JPS6113968Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an ultrasonic flaw detection device for tubular bodies, and particularly to a probe rotation type ultrasonic flaw detection device.

When testing tubular bodies such as small diameter steel pipes,
BACKGROUND ART A rotary ultrasonic flaw detection device is commonly used, which detects flaws by rotating a probe around a tube to be inspected and scanning the surface of the tube in a spiral manner while moving the tube to be inspected in a straight line. In one example, as shown in FIG. 1, a tube to be inspected 1 is provided with a fixed tube 2 through which it passes in the direction of arrow D, and a tubular rotating body 4 is rotatably attached to the outer periphery of the fixed tube 2 via a bearing 3. The pulley 5 is fitted and installed at an appropriate position (in the drawing, on the inlet side of the pipe to be inspected).
It is rotated by an external driving source via the . The rotating body 4 is equipped with one or more probes 6 facing toward the tube 1 in the circumferential direction on the outlet side of the tube to be inspected, and an ultrasonic transmission medium is provided in front of the probe 6. The probe holder is equipped with a water supply channel 7 for supplying water. The water supply channel 7 is connected to an external water supply pipe 9 via the rotating body 4, the seal 8, and the fixed pipe 2. In such a conventional structure, a probe holder is provided at the end of the rotating body 4, and a mechanism for supplying water to the probe from the outside and an electrical connection circuit between the probe and the outside are provided on the rotating body 4. Since the rotation speed of the rotating body 4 is usually around 1500 rotations/minute, this will not cause problems, but if the rotation speed is much higher than this normal rotation speed, for example around 3000 rotations/minute, a problem will occur. When the rotation speed increases, the vibration becomes large due to high-speed rotation because one end of the probe holder is open, and the effect of this vibration of the probe holder on flaw detection accuracy can be ignored. It disappears. In addition, in such a water supply system, it is necessary to apply high water pressure in order to ensure the stability of water supply directly below the probe during high-speed rotation, but this reduces the sealing function of the seal 8 and reduces the water supply. If this becomes insufficient, a problem arises in that water gets mixed into the bearing 3 or the lubricating oil of the bearing 3 gets mixed into the water. Some bearings use hydrodynamic bearings, but the sealing function of water supplied to the probe deteriorates during high-speed rotation, making it difficult to stably supply water directly below the probe. Another method is to install a relatively large water chamber directly below the probe and supply a large amount of water through the fixed part.
If a large amount of water is used, water will enter from the end of the pipe to be inspected, causing a false defect signal and making flaw detection impossible. For this reason, it is necessary to attach tube end caps to prevent water from entering the tubes, but attaching and detaching the caps to each tube to be inspected is a heavy workload. Furthermore, in the conventional structure, there is no mechanism to support and guide the tube to be inspected just before and after the probe holder, so the probe is attached to the upper and lower sides of the tube to be inspected due to deflection due to the tube's own weight. The distance between the test tube and the outer surface of the tube to be inspected changes, and in extreme cases, the lower side of the tube to be inspected comes into contact with the inner surface of the probe holder, causing problems in terms of accuracy and work.

In view of the above-mentioned points, the present invention is designed to maintain excellent flaw detection accuracy even during high-speed rotation. The structure includes a fixed cylindrical body with an introduction guide for the pipe to be inspected at the inlet end, and a rotary cylinder rotatably provided around the fixed cylindrical body. In a probe rotating type ultrasonic flaw detection device for a tubular body, which has a support mechanism that supports the rotating cylindrical body at at least two points in the longitudinal direction via bearings, the inner diameter is slightly larger than the outer diameter of the tube to be inspected. A probe holder having a rotary cylindrical body is removably connected to the outlet end of the rotary cylindrical body to rotate the outer periphery of the tube to be inspected, while a plurality of probes are arranged in the circumferential direction of the probe holder. An inlet and a supply channel for supplying a couplant to the front surface of each probe are provided inside the holder, and an outlet end of the fixed cylindrical body and an outlet side of the probe holder are covered with The present invention is characterized in that guide rollers are provided to support and guide the inspection tubes.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. The fixed cylindrical body 11 has a cylindrical shape so that the tube to be inspected passes through it, and has an introduction guide tool 1 at its inlet end for guiding the tube to be inspected.
2, whose inlet end is supported by a base body 13. A rotary cylindrical body 14 is rotatably fitted from the inlet side end to the outlet side end of the fixed cylindrical body 11 supported by the base body 13, and the rotary cylindrical body 14 maintains stability even during high-speed rotation. Bearing 1 located on the inlet side and outlet side to avoid loss
It is supported at at least two points in the longitudinal direction by a support mechanism comprising 5 and 16. The rotating cylindrical body 1
4 is a part that transmits rotational force to the probe holder 17 and connects the probe 18 with an external electric circuit; the probe 18 is connected between the bearing 15 and the bearing 16;
A slip ring 19 is provided which connects with the slip ring 19 and is contacted by an externally supported connecting brush 20. On the other hand, a pulley 21 connected to an external drive source is provided at the inlet side end of the rotating cylindrical body 14.
is fitted.

Next, a tubular probe holder 17 that rotates around the outer periphery of the tube to be inspected is detachably connected to the outlet side end of the rotating cylindrical body 14. The probe holder 17 is
It has an inner diameter slightly larger than the outer diameter of the tube to be inspected so as to form a thin film of water between it and the outer circumferential surface of the tube to be inspected passing through it. The probe holder 17 is connected to the rotating cylindrical body 14, while its outlet end is supported by a support mechanism equipped with a bearing 22, and the probe holder 17 is connected to the rotating cylindrical body 14 and integrally supports the outer periphery of the tube to be inspected. 3000
It rotates at a high speed of about 100 times per minute. Note that if the swing of the exit side end of the probe holder is not substantially large, the bearing at the end may be omitted. The tube to be inspected passes through the fixed cylindrical body 11 and moves inside the probe holder 17 toward the exit in the direction of arrow D. At this point, in order to prevent the tube to be inspected from bending, the probe holder 17 is closed. Guide rollers 2 that support and guide the pipe to be inspected on the entry and exit sides
3 and 32 are provided. Entry side guide roller 23
Since the probe holder 17 itself rotates, the second
As shown in the figure, a roller support 24 is fitted and supported at the outlet end of the fixed cylindrical body 11, and a guide roller 23 is provided so as to be in rolling contact with the outer periphery of the tube to be inspected. The guide roller 32 on the exit side is attached to a fixed base 28 that supports the bearing 22 and a water supply pipe 30, which will be described later.
Install as shown. The tube to be inspected passing through the probe holder 17 is supported by guide rollers 23 and 32, and since the interval between these two sets of guide rollers is small, the tube to be inspected will not bend between them. A plurality of probes 18 are arranged radially in the circumferential direction of the probe holder 17.
8 forms a slight gap between the tip and the outer peripheral surface of the tube to be inspected. A water supply channel 25 for forming a thin film of water in this gap is provided inside the probe holder 17. The inlet 26 of the water supply channel 25 is an annular groove on the outer peripheral surface of the probe holder 17 to receive water during rotation. This inlet 2
6 is provided on the exit side of the probe 18, while its water supply channel 25 extends toward the tip of the probe 18 and includes a plurality of water injection ports that inject water into the outer peripheral surface of the pipe to be inspected near the probe 18. Equipped with 27. In this case, if the feeding speed of the tube to be inspected becomes very high, the amount of water that adheres to the moving tube to be inspected and flows out will increase with the conventional water supply pressure, making it difficult to form a thin film of water, so the probe 1
It is preferable to provide a preliminary water injection port 29 on the upstream side of the probe 8 to inject water into the tube to be inspected in advance to facilitate the formation of a thin film of water at the position of the probe 18. Further, a seal 31 is provided at the connection portion between the inlet 26 and the water supply pipe 30 to seal the water supply flow. Bearing 22
Even if the seal 31 becomes defective, the lubricating oil will be discharged from the discharge port 3 due to the centrifugal force of the rotating probe holder 17.
Since it is discharged to the outside from 3, it does not mix into the water supply channel 25. In this way, in the device devised in the present application, since water, which is a couplant, is supplied in the vicinity of the probe, a stable thin film of water can be formed even during high-speed rotation. Since a mechanism is provided to support and guide the tube to be inspected, it is possible to prevent the tube to be inspected from bending, and the reliability of the flaw detection accuracy is high.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of a conventional rotating probe type ultrasonic flaw detection device, Fig. 2 is a cross-sectional view showing an embodiment of the ultrasonic flaw detection device of the present invention, and Fig. - is a sectional view taken along the line. In the drawing, 11 is a fixed cylindrical body, 12 is an introduction guide, 14 is a rotating cylindrical body, 15 and 16 are bearings, and 17
is a probe holder, 18 is a probe, 25 is a water supply channel,
A is a support mechanism for the rotating cylindrical body, and B is a support mechanism for the probe holder.

Claims (1)

[Scope of utility model registration request] A fixed cylindrical body provided with an introduction guide for the tube to be inspected at the inlet side end, a rotating cylindrical body rotatably provided on the outer periphery of the fixed cylindrical body, and a longitudinal direction of the rotating cylindrical body via a bearing. In a rotary probe type ultrasonic flaw detection device for a tubular body, which has a support mechanism that supports the tube at at least two points, a probe holder having an inner diameter slightly larger than the outer diameter of the tube to be inspected is attached to the outlet of the rotating cylindrical body. It is detachably connected to the side end to rotate the outer periphery of the tube to be inspected, while a plurality of probes are provided in the circumferential direction of the probe holder, and a couplant is supplied to the front surface of each probe. An injection port and a supply path are provided inside the holder, and guide rollers are provided at the outlet side end of the fixed cylindrical body and the outlet side of the probe holder, respectively, to support and guide the tube to be inspected. Features: Rotating probe type ultrasonic flaw detection equipment.