JPH10332646A - Ultrasonic flaw detection/inspection device of fin welding part of spiral fin tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device that can effectively and non-destructively inspect the degree of solvent welding at the fin welding part of a spiral fin tube, at the same time, can confirm the continuity of the solvent welding part of the fin welding part, and can improve the quality of a product. SOLUTION: A flaw detection/inspecting device has a ultrasonic flaw detection control unit 43 where a spiral fin tube 3 is mounted on a turntable 5 being provided in a tank 4 where a contact medium such as water is stored so that the turntable can pivot horizontally, a supersonic probe 6 is provided at the upper part of the pivot center part of the turntable 5, the elevation of the ultrasonic probe 6 and the turning of the turntable 5 are controlled for performing the ultrasonic flaw detection throughout the entire peripheral surface of the spiral fin tube 3, and at the same time the unevenness in the sound pressure of a ultrasonic wave that is generated from the ultrasonic probe 6, is reflected at the welding part of a fin 2 of the spiral fin tube 3 and on an outer-periphery surface other than the welding part of the fin 2, and is received is converted into a color for displaying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic inspection apparatus for inspecting a fin weld of a spiral fin tube.

[0002]

2. Description of the Related Art In recent years, a spiral fin tube 3 formed by spirally winding a fin 2 around a tube 1 and welding the tube 1 as shown in FIG.

The spiral fin tube 3 is shown in FIG.
As shown in FIG. 1, while rotating the tube 1 about its axis, the tube 1 is moved in the axial direction, and the fin 2 is supplied to the tube 1 in the tangential direction. Direct supply of high frequency current,
The fin 2 is formed by intensively heating and welding the contact portion of the fin 2 to the tube 1 by the proximity effect of the high-frequency current itself.

When the penetration amount of the spiral fin tube 3 at the fin 2 welding portion is small and the degree of welding is low, a small gap is generated between the tube 1 and the fin 2.
Since the thermal conductivity is reduced and affects the efficiency of the boiler, it is necessary to check the welding degree.

For this reason, conventionally, a sample of the spiral fin tube 3 is cut in the axial direction of the tube 1 and the cut surface is polished, then appropriately corroded with a chemical, and subjected to a macrostructure inspection to perform a spiral fin tube 3 test. The degree of welding was determined by confirming the degree of welding at the fin 2 weld of the spiral fin tube 3 or performing a tensile test at the fin 2 weld of the spiral fin tube 3.

[0006]

However, since the macro structure inspection or the tensile test of the sample of the spiral fin tube 3 as described above is a destructive inspection, a partial check is possible, but the fin 2 welding is not possible. The continuity of the welded portion in the portion (confirmation of the ratio between the welded portion and the unwelded portion in the fin 2 welded portion) could not be confirmed, and the inspection took time.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention is capable of nondestructively and efficiently inspecting the degree of welding at a fin weld of a spiral fin tube and checking the continuity of the weld at the fin weld. It is an object of the present invention to provide an ultrasonic inspection device for a fin weld of a spiral fin tube, which can contribute to the improvement of product quality.

[0008]

SUMMARY OF THE INVENTION The present invention provides a turntable in which a spiral fin tube is disposed so as to be horizontally rotatable in a tank in which a couplant is stored, and a spiral fin tube is mounted so that its axis coincides with the center of rotation. An ultrasonic probe which is disposed so as to be able to ascend and descend above the center of rotation of the turntable and emits ultrasonic waves to the inner peripheral surface of a spiral fin tube placed on the turntable; The ultrasonic probe is controlled over the entire peripheral surface of the spiral fin tube by controlling the raising and lowering of the ultrasonic probe and the turning of the turntable, and the fin welding portion of the spiral fin tube emitted from the ultrasonic probe. And an ultrasonic flaw detection control unit for displaying the level of the sound pressure level of an ultrasonic echo reflected and received on the outer peripheral surface other than the fin welded portion. In which according to the ultrasonic flaw detection apparatus of the fin weld pie Lal fin tube.

According to the above means, the following effects can be obtained.

With the spiral fin tube placed on the turntable such that the axis of the spiral fin tube coincides with the center of rotation, the ultrasonic inspection control unit controls lifting and lowering of the ultrasonic probe and rotation of the turntable. When ultrasonic inspection is performed over the entire peripheral surface of the spiral fin tube, the ultrasonic probe emits the ultrasonic fin tube, and the fin welding portion of the spiral fin tube and the outer peripheral surface other than the fin welding portion are reflected and received. The level of the sound pressure level of the ultrasonic echo is displayed.

In other words, in a portion where the fin of the spiral fin tube is not welded, a part of the ultrasonic wave emitted from the ultrasonic probe is reflected by the inner peripheral surface of the spiral fin tube and the ultrasonic probe is used. Return to the child, but otherwise,
Since the fins of the spiral fin tube are reflected on the outer peripheral surface that is not welded and return to the ultrasonic probe, the sound pressure level of the received echo increases, whereas the fin weld of the spiral fin tube has When the penetration amount is sufficient and complete, part of the ultrasonic waves emitted from the ultrasonic probe at the fin welded portion is reflected by the inner peripheral surface of the spiral fin tube as described above. Return to the ultrasonic probe, but otherwise the sound is transmitted from the thick part of the spiral fin tube to the fin side through the fin weld, so that the sound pressure level of the received echo becomes low, The level of the sound pressure level of the echo is displayed by the ultrasonic inspection control unit.

Here, when the penetration amount is insufficient at the fin weld portion of the spiral fin tube and the insufficient penetration width is large, the ultrasonic probe is emitted at the fin weld portion. As described above, some of the ultrasonic waves are reflected on the inner peripheral surface of the spiral fin tube and return to the ultrasonic probe as described above, but otherwise, the width of the fin weld is wide from the thick portion of the spiral fin tube. The sound pressure level of the received echo is reflected by the insufficient penetration part and returns to the ultrasonic probe, and the sound pressure level of the echo detected by reflection on the outer peripheral surface of the spiral fin tube other than the fin weld is The location that should be displayed in the same manner as the location corresponding to the fin weld where the penetration of the spiral fin tube is sufficient and complete is different The same as to be) that a portion corresponding to the outer peripheral surface other than the fin weld Ira Le fin tube, it is possible to see where defective at a glance.

As a result, it is not necessary to carry out a destructive inspection such as a macro structure inspection or a tensile test of a sample of a spiral fin tube as in the prior art. Shorter.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 5 show an embodiment of the present invention, in which a turntable 5 is arranged in a tank 4 in which a couplant W such as water (see FIG. 2) is stored so as to be able to turn horizontally. Set up
Spiral fin tube 3 on turntable 5
Is placed so that its axis coincides with the turning center of the turntable 5, and above the turning center of the turntable 5, to the inner peripheral surface of the spiral fin tube 3 placed on the turntable 5. Ultrasound U (see Fig. 3)
The ultrasonic probe 6 that emits the ultrasonic wave is disposed so as to be able to move up and down, and the raising and lowering of the ultrasonic probe 6 and the turning of the turntable 5 are controlled so that the ultrasonic inspection is performed over the entire peripheral surface of the spiral fin tube 3. And the sound pressure level of the echo of the ultrasonic wave U which is emitted from the ultrasonic probe 6 and is reflected and received by the fin 2 welding portion of the spiral fin tube 3 and the outer peripheral surface other than the fin 2 welding portion. The ultrasonic flaw detection control unit 43 for converting the height of the image into a color and displaying the color is provided.

As shown in FIG. 2, the turntable 5 is provided on a base plate 5a installed at the bottom of the tank 4,
A disk-shaped turntable main body 5b is attached to be pivotable about a pivot 5c extending in a vertical direction (Z-axis direction),
A driven gear 5d is fitted on the lower surface side of the turntable body 5b of the turning shaft 5c, and an intermediate gear 5e meshed with the driven gear 5d, and a drive pinion 5f meshed with the intermediate gear 5e.
Are rotatably disposed on the base plate 5a, and the drive pinion 5f is rotationally driven by the turning motor 7 to rotate the driven gear 5d via the intermediate gear 5e, thereby moving the turntable body 5b horizontally. It has a configuration that can be turned. The turning motor 7 is provided with a manual knob 7a, and by turning the manual knob 7a, the turning motor 7 can be rotated manually.

As shown in FIGS. 3 and 4, the ultrasonic probe 6 has a hollow inserted slidably in a vertical direction (Z-axis direction) with respect to a movable block 8 whose position can be adjusted in the Y-axis direction. The ultrasonic wave U is attached to the lower end of the shaft 9 via an angle adjusting mechanism 10 so that the ultrasonic wave U is reflected by an acoustic mirror 6a arranged at 45 ° and emitted toward the inner peripheral surface of the spiral fin tube 3. On the back side of the hollow shaft 9, a rack groove 14 is formed in which a gear 13 fitted to a rotating shaft 12 of a worm gear 11 described later is carved, and a worm 16 is driven to rotate by an elevating motor 15. By rotating the worm gear 11 meshing with the worm 16 and rotating the gear 13 integral with the rotating shaft 12 of the worm gear 11, the hollow shaft 9 is slid vertically with respect to the movable block 8. , So that capable of lifting the ultrasonic probe 6. The lifting motor 15 is provided with a manual knob 15a, and by rotating the manual knob 15a, the lifting motor 15 can be rotated manually.

The angle adjusting mechanism 10 of the ultrasonic probe 6
As shown in FIG. 3, a tilt motor 17 is installed at the upper end of the hollow shaft 9, a drive shaft 18 of the tilt motor 17 is inserted through the hollow shaft 9, and a drive pinion 19 is fitted to the lower end thereof. An intermediate gear 21 fitted on a rotation shaft 20 parallel to the drive shaft 18 is meshed with the drive pinion 19, and a worm gear 23 is meshed with a worm 22 integral with the rotation shaft 20 of the intermediate gear 21. The probe holder 25 extends vertically downward from the rotation shaft 24 of the worm gear 23, and the ultrasonic probe 6 is attached to the probe holder 25. The probe holder 25 is driven by the tilt motor 17. By rotating the pinion 19, rotating the intermediate gear 21 meshing with the drive pinion 19, rotating the worm 22, and rotating the worm gear 23 meshing with the worm 22, The ultrasonic probe 6 via the probe holder 25 is adapted to be is tilted, thereby,
The ultrasonic probe 6 can be adjusted so that the ultrasonic waves U emitted from the ultrasonic probe 6 strike the inner peripheral surface of the spiral fin tube 3 at right angles. The tilt motor 17 has a manual knob 17a.
The tilt motor 17 can also be rotated manually by rotating the manual knob 17a.

The movable block 8 is, as shown in FIG.
It is slidably fitted to two guide rods 26 and 27 provided in the Y-axis direction, and is screwed to a screw shaft 28 provided in the Y-axis direction. The movable block 8 can be moved in the Y-axis direction by being rotationally driven by a position adjusting motor 29. Both ends of the guide rods 26 and 27 and both ends of the screw shaft 28 are connected to the X-axis. The one movable block 30 is slidably fitted on a guide rod 32 provided in the X-axis direction, and is supported so as to be bridged between movable blocks 30, 31 whose position can be adjusted in the direction. The other movable block 31 is screwed onto a screw shaft 33 provided in the X-axis direction.
Is slidably fitted on a guide rod 34 arranged in the X-axis direction, and the movable blocks 30, 31 are moved in the X-axis direction by rotating the screw shaft 33 by a position adjusting motor 35. Thus, the position of the ultrasonic probe 6 can be moved in the X-axis or Y-axis direction so as to coincide with the turning center of the turntable 5. The position adjusting motors 29 and 35 are provided with manual knobs 29a and 35a, and by rotating the manual knobs 29a and 35a, the position adjusting motors 29 and 35 can be manually rotated. ing.

On the other hand, the ultrasonic inspection control unit 43
Has a configuration including an ultrasonic flaw detector 36, a data processing control device 37, a color monitor 40, a color printer 41, and a micro step motor driver 42, as shown in FIG. The ultrasonic probe 6 is connected to an ultrasonic flaw detector 36, and based on a command signal 37 a from a data processing control device 37,
Ultrasonic wave U via ultrasonic inspection cable 38 (see FIG. 3)
Is transmitted to the ultrasonic probe 6, and the echoes reflected by the inner and outer peripheral surfaces of the spiral fin tube 3 and the insufficient penetration portion of the fin 2 welding portion and returned to the ultrasonic probe 6 are received and detected. A signal 39 is sent to the data processing control device 37.

The data processing controller 37 processes the detection signal 39 from the ultrasonic flaw detector 36 and outputs processing signals 37b and 37c to the color monitor 40 or the color printer 41, while the micro step motor driver 42 Control signal 37d from the micro-stepping motor driver 42, and based on the control signal 37d, the swing motor 7, the lifting motor 15, the tilt motor 1
7. Drive signals 7 to position adjustment motors 29 and 35, respectively.
b, 15b, 17b, 29b, and 35b are output. Before performing the actual flaw detection inspection, the ultrasonic probe 6 is tilted, and the ultrasonic wave emitted from the ultrasonic probe 6 is emitted. U is adjusted so as to be perpendicular to the inner peripheral surface of the spiral fin tube 3, and the position of the ultrasonic probe 6 is moved in the X-axis or Y-axis direction so as to coincide with the turning center of the turntable 5. In addition, at the time of actual flaw detection inspection, measurement is performed while lowering the ultrasonic probe 6 from the upper end to the lower end of the spiral fin tube 3, and when the ultrasonic probe 6 reaches the lower end of the spiral fin tube 3 After stopping the lowering by turning the turntable 5 by a required angle and stopping, the ultrasonic probe 6 is measured while being raised from the lower end to the upper end of the spiral fin tube 3, and the measurement is performed. When the wave probe 6 reaches the upper end of the spiral fin tube 3, the ascent is stopped, the turntable 5 is turned by a required angle and stopped, and thereafter, the same operation is repeated, and the color monitor 40 or the color printer is repeated. A measurement result as shown in FIG.

Next, the operation of the illustrated example will be described.

First, the spiral fin tube 3 is placed on the turntable 5 so that its axis coincides with the center of rotation of the turntable 5, and then the ultrasonic probe 6 is inserted into the spiral fin tube 3. In this state, the ultrasonic probe 6 is tilted by a manual operation or an input operation by the data processing control device 37, and the ultrasonic waves U emitted from the ultrasonic probe 6 are moved inside the spiral fin tube 3. At the same time, the ultrasonic probe 6 is adjusted so as to strike the peripheral surface at a right angle, and the position of the ultrasonic probe 6 is moved in the X-axis or Y-axis direction so that the ultrasonic probe 6 is adjusted to coincide with the turning center of the turntable 5. In addition, as to whether the ultrasonic wave U emitted from the ultrasonic probe 6 hits the inner peripheral surface of the spiral fin tube 3 at right angles, the ultrasonic probe 6 was tilted to emit the ultrasonic wave U. At this time, it is sufficient to find the tilt position of the ultrasonic probe 6 at which the echo reflected on the inner peripheral surface of the spiral fin tube 3 and returned to the ultrasonic probe 6 is received most strongly. The position of the probe 6 is the turntable 5
Whether the ultrasonic probe 6 is aligned with the center of rotation of the ultrasonic probe 6 at a required position in the height direction inside the spiral fin tube 3 while the turntable 5 is being rotated and the ultrasonic probe 6 When emitted, the echo reflected on the inner peripheral surface of the spiral fin tube 3 and returned to the ultrasonic probe 6 is received substantially uniformly over the entire circumference of the spiral fin tube 3. What is necessary is just to find the horizontal position of the child 6.

After the adjustment of the tilt angle and the horizontal position of the ultrasonic probe 6 is completed, when performing an actual flaw detection inspection, a control signal 37 d is sent from the data processing control device 37 to the microstep motor driver 42. The control signal 37 is output from the micro step motor driver 42.
d, drive signals 7b and 15b are output to the turning motor 7 and the lifting / lowering motor 15, respectively, and a command signal 37a is sent from the data processing controller 37 to the ultrasonic flaw detector 36.
Is output, the ultrasonic probe 6 descends from the upper end to the lower end of the spiral fin tube 3, and in conjunction with this operation, the ultrasonic wave U is transmitted from the ultrasonic flaw detector 36 via the ultrasonic flaw detection cable 38 to the ultrasonic wave U. The echo transmitted to the probe 6 and reflected by the inner and outer peripheral surfaces of the spiral fin tube 3 and the portion of the fin 2 welded portion that has insufficient penetration and returned to the ultrasonic probe 6 is received, and the detection signal 39 is output. Ultrasonic flaw detector 36
Is sent to the data processing control device 37, the data processing control device 37 performs data processing of the detection signal 39, and the processing signals 37b and 37c are output to the color monitor 40 or the color printer 41. Child 6
When the ultrasonic probe 6 reaches the lower end of the spiral fin tube 3, the lowering of the ultrasonic probe 6 is stopped, and after the turntable 5 is turned by a required angle (for example, about 1 °), the ultrasonic probe 6 is The spiral fin tube 3 rises from the lower end to the upper end, and in conjunction with this operation, the ultrasonic wave U is transmitted from the ultrasonic flaw detector 36 to the ultrasonic probe 6 via the ultrasonic flaw detection cable 38 as described above. Then, the echo reflected on the inner and outer peripheral surfaces of the spiral fin tube 3 and the penetration insufficient portion of the fin 2 welding portion and returned to the ultrasonic probe 6 is received, and the detection signal 39 is transmitted from the ultrasonic flaw detector 36 to The data is sent to the data processing control device 37, and the data processing control device 37 performs data processing of the detection signal 39, and the processing signals 37b and 37c are output to the color monitor 40 or the color printer 41. When the ultrasonic probe 6 is output and reaches the upper end of the spiral fin tube 3, the lifting of the ultrasonic probe 6 is stopped, and the turntable 5 is turned by a required angle. Is repeated.

When the flaw detection inspection is performed over the entire circumference of the spiral fin tube 3, a measurement result as shown in FIG. 5 is finally output to the color monitor 40 or the color printer 41.

In FIG. 5, the black portion is the outer peripheral surface of the spiral fin tube 3 where the fins 2 are not welded, and the white portion is the fin 2 welded portion of the spiral fin tube 3, which is a spiral fin tube. At the portion of the tube 3 where the fins 2 are not welded, a part of the ultrasonic waves U emitted from the ultrasonic probe 6 is reflected on the inner peripheral surface of the spiral fin tube 3 and
In other cases, the fins 2 of the spiral fin tube 3 are reflected on the outer peripheral surface where the welding is not performed and return to the ultrasonic probe 6, so that the sound pressure level of the received echo becomes higher. If the penetration of the spiral fin tube 3 at the fin 2 weld is sufficient and complete, one of the ultrasonic waves emitted from the ultrasonic probe 6 at the fin 2 weld is obtained. The portion is reflected on the inner peripheral surface of the spiral fin tube 3 and returns to the ultrasonic probe 6 in the same manner as described above, but otherwise the portion from the thick portion of the spiral fin tube 3 passes through the fin 2 weld to the fin 2 side. The sound pressure level of the received echo will be lower,
This is a result of converting the level of the sound pressure level of the received echo into a color by the data processing control device 37 of the ultrasonic inspection control unit 43 and displaying the color.

Here, the spiral fin tube 3
In the case where the penetration amount is insufficient and the penetration shortage width is large at the fin 2 welded portion, one of the ultrasonic waves U emitted from the ultrasonic probe 6 at the fin 2 welded portion The portion is reflected on the inner peripheral surface of the spiral fin tube 3 and returns to the ultrasonic probe 6 in the same manner as described above, but otherwise the wide penetration of the fin 2 welding portion from the thick portion of the spiral fin tube 3 The sound pressure level of the received echo is reflected by the insufficient portion and returns to the ultrasonic probe 6, so that the sound pressure level of the echo reflected and detected by the outer peripheral surface of the spiral fin tube 3 other than the fin 2 welding portion Since the level is substantially equal to the level, and a portion that should be displayed in white originally becomes black, it is possible to confirm a defective portion at a glance.

In FIG. 5, the level of the sound pressure level of the received echo is simply displayed in two stages of black and white. However, the level of the sound pressure level is further subdivided into multiple levels. It goes without saying that the sound pressure level may be displayed as a multi-level shading in black and white without color coding.

As a result, it is not necessary to carry out a destructive test such as a macro structure test or a tensile test of the sample of the spiral fin tube 3 as in the prior art, and it is possible to confirm the continuity of the welded portion at the fin 2 welding portion. Time is short.

In this manner, the degree of welding at the fin 2 weld of the spiral fin tube 3 can be inspected nondestructively and efficiently, and the continuity of the weld at the fin 2 weld can be confirmed. It can contribute to quality improvement.

The ultrasonic inspection apparatus for inspecting a fin welded portion of a spiral fin tube according to the present invention is not limited to the above-described example, and various modifications may be made without departing from the scope of the present invention. Obviously you can get it.

[0032]

As described above, according to the ultrasonic flaw detector for a fin weld of a spiral fin tube according to the present invention, the degree of welding at the fin weld of a spiral fin tube can be inspected nondestructively and efficiently. In addition, the continuity of the welded portion in the fin welded portion can be confirmed, and an excellent effect of contributing to the improvement of product quality can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall schematic perspective view of an example of an embodiment of the present invention.

FIG. 2 is a side view illustrating a rotary drive system of a turntable according to an example of an embodiment of the present invention.

FIG. 3 is a side view showing a lifting drive system and a tilt drive system of the ultrasonic probe according to an example of the embodiment of the present invention.

4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is an output diagram showing a measurement result in an example of an embodiment of the present invention.

FIG. 6 is a perspective view showing a spiral fin tube.

FIG. 7 is a schematic view illustrating a process of manufacturing a spiral fin tube.

[Explanation of symbols]

 2 Fin 3 Spiral fin tube 4 Bath 5 Turntable 6 Ultrasonic probe 7 Rotating motor 15 Elevating motor 36 Ultrasonic flaw detector 37 Data processing controller 40 Color monitor 41 Color printer 42 Microstep motor driver 43 Ultrasonic flaw detection control unit U ultrasonic W couplant

Claims (1)

[Claims] 1. A turntable which is horizontally rotatably disposed in a tank in which a couplant is stored, and on which a spiral fin tube is placed with its axis aligned with the center of rotation, and a center of rotation of the turntable. An ultrasonic probe which is disposed so as to be able to move up and down and emits ultrasonic waves to the inner peripheral surface of a spiral fin tube placed on the turntable; By controlling the rotation of the table, ultrasonic flaw detection is performed over the entire peripheral surface of the spiral fin tube, and the fin welded portion of the spiral fin tube emitted from the ultrasonic probe and the outer periphery other than the fin welded portion A spiral fin tube, comprising: an ultrasonic flaw detection control unit for displaying the level of the sound pressure level of an ultrasonic echo reflected and received on a surface. Ultrasonic testing apparatus of the fin weld.