JPH05107004A - Sensor holding device - Google Patents

Abstract

PURPOSE:To obtain a sensor holding device which can enhance reliability in flaw detection by improving the high-speed stability of the holding device, and shortening the part of a tire-type sensor, which cannot be used for measurement. CONSTITUTION:One end of U-shaped plate spring 6 is attached to a main body 5a. A tire-type sensor 8, which is relatively moved on bodies to be detected A and B and detects the thicknesses of the plates, is mounted on the other end of the plate spring 6. An inextensible flexible tube, which is filled with polyurethane foarm 20 or water wherein bubbles are continued, is provided at the inside of the plate spring 6. When the tire-type sensor rides over a projection 13, the amplitude of the oscillation of the plate spring is suppressed, and the part of the sensor, which cannot be used for measurement, is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor holding device for inspecting, for example, pipe wall thickness and cracks.

[0002]

2. Description of the Related Art Conventionally, there has been known a pipeline inspection apparatus for automatically inspecting the wall thickness and cracks while traveling in the pipe. In such a structure, the sensor for detecting the wall thickness and the crack of the pipe is attached to the main body of the inspection device via a holding device composed of a U-shaped leaf spring. FIG. 11 shows an example thereof.
In the figure, 1 is a pipeline inspection device in which a plurality of pigs are connected via coil springs 2, 3 is a controller pig equipped with a storage device and a control device, and arranged at the tip side of the inspection device 1, 4 is a controller pig A transmitter pig, which is mounted with a transmitter and is connected to a controller pig 3 via a coil spring 2, includes a plurality of tire-type ultrasonic waves through a holding device 7 formed of a U-shaped leaf spring 6 around a main body 5a. Sensor 8
Is attached to the transmitter pig 4 via the coil spring 2, and a similar sensor 8 is attached around the main body 9a and is attached to the first sensor pig 5 via the coil spring 2. Second sensor pigs connected, 10
Is a third sensor pig in which a similar sensor 8 is attached around the main body 10a and is connected to a second sensor pig 9 via a coil spring 2, and the sensors 8 attached to these sensor pigs are surrounded by each other. It is set by shifting the direction position. In addition, 11 is a major link roller provided at the rear end of the inspection device 1, and 12 is a piggulator, which detect the position of the inspection device 1 in the pipe.

In such an apparatus, the inspection device 1 is
The leaf spring 6 of the holding device 7 is inserted into a pipe to be inspected and is driven by a not-shown traction means (for example, one utilizing a fluid pressure difference between the front and rear of the inspection device 1) to travel therein.
The wall thickness inspection and crack inspection of the pipe are performed by each sensor 8 pressed against the inner surface of the pipe.

[0004]

By the way, as shown in FIG. 12, on the inner peripheral surface of the pipeline to be inspected, there are projections such as the back bead 13 at the welded joint between the pipes A and B. .. Therefore, when the sensor pig is traveling at a high speed or when the sensor 8 passes over the back bead 13, the leaf spring 6 of the holding device 7 is vibrated with a large amplitude, and the back bead 1
There was a problem that the original function of the sensor could not be fulfilled within a certain range around 3.

This will be described in more detail based on the experimental data shown in FIGS. 14 and 15. FIG. 14 shows a part of a test material C having a plate thickness of 14.3 mm having a protrusion 14 having a height of 3 mm and a plurality of slits 15 having different depths, which corresponds to a back bead. It is 2000 mm. Figure 15
Is a sensor 8 supported by a holding device 7 on the test material C.
Shows the plate thickness measurement result and the vibration measurement result when traveling over the protrusion 14 to the right in the figure at a speed of 5 m / s. The plate thickness is measured by the sensor 8 and the vibration is held as shown in FIG. The measurement was performed with a laser displacement meter 16 attached to the device 7.

That is, as shown in FIG.
Although the vibration with a large amplitude generated when the vehicle has passed over is gradually attenuated, it continues even at a point of 2,000 mm after the vehicle has passed over, and a large unmeasurable portion 17 of the sensor 8 is generated near the protrusion 14.

Such vibrations, as shown in FIG.
Attach the dynamic vibration reducer 18 to the tip of the leaf spring 6 of the holding device 7,
It can be reduced by adjusting the set position of the weight 19 of the dynamic vibration reducer 18 according to the natural frequency of the leaf spring 6, but this adjustment is not only troublesome, but also results of experiments show that
Even in such a case, as shown in FIG. 16, it has been found that the unmeasurable portion 17 of the sensor 8 is not sufficiently reduced. In view of the above points, the present invention improves the high-speed stability of the holding device. It is an object of the present invention to obtain a sensor holding device which can improve the reliability of flaw detection by improving the sensor measurement by reducing the unmeasurable portion.

[0008]

A sensor holding device according to a first aspect of the present invention is one in which a U-shaped leaf spring supporting a tire type sensor is filled with polyurethane foam having continuous air bubbles inside. Further, the sensor holding device according to the second aspect of the present invention is provided with a non-stretchable flexible tube filled with water inside a U-shaped leaf spring that supports the tire type sensor.

[0009]

In the present invention, the polyurethane foam having continuous air bubbles or the flexible tube filled with water acts as a damper to suppress the vibration amplitude of the U-shaped leaf spring when the tire type sensor gets over the protrusion. , Reduce the unmeasurable part of the sensor.

[0010]

The present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a side view showing the structure of a sensor holding device according to an embodiment of the first invention of the present invention, and FIG. 2 is a front view of the same as seen from the left side of the drawing. Are given the same reference numerals. In this embodiment, one of the sensor holding devices on the first sensor pig 5 side will be described as an example, but the other sensor holding devices are similar.

In the figure, reference numeral 20 denotes a polyurethane foam filled in the curved portion 6a of the U-shaped leaf spring 6 of the holding device 7 and having continuous bubbles with a specific gravity of 0.3 or less. Is. This polyurethane foam 2
0 acts as a damper with respect to the leaf spring 6, suppresses large-amplitude vibration generated in the leaf spring 6 when the tire type sensor 8 passes over the back bead 13, and reduces the unmeasurable portion 17 of the sensor 8. ..

FIG. 7 shows plate thickness measurement results and vibration measurement results when the laser displacement meter 16 shown in FIG. 12 is attached to the apparatus of this embodiment and the test material C of FIG. 14 is flaw-detected. As is apparent from the figure, the vibration with a large amplitude generated when getting over the projection 14 is more attenuated than that of FIG. 12 in which the conventional dynamic vibration absorber is not attached, and the unmeasurable portion 17 is The size is smaller than that of the vibration absorber 18 shown in FIG. 13, and the reliability of flaw detection is improved.

FIG. 3 is a side view showing the configuration of a sensor holding device according to another embodiment of the first aspect of the present invention. In this embodiment, the same polyurethane foam 20 as shown in FIG. 1 is used, and the curved portion 6a of the U-shaped leaf spring 6 of the holding device 7 is used.
To the tip of the leaf spring so that part of the polyurethane foam 20 can be interposed between the pig body 5a and the leaf spring 6.

In this embodiment, as shown in FIG. 8, the vibration damping effect is shown in FIG.
The effect equivalent to that of No. 3 is obtained, and the unmeasurable portion 17
Is smaller than that of FIG.

FIG. 4 is a side view showing the structure of a sensor holding device according to still another embodiment of the first aspect of the present invention. In this embodiment, the above-mentioned polyurethane foam 20 is used.
Is filled in the entire U-shaped leaf spring inside from the curved portion 6a of the U-shaped leaf spring 6 of the holding device 7 to the mounting portion of the tire type sensor 8 beyond the tip of the leaf spring. The portion can be interposed not only between the pig body 5a and the leaf spring 6 but also between the pig body 5a and the tire type sensor 8 mounting portion.

In this embodiment, as shown in FIG. 9, both the vibration damping effect and the reduction effect of the unmeasurable portion 17 are improved as compared with the conventional dynamic vibration absorber 18 of FIG. ..

FIG. 5 is a side view showing the structure of a sensor holding device according to one embodiment of the second invention of the present invention, and FIG. 6 is a front view of the same as seen from the left side of the drawing. In this embodiment, a non-stretchable flexible tube 30 filled with water is provided inside the U-shaped leaf spring 6 supporting the tire type sensor 8 in place of the above-mentioned polyurethane foam 20. It is a thing.
In this embodiment, the flexible tube 30 includes a pig body 5a.
Each sensor 8 was fitted to each sensor 8 part to be a pillow of each sensor 8 and constituted by a single annular flexible tube.

In this embodiment, as shown in FIG. 10, both the vibration damping effect and the reduction effect of the unmeasurable portion 17 are improved as compared with the conventional dynamic vibration absorber 18 of FIG. It was confirmed that the plurality of slits 15 of the inspection material C were reliably detected.

In the second invention of FIGS. 5 and 6,
As a result of an experiment in which the flexible tube is divided and installed for each sensor 8, the same effect as that of the single annular flexible tube was obtained.

[0021]

As described above, according to the present invention, a U-shaped leaf spring when a tire type sensor gets over a projection is formed from a polyurethane foam having continuous cells or a flexible tube filled with water. Since the amplitude of the vibration is suppressed, the unmeasurable portion of the sensor is reduced, and the reliability of flaw detection is improved.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of an embodiment of a first invention of the present invention.

FIG. 2 is a front view showing the configuration of an embodiment of the first invention of the present invention.

FIG. 3 is a side view showing the configuration of another embodiment of the first aspect of the present invention.

FIG. 4 is a side view showing the configuration of still another embodiment of the first aspect of the present invention.

FIG. 5 is a side view showing the configuration of an embodiment of the second invention of the present invention.

FIG. 6 is a front view showing the configuration of an embodiment of the second invention of the present invention.

FIG. 7 is an explanatory diagram of a plate thickness measurement result and a vibration measurement result according to those in FIG. 1.

FIG. 8 is an explanatory diagram of a plate thickness measurement result and a vibration measurement result according to those in FIG. 3;

9 is an explanatory diagram of a plate thickness measurement result and a vibration measurement result according to those in FIG.

10 is an explanatory diagram of a plate thickness measurement result and a vibration measurement result according to those in FIG.

FIG. 11 is a configuration diagram of an example of a pipeline inspection device.

FIG. 12 is a side view showing a configuration of an example of a conventional sensor holding device.

FIG. 13 is a side view showing the configuration of another example of the conventional sensor holding device.

FIG. 14 is an explanatory diagram of a test material.

FIG. 15 is an explanatory diagram of a plate thickness measurement result and a vibration measurement result according to those in FIG. 12;

16 is an explanatory diagram of a plate thickness measurement result and a vibration measurement result according to those in FIG.

[Explanation of symbols]

 5a, 9a, 10a Main body 6 U-shaped leaf spring 7 Sensor holding device 8 Tire type sensor 20 Polyurethane foam 30 Flexible tube A, B pipe (object to be detected)

 ─────────────────────────────────────────────────── ─── Continued front page (72) Akira Hagiwara Akira Marunouchi 1-2-2, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Masaru Morimoto 1-2-1 Marunouchi, Chiyoda-ku, Tokyo Date Inside the steel pipe company

Claims (2)

[Claims] 1. A sensor holder having a U-shaped leaf spring attached to a main body, and a tire type sensor attached to the other end of the leaf spring to detect the thickness of the U-shaped leaf spring by moving it relative to the object to be detected. In the device, a sensor holding device characterized in that the leaf spring is filled with polyurethane foam having continuous air bubbles. 2. A sensor holder comprising one end of a U-shaped leaf spring attached to a main body and a tire type sensor attached to the other end of the leaf spring to detect a plate thickness by relatively moving on an object to be detected. In the device, a non-stretchable flexible tube filled with water is provided inside the leaf spring.