JPH0630604U - Defect detection device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a defect detection device capable of nondestructively detecting a defect generated around a hole or a tube having an enlarged lumen at the tip. A device that inserts into an inner hole of a nozzle base 2 attached to the header 1 to generate induced magnetism in a ligament portion of the header 1 at an insertion position, and is a support that is inserted into the inner hole of the nozzle base 2. A plurality of coil attachment bars 4 pivotally attached to the tip of the rod 3 in the shape of an umbrella, a coil 5 annularly attached to the free end of the coil attachment bar 4, and a sliding rod attached to the support rod 3. 6 and an opening / closing bar 7 which is provided at the tip of the sliding bar 6 and in the center of the coil mounting bar 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a defect detection device suitable for detecting a defect in a ligament part of a boiler head.

[0002]

[Prior art]

 Conventionally, various magnetic particle flaw detectors have been proposed as defect detection devices, but the boiler header is a sealed container, and the defects generated in the ligament part of the header where the nozzle is attached are non-destructive. There is no suitable device that can detect it.

[0003]

[Problems to be solved by the device]

 The present invention has been proposed in view of such circumstances, and it is an object of the present invention to provide a defect detection device capable of nondestructively detecting a defect generated around a hole or a tube having an enlarged lumen at the tip. To aim.

[0004]

[Means for Solving the Problems]

 To this end, the present invention is a device for inserting into a hole or tube having an enlarged lumen at the tip to generate induced magnetism around the hole or tube at the insertion position. A plurality of coil attachment bars pivotally attached to the tip in the shape of an umbrella, a coil annularly attached to the free end of the coil attachment bar, a slide rod attached to the support rod, and the same slide It is characterized in that the tip of the rod and the opening / closing rod provided at the center of the coil mounting bar are provided.

[0005]

[Action]

 The defect detecting device according to the present invention keeps the umbrella closed when it is loaded into the hole or tube, and opens it when it reaches the inside of the tip lumen after passing through the hole or tube. The coil attached to the end is energized, and the defect generated in the hole of the lumen or the peripheral part of the tube is detected by the induced magnetism generated in the coil.

[0006]

【Example】

 An embodiment in which the defect detecting device of the present invention is applied to detect a defect in a ligament portion of a boiler pipe is described with reference to the drawings. FIG. 1 is a longitudinal sectional view and FIG. 2 is a plan view of the same. In the above figure, a plurality of coil attachment bars 4 are pivotally attached to the tip of a support rod 3 to be inserted into an inner hole of a nozzle base 2 attached to a pipe header 1 in the shape of an umbrella. An electrically conductive coil 5 whose outer surface is insulation-coated is annularly attached to the free end of 4. A sliding rod 6 is slidably attached to the support rod 3, and an opening / closing rod 7 is provided between the tip of the sliding rod 6 and the central portion of the coil mounting bar 4.

In such a device, when passing through the inner hole of the nozzle 2, the sliding rod 6 is slid downward along the supporting rod 3 so that the coil mounting bar 4 is closed and the coil is closed. When the rod 5 passes through the inner hole of the nozzle base 2 and reaches the inner surface of the header 1, the sliding rod 6 is slid upward along the support rod 3, and the coil mounting bar 4 is moved through the opening / closing rod 7. Fix the umbrella in the open position. After that, a current is passed through the coil 5 for about 30 seconds from an AC power supply of 100V (not shown) to generate induced magnetism, and the device is removed in the reverse procedure. The generated induced magnetism passes through the inside of the ligament part of the pipe head 1 and gives magnetism to the iron powder that has been scattered in advance. When the fiberscope is inserted through the inner hole of the nozzle base 2 and observed, the density of the magnetism passing through the inside of the ligament part A defect is detected by. Thus, such a device facilitates magnetic flaw detection of the ligament portion of the header 1 that was difficult to implement in the past, improves the accuracy of boiler maintenance and inspection, and helps improve the reliability of the boiler. .

[0008]

[Effect of device]

 In short, according to the present invention, there is provided a support rod which is inserted into a hole or tube having an enlarged lumen at its tip to generate induced magnetism around the hole or tube at the insertion position. A plurality of coil attachment bars pivotally attached to the tip of the rod in the shape of an umbrella, a coil annularly attached to the free end of the coil attachment bar, and a slide rod attached to the support rod. By equipping the tip of the sliding rod and the opening and closing rod that is passed over the center of the coil mounting bar, nondestructive detection of defects around holes or pipes with an enlarged lumen at the tip The present invention is extremely useful industrially because it can obtain a defect detecting device.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an embodiment in which the defect detecting device of the present invention is applied to detect a defect in a ligament portion of a boiler pipe header.

FIG. 2 is a plan view of the above.

[Explanation of symbols]

 1 Pipe puller 2 Tube base 3 Support rod 4 Coil mounting bar 5 Coil 6 Sliding rod 7 Opening / closing rod

Claims (1)

[Scope of utility model registration request] 1. A device which inserts into a hole or tube having an enlarged lumen at its tip to generate induced magnetism around the hole or tube at the insertion position, at the tip of a support rod inserted into the hole or tube. A plurality of coil mounting bars pivotally attached to the skeleton of the umbrella, and a coil mounted annularly on the free end of the coil mounting bar;
A defect detecting device comprising: a slide rod attached to the support rod; and an opening / closing rod provided at a tip of the slide rod and a central portion of the coil mounting bar.