JPS60196614A - Apparatus for measuring thickness of pipe - Google Patents

Abstract

PURPOSE:To improve measuring accuracy, by energizing steel balls on a ring, which is attached to an inserting rod, by a spring in an outward radial shape for the large-diameter application; and compressing the balls in the direction of the center equally by wire springs for the small diameter application. CONSTITUTION:For the large-diameter application, a device A comprises an inserting rod 7 into a steel pipe to be measured 6 and a pair of supporting tools 6, which is attached to the tip part of said inserting rod 7. The supporting tools 8 are provided with a ring 9, which is fixed to the inserting rod 7. A plurality of holes 12, which support a spring 10 and steel balls 11, are arranged in the outer surface of the ring. A transducer 1 is fixed between a pair of the supporting tools 8 of the inserting rod 7 by a bolt 16. For the small-diameter application, wire springs 19, which are bent in a cheuron shape, are provided at the tip part of the inserting rod in a pair on the right and left sides. The springs are provided at a plurality of 7 places of the outer surfaces of the inserting rod 7. One end of each wire spring 19 is fixed on the inserting rod 7 by a screw 20. The free end of the spring can be moved along a long groove 21, which is provided in the axial direction on the surface of the inserting rod.

Description

DETAILED DESCRIPTION OF THE INVENTION (Related Field) The present invention relates to a so-called ultrasonic pipe wall thickness measuring device that measures the wall thickness of a steel pipe or the like using an ultrasonic thickness gauge. This device can be used to remove meat such as steel pipes. When measuring [, the measurement accuracy and measurement limits are determined by whether or not the transducer (ultrasonic transmitter/receiver) can be correctly set parallel to the inner surface of the steel pipe, etc., and at the center of the steel pipe, etc. . The present invention relates to such an ultrasonic tube wall thickness measuring device.

(Prior art) Conventionally, in order to insert a transducer inside a steel pipe, etc., the transducer was held down by hand using a guide plate or the like, or the object to be measured was placed on a drilling machine and the transducer was gripped with a chuck.
A parallel and centered state was created mechanically with respect to the measurement surface. This limits the flexibility and operability of the device,
Accuracy was low and there were problems with reproducibility.

(Objective) The present invention aims to provide a wall thickness measuring device in which a transducer for measuring the wall thickness of a steel pipe can be easily set parallel to the inner surface of the steel pipe and at the center of the steel pipe. .

(Summary of configuration) Attach 1 Herans deducer to the tip of the insertion rod, and
- By installing a plurality of spring devices equidistantly on the circumferential surface near the transducer and at predetermined intervals in the lengthwise direction of the pipe, the insertion rod can be attached to the one to be measured. When inserted into the tube, the spring device is able to apply compressive force evenly to the inner surface of the tube. The reaction of this compressive force automatically places the transducer at the center of the tube to be measured, making it parallel to the center of the tube to ensure accurate ultrasonic echoes. be.

(Embodiments of the Invention) Before explaining the present invention in detail, the principle of an ultrasonic thickness gauge will be explained with reference to FIGS. 1 and 2.

Ultrasonic waves generated by the transducer 1 are propagated to the object to be measured 3 by a couplant 2 such as water. The propagated ultrasonic waves are reflected by the surface 4 of the object to be measured 3 and return as an S echo, and transmitted through the object to be measured and reflected from the back surface 5 and returned ■3
I get an echo. S echo and S where ultrasound waves are reflected back
The time difference T between the echoes is measured, and the thickness D is obtained using the following equation.

L) = 1/2"l"・V D = Thickness T: Time between S echoes V: Sound speed inside the object to be measured By the way, the measurement accuracy of the thickness of tit etc. depends on the position of transducer 1. causes a difference in FIG. 3(a) is an ideal set state, and FIG. 3(b) and (C) are unfavorable set states. That is, in (a), the correct wall thickness can be obtained because the run steerer 1 is placed at the center of the steel pipe etc. 6 and parallel to the pipe length direction, but in (b), the correct wall thickness is obtained, and (c ) has the disadvantage that not only the true wall thickness cannot be obtained, but also the intensity of the echo is weakened.

FIG. 4 shows a first embodiment of the present invention. A is a pipe wall thickness measuring device according to the present invention. The apparatus A consists of an insertion rod 7 for insertion into the steel pipe 6 to be measured, and a pair of supports 8 attached to the tip of the insertion rod 7.

The support 8 comprises a ring 9 fixed to the insertion rod 7. A plurality of holes 12 for holding springs 10 and steel balls 11 are equally distributed on the circumferential surface of the ring 9. Reference numeral 13 denotes a dish-shaped flying ball holding cover, which has a hole 14 for holding a ball 11 in the same phase as the hole 12 provided in the ring 9. Of course, since the hole 14 is smaller than the diameter of the steel ball 11, the steel ball will not pop out due to the spring force. Steel ball holding cover 13
is fixed to the side of the ring 9 at its bottom.

The support 8 is fixed to the insertion rod 7 as appropriate, but at the tip of the insertion rod 7, for example, a barbed portion 15 provided at the tip of the insertion rod 7 is used.
is screwed into ring 9 and fixed.

1-The transducer 1 has a pair of supports 8 for the insertion rod 7,
8 and fixed with bolts 16. 17 is the insertion rod 7
A wiring hole 18 drilled in the center of the insertion rod is a scale engraved on the surface of the insertion rod, which allows you to know the insertion tray of the 1-transducer.

The device shown in FIG. 4 is a measuring device for a single diameter canine.

In the apparatus shown in FIG. 4, it is not possible to determine the diameter of steel balls with a diameter smaller than that of the steel ball holding cover [3].

FIG. 5 shows an embodiment of a measuring device for small diameter pipes.

In this case, a bent wire spring J9 is attached to the tip of the insertion rod 7.
are arranged in left and right pairs, and a plurality of these are equally spaced on the circumferential surface of the insertion rod 7. The wire spring 19 has one end inserted into the insertion rod 7.
It is fixed to the top with a screw 20, and the free end is movable by being guided by a long groove 21 provided in the axial direction on the surface of the insertion rod.

(Setting method for measurement) In the case of measuring device A for large diameter pipes: The operator holds the insertion rod 7 and inserts the lance deducer 1 to the measurement position into the pipe to the measurement position indicated by the scale 18. Move the insertion rod 7 up and down and left and right so that all the copper balls 1] are uniformly brought into contact with the inner surface of the steel pipe 6 by the spring 12. As a result, the transducer 1 is automatically located at the center of the steel pipe and parallel to the axial direction of the steel pipe.

In the case of measuring device B for small diameter pipes: As in the case of large diameter pipes, insert the insertion rod 7 into the steel pipe 6. Then, the bent portion of the wire spring 19 comes into contact with the inner surface of the steel pipe 6. At this time, the free end of the wire spring 19 does not move in the direction perpendicular to the long groove 1ζ 21, but moves freely along the long groove 21 so that no unreasonable force is applied. Moreover, it is located parallel to the axis of the steel pipe. In measuring the tube wall thickness, a couplant such as water, oil, or glycerin is filled between the 1-transducer 1 and the tube 6 to be measured.

(Effect) In the case of a device for large diameters, the steel balls of 4-digit links attached to the insertion rod are urged outward radially by springs against the inner surface of the steel pipe to be measured. The deducer must be set correctly at the center of the pipe to be measured, such as a steel pipe, and parallel to the length of the pipe.

In addition, even in the case of a device for small diameters, the wire spring suppresses the device evenly toward the center, so it can be set correctly at the center of the tube to be measured and parallel to the length of the tube, resulting in high measurement accuracy. . Furthermore, since the measuring device is attached to the insertion rod, it has excellent flexibility and operability.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams explaining the principle of an ultrasonic thickness gauge. FIGS. 3(a), 3(b), and 3(c) are diagrams showing the relationship between the position of the transducer and the steel pipe to be measured. FIG. 4 is a side sectional view of the large diameter measuring device of the present invention. FIG. 5 is a side view of the measuring device for small diameters. In the figure: A Small 1" diameter measuring device B Large diameter measuring device] 1 to
Lance deducer 2 couplant 3 object to be measured 4 (
(Object to be measured) Surface 5 (Object to be measured) Back surface 6 (Object to be measured)
T! l fixed) Steel pipe 7 Insertion rod 8 Support 9 Link 10 Spring ■J Steel ball ] 2 Hole 13 nJ ball holding cover 14 Hole 15 Threaded portion 16 Bolt 17 Wiring hole 18 Scale 19 Wire spring 20 Bolt 21 Long groove

Claims (1)

[Scope of Claims] (1) A plurality of spring devices are installed equidistantly on the circumferential surface near the insertion end of the insertion rod to which the transducer is attached at predetermined intervals in the pipe length direction, and A pipe wall thickness measuring device characterized in that the pipe is brought into contact with the inner surface of the pipe to be measured. 2) A steel ball retaining cover that restrains the steel ball and the amount of protrusion of the steel ball, which are urged outward by springs in which the spring device is installed in holes equally distributed on the circumferential surface of a ring fixed to the insertion rod. A pipe wall thickness measuring device according to claim 1), characterized in that: 3) The pipe wall thickness measuring device according to claim 1), wherein the spring device is comprised of a shadow spring whose one end is fixed to the insertion rod and is arranged equidistantly around the circumference of the insertion rod.