JP2579324Y2 - Magnetic particle flaw detector - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic particle flaw detector which detects a flaw existing at an end of a steel pipe by using magnetic powder, and more particularly to a magnetic particle flaw detector which can be easily incorporated into an inspection and production line.

[0002]

2. Description of the Related Art Normally, the end of a steel pipe is a part which becomes a joint with the end of another steel pipe, and is subjected to two-dimensional processing such as screw processing and welding processing, and is used for various purposes. For this reason, if there is a defect on the outer surface or the inner surface of the end, there is a concern that the secondary processing may cause damage or the like, leading to a serious accident.

Therefore, it is necessary to detect flaws on the inner and outer surfaces of the end of this kind of steel pipe. Conventionally, a magnetic particle flaw detection method for judging the presence or absence and size of a defect by, for example, visually observing a magnetic powder pattern caused by the defect by uniformly attaching the magnetic powder to the magnetized material to be inspected is practical. Has been

When using the magnetic particle flaw detection method, it is necessary to magnetize the flaw detection material, that is, the end of the steel pipe.
Conventionally, such a steel pipe end magnetizing device is used. JP 5
As described in Japanese Patent Application Laid-Open No. 9-225348, the outer surface and the inner surface of the end of the steel pipe to be inspected are magnetized by separate magnetizers.

[0005]

However, in such a method, the range that can be magnetized by the magnetizer is limited to only below the magnetized yoke. It is necessary to magnetize the entire surface of the outer surface and inner surface of the flaw-detecting steel pipe, so that the entire apparatus becomes large-scale and the equipment cost increases. In addition, there is a problem that the time until the completion of the magnetization becomes longer, and the efficiency of the defect flaw detection operation is reduced.

As described above, in the conventional magnetic particle flaw detection apparatus, the equipment is large and the time required for flaw detection for a single flaw detection tube becomes long. Inspection cannot be performed on all steel pipes that are sequentially carried in. Further, the device is too large to be incorporated into such a production line or an inspection line, and interferes with other production devices or inspection devices. Therefore, up to now, it is impossible to incorporate the magnetic particle flaw detector into an inspection line or a production line in consideration of the productivity of steel pipes.

The present invention has been made in view of such circumstances, and is provided with a moving mechanism for simultaneously controlling the movement of a plurality of magnetic powder heads each having a # -type twin coil built around a steel pipe to be inspected. Inspection of multiple steel pipes to be inspected at the same time without rotating the steel pipes can be carried out at the same time. It is an object of the present invention to provide a magnetic particle flaw detector capable of being incorporated into a production line with a margin and improving the quality of a steel pipe product.

[0008]

In order to solve the above-mentioned problems, in the magnetic particle flaw detection apparatus of the present invention, four B-shaped coils are provided outside a cylindrical coil into which a steel pipe to be flaw-detected is inserted along an axis. A plurality of magnetic powder heads, each of which has a # -type twin coil, and a plurality of magnetic powder spray nozzles in a cylindrical coil, an excitation power supply for supplying an exciting current to each coil of each magnetic powder head, and each magnetic powder head A magnetic powder head support mechanism that is movably supported in a direction perpendicular to the pipe axis of each of the steel pipes to be inspected arranged in parallel with each other, and a magnetic powder head support mechanism is mounted on the steel pipe in a direction parallel to the pipe axis of each of the steel pipes to be inspected. Based on the moving trolley, the flaw detection condition storage unit for storing the shape of the steel tube to be flawed, such as the outer diameter and wall thickness, and the magnetization time and magnetic powder dispersal time corresponding to the steel type, and the shape stored in the flaw detection condition storage unit. Magnetic powder head support The mechanism is controlled to move each cylindrical coil of each magnetic powder head to each end face of each steel pipe to be inspected, and then the carriage is controlled to move each cylindrical coil of each magnetic powder head to each end of each steel pipe to be inspected. A magnetic powder head position control unit to be inserted and a magnetic powder head control unit that controls the operation of an excitation power supply and a magnetic powder spray nozzle based on the magnetization time, the magnetic powder spray time, and the like stored in the flaw detection condition storage unit are provided.

[0009]

[Function] With the magnetic particle flaw detector configured as described above,
Since each magnetic powder head incorporates a # -type twin coil including a cylindrical coil and four B-shaped coils, the outer surface, end surface, and inner surface of the steel tube can be magnetized without rotating the steel tube to be inspected.

A plurality of magnetic powder heads are supported by a magnetic powder head supporting mechanism and a truck so as to be movable in the pipe axis direction and the vertical direction with respect to each end of each flaw-detected steel pipe. Then, under the control of the magnetic particle head position control unit, each magnetic particle head is automatically extrapolated to the optimum position at the end of each steel pipe to be inspected. The magnetic powder head control unit automatically magnetizes the steel pipe to be inspected to an optimum value using the magnetization time, the magnetic powder spraying time, and the like stored in the flaw detection condition storage unit, and adheres the magnetic powder in an optimum state.

Therefore, the size of each coil constituting each magnetic powder head can be reduced, the entire apparatus can be reduced in size, and the time required for dispersing magnetic powder to the end of each steel pipe to be inspected can be greatly reduced, thereby improving the efficiency of flaw detection work. Since it rises, it becomes possible to sufficiently incorporate this magnetic particle flaw detector into an inspection line or a production line.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a schematic configuration of a magnetic particle flaw detector according to one embodiment of the present invention, FIG. 2 is a side view of the same embodiment, and FIG. 3 is a top view of the same embodiment.

Four rails 2a, 2b, 2c, 2d are laid on a base frame 1 fixed to the floor of a building. The bogie 3 has four wheels 4 on the outer rails 2a and 2d.
a, 4b, and 4c. The carriage 3 is controlled to move in the direction of laying on the rails 2a and 2d by a driving mechanism 5 including a cylinder incorporated in the base frame 1.

On the upper surface of the carriage 3, three magnetic powder heads 7a,
A magnetic powder head support mechanism 6 that supports the movable members 7b and 7c simultaneously in the vertical direction is mounted. In the magnetic powder head support mechanism 6, the magnetic powder heads 7
a, 7b, 7c are mounted, and the threaded rods 10a. 10b penetrates through the ceiling of the frame 8 and engages with the worm gears 11a and 11b.
Worm gear 11a. 11b is rotationally controlled by the drive motor 12. Therefore, by driving the drive motor 12, each of the magnetic powder heads 7a to 7c is moved in the vertical direction.

An auxiliary trolley 13 is mounted on two central rails 2b and 2c on the base frame 1. A cylinder 14 is fixed on the auxiliary carriage 13, and a pivot arm 15 a is pivotally supported at the tip of the cylinder 14. The other end of the pivot arm 15 a is connected to another pivot arm 15 a.
b, it is pivotally supported on the side surface of the frame 8 of the magnetic powder head support mechanism 6. Therefore, when the cylinder 14 is moved, each of the turning arms 15a and 15b turns in the direction of the arrow in the drawing, and the distance between the auxiliary trolley 13 and the trolley changes. Normally, since the auxiliary trolley 13 is fixed to the base frame 1 by the locking member 16, when the cylinder 14 is driven, the trolley 3 moves the rails 2 a. 2b moves in the laying direction.

In the drawing, reference numeral 17 denotes a flexible cable for transmitting various exciting currents and control signals to the magnetic powder heads 7a to 7b and the drive motor 12 mounted on the carriage 3. Further, a mounting table 30 for mounting the three steel pipes 8 to be inspected carried in from the inspection line or the production line in the direction in which the rails 2a to 2d are laid is provided.

The magnetic powder head 7a is configured as shown in FIG. A cylindrical coil 19 is spirally wound along the tube axis direction of the steel tube 18 to be detected. Naturally, the steel pipe 18 to be detected can be inserted into and removed from the cylindrical coil 19. Four # -shaped coils 20a, 20b, 20c, 20d wound in parallel to the surface of the steel pipe 18 to be inspected are arranged in a # -shape. The four # -shaped coils 20a to 20d arranged in the # -type form one # -type twin coil 20.

As shown in FIG. 5, the cylindrical coil 19 is DC-excited by a DC power supply 23. In addition, three-phase AC power supplies 22a and 22b, which are out of phase with each other by 120 °, are connected between the respective rectangular coils 20a and 20c and 29b and 29d of the # -type twin coil 20 facing each other. Therefore, a rotating magnetic field is generated by the # -type twin coil 20 including the four B-shaped coils 20a to 20d.

Since the magnetic permeability of the steel tube 18 to which the DC magnetic field is applied by the cylindrical coil 19 is reduced and the rotating magnetic field is applied to the # type twin coil 20, the outer surface and the inner surface of the steel tube 18 to be detected are A vertical magnetic field and a horizontal magnetic field are generated, and the outer surface, the inner surface, and the end surface 18a of the steel pipe 18 to be inspected are uniformly magnetized in all directions.

Further, the cylindrical coil 19 of the magnetic powder head 7a
As shown in FIG. 2, four magnetic powder spray nozzles 24a, 24b, 24c, 24d are arranged inside with a tip inward. Further, one magnetic powder spray nozzle 24e is provided at the axis of the cylindrical coil 19. That is,
Four magnetic powder spray nozzles 24a to 24d arranged on the circumference
The liquid magnetic powder is sprayed on the outer surface of the steel tube 18 to be inspected, and the liquid magnetic powder is sprayed on the inner surface of the steel tube 18 by the central magnetic particle spray nozzle 24e. In addition, the end surface 18 of the steel pipe 18 to be inspected is
When a is located in the vicinity of the magnetic powder spray nozzles 24a to 24e, the magnetic powder is also sprayed on the end face 18a. In addition,
The other magnetic powder heads 7b and 7c have the same configuration as the magnetic powder head 7a described above.

FIG. 6 shows the driving mechanism 5 and the driving motor 12 shown in FIGS. Drive control of the cylinder 14. FIG. 3 is a block diagram illustrating a schematic configuration of a control device that operates each of the magnetic powder heads 7a to 7c.

This control device is composed of a kind of computer, and the control unit 25 receives the type information of the steel pipe currently flowing in the line from the process controller 26 which controls the inspection line or the production line.

The control unit 25 includes a flaw detection condition storage unit 27, the power supplies 22a to 23, a display unit 28a, and a keyboard 28.
b, a steel pipe transfer mechanism 29 and the like are connected. Further, in the control unit 25, a magnetic powder head position control unit 25a and a magnetic powder head control unit 25b configured by a program method are housed. Each of the magnetic powder heads 7a to 7
The excitation current and the control signal for the drive motor 12, the cylinder 14, and the control signal are transmitted via the flexible cable 17 as described above.

In the flaw detection condition storage unit 27, the shape and steel type such as the outer diameter and the wall thickness are stored for each type of each steel pipe 18 to be flawed flowing through the inspection line or the production line in which the magnetic particle flaw detection apparatus is incorporated. Each flaw detection condition such as a magnetization time and a magnetic powder spraying time determined by the shape is stored in advance. Next, the operation of the thus configured magnetic particle flaw detector will be described. At first, the locking portion 16 of the holding trolley 13 is released, and the trolley 3 and the auxiliary trolley 13 are in the standby position (maintenance position) at the left end in FIG.
I'm in.

(1) When the line actually starts operation, operation start information is input from the process computer 26.
The magnetic powder head position control unit 25a is activated, and the keyboard 2
In response to the start command from 8b, the drive mechanism 5 is driven to move the carriage 3 to a prescribed position near the mounting table 30 shown in FIG. Note that the auxiliary trolley 13 is also attached to the trolley
Since they are connected via 5a and 15b, they follow the truck 3.

(2) At the same time, the steel pipe transport mechanism 29 is activated, and the three steel pipes 18 to be inspected which flow in the line are carried into the 30 mounting units opposed to the magnetic powder head support mechanism 6. In this state, the end face 18a of each steel pipe 18 to be detected faces the magnetic powder head support mechanism 6, as shown in FIG.

(3) The locking portion 16 of the auxiliary truck 13 is fixed to the base frame 1. Then, when the type information of the steel pipe flowing through the line is input from the process computer 26 to the control unit 25, the outer diameter, the magnetization time, and the time of magnetic powder spraying corresponding to the steel pipe type are read from the flaw detection condition storage unit 27.

(4) The magnetic particle head position controller 25a is started again, and the magnetic particle heads 7a to 7a are determined based on the previously read outer diameter.
The drive of the drive motor 12 is controlled so that the center (axis) of the cylindrical coil 19c coincides with the axis of the steel pipe 18 to be detected.
Since the three steel pipes 18 to be inspected are arranged in a row on the mounting table 30, when the outer diameter is determined, the cylindrical coil 19 is formed.
The height position of the axis center is determined.

(5) Activate the cylinder 14 on the auxiliary carriage 13 to rotate each of the rotating arms 15a and 15b by a predetermined amount. When each of the rotating arms 15a and 15b rotates,
Since the auxiliary trolley 13 is fixed, only the trolley 3 moves forward by a predetermined amount toward the steel pipe 18 to be detected. At this point, the carriage 3 is free from the regulation of the drive mechanism 5 and is freely movable. As a result, the end of each steel tube 18 to be detected is inserted into each cylindrical coil 19 of each of the magnetic powder heads 7a to 7c.

(6) Next, the magnetic powder head control unit 25b is activated, and the DC power supply 23 and the three-phase AC power supplies 22a and 22b are activated.
And supplies an exciting current to each cylindrical coil 19 and each # -type twin coil 20 for the magnetization time read from the flaw detection condition storage unit 27 previously. As a result, each of the steel pipes to be inspected 18
The outer surface, inner surface, and end surface 18a of the end portion are uniformly magnetized.

(7) When the end of each of the steel pipes 18 to be inspected is uniformly magnetized, the five magnetic powder spray nozzles 24a to 24e of each of the magnetic powder heads 7a to 7c are activated to first store the flaw detection conditions. The magnetic powder is sprayed for the magnetic powder spraying time read from the unit 27. As a result, the magnetic powder uniformly adheres to the outer surface, the inner surface, and the end surface 18a of the end portion of each of the steel pipes 18 to be inspected.

(8) When the injection of the magnetic powder liquid is completed, the exciting current is cut off, the cylinder 14 of the auxiliary trolley 13 is moved in the reverse direction, and the trolley 3 on which the magnetic powder heads 7a to 7b are mounted is moved backward. Sends an end command to the steel pipe transport mechanism 29.

(9) The steel pipe transport mechanism 29 moves the steel pipe 18 to be inspected with the magnetic powder attached to the end to the next stage in the line, and moves the next three steel pipes 18 to be inspected as shown in FIG. Then, it is carried onto the mounting table 30 disposed at a position facing the magnetic powder head support mechanism 6.

(10) The observer visually observes the pattern of the magnetic powder attached to the outer surface, the inner surface, and the end surface 18a of the end portion of each of the steel pipes 18 to be moved to the next stage. Is read.

In the magnetic particle flaw detector configured as described above, the magnetic powder heads 7a to 7c for generating a rotating magnetic field at the end of the steel pipe 18 to be flaw-deposited and adhering the magnetic powder, as shown in FIG. Cylindrical coil 19 having the same axis as the axis of flaw detection steel tube 18 and four b-shaped coils 20a to 20d
Is adopted.

Therefore, it is not necessary to rotate the steel tube 18 to generate a magnetic field uniformly at the end of the steel tube 18 to be detected. Further, it is not necessary to rotate the magnetizer around the steel pipe 18 to be inspected. As described above, since there is no need to provide a rotating mechanism, each of the magnetic powder heads 7a to 7c can be configured to be small and lightweight.

Since each of the magnetic powder heads 7a to 7c can be made compact, a plurality of magnetic powder heads 7a to 7c can be incorporated in one magnetic head support mechanism 6, as shown in FIGS. Therefore, the whole magnetic particle flaw detector can be configured to be small.

The shape, such as the outer diameter and wall thickness, the magnetizing time, and the magnetic particle scattering time of each of the steel pipes 18 to be inspected carried into the magnetic particle inspection apparatus from the line by the steel pipe transport mechanism 29 are stored in advance in the inspection condition storage unit 27. Have been. Therefore, the magnetic powder heads 7a to 7c are automatically moved to the optimum position by the magnetic powder head position control unit 25a and the magnetic powder head control unit 25b, and the magnetic powder is attached to the end of each of the steel pipes 18 to be inspected under the optimum conditions. Further, as described above, each of the steel pipes to be inspected 1
There is no need to rotate 8.

Therefore, it is possible to greatly reduce the time required from carrying the steel pipe 18 to the magnetic particle flaw detector to completion of the defect observation in another stage by the inspector. As a result, even if this magnetic particle flaw detector is incorporated into a steel pipe production line or an inspection line, the productivity in each line will not be alienated.

Therefore, by incorporating the magnetic particle flaw detector into a line, flaw detection inspection can be performed on all the steel pipes flowing through the line, and the quality of steel pipes and joints finally shipped can be improved.

[0041]

As described above, according to the magnetic particle flaw detector of the present invention, a plurality of magnetic particle heads having # -type twin coils incorporated around the steel pipe to be detected are employed, and these magnetic particle heads are simultaneously moved. A moving mechanism for controlling is provided. Therefore, it is possible to detect a plurality of steel pipes at the same time without rotating the steel pipes, and it is possible to greatly increase the efficiency of a single inspection.
Inspection. It can be incorporated with sufficient time into the production line, and the quality of the final steel pipe product can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of a magnetic particle flaw detector according to an embodiment of the present invention;

FIG. 2 is a side view of the device of the embodiment,

FIG. 3 is a top view of the apparatus of the embodiment,

FIG. 4 is a perspective view showing a schematic configuration of a magnetic powder head incorporated in the apparatus of the embodiment;

FIG. 5 is an excitation circuit diagram of the magnetic powder head,

FIG. 6 is a block diagram showing an electrical configuration of the apparatus of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base frame, 2a-2d ... Rail, 3 ... Dolly,
5 drive mechanism, 6 magnetic powder head support mechanism, 7a to 7c
Magnetic powder head, 8 ... frame, 12 ... drive motor, 13
... Auxiliary carriage, 14 ... Cylinder, 15a, 15b ... Rotating arm, 18 ... Steel pipe to be inspected, 19 ... Cylinder coil, 20 ...
# Type twin coil, 20a to 20d ... b type coil, 22
a, 22b ... three-phase AC power supply, 23 ... DC power supply, 25a ...
Magnetic powder head position controller, 25b ... magnetic powder head controller, 2
6 process computer, 27 flaw detection condition storage unit, 2
9: steel pipe transport mechanism, 30: mounting table.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Michio Numaguchi 1 Greenheim 3 Hyugayama 3307, 7315 Izumi-cho, Izumi-ku, Yokohama-shi, Kanagawa Prefecture (56) References JP-A-3-223668 (JP, A JP-A-58-58460 (JP, A) JP-A-60-79156 (JP, U) JP 7-20593 (JP, Y2) JP 6-48410 (JP, Y2) (58) Field (Int.Cl. ⁶ , DB name) G01N 27/72-27/90

Claims (1)

(57) [Scope of request for utility model registration] 1. A # -type twin coil composed of four square coils is arranged outside a cylindrical coil into which a steel pipe to be inspected is inserted along an axis, and a plurality of magnetic powder spray nozzles are provided in the cylindrical coil. A plurality of magnetic powder heads, an excitation power supply for supplying an exciting current to each coil of each magnetic powder head, and a direction perpendicular to the tube axis of each of the flaw-detected steel pipes arranged in parallel with each other. A magnetic powder head support mechanism that movably supports, and this magnetic powder head support mechanism is mounted,
A bogie that moves in a direction parallel to the pipe axis of each of the steel pipes to be inspected, and flaw detection conditions for storing, for each type of the steel pipes to be inspected, a shape such as an outer diameter and a wall thickness and a magnetizing time and a magnetic powder scattering time corresponding to the steel type. A storage unit, based on the shape stored in the flaw detection condition storage unit, controls the movement of the magnetic particle head support mechanism so that each cylindrical coil of each magnetic particle head faces each end face of each of the steel pipes to be inspected, and thereafter, A magnetic particle head position control unit for controlling the movement of the carriage to extrapolate each cylindrical coil of each magnetic particle head to each end of each of the steel pipes to be inspected, and the magnetizing time and magnetic particle distribution stored in the inspection condition storage unit A magnetic particle flaw detection apparatus comprising: a magnetic powder head control unit that controls the operation of the excitation power supply and the magnetic particle spray nozzle based on time or the like.