JP2015169547A - Ultrasonic inspection device for pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic inspection device for pipe which can measure thickness or corrosion of a 360-degree position on a pipe inner side with an ultrasonic probe fixed without using a slip ring.SOLUTION: An ultrasonic inspection device 10 for pipe which inspects thickness or erosion state of a pipe 11 by emitting an ultrasonic wave to the inner surface of the pipe 11, comprises: a hollow shaft motor 16 which is arranged with the shaft center aligned with the center of the pipe 11; a supporting carriage 14 which has a plurality of wheels 13 brought into contact with the inner wall of the pipe 11 and positions the hollow shaft motor 16 at the center of the pipe 11; an inclined mirror 19 which is fixed to one side of a hollow shaft 18 of the hollow shaft motor 16, and arranged so as to be inclined at 45 degrees with respect to the shaft center of the hollow shaft motor 16; an ultrasonic probe 21 which is provided on the other side of the hollow shaft 18 with a gap held therebetween, supported by the supporting carriage 14, and provided so as to be aligned to the shaft center of the hollow shaft 18; and a rotation sensor 29 which detects the rotation of the hollow shaft 18.

Description

The present invention relates to an ultrasonic inspection apparatus for a pipe that can be used by being put in a pipe (also referred to as piping) and capable of measuring the damaged state of the pipe, the thickness of the pipe, and the like.

For example, as described in Patent Document 1, pipes used in heat exchangers of power generation facilities are narrowly and complicatedly arranged, and furthermore, fins may be attached to the outer surface to improve thermal efficiency. It was difficult to non-destructively inspect the tube from the outside. Therefore, as shown in FIG. 7 of the publication, the conventional in-pipe insertion type ultrasonic flaw detector is divided into a probe main body, a signal coupling unit, and a drive unit that are held on the tube axis center line of the tube. The constituent units were connected by a coupler capable of transmitting rotation, and an ultrasonic transmitter / receiver was installed outside the tube.

In this flaw detection apparatus, in order to perform flaw detection over the entire circumference of the tube, a probe main body in which one vibrator is arranged by a motor is rotated and scanned through a drive shaft, and an ultrasonic transceiver, vibrator, The electric signals sent and received between them were sent to the outside using a slip ring as a medium.

In Patent Document 2, an ultrasonic probe and a rotating body are placed in a tube, and a mirror inclined by 45 degrees is provided on the front side of the rotating body, so that an ultrasonic wave emitted from the ultrasonic probe is transmitted. It was reflected by a mirror and the reflected wave was detected by an ultrasonic probe.

JP-A-11-352113 JP 2001-83124 A

However, the technique described in Patent Document 1 has a problem that the configuration of the apparatus becomes complicated because a slip ring is used to transmit a signal line to a rotating ultrasonic probe. In order to solve this problem, the signal line of the ultrasonic probe is used by fixing the ultrasonic probe and rotating the reflection mirror inclined by 45 degrees as in the technique described in Patent Document 2. It is conceivable to eliminate the need to connect the two via a slip ring. However, the technique described in Patent Document 2 uses a rotary drive mechanism using a water jet nozzle, and therefore, particularly in the case of inspection of a large pipe, there is a problem that the rotating part becomes large as it is and is difficult to apply. In order to solve this problem, it is conceivable to drive the rotating body of Patent Document 2 instead of a normal electric motor. However, such an alternative causes a new problem that the mechanism becomes complicated due to the necessity of connecting the rotating body to the rotating shaft of the motor via the power transmission means and driving the mirror to rotate. In addition, the technique described in Patent Document 2 has another problem that the position of damage in the pipe cannot be accurately determined.

The present invention has been made in view of such circumstances, and has a simple structure suitable for inspecting a large-sized pipe while having a mechanism in which an ultrasonic probe is fixed without using a slip ring, and a pipe. An object of the present invention is to provide an ultrasonic inspection apparatus for a pipe capable of measuring the thickness or corrosion at an inner 360 degree position.

An ultrasonic inspection apparatus for a tube according to the present invention that meets the above-described object is an ultrasonic inspection apparatus for a tube that applies ultrasonic waves to the inner surface of the tube to inspect the thickness or erosion state of the tube.
A hollow shaft motor arranged with its axis aligned in the center of the tube;
A support carriage having a plurality of wheels in contact with the inner wall of the pipe and positioning the hollow shaft motor at the center of the pipe via a connecting member;
An inclined mirror that is fixed to one side of the hollow shaft of the hollow shaft motor and is inclined by 45 degrees with respect to the axis of the hollow shaft motor;
An ultrasonic probe that is fixedly disposed on the other side of the hollow shaft with a gap between the hollow shafts, and is provided with a direction aligned with the axis of the hollow shaft;
A rotation sensor for detecting the rotation of the hollow shaft.
The tube to be inspected by the ultrasonic inspection apparatus according to the present invention is a straight tube or a curved tube having a predetermined inner diameter.

In the ultrasonic inspection apparatus for a tube according to the present invention, the rotation sensor is preferably a one-rotation sensor that detects one rotation of the hollow shaft.

In the ultrasonic inspection apparatus for a tube according to the present invention, the one-rotation sensor has a magnet provided on the hollow shaft and a detection unit fixedly provided with a Hall element for detecting the magnet. Is preferred. In this case, an angle smaller than one rotation is calculated from the partial rotation time based on the time required for one rotation.

In the tube ultrasonic inspection apparatus according to the present invention, the wheel of the support carriage is provided at a front portion of a bearing member including an adjuster capable of fixing a protruding length in the radial direction to a length corresponding to the inner diameter of the tube. It is preferred that

An ultrasonic inspection apparatus for a tube according to the present invention is provided with a 45-degree inclined mirror on one side of a hollow shaft of a hollow shaft motor arranged with its axis aligned in the center of the tube, and ultrasonic waves on the other side of the hollow shaft. Since the probe is arranged, an ultrasonic path can be formed by effectively using the hollow shaft of the hollow shaft motor.
Further, since the ultrasonic probe is fixedly arranged on the other side of the hollow shaft and transmits and receives ultrasonic waves, the signal line is not twisted and a slip ring is not necessary.
As described above, the ultrasonic inspection apparatus for a tube according to the present invention has a simple structure suitable for inspecting a large pipe, while using a mechanism in which an ultrasonic probe is fixed without using a slip ring.

Further, since the rotation sensor for detecting the rotation of the hollow shaft is provided, the ultrasonic flaw detection range (flaw detection angle) by the tilt mirror can be clearly detected, and the location can be clearly identified.
That is, the ultrasonic inspection apparatus for a pipe according to the present invention can measure the thickness or corrosion at a position of 360 degrees inside the pipe.

Further, since the support carriage for positioning the hollow shaft motor at the center of the tube is used, the inspection position can be easily positioned.
Moreover, since the support carriage is installed in the pipe via a plurality of wheels, it can be easily moved along the pipe.
In addition, since a slip ring is not used, the entire length can be made short, so that it can be easily applied to a bent pipe.

(A) is a side view of the ultrasonic inspection apparatus for a tube according to an embodiment of the present invention, and (B) is a rear view of the apparatus. FIG. (A) is a front view of the main part of the apparatus, and (B) is a rear view of the main part of the apparatus. (A) is an assembly drawing of the main part of the apparatus, (B) is an AA view of FIG. 4, and (C) is an BB view of FIG. 4.

Next, a tube ultrasonic inspection apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 to 4, the ultrasonic inspection apparatus 10 for a tube according to an embodiment of the present invention irradiates the inner surface of the tube 11 with ultrasonic waves, and reaches the tube (piping) at the arrival time of the reflected wave. ) 11 is a device for inspecting the thickness or erosion state, the metal part is made of stainless steel, and a part of synthetic resin such as MC nylon is used.

As shown in FIGS. 1 (A) and 1 (B), the ultrasonic inspection apparatus 10 for a tube has a support carriage 14 having wheels 13 provided around a plurality (three or more) arms 12 around the tube. ing. The wheels 13 of the support carriage 14 may be a free carriage without a rotational drive source, or may have a rotational drive source and move to a predetermined position in the pipe 11. In the case of a free carriage, the ultrasonic inspection apparatus 10 for this tube is pulled or pushed from one side or both sides.
The arm 12 is provided with a bearing member having a fixed length corresponding to the inner diameter of the tube 11 to be inspected, and a wheel 13 is provided at the tip.
The arm 12 may include an adjuster that adjusts the protruding length of the tube in the radial direction. In this case, the adjuster is adjusted before the ultrasonic inspection apparatus 10 is arranged at a predetermined position, and the protruding length of the arm 12 is fixed to the protruding length corresponding to the inner diameter of the tube 11 to be inspected. Accordingly, it is possible to cope with a plurality of types of pipes having different inner diameters. The arm 12 may be a rotating leg. The wheel 13 is preferably urged in the radial direction toward the inner wall by a spring or the like so as to always contact the inner wall of the pipe.

An inspection apparatus main body 15 shown in FIG. 2 is provided at the front center of the support carriage 14 via a connecting member 17. The inspection device main body 15 is fixed to one side of the hollow shaft 18 of the hollow shaft motor 16 and the hollow shaft motor 16 that is arranged in the center of the tube 11 with the shaft center aligned. And a front metal fitting 20 provided with an inclined mirror 19 disposed at an angle of 45 degrees.

An ultrasonic probe 21 is provided on the other side of the hollow shaft 18 with a slight gap (for example, 0.1 to 0.5 mm) from the inner wall of the pipe-shaped hollow shaft 18. The child 21 is not rotated by the hollow shaft 18. The ultrasonic probe 21 is supported by the support carriage 14 via the connecting member 17, and is screwed to the annular rear metal fitting 22 so that the direction is aligned with the axis of the hollow shaft 18. Reference numerals 23 shown in FIGS. 3B and 4C denote female screws (three at 120 degree intervals) that are one of screws for fixing the ultrasonic probe 21. Details of the front metal fitting 20 and the ultrasonic probe 21 connected thereto will be described later.

As shown in FIG. 2, the hollow shaft 18 of the hollow shaft motor 16 has a pipe shape and has a protruding ring 26 on one side. A permanent magnet 27 is provided at a predetermined angular position of the protruding ring 26. A one-rotation sensor 29 (an example of a rotation sensor) is provided by a hall element (an example of a detection unit) and a permanent magnet 27 that are provided inside a casing 28 that houses the hollow shaft motor 16 and are fixed to the outside of the hollow-axis motor 16. ) And the permanent magnet 27 at a specific angle (for example, the origin) is detected by the one rotation sensor 29, that is, the time for one rotation of the hollow shaft 18 is detected.

As shown in FIGS. 2, 4 </ b> A, and 4 </ b> B, the casing 28 includes a cylindrical body portion 30 and an inner flange portion 31 that is integrally provided on the front side of the cylindrical body portion 30. The center of the inner flange portion 31 is opened so that the front metal fitting 20 can be inserted therethrough. 32 and 32a are annular grooves for inserting an oil seal. The hollow shaft motor 16 is screwed to the inner flange portion 31. Reference numeral 33 shown in FIG. 3B denotes a screw for fixing the hollow shaft motor 16.

As shown in FIG. 4A, the front metal fitting 20 has a tubular shape that is a passage (space portion, filled with water) through which ultrasonic waves pass inside the hollow shaft 18 of the hollow shaft motor 16. The ultrasonic wave propagation part 34, the mirror storage part 35 provided integrally on the front side thereof, and the mirror storage part 35 are mounted, and the angle of the reflection surface 36 is 45 with respect to the axis of the hollow shaft motor 16. And the mirror part 37 having the tilted mirror 19 of the degree, and the mirror part 36 is attached to the mirror housing part 35 to complete the front side metal fitting 20.

Further, the ultrasonic wave propagation part 34 at the rear part of the front metal fitting 20 has a length that penetrates the hollow shaft 18 of the hollow shaft motor 16, and is provided by one or a plurality of screws provided on the protruding ring 26 of the hollow shaft 18. The hollow shaft 18 and the front metal fitting 20 are integrated so that they can rotate at a low speed. The hollow shaft motor 16 has a square shape with chamfered corners when viewed from the front, and is housed in the casing 28 while maintaining a predetermined angle. Therefore, when the hollow shaft motor 16 is driven, the hollow shaft 18 is rotated, and the front metal fitting 20 is rotated accordingly. The rotation state can be detected by the single rotation sensor 29, and the detailed flaw detection position can be detected from the detection timing (cycle T) and the operation time (<T) of the single rotation sensor 29.

The ultrasonic probe 21 has a cylindrical ultrasonic wave propagation part 39, an ultrasonic wave oscillating part 40, and a cord 41 connected to the oscillating part 40. The diameter of the ultrasonic wave propagation part 39 is smaller than the inner diameter of the ultrasonic wave propagation part 34, and the ultrasonic probe 21 is held in a fixed state so that the front metal fitting 20 can rotate. This eliminates the slip ring and simplifies the apparatus itself.

A motor cover 43 made of MC nylon is provided on the rear side of the casing 28, and the rear metal fitting 22 for fixing the ultrasonic probe 21 is fixed to the motor cover 43 with screws that are inserted through the screw holes 43 a. . The motor cover 43 and the casing 28 are fixed using a plurality of screws. In FIG. 4, 45 is an O-ring groove, 46 is a screw hole, and 47 is a female screw hole. Further, the seal between the motor cover 43 and the rear metal fitting 22 is also performed by an oil seal or an O-ring. Reference numerals 48 and 49 denote these sealing grooves.

Therefore, when using the ultrasonic inspection apparatus 10 of this tube, the ultrasonic inspection apparatus 10 of this tube is brought into contact with the inner wall of the tube 11 at a predetermined position of the tube 11 to be measured. Arrange as follows. When the tube 11 is inclined or vertical, the wheel 13 is locked or held at a predetermined position by a support member or the like so that the tube ultrasonic inspection device 10 itself does not move. deep. Through the above operation, the inspection apparatus body 15 (hollow shaft motor 16) is installed (positioned) so that the axis of the tube 11 becomes the axis of the tube 11.

Thereafter, water is introduced into the tube 11 to create an environment in which ultrasonic waves are easy to propagate, ultrasonic waves connected to the tube ultrasonic probe 10 are rotated by sending predetermined power to the hollow shaft motor 16. The probe 21 is operated, and the one rotation sensor 29 is also operated. In addition, since the hollow shaft motor 16 and the one rotation sensor 29 in the casing 28 are sealed, water does not enter the inside.

As a result, the pulsed ultrasonic wave from the ultrasonic probe 21 is reflected by the tilting mirror 19, hits a predetermined position on the inner wall of the tube 11, and returns to the ultrasonic probe 21 via the tilting mirror 19. . Here, the origin position is detected by the one-turn sensor 29, and the output of the ultrasonic probe 21 is graphed during the time until the next one-turn sensor 29 detects the origin, and the inner diameter of the tube 11 is calculated. The position can be detected.

The inspection apparatus main body 15 does not need to have its axis exactly aligned with the axis of the tube 11. When the axis of the tube 11 and the axis of the inspection apparatus main body 15 are shifted, the angular position (θ) of the detected signal and its radius r (the time until reception-the distance from the ultrasonic probe to the tilted mirror) It can be easily corrected by moving the center of the circle only by decentering the data of the sound wave propagation time.
Furthermore, the present invention is not limited to the above-described embodiment, and improvements and member changes can be made without changing the gist of the present invention.
Moreover, in the said embodiment, although 1 rotation sensor was used as a rotation sensor, a rotary encoder etc. may be sufficient.

10: Ultrasonic inspection device for tube, 11: Tube, 12: Arm, 13: Wheel, 14: Supporting carriage, 15: Inspection device body, 16: Hollow shaft motor, 17: Connecting member, 18: Hollow shaft, 19: Inclined mirror, 20: front metal fitting, 21: ultrasonic probe, 22: rear metal fitting, 23: female thread, 26: protruding ring, 27: permanent magnet, 27a: detector, 28: casing, 29: 1 rotation Sensor: 30: cylinder part, 31: inner flange part, 32, 32a: annular groove, 33: screw, 34: ultrasonic wave propagation part, 35: mirror housing part, 36: reflecting surface, 37: mirror part, 39: Ultrasonic wave propagation part, 40: Oscillating part, 41: Code, 43: Motor cover, 43a: Screw hole, 45: O-ring groove, 46: Screw hole, 47: Female screw hole, 48, 49: Sealing groove

Claims (4)

In an ultrasonic inspection apparatus for a tube that applies ultrasonic waves to the inner surface of the tube to inspect the thickness or erosion state of the tube,
A hollow shaft motor arranged with its axis aligned in the center of the tube;
A support carriage having a plurality of wheels in contact with the inner wall of the pipe and positioning the hollow shaft motor at the center of the pipe via a connecting member;
An inclined mirror that is fixed to one side of the hollow shaft of the hollow shaft motor and is inclined by 45 degrees with respect to the axis of the hollow shaft motor;
An ultrasonic probe that is fixedly disposed on the other side of the hollow shaft with a gap between the hollow shafts, and is provided with a direction aligned with the axis of the hollow shaft;
An ultrasonic inspection apparatus for a tube, comprising: a rotation sensor that detects rotation of the hollow shaft. 2. The ultrasonic inspection apparatus for tubes according to claim 1, wherein the rotation sensor is a single rotation sensor that detects one rotation of the hollow shaft. 3. The ultrasonic inspection apparatus for a tube according to claim 2, wherein the one-rotation sensor includes a magnet provided on the hollow shaft and a detection unit fixedly provided with a Hall element that detects the magnet. An ultrasonic inspection apparatus for tubes. The ultrasonic inspection apparatus for a pipe according to any one of claims 1 to 3, wherein a wheel of the support carriage includes an adjuster capable of fixing a protruding length in a radial direction to a length corresponding to an inner diameter of the pipe. An ultrasonic inspection apparatus for a tube, characterized by being provided at the tip of the tube.

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