JP2006329727A - Magnetic powder flaw detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the washing-off of the magnetic powder bonded to the surface of a steel piece released from a magnetized state in a magnetic powder flaw detector. <P>SOLUTION: The magnetic powder flaw detector is constituted so as not only to magnetize the steel piece 10 but also to sprinkle a magnetic powder liquid from the sprinkling nozzle 34 arranged above the steel piece 10. The sprinkling nozzle 34 is fronted to the steel piece 10 in sprinkling the magnetic powder liquid and the magnetic powder liquid sprinkled from the sprinkling nozzle 34 is arranged at the position where the magnetic powder liquid is struck against the steel piece 10. The sprinkling nozzle 34 is detached from the upper region R of the steel piece 10 when the sprinkling of the magnetic powder liquid is completed to be moved to a position, where the magnetic powder liquid dripped from the sprinkling nozzle 34 is turned aside from the sprinkling nozzle 34, by a moving mechanism 42. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a magnetic particle flaw detector for inspecting the presence or absence of surface defects by spraying a magnetic powder liquid on a material to be inspected in a magnetized state, and using magnetic particles attached to the surface of the material to be inspected.

  2. Description of the Related Art Conventionally, a magnetic particle flaw detection method is known as one of methods for inspecting defects such as scratches generated on a surface of a material to be inspected such as a steel piece. This magnetic particle flaw detection method uses a magnetic particle flaw detection apparatus to magnetize a steel piece by energizing between a pair of electrodes sandwiching the steel piece, and to inject a test liquid (magnetic powder liquid) containing fluorescent magnetic powder from the spraying means. The presence or absence of a defect is detected by the magnetic powder pattern generated on the surface by spraying on the surface and attaching the magnetic powder.

  As shown in FIG. 3, the spraying means 12 includes a spray nozzle 14 disposed above the steel piece 10, and a tank 16 that stores a required amount of the magnetic powder liquid and supplies the magnetic powder liquid to the spray nozzle 14. The magnetic powder liquid is sprayed by opening and closing the on-off valve 18 disposed in the tank 16. The on-off valve 18 opens or closes a hole 16a communicating with the spray nozzle 14 provided at the bottom of the tank 16 with a spherical valve body 18a, thereby spraying the magnetic powder liquid on the steel piece 10 or stopping the spraying. Do.

  Moreover, the structure which interrupts | blocks magnetic powder liquid with the shutter arrange | positioned under the spraying nozzle like the magnetic particle flaw detector disclosed by patent document 1 is proposed. The shutter is connected to a parallel link that moves forward and backward by a cylinder and is configured to move horizontally. By moving backward from below the spray nozzle, the shutter is allowed to spray the magnetic powder liquid on the steel slab and is positioned below the spray nozzle. It is the structure which interrupts | blocks a magnetic powder liquid by doing.

Further, as shown in FIG. 4, the shielding plate 60 disposed below the spray nozzle 14 is horizontally supported in a cantilevered state by the support rod 62, and the shielding plate 60 is rotated with the rotation of the support rod 62. Some are configured to do so. That is, the shielding plate 60 is rotated to a position deviated from the upper region of the steel piece 10 to allow the magnetic powder liquid to be applied from the spray nozzle 14 to the steel piece 10, and below the spray nozzle 14 by the support rod 62. It is the structure which receives the magnetic powder liquid spread | dispersed from the spreading | diffusion nozzle 14, and guides to the area | region which does not cover the steel piece 10 by rotating to the position which faces (refer the solid line arrow of FIG. 4).
JP-A-6-18483

  As described above, there are various means for blocking the spraying of the magnetic powder liquid on the steel piece, but these means have the following drawbacks. (1) In the on-off valve 18, dust and scale accumulate in the vicinity of the hole 16 a, and if dust or the like is caught when the hole 16 a is closed by the valve body 18 a, the hole 16 a cannot be sealed, and the spray nozzle 14 There is a possibility that the supply of the magnetic powder liquid cannot be completely stopped. (2) In the shutter disclosed in Patent Document 1, dust and scale may accumulate on the shutter because the shutter receives the magnetic powder, and the shutter may not be able to open and close due to the bite of dust. In addition, if the shutter is broken and slanted, the magnetic powder liquid cannot be guided to an area that does not cover the steel piece, and the magnetic powder liquid may be applied to the steel piece. (3) Since the shielding plate 60 is cantilevered by the support rod 62, it is easily damaged at the connecting portion with the support rod 62, and when the shielding plate 60 is inclined, the magnetic powder liquid is not applied to the steel piece 10. It cannot be guided and the magnetic powder liquid may be applied to the steel piece 10 (see the two-dot chain line in FIG. 4).

  Thus, in any configuration, there is a possibility that the magnetic powder liquid may be applied to the steel piece without completely blocking the magnetic powder liquid, although it is desired to stop the spraying of the magnetic powder liquid. That is, when the magnetic powder liquid drips on the steel piece whose magnetization state has been released, the magnetic powder attached to the steel piece in the magnetized state flows down, resulting in a disadvantage that surface defects cannot be found in the inspection process. Thus, when the so-called trailing of the magnetic powder liquid occurs from the magnetic powder liquid blocking means such as the spray nozzle or the shutter or the shielding plate, the inspection accuracy in the defect inspection process is reduced, or the trouble of re-starting the magnetic powder liquid spraying process is repeated. There is a difficulty that occurs.

  That is, the present invention has been proposed in order to suitably solve these problems inherent in the conventional magnetic particle flaw detector according to the prior art. An object of the present invention is to provide a magnetic particle flaw detector capable of preventing the magnetic powder liquid from dripping on the released material to be inspected and preventing washing of the magnetic powder adhering to the surface of the material to be inspected.

In order to overcome the above-mentioned problems and achieve the intended purpose, a magnetic particle flaw detector of the invention according to claim 1 of the present application,
In the magnetic particle flaw detector that magnetizes the material to be inspected and distributes the magnetic powder liquid from the spray nozzle disposed above the material to be inspected,
The spray nozzle faces the material to be inspected, the position where the magnetic powder liquid sprayed from the spray nozzle hits the material to be inspected, and the magnetic powder liquid dropped from the spray nozzle from the upper region of the material to be inspected is inspected. It is characterized in that it can be moved by a moving mechanism between positions deviating from the material.
According to the first aspect of the invention, the spray nozzle is configured to be movable between the position facing the material to be inspected and the position deviating from the upper region of the material to be inspected. Is moved away from the upper region of the material to be inspected, so that the magnetic powder that hangs down from the spray nozzle will not come into contact with the material to be inspected. It can be avoided.

According to a second aspect of the present invention, in the magnetic particle flaw detector according to the first aspect, the spray nozzle is attached to the main body of the apparatus so that the discharge end thereof is tilted in a direction intersecting the longitudinal direction of the material to be inspected by the moving mechanism. It is supported so that it can tilt.
According to the second aspect of the present invention, the discharge end is moved between the position facing the material to be inspected and the position deviating from the upper region of the material to be inspected simply by tilting the spray nozzle by the moving mechanism. be able to.

According to a third aspect of the present invention, in the magnetic particle flaw detector according to the first or second aspect, the spray nozzle is moved to the side opposite to the transfer direction to the post-process of the material to be inspected.
According to the third aspect of the present invention, since the material to be inspected does not pass below the spray nozzle when the material to be inspected is transferred, it is possible to avoid damaging the adhesion state of the magnetic powder adhering to the material to be inspected even during the transfer. Can do.

According to a fourth aspect of the present invention, in the magnetic particle flaw detector according to any one of the first to third aspects, the spray nozzle is moved to a position deviating from the hit position every time the spraying of the magnetic powder liquid is completed.
According to the fourth aspect of the invention, the spray nozzle is deviated from the position where the magnetic powder liquid hits the material to be inspected every time the spray of the magnetic powder liquid is completed, regardless of whether or not the magnetic powder liquid leaks from the spray nozzle. Therefore, it is possible to reliably avoid damaging the adhesion state of the magnetic powder adhered to the material to be inspected by the magnetic powder liquid.

  According to the magnetic particle flaw detector according to the present invention, even if a magnetic powder liquid stoppage failure occurs, the magnetic powder liquid hanging from the spray nozzle is not applied to the inspected material released from the magnetized state, and the surface of the inspected material is not affected. It is possible to prevent washing of the adhering magnetic powder.

  Next, the magnetic particle flaw detector according to the present invention will be described below with reference to the accompanying drawings by giving a preferred embodiment. In the embodiment, a case where a long bar-shaped steel piece obtained through a rolling process is inspected as an inspection material will be described as an example.

  As shown in FIG. 1 and FIG. 2, the magnetic particle inspection device 20 includes a spraying means 30 having a plurality of spraying nozzles 34 for uniformly spraying the magnetic powder liquid on the steel piece 10, and a position below the spraying nozzle 34 (spreading position). And a magnetizing means 50 having a pair of electrode portions 52 and 52 (only one is shown) for energizing and magnetizing the steel piece 10.

  The mounting table 26 receives the steel slab 10 from the carry-in conveyor 22 connected to the upstream side, transfers the steel slab 10 to a spraying position below the plurality of spraying nozzles 34 arranged in a line, and steel after the magnetic powder is sprayed. It is comprised so that the piece 10 may be delivered to the carry-out conveyor 24 connected downstream. The mounting table 26 includes a groove portion 26a that is open in a V-shape. The groove portion 26a is fitted with a ridge angle extending along the longitudinal direction of the steel piece 10, and transferred to the groove portion 26a. Are arranged so that the alignment direction and the longitudinal direction of the steel slab 10 are aligned.

  The magnetizing means 50 includes a pair of electrode portions 52 and 52 disposed corresponding to each end face in the longitudinal direction of the steel piece 10 that has arrived at the spreading position, and a power supply device (not shown) that feeds power to both electrode portions 52 and 52. Consists of Each electrode portion 52 is configured to be movable back and forth with respect to the corresponding end face of the steel piece, and in a state where the steel piece 10 is sandwiched between the pair of electrode portions 52 and 52, current is passed between these electrode portions 52 and 52. By doing so, the steel piece 10 is magnetized. The pair of electrode portions 52 and 52 are energized until the supply of the magnetic powder liquid to the spray nozzle 34 is stopped by an on-off valve 38 of the spraying means 30 described later, and after the spraying of the magnetic powder liquid is stopped, the steel piece Ten magnetization states are released.

  The spraying means 30 is provided in a storage tank 32 for storing a required amount of magnetic powder liquid, a spray nozzle 34 for spraying the magnetic powder liquid supplied from the storage tank 32 to the surface of the steel piece 10, and a storage tank 32. The on-off valve 38 for stopping the supply of the magnetic powder and the moving mechanism 42 for moving the spray nozzle 34 are configured. At the bottom of the storage tank 32, a hole 32a that is connected in communication with the other end of the hose 33 that has one end connected to the spray nozzle 34 is opened, and the hole 32a is opened and closed by the valve body 38a of the on-off valve 38. Then, the supply or stop of the magnetic powder liquid to the spray nozzle 34 is performed. In other words, the opening / closing valve 38 is spread through the hose 33 by opening the hole 32a by pulling upward through the connecting member 40a by the opening / closing mechanism 40 having the valve body 38a disposed outside the storage tank 32. The magnetic powder liquid is supplied to the nozzle 34, and the magnetic powder liquid is sprayed from the spray nozzle 34. When the magnetic powder liquid is evenly sprayed on the surface of the steel slab 10, the opening / closing mechanism 40 is reversely operated to block the hole 32a with the valve body 38a, thereby shutting off the supply of the magnetic powder liquid to the spray nozzle 34. The spraying of the magnetic powder liquid from 34 is stopped.

  The spray nozzle 34 is a cylindrical body having a predetermined length extending in the vertical direction. A hose 33 is connected to an upper portion of the spray nozzle 34 and is disposed in an upper region R of the steel piece 10 disposed at the spray position. ing. Further, the spray nozzle 34 has a position where the discharge end (lower end) 34a of the magnetic powder liquid faces the steel piece 10 (see FIG. 1) and a position outside the upper region R of the steel piece 10 (see FIG. 2). It is comprised so that it can move selectively by the moving mechanism 42. Here, in the spray nozzle 34, the magnetic powder liquid sprayed from the spray nozzle 34 hits the steel piece 10 at the position where the discharge end 34 a faces the steel piece 10, and the discharge end 34 a is in the upper region R of the steel piece 10. It is set so that the magnetic powder dripping from the spray nozzle 34 deviates from the steel piece 10 at a position deviating from the position (a position deviating).

  The moving mechanism 42 includes an arm 44 pivotally supported on a lower surface of a first mounting member 20b projecting upward from the spraying position from the apparatus main body 20a by a shaft supporting portion 44a positioned substantially in the middle thereof, and a first mounting. It comprises an advancing / retreating means 46 such as a fluid pressure cylinder disposed on the second mounting member 20 c that protrudes from the apparatus main body 20 a above the member 20 b, and a support member 48 disposed on one end of the arm 44. The support member 48 is a member that extends in the vertical direction with its upper end connected to one end of the arm 44, and the spray nozzle 34 is disposed on the side surface in parallel along the vertical direction. The other end of the arm 44 is pivotally connected to a lower end of a rod 46a protruding downward from the advance / retreat means 46. As the rod 46a moves up and down due to the bias of the advance / retreat means 46, the arm 44 is pivotally supported. The spray nozzle 34 is tilted along with the support member 48. In addition, when the spraying nozzle 34 finishes spraying of the magnetic powder liquid on the steel slab 10, the spray nozzle 34 intersects with the longitudinal direction of the steel slab 10 (opposite direction of the pair of electrode portions 52 and 52) (in the embodiment, orthogonal). The discharge end 34a is set to tilt in a direction along the transfer direction of the steel piece 10 transferred by the mounting table 26.

  In the moving mechanism 42, the rod 46a is lifted upward by the advancing / retracting means 46, and the support member 48 suspended from one end of the arm 44 and the spray nozzle 34 supported on the side surface of the support member 48 are in a vertical posture and discharged. The end 34 a is configured to face the steel piece 10. Further, the moving mechanism 42 projects the rod 46a downward by the advancing / retracting means 46 and tilts the arm 44, thereby tilting the support member 48 and the spray nozzle 34 which are in a vertical posture, and the discharge end 34a of the spray nozzle 34 is moved. The inclined posture is set at a position deviating from the upper region R of the steel piece 10. Here, when the spray nozzle 34 retreats from the upper region R of the steel slab 10 with the tilting from the vertical posture to the tilting posture, the tilting direction of the discharge end 34a is the inspection step of the steel slab 10 by the mounting table 26 ( It is configured to move in the direction opposite to the transfer direction to the post-process. That is, the steel piece 10 after spraying the magnetic powder liquid does not pass below the spray nozzle 34.

  The spray nozzle 34 is tilted from a vertical posture to an inclined posture at an appropriate timing by the moving mechanism 42, and before the energization of the steel piece 10 by at least the pair of electrode portions 52, 52 is stopped, the upper region of the steel piece 10. The discharge end 34a of the spray nozzle 34 is set to be retracted from R. Prior to the start of spraying of the magnetic powder liquid on the steel pieces 10 arriving at the spraying position, the spray nozzle 34 is tilted from the inclined posture to the vertical posture by the moving mechanism 42, and the discharge end 34 a is made to face the steel pieces 10. Return to position. The spray nozzle 34 is inclined every time the spray of the magnetic powder liquid ends, for example, at the same time as or after the supply of the magnetic powder liquid to the spray nozzle 34 is stopped by closing the on-off valve 38 of the spray means 30. However, it may be the timing before the on-off valve 38 is closed.

(Effects of Example)
Next, the operation of the magnetic particle flaw detector according to the embodiment will be described. The steel piece 10 is carried in by the carry-in conveyor 22 from the previous process, delivered to the mounting table 26, transferred by the mounting table 26, and arranged at the spraying position. With respect to the steel piece 10 that has arrived at the spreading position, each electrode part 52 is moved in a direction close to the corresponding end face, and in a state where each electrode part 52 is in contact with each end face, a pair of electrode parts 52, By energizing between 52, the steel piece 10 is magnetized. And the magnetic powder liquid is supplied to the spray nozzle 34 via the hose 33 by pulling up the valve body 38a closing the hole 32a of the storage tank 32 by the opening / closing mechanism 40 to open the hole 32a. The magnetic powder liquid is discharged from the discharge end 34a. At this time, since the spray nozzle 34 is supported in a vertical posture by the moving mechanism 42 and the discharge end 34a faces the steel piece 10 disposed below, the sprayed magnetic powder liquid is applied to the surface of the steel piece 10 ( (See FIG. 1).

  When the magnetic powder liquid is sprayed from the spray nozzle 34 for a required time and the magnetic powder liquid is evenly applied to the entire surface of the steel slab 10, the opening / closing mechanism 40 closes the hole 32 a of the storage tank 32 with the valve body 38 a to the spray nozzle 34. The supply of magnetic powder liquid is stopped. At this time, after the spraying nozzle 34 is tilted from the vertical posture to the tilted posture by the moving mechanism 42, the pair of electrodes are retracted from the upper region R of the steel piece 10 to the position where the discharge end 34 a of the spray nozzle 34 is removed. The energization between the parts 52 and 52 is stopped, and the magnetization state of the steel slab 10 is released. More specifically, the moving mechanism 42 projects the rod 46a downward by the advancing / retreating means 46, thereby displacing the other end of the arm 44 downward and displacing one end of the arm 44 upward about the shaft support portion 44a. Tilt to do. Along with this, the support member 48 and the spray nozzle 34 connected to one end of the arm 44 are rotated in the direction opposite to the transfer direction from the spray position of the steel slab 10, so that from the upper region R of the steel slab 10. The inclined posture is retracted to a position where the discharge end 34a of the spray nozzle 34 is removed (see FIG. 2).

  In this way, in the state where the magnetized state of the steel piece 10 is released, the discharge end 34a of the spray nozzle 34 is retracted to a position deviated from the upper region R of the steel piece 10, so that, for example, the closing failure of the on-off valve 38 is poor. Thus, the supply of the magnetic powder liquid cannot be completely stopped, and even if the magnetic powder liquid drips from the spray nozzle 34, it does not deviate from the steel piece 10 and is not applied to the surface. That is, the magnetic powder liquid hangs down from the spray nozzle 34 on the steel piece 10 whose magnetization state has been released, and the magnetic powder adhering to the surface of the steel piece 10 in the magnetized state is not washed away. Moreover, when the direction which the discharge | release end 34a of the spray nozzle 34 moves is the side which transfers the steel piece 10, when transferring the steel piece 10 to the carrying-out conveyor 24 by the mounting base 26, it passes under the discharge end 34a. Therefore, there is a possibility that the magnetic powder liquid dripping from the spray nozzle 34 falls on the steel piece 10. However, since the direction in which the spray nozzle 34 moves is set on the opposite side to the direction in which the steel piece 10 is transferred, the steel powder 10 does not pass below the discharge end 34a when the steel piece 10 is transferred. It does not fall on the steel piece 10, and it can be avoided reliably that the adhesion state of the magnetic powder adhering to the steel piece 10 is impaired. In addition, the moving mechanism 42 that moves the spray nozzle 34 does not receive the magnetic powder liquid sprayed from the spray nozzle 34, and the members 44, 46, and 48 that constitute the moving mechanism 42 have dust and dirt contained in the magnetic powder liquid. Scale does not accumulate, malfunction due to biting of dust and the like hardly occurs, and dripping of the magnetic powder liquid onto the steel piece 10 after magnetization can be reliably prevented.

  Next, after the pair of electrode portions 52, 52 are moved away from each other and separated from the respective end surfaces, the steel piece 10 is transferred from the mounting table 26 to the carry-out conveyor 24, and visually or in a dark room or the like. Is used for an inspection process for inspecting a surface defect of the steel piece 10. At this time, the magnetic powder adhering to the steel slab 10 is not damaged by the magnetic powder liquid leaked from the spray nozzle 34, so that it is possible to avoid the trouble of performing the step of spraying the magnetic powder liquid again, and the surface. Defects can be found well and the inspection accuracy can be improved.

  When the next steel piece 10 arrives at the spreading position by the mounting table 26, the moving mechanism 42 pulls the rod 46a upward by the advancing / retreating means 46, thereby displacing the other end of the arm 44 upward, and the shaft support 44a. Is tilted so that one end of the arm 44 is displaced downward. Along with this, by tilting the support member 48 and the spray nozzle 34 connected to one end of the arm 44 in the transfer direction of the steel piece 10, the tilted posture is returned to the vertical posture, and the discharge end 34a of the spray nozzle 34 is changed. It is a position facing the steel piece 10.

Note that the present invention is not limited to the magnetic particle flaw detector of the above-described embodiment, and various modifications can be made.
(1) In the embodiment, the spray nozzle is configured to be retracted from the upper region of the steel piece every time the spraying of the magnetic powder liquid is completed. The spray nozzle may be retracted only when the supply of the magnetic powder liquid cannot be completely stopped. In this case, the spraying means is provided with a sensor for detecting the open / close state of the open / close valve, a flow meter for measuring the flow of the magnetic powder liquid to the spray nozzle, and the open / close valve is moved to the closed state, What is necessary is just to make it move a dispersion | spreading nozzle to the position which remove | deviates from the upper area | region of a steel piece, when a closing failure is detected with a sensor or the flow of magnetic powder liquid is detected with a flowmeter.
(2) In the embodiment, the spray nozzle is tilted with respect to the device main body by the moving mechanism, so that the discharge end is retracted from the upper region of the steel piece, but the spray nozzle can be moved in parallel to the device main body. It is also possible to adopt a configuration in which it is disposed at a position where it is retracted to a position deviated from the upper region by being moved forward and backward.
(3) The means for controlling the dispersion and stopping of the magnetic powder liquid is not limited to the configuration of the on-off valve of the embodiment, and any means such as an electromagnetic valve, an electric valve or the like can be adopted as long as it can block the magnetic powder liquid. Moreover, you may provide the arrangement | positioning position of an on-off valve in the hose and spray nozzle which connect a storage tank and a spray nozzle.

In the magnetic particle flaw detector according to a preferred embodiment of the present invention, FIG. In the magnetic particle flaw detector of an Example, it is the schematic which shows the dispersion | spreading stop state of a magnetic powder liquid. It is a schematic sectional drawing which shows an example of the conventional spreading | diffusion means. It is the schematic which shows the conventional magnetic powder liquid interruption | blocking means.

Explanation of symbols

10 Steel slab (material to be inspected), 20a device main body, 34 spray nozzle, 34a discharge end,
42 Moving mechanism, R Upper region

Claims (4)

In the magnetic particle flaw detector that magnetizes the material to be inspected (10) and sprays the magnetic powder liquid from the spray nozzle (34) disposed above the material to be inspected (10),
The spray nozzle (34) faces the material to be inspected (10), a position where the magnetic powder liquid sprayed from the spray nozzle (34) hits the material to be inspected (10), and an upper region of the material to be inspected (10) (R) is configured to be able to move by the moving mechanism (42) between the position where the magnetic powder liquid dripping from the spray nozzle (34) deviates from the material to be inspected (10). Magnetic particle inspection equipment.   The spray nozzle (34) can be tilted with respect to the apparatus body (20a) so that the discharge end (34a) tilts in a direction intersecting the longitudinal direction of the material to be inspected (10) by the moving mechanism (42). The magnetic particle flaw detector according to claim 1, which is supported by the magnet.   The magnetic particle flaw detector according to claim 1 or 2, wherein the spray nozzle (34) is moved to a side opposite to a transfer direction to a subsequent process of the inspection object (10). The magnetic particle flaw detector according to any one of claims 1 to 3, wherein the spray nozzle (34) is moved to a position deviating from the contact position every time the spraying of the magnetic powder liquid is completed.

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