JPS60249009A - Measuring instrument for length of tapered surface formed on inside surface of pipe end - Google Patents

Abstract

PURPOSE:To measure quickly and exactly the length of the tapered surface formed on the inside surface of a pipe end by providing a pair of profiling sensors on the inside and outside surface sides of a pipe to be measured and detecting the displacement electric signals corresponding to the ruggedness of the inside and outside surfaces by means of a pair of displacement detectors. CONSTITUTION:A pair of the profiling sensors 7 are provided on the inside and outside surface sides of the pipe 14 to be measured and the displacement electric signals corresponding to the ruggedness on the inside and outside surfaces are respectively detected by a pair of the displacement detectors 8. The simultaneous measurement of the length of the tapered surface at the pipe end as well as the wall thickness thereof is made possible if the instrument is so arranged that the image of the tapered surface part is obtd. in accordance with said signals. More specifically, the length of the tapered surface formed on the inside surface of the pipe end is quickly and exactly measured according to this invention.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a device for measuring the length of a cross section formed on the inner surface of a tube end.

[Prior art and its problems]

For example, the length of the inside taper surface formed on the upset part of a drill pipe in the pipe axis direction! (See Figure 1) is
It is defined by the API standard, and it is necessary to measure whether the length of the tapered surface meets the standard.

Conventionally, the length of the tapered surface has been visually measured for each steel pipe by a worker using a reflector with a built-in light bulb.

However, this length measurement took time and effort, and also relied on intuition to some extent, resulting in large measurement errors.

[Purpose of the invention]

An object of the present invention is to provide a device that can quickly and accurately measure the length of a tapered surface formed on the inner surface of a tube end.

[Summary of the invention]

The present invention includes a lever having a profiling sensor attached to its tip that moves along the inner surface of the end of a pipe to be measured, a movable table rotatably supporting an intermediate portion of the lever, and a movable base for rotatably supporting the profiling sensor. a displacement detector attached to the other end of the lever that moves up and down as the lever moves up and down, and that converts the vertical displacement of the other end into an electrical signal; and a displacement detector that moves the moving platform in the axial direction of the lever. and means for calculating the length of a tapered surface formed on the inner surface of the end of the tube to be measured based on the movement amount of the copying sensor and the electric signal from the displacement detector. It is characterized by becoming.

[Structure of the invention]

One embodiment of this invention will be described with reference to the drawings.

FIG. 1 is a front view showing a state in which an apparatus according to an embodiment of the present invention is used. As shown in FIG. 1, a screw shaft 2 horizontally attached to a base 1 is rotated by a pulse motor 3. As shown in FIG. The moving table 4 is screwed onto the screw shaft 2. The lever 5 is rotatably mounted on a support shaft 6 provided on the movable table 4. The copying sensor 7 is attached to the tip of the lever 5 so as to face vertically downward. A displacement detector 8 consisting of a differential transformer or the like is installed between the rear end of the lever 5 and the movable table 4. The spring 9 is attached between the lever 5 on the side of the copying sensor 7 and the moving table 4, and constantly applies a downward force to the copying sensor 7. cylinder 1
o is mounted on the movable table 4 between the support shaft 6 and the spring 9. If the cylinder 10 is raised, the copying sensor 7
is fixed. The controller 11 controls the rotation of the pulse motor 3 and causes the display 12 to draw an image of the tapered portion based on the displacement signal detected by the displacement detector 8. The computing unit 13 computes the length of the tapered surface formed on the inner surface of the tube end by processing the image of the tapered portion.

The above-mentioned length measuring device is installed on the end side of the pipe to be measured 14 which is fixed horizontally, and the lever 5 and the scanning sensor are located further back than the tapered surface S formed on the inner surface of the end of the pipe to be measured 14. Insert it so that it is located on the inner surface of the tube. When the setting of the length measuring device is completed in this way, the cylinder 10 is lowered and the tip of the copying sensor 7 is brought into contact with the inner surface of the pipe to be measured 14 by the tensile force of the screw 9. Next, the controller By the command of 11) Kurusmoke 3
Rotate. As a result, the copying sensor 7 moves together with the movable table 4 toward the inner surface of the tube toward the end of the tube. On this occasion,
The copying sensor 7 moves in the tube axis direction while moving up and down according to the irregularities on the inner surface of the tube. The displacement in the vertical direction of the copying sensor 7 is directly converted into an electric signal by the displacement detector 8 via Reno (-5). Have the students draw an image of the surface area as shown in Figure 2.

In this way, once the image of the tapered part is obtained, the three lines that have been slightly fluctuating are approximated by a straight line, and a perpendicular line is drawn from the intersection point A of the straight line Z and the straight line Y on the extension of the straight line X, and the intersection point is Let H be the distance between points H and B, and this becomes the distance of the tapered surface S.

These operations are automatically performed by the computing unit 15.

In FIG. 2, straight lines x and 2 are both inclined because the axis of the tube to be measured 14 and the axis of the lever 5 are not parallel. As described above, the length 1 of the tapered surface S can be accurately determined even if the length measuring device is not set so that the two axes are parallel to each other.

As shown in FIG.
A pair of tracing sensors 7 are provided, and a pair of displacement detectors 8 detect displacement electric signals corresponding to the irregularities on the inner and outer surfaces, respectively, and based on these, an image of the tapered surface portion (see Fig. 4) is provided.
By obtaining this, it becomes possible to simultaneously measure the length and wall thickness of the tapered surface of the tube end. In FIG. 3, the same numbers as those in FIG. 2 indicate the same components, and their explanation will be omitted.

[Effects of the Invention] As described above, according to the present invention, the length of the tapered surface formed on the inner surface of the tube end can be measured quickly and accurately.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the usage state of an apparatus according to an embodiment of the present invention, FIGS. 2 and 4 are diagrams showing the relationship between the amount of movement and displacement of the scanning sensor, and FIG. FIG. 7 is a front view showing how the device according to another embodiment of the present invention is used. In the drawing, l... Base 2... Screw shaft 3... Pulse motor 4... Moving table 5... Lever 6... Support shaft 7... Copying sensor 8... Displacement detection Device 9... Spring 10... Cylinder 11... Controller 12... Display 13...
...Calculator 14...Pipe applicant Applicant: Nippon Kokan Co., Ltd. Agent Natsuo Shioya (and 2 others)

Claims (1)

[Claims] A lever with a scanning sensor attached to its tip that moves along the inner surface of the end of the pipe to be measured, a moving table that rotatably supports the middle part of the lever, and a lever that moves up and down as the scanning sensor moves up and down. a displacement detector attached to the other end of the moving lever for converting vertical displacement of the other end into an electrical signal; and means for moving the moving table in the axial direction of the lever; The method is characterized by comprising means for calculating the length of a tapered surface formed on the inner surface of the tube end of the tube to be measured based on the amount of movement of the copying sensor and the electric signal from the displacement detector. , a device for measuring the length of a tapered surface formed on the inner surface of a tube end.