thread wall thickness at a predetermined distance from the pipe end. It is something to do.

According to the present invention, it is possible to fix a thread cutting tool for pipe thread cutting at a predetermined distance from the thread cutting tool so as to face the thread cutting surface of the thread cutting tool.
A pipe thread part wall, comprising a displacement side for measuring the position of the pipe surface opposite to the pipe thread cutting surface, and measuring the wall thickness of the pipe thread part based on the measurement value by the displacement meter. A thickness measuring device is provided.

As described in (2) below, by providing a displacement mark opposite to the thread cutting tool and sandwiching the pipe wall between the thread cutting tool and the thread cutting tool, the wall thickness of the threaded part can be measured in parallel with the thread cutting process.

Therefore, it is possible to know the thickness of the threaded portion during the thread cutting process or at the end of the thread cutting process, and it is also possible to determine whether the thickness of the threaded portion is sufficient as necessary. Furthermore, since the thickness of the threaded portion can be measured using only the measured value by the displacement meter, the thickness of the threaded portion can be automatically and quantitatively measured by one measuring means without the need for calculations based on profile data.

Furthermore, according to the present invention, the thread cutting surface of the pipe is configured to face the thread cutting surface of the thread cutting tool for pipe thread cutting and can be fixed at a predetermined distance with respect to the thread cutting tool. and a tube end sensor placed at a predetermined distance in the axial direction of the tube from the displacement meter to detect the end of the tube. There is provided a wall thickness measuring device for a pipe threaded portion, characterized in that when the pipe end sensor detects the pipe end during cutting, the wall thickness of the pipe threaded portion is measured based on the measurement value by the displacement meter. .

As described above, if the wall thickness is measured based on the output of the displacement meter when the tube end sensor placed at a predetermined distance from the tube end detects the tube end, then at a point at a predetermined distance from the tube end, You can easily measure the wall thickness of a screw.

Embodiments Hereinafter, embodiments of a pipe thread wall thickness measuring device according to the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a schematic configuration diagram of a pipe thread thickness measuring device of the present invention. Thread cutting equipment is roughly divided into a thread cutting tool fixed parallel movement-tube rotation type and a thread cutting tool rotation parallel movement - pipe fixed type. Built into thread cutting equipment.

In order to thread-thread the end of the rotating tube 20, the frame 2 moves in the tube axis direction following the taper guide l-' 22.
A thread cutting tool such as a chaser 26 is attached to 4. The illustrated chaser 26 has a function as shown in FIG.
A single blade X, a medium cutting blade Y, and a rough cutting blade Z are provided side by side, and it is possible to perform everything from rough cutting to finishing at one time. The pedestal 24, which is fitted with a chaser 26, is made in a U-shape so that its tip 2B can enter the inside of the tube end. A displacement meter 30 is attached via a feeding device 32.

In the illustrated example, the displacement meter 30 is a contact type displacement meter such as a plunger type electric micrometer incorporating a differential transformer. However, an optical non-contact displacement meter may be used as the displacement side 30.

The feeding device 32 moves the displacement meter 30 forward and backward in the diameter direction of the tube, and when the displacement meter 30 is inserted into the tube, it retracts the displacement J130 so that the probe 30A of the displacement meter 30 does not collide with the tube. At the time of measurement, the displacement meter 30 is controlled to be sent to a predetermined protruding position so as to bring the measuring element 30A into contact with the inner wall surface of the pipe.

As described above, the chaser 26 and the feed mechanism 32 are attached to the pedestal 24, while the displacement meter 30 is at a predetermined distance from the feed mechanism 32 when in its predetermined protruding position. Therefore, as shown in FIGS. 3 and 4, the displacement meter 3
0 is in the protruding position, the distance between the displacement meter 30 and the chaser 26 is a predetermined constant distance 11, and the cutting edge of the finishing blade X of the chaser 26, that is, the bottom of the male thread ■
The distance 12 between this and the displacement meter is a constant distance that can be known in advance.

Therefore, the distance from the displacement meter 30 to the tube inner surface 20Δ, il
! .

By obtaining the measured value from the displacement meter 30, the wall thickness t (=f12-.f!3) at the root of the screw can be determined.

However, in reality, it is cumbersome for the measurer to perform the calculation ``2,(j?2-A,)'' for each measurement, and a computer must be installed in order to have the computer perform the calculation. Therefore, before carrying out the thread cutting process by the chaser 26, the displacement meter 30 is placed in the protruding position by the feed mechanism 32, and the measuring element 30Δ on the displacement side 30 is placed in the position of the chaser 26.
The displacement meter is set in advance so that the output value of the displacement meter 30 at that time is zero when brought into contact with the cutting edge of the blade X.

Next, a description will be given of measuring the wall thickness of a pipe thread using the pipe thread wall thickness measuring device shown in FIG. 3 in which the displacement meter 30 is adjusted as follows. In FIG. 3, when thread-cutting the end of the tube 20 by moving the pedestal 24 following the taper guide 22, the feed mechanism is 32, the displacement meter 30 is retracted, and when the displacement word 30 has almost entered the pipe, the displacement side 30 is sent out by the feeding mechanism 32 to a predetermined protruding position. At the time point Jl, the measuring element 30Δ of the displacement meter 30 comes into contact with the inner surface 20Δ of the tube 20, and the output of the displacement word 430 is the thickness of the threaded portion. Therefore, the output of the displacement meter 30 can be read at any time from the cutting process to the end of the cutting process to know the wall thickness at that location.

FIG. 5 is a schematic configuration diagram of a head section including a feeding mechanism and a displacement meter, and its operating mechanism. Herad base 4 with U-shaped cross section
0, air piston cylinder 42 and displacement word outer case 4
4 are fixed differently from each other. A displacement meter is slidably housed in the outer case 44, and is moved by a coil spring 48 in the protrusion 114 direction, that is, in FIG.
being pushed in one direction. In the illustrated example, the displacement plate is a plunger-type electric micrometer 46 incorporating a differential transformer.

A probe 50 protrudes from the electric micrometer 46. This probe 50 is an electric micrometer 4.
It is pressed in the protruding direction by a spring (not shown) in 6, and is coupled to a core piece that opens between a built-in differential transformer (not shown).

A presser fitting 52 is engaged with the end surface of the electric micrometer 46 on the side of the probe 50, and the presser fitting 52 is coupled to the piston rod 42A of the air piston cylinder 42 via a connecting rod 54Δb coupling fitting 54B. has been done.

Therefore, when the air piston cylinder 42 places the piston rod 42Δ in the pushing position as shown in FIG. As it is pushed down, the probe 50, which is at the maximum protrusion position, is also pushed together with the electric microphone T-cometer 46 by the built-in spring of the electric micrometer 4[i, and comes to the retracted position.

Conversely, the piston rod 4 is moved by the air piston cylinder 42.
When placed in the 2Δ4 retracted position, the connecting rod 54Δ will push.
Then, the electric microphone D meter 46 is pushed up by the spring 48 to a predetermined protruding position. Along with this, the measuring tip 50, which has been pushed out by the spring built into the electric micrometer 46, is also pushed up together with the electric micrometer 46, comes into contact with the inner wall 20Δ of the tube 20, and the built-in spring is compressed, causing the measuring tip 50 to is pushed back to some extent into the electric microphone +1 meter 46, and the distance to the inner surface of the tube can be measured.

On the back side of the head base 40, as shown in FIG. 6, a light beam type tube end sensor 56 is attached. This light beam type tube end sensor 56 may be of the type that receives a light beam from a light beam source placed on the pedestal 24 facing it, and detects the tube end when the light beam is interrupted by the tube end. Alternatively, it may be of a type that utilizes the fact that the inner surface of the tube functions as a reflective surface, emits a light beam, receives the reflected light when the tube is positioned in front of the sensor, and detects the end of the tube.

The various members attached to the head base 40 described above constitute the head portion of the pipe thread wall thickness measuring device.

A boss member 58 is fixed to the deck 40A of the head base 40, and a large diameter shaft 60 extends from the boss member 58 through a bearing 62 and is supported by the bearing 62.

Plates 64A and 64B are fixed to the bearing 62 and the boss member 58, respectively, and a bellows 66 is attached between the plates 64A and 64B.

The bearing 62 has an extension 62A.
2Δ is fixed to a pedestal 24 for mounting a chaser.

2. A small diameter shaft 70 is coupled to the tip of the large diameter shaft 60 protruding from the other end of the bearing 62 via a coupling fitting 68. Further, a support plate 72Δ is fixed to the other end of the bearing 62, one end of a plurality of spacer rods 74 is fixed to the support plate 72Δ, and another one is fixed to the other end of the spacer rod 74. A support plate 72Fl is fixed.

Furthermore, another air piston cylinder 76 is fixed to the support plate 72B in parallel with the small diameter shaft 70.

The piston rod 76△ of the air piston cylinder 76 is
It is coupled to the other end of the small diameter shaft 70 via a coupling fitting 78.

When the air piston cylinder 76 is operated to push the piston rod 76B to the left in FIG. 5, the small diameter rod 70 and the large diameter rod 60 move to the left in FIG. It can be retracted in the tube axis direction. Conversely, when the piston rod 76B is pulled to the right in FIG. 5 by the air piston cylinder 76, the small diameter rod 70 and the large diameter rod 60 move to the right in FIG. It can be advanced in the direction of the tube axis. Therefore, air piston cylinder 7
By appropriately operating the measuring device 6, the position of the measuring device head, particularly the measuring stylus 50 of the electric micrometer, can be adjusted relative to the chaser 26 in the tube axis direction.

The device shown in FIG. 5 can therefore be used as follows. The air piston cylinder 42 is operated -0- to retract the electric micrometer 46 to the retracted position.
As the chaser 26 moves in the tube axis direction, the measuring device fixed to the pedestal 24 to which the chaser 26 is fixed also moves in the tube axis direction. Move to the waist and head area as well as the rH of tube 20. When the tube end sensor II 56 detects the end of the tube 20, the air piston cylinder 42 is operated to move the electric micrometer 46 to the protruding position.
0 against the inner wall of the pipe. Thereafter, the thickness of the threaded portion can be measured by reading out the output value of the electric micrometer 46 representing the thickness t of the threaded portion in accordance with the progress of the thread cutting oil]- by the chaser 26.

When pulling out the head section from the tube 20, the electric micrometer 46 may be retreated to the retracted position by the air piston cylinder 42, and then pulled out together with the chaser 26, or the air piston cylinder 76 may be operated to remove only the head section. It may be retreated outside the tube.

FIG. 7 is a schematic diagram of another pipe thread wall thickness measuring device according to the present invention. Components that are the same as those in FIG. 3 are designated by the same reference numerals, and descriptions of those portions will be omitted. In the pipe thread wall thickness measuring device shown in FIG. 7, a pipe end sensor 34 is provided outside the feeding mechanism 32 of the pedestal 24. The detection axis and displacement of this tube end sensor +134; it
For example, the distance between the measurement axis of 30 and the measurement axis of
or 1,]] matches -l-ru.

Also, the displacement 3J30 should be adjusted to zero output in advance in the same way as the device shown in Fig. 53. In other words, when measuring the wall thickness at point B, the measuring element 30Δ on the displacement side 30 should be adjusted to the position of the cutter of the chaser 26. The output of the displacement 5130 is set to zero when it comes into contact with the cutting edge of The setting is made so that the output on the displacement side 30 becomes zero when it comes into contact with the blade base T as shown in FIG.

Next, a description will be given of measuring the wall thickness of a pipe thread using the pipe thread wall thickness measuring device shown in FIG. 7 as described above.

In FIG. 7, when moving the pedestal 24 following the taper guide 22 to thread-cut the end of the tube 20, the feed mechanism 3 The displacement meter 30 is evacuated by
When the displacement gauge 30 has completely entered the pipe, the displacement gauge is sent out to a predetermined protruding position by the feeding mechanism 32.

At this point, the measuring element 30A of the displacement meter 30 comes into contact with the inner surface 2OA of the tube 20. After that, as the screw cutting process by the chaser '26 progresses, the tube end sensor +l-34 is
When the end of the displacement meter 30 is detected, the output value of the displacement meter 30 is read out.

In this way, the wall thickness t at the distance from the tube end can be determined. Therefore, if the tube end sensor 34 is attached to the frame 24 so that L becomes La or Lb, the thread thickness Ta or Tb at point A or point B can be measured.

In order to measure the wall thickness of two threaded parts during one cutting process, a pipe threaded part thickness measuring device is constructed as shown in FIG. In the apparatus shown in FIG. 8, parts that are the same as those in FIG. 3 are designated by the same reference numerals, and explanations of those parts will be omitted. In the pipe thread wall thickness measuring device shown in FIG.
Two tube end sensors +J34 and 34B are provided outside of the tube end sensor 2. These tube end sensors 34. The distance between the detection axis displacement 7130 of Th34B and the measurement axis of 30B is made to match 1, b, and La described above.

Furthermore, the displacement presses 30 and 30B are also adjusted to zero output in advance, similar to the apparatus shown in FIG. That is, when measuring the wall thickness at point B using the displacement sensor 30, the measuring head 30 of the displacement meter 30
When Δ is set so that the output of displacement 30 is zero when it comes into contact with the cutting edge of chaser 26 - blade X, and on the other hand, when measuring the wall thickness at point Δ using displacement 1f - 30B , the measuring head 30△ of the displacement meter 30B is connected to the rough cutting blade Z of the chaser 26.
The displacement when brought into contact with the blade base T as shown in Figure 4 is -
Set so that the output of t30B is zero.

Next, a description will be given of an apparatus for measuring the thickness of a pipe threaded part using the apparatus for measuring the thickness of a pipe threaded part shown in FIG. 8 as shown in (2) below. In FIG. 8, when the pedestal 24 is moved following the taper guide 22 and the end of the tube 20 is threaded, the tip 2 of the pedestal 24 is
Until the displacement gauges 30 and 30B, which are set aside at 8, enter the pipe, the displacement gauges 30 and 30B are
is evacuated and set aside, and when the displacement gauges 30 and 30B are completely inside the pipe, the displacement gauges are sent out by the feeding mechanism 32 to a predetermined protruding position. At this point, each probe of the displacement meters 30 and 30B comes into contact with the inner surface 2OA of the tube 20. after that,
As the thread cutting process by the chaser 26 progresses, when the tube end sensor 34 detects the end of the tube 20, the output of the displacement meter 30 is read. The measured value at this time is the wall thickness Tb at point B
It is. The thread cutting process further progresses and the tube end sensor 34B
When the end of the tube 20 is detected, the output of the displacement meter 30B is read out. The output of the displacement meter 30B at this time indicates the wall thickness Ta at point A. In this way, the thicknesses Ta and Tb of the threaded portion at distances La and Lb from the tube end can be measured.

In measurements using the apparatus shown in Figures 7 and 8,
The thickness Tb of the threaded portion at point B in FIG. 1 is the thickness at the bottom of the thread valley. However, when adding 1 wa Tm of thickness of the threaded part at the midpoint between the bottom of the thread valley and the top of the thread, the height of the thread thread is )], then Tm=Th-1-(l ] / 2
) can be determined by calculating 31.

When measuring using the pipe thread wall thickness device shown in Figures 7 and 8, the zero output of displacement 31 is reserved and set as described above so that the output of the displacement meter indicates the wall thickness. I made it.

However, when the displacement 3-1 is in the protruding position, the displacement meter and the chaser are at a predetermined distance, so each displacement meter is set to output the distance from the displacement side to the inner surface of the tube. Alternatively, the thickness may be determined based on the difference between a predetermined distance and a measured value.

In addition, instead of providing the tube end sensor 34B in the apparatus shown in FIG. 8, it is installed at the end of the taper guide 22 to detect the end of the cutting process, or to read the output of the displacement g+30B upon receiving the output of the mitswitch 36. 9 Good. Alternatively, instead of providing the tube end sensor 34B,
The two displacement meters may be positioned such that the measurement axes of the displacement meters 30 and 30B are located at distances Lb and La from the detection axis of the tube end sensor 34. In this case, at the same time, the wall thickness T
a and Tb are output from the two displacement meters 30 and 30B.

Furthermore, the displacement meter 30B is omitted in the apparatus shown in FIG.
The two tube end sensors may be arranged so that the respective detection axes of the tube end sensors IJ34 and 34B are located at the points of distance], l] and La with respect to the measurement axis of the displacement meter 30. In this case, ,2
Displacement 3 when each tube end sensor detects the tube end
]30, the wall thickness ``a and T
+] can be added.

Feeding mechanism 3 of the pipe thread wall thickness measuring device shown in Figs. 7 and 8
2 and displacement meters 30 and 30B can also be constructed in the same manner as those shown in FIG. In the case of the pipe thread wall thickness measuring device shown in FIG. 7, in addition to the pipe end sensor 56, an electric micrometer 46
Another tube end sensor may be provided at a point far from the point.

In the case of the pipe thread wall thickness measuring device shown in FIG. It can be installed in several places.

Although all the embodiments described above are for male thread cutting, they can also be applied to female thread cutting if the positional relationship between the thread cutting tool and the displacement meter is reversed.

Effects of the Invention - As is clear from the above, if the pipe thread thickness measuring device according to the present invention is used, the wall thickness of a threaded part can be measured in parallel with the thread cutting process.

Therefore, it is possible to measure the wall thickness of the threaded portion while thread cutting is being performed or at the end of the thread cutting, and it is also possible to determine whether the wall thickness is sufficient as necessary. Furthermore, since the thickness of the threaded portion can be measured using only the measured value based on displacement acclimatization, the thickness of the threaded portion can be measured automatically and quantitatively using a single measuring means without the need for calculations based on profile data. Furthermore, the thread thickness at a predetermined distance from the tube end can be easily measured.

[Brief explanation of the drawing]

FIG. 1 is a schematic illustration of a threaded portion of a pipe end, FIG. 2 is a diagram illustrating a conventional method for measuring the thickness of a threaded portion, and FIG. 3 is a schematic configuration of a device for measuring thickness of a threaded portion of a pipe according to the present invention. 4 is a principle diagram of wall thickness measurement by the pipe thread wall thickness measuring device according to the present invention, and FIG. 5 is a head portion including the feeding mechanism and displacement 31 of the pipe thread wall thickness measuring device according to the present invention. 6 is a plan view of the head portion shown in FIG. 5, FIG. 7 is a schematic diagram of another pipe thread thickness measuring device according to the present invention, and FIG. 8 is a schematic diagram of the operating mechanism thereof. The figure is a schematic configuration diagram of yet another pipe thread wall thickness measuring device according to the present invention. (Main reference numbers) 10...Pipe end, 12...Joint, 14...Threaded part, 16
... Tuning fork-shaped cage, 20 ... Tube, 22 ... Taper guide, 24 ... Frame, 26 ... Chaser, 30.30B ... Displacement meter 32 ... Feeding device, 34
．． 34Il ... Pipe end sensor, patent applicant Sumitomo Metal Industries Co., Ltd. agent Patent attorney Masahiko Arai 3 4

Claims (2)

[Claims] (1) A pipe on the opposite side to the thread cutting surface of the pipe, which can be fixed at a predetermined distance with respect to the thread cutting tool so as to face the thread cutting surface of the thread cutting tool for pipe thread cutting. What is claimed is: 1. A wall thickness measuring device for a pipe threaded portion, comprising a displacement meter for measuring a surface position, and measuring the wall thickness of the pipe threaded portion based on a value measured by the displacement meter. (2) A pipe on the side opposite to the thread cutting surface of the pipe, which can be fixed at a predetermined distance with respect to the thread cutting tool so as to face the thread cutting surface of the thread cutting tool for pipe thread cutting. It is equipped with a displacement meter that measures the position of the surface, and a tube end sensor that is placed a predetermined distance away from the displacement meter in the axial direction of the tube to detect the end of the tube. A wall thickness measuring device for a pipe threaded portion, characterized in that when an end sensor detects a pipe end, the wall thickness of the pipe threaded portion is measured based on a measurement value by the displacement meter.