JPH07225221A - Magnetic-particle flaw detector for steel pipe - Google Patents

Abstract

PURPOSE:To make it possible to detect the defects of the entire surface along the entire length automatically with a compact equipment by aligning a magnetizing/ magnetic-particle spraying device comprising #-shaped twin coils or the like and a rotary imaging device in series along a straightforward line for a steel pipe under inspection. CONSTITUTION:A cylindrical coil 41 is spirally wound along the pipe axis of a steel pipe under inspection 1, and the steel pipe 1 is freely inserted into and removed from the tube part. The coils is excited with a DC power supply. For twin coils 42, three- phase AC power supplies, whose phases are deviated by 120 degrees to each other, are connected between facing rectangular-shaped coils 42a and 42c and 42b and 42d, and the rotating magnetic field is generated. Then, magnetic particle liquid is sprayed from a magnetic-particle-liquid spraying nozzle 45 toward the steel pipe 1. When the steel pipe 1, to which the magnetic particles are attached, is conveyed to the position of a rotary magnetic-particle-pattern imaging device 5 provided on a frame, a rotary body 56 is rotated, and the steel pipe 1 is illuminated with an ultraviolet-ray source 57 arranged at the rotary body 56. The image of the entire surface of the steel pipe 1 along the entire length is picked up with a CCD line sensor 54. The picked-up image signal is sent into an imaging device, and the defect is automatically detected and judged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a magnetic powder flaw detection in the non-destructive inspection method of metal, and more particularly to a continuous automatic flaw detection in the magnetic powder flaw detection of the entire length and the entire surface of a steel pipe.

[0002]

2. Description of the Related Art Conventional techniques for detecting magnetic particles on the entire length and surface of a steel pipe are described in "Magnetic Particle Inspection Method for Steel Products" (published by the Iron and Steel Institute of Japan), pp. 95-97. And
The specific flaw detection device has the configuration shown in FIG. 7, and the working method is the following procedure.

1) The non-flaw detection material (steel pipe) 1 is a skid 10
It rolls on 1 and is conveyed to the magnetization stage. 2) The alignment roller 102 feeds it toward the fixed magnetizing head 103 to bring it into contact with it and stop it.

3) Move the movable magnetizing head 104 forward to bring it into contact with the tube. 4) After turning on the magnetizing current and magnetizing the steel pipe 1,
The magnetic powder liquid spraying device 105 sprays the magnetic powder liquid.

5) The steel pipe 1 is conveyed to an inspection stage which is a dark room. 6) Turn the steel pipe 1 into 1/3 to 1 with the turning roller 106.
/ 4 rotation, under the ultraviolet lamp 107, the operator visually inspects. 7) After the entire circumference inspection, the pipe is carried out by the carrying roller 108.

[0006]

Since the conventional magnetic particle flaw detector for the entire length and surface of the steel pipe is constructed as described above, 1) the equipment cost is high and the installation area is large.

A dark room capable of accommodating the length of the target material is required, and the magnetic powder receiving and collecting groove, the turning roller,
Alignment rollers, skids, transport rollers and UV lamps are required.

2) Since the axial energization method is the main method on the detection surface, it is difficult to detect flaws in the circumferential direction, and oversight occurs due to visual inspection. 3) In terms of environment, it is dark, and there is also a scattering of magnetic powder liquid, which is dirty and the operator walks, and is in a poor condition because the inspection is performed.

The present invention has been made in order to solve the above problems, and is sufficiently small in size, does not require a dark room for the length of the target material, improves the processing capacity, and can be detected. Is capable of detecting defects in all directions and makes automatic judgments.
The operator's inspection work is to provide a magnetic particle flaw detector for the entire length and surface of the unnecessary steel pipe.

[0010]

A steel pipe magnetic particle flaw detector of the present invention is a line for directly feeding a steel pipe to be inspected; a cylindrical coil wound in a spiral shape along a pipe axis of the steel pipe to be inspected, and a pipe. A # type twin coil in which four B type coils wound in parallel to the surface are arranged in a # type surrounding the steel pipe,
A plurality of magnetic powder spraying devices mounted in the coil,
A rotary image pickup device provided with an ultraviolet lamp and an image pickup device, which are provided subsequently to the image pickup device, and an image processing device for processing a signal from the image pickup device; It is what

[0011]

[Function] Since the magnetizing and magnetic powder spraying device consisting of # type twin coil and the rotary type magnetic powder pattern image pickup device are configured in tandem, the equipment size is sufficiently smaller than the conventional one, and the magnetizing and rotating by the # type twin coil. It is possible to detect defects in all directions with the image pickup device, and with the image processing device,
The operator's inspection work is unnecessary, automatic determination is possible, and the processing capacity and flaw detection accuracy can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a basic configuration diagram of an embodiment of the present invention. Figure 1
In the above, the magnetizing / magnetic powder spraying device 4 and the rotary magnetic powder pattern imaging device 5 are provided in tandem in a line for directly feeding the inspected steel pipe 1.

Reference numeral 3 denotes a feeding device such as a conveying roller, a conveyor and a caterpillar, and 2 is a pinch roll for preventing the misalignment of the pipe, which is installed before and after the flaw detection device. FIG. 2 shows the basic configuration of the control system.

Reference numeral 11 is a host computer, 12 is an interface control unit, 13 is a transfer / magnetization control unit, 14 is a control unit for a magnetic powder spraying device, 15 is a control unit for a magnetic powder pattern imaging device, and 16 is an operation panel and a keyboard. , A terminal group such as a printer.

FIG. 3 shows the structure of the magnetizing / magnetic powder dispersing device 4 used in this device. In the figure, 1 is a material to be detected. The cylindrical coil 41 is spirally wound along the pipe axis of the flaw detection target material (steel pipe) 1, and the flaw detection target material can be inserted into and removed from the cylindrical portion of the cylindrical coil 41. The # -type twin coil 42 is configured by arranging four B-type coils 42 a to 42 d wound in parallel with the surface of the steel pipe 1 so as to surround the steel pipe 1.

The cylindrical coil 41 is DC-excited by a DC power supply, and a three-phase AC power supply having a phase difference of 120 ° is connected between the opposed coil-shaped coils 42a, 42c and 42b, 42d. Therefore, a rotating magnetic field is generated by the # -type twin coil 42 including the four b-type coils 42a to 42d.

The magnetic powder liquid is sprayed from the magnetic powder liquid spray nozzle 45 toward the material to be inspected (steel pipe) 1, and the excess magnetic powder liquid is collected from the magnetic powder liquid recovery tray 46.
Then, the # -type twin coil 42 and the magnetic particle liquid recovery dish 4
6 and the like are provided on a pedestal 26, and the pedestal 26 is arranged so as to be able to move up and down on a retract-driven carriage 23 (FIG. 5).

FIG. 4 shows the structure of the rotary magnetic powder pattern image pickup device 5 used in the present device. In the figure, reference numeral 56 denotes a rotating body provided on the box body 51 provided on the frame 26 so as to be rotationally driven by the drive motor 57, for example, via the V-belt. The ultraviolet light source 52 and the light projecting side filter 53 can be adjusted in height position, and the CCD line sensor as the image pickup device 54 and the light receiving side filter 55 are attached to the rotating body 56.

A signal from the image pickup device 5 is sent to a computer as an image processing device, and a defect is automatically judged.
In this case, in consideration of the processing capacity and the detection capacity, the imaging device 54 may be four units at 90 ° intervals or two units at 180 ° intervals.

As shown in FIGS. 5 and 6, the trolley 23 has wheels 2 that are driven by a traveling motor 24 on the rail 21.
The pedestal 26 is provided so as to reciprocate (retract) via the carriage 2, and a pedestal 26 is provided on the carriage 23 so as to be movable up and down by a lifting motor 27, for example, via a worm mechanism.

The rotary magnetic powder pattern image pickup device 5 is installed on the frame 26. In addition, this mount 26 is
Magnetization / Magnetic powder spreading device 4 and Rotating magnetic powder pattern imaging device 5
It is conceivable that they are separately configured for use or shared.

For signal transmission / reception in the image pickup device, any of a slipping brush, a condenser coupling, and an electromagnetic coupling can be applied. Further, the transmission / reception of signals from each control unit, the connection of a power source to each motor and the like are performed via a signal relay box 17 and a cable bear 18. In this way, automatic flaw detection can be performed by sending and receiving signals from each control unit, and automatic defect determination can be performed by image analysis of signals from the image pickup apparatus.

[0023]

As described above, according to the present invention,
The magnetizing / magnetic powder spraying device and the rotary magnetic powder pattern imaging device are configured in tandem, so the equipment size is sufficiently smaller than before, and the detection of defects in all directions by the # type twin coil magnetization and the rotary imaging device. In addition, the image processing apparatus makes it possible to perform automatic determination without the need for operator's inspection work, and improve the processing capacity and flaw detection accuracy.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a block diagram of control relationships.

FIG. 3 is a perspective view around a magnetized portion.

FIG. 4 is an explanatory diagram of a rotary imaging device.

FIG. 5 is a front view of the periphery of a rotary type imaging device.

FIG. 6 is a side view of the same.

FIG. 7 is an explanatory view of a conventional magnetic particle flaw detector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Steel pipe to be inspected, 4 ... Magnetizing / magnetic powder spraying device, 5 ... Rotational imaging device, 41 ... Cylindrical coil, 42 ... # type twin coil, 45 ... Magnetic powder spraying device, 52 ... Ultraviolet lamp, 54 ... Imaging device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuo Numaguchi 1-2-13 Higashishimbashi, Minato-ku, Tokyo Sakae Evolution Gaku Co., Ltd.

Claims (1)

[Claims] 1. A line for directly feeding an inspected steel pipe;
A cylindrical coil wound in a spiral shape along the pipe axis of the steel pipe to be inspected, and four ro-shaped coils wound in parallel with the pipe surface in a # type surrounding the steel pipe in a # type. A twin coil, a plurality of magnetic particle liquid spraying devices mounted in the coil, a rotary image pickup device provided with an ultraviolet lamp and an image pickup device provided subsequently to the twin coil, and a signal from the image pickup device An image processing device; and a steel tube magnetic powder flaw detection device characterized by being capable of continuous automatic flaw detection.