JP2011169861A - Device for detecting surface defect and defect under surface skin, and method for detecting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for detecting a surface defect and a defect under the surface skin, and a method for detecting the same wherein an ultrasonic surface wave can carry out flaw detection of a whole surface by going around a width direction of an inspection object, and reflected waves from other than a defect are reduced. <P>SOLUTION: The device for detecting a surface defect and a defect under the surface skin is equipped with: a probe 10 having a transmission part sending out ultrasonic waves propagating directly under a surface of the inspection object 2 with respect to the inspection object 2, and a receiving part receiving at least a returning ultrasonic wave reflected by a defect in the inspection object 2 of sent out ultrasonic waves; and an air blower 3a removing in a substantially vertical direction with respect to a propagation direction a surface deposit of the inspection object 2 in the propagation direction of the ultrasonic wave sent out from the transmission part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a surface defect and a surface subcutaneous defect detection apparatus for detecting defects existing on the surface and surface of a steel bar or a steel piece, and a detection method thereof.

As a method for nondestructively detecting defects existing on the surface of a metal material such as steel bars or steel pieces, or a subsurface surface, a magnetic particle inspection method, a penetrating flaw detection method, an eddy current flaw detection method, an ultrasonic flaw detection method, or the like is known.
In the magnetic particle flaw detection method, surface defects are detected by observing a magnetic particle indicating pattern obtained by spraying magnetic particles having fluorescence characteristics on a magnetized inspection object and irradiating the magnetic powder with an ultraviolet light source.
In the penetrant flaw detection method, a fluorescent penetrant is applied to the surface of the object to be infiltrated and soaked into the crack, and the fluorescence obtained by irradiating the indicator pattern formed by the penetrant in the crack oozing out onto the surface of the inspected object By observing, surface defects are detected.

These magnetic particle inspection methods and penetrant flaw detection methods are wet inspections, and are greatly affected by fluctuations in brightness due to changes in the amount of magnetic powder and fluorescent penetrant applied, and the surface roughness distribution of the test object. Reproducibility is not good. Therefore, there are a problem that the inspection result varies depending on the inspection operator, and a problem that only a defect opened on the surface to be inspected can be detected.
In the eddy current flaw detection method, a detection coil is brought close to the surface of an object to be inspected, an eddy current is caused to flow on the surface of the object to be inspected, and a change in induced current is detected while the detection coil is moved on the object to be inspected. It detects the defect and depth of the inspection object.

Although this eddy current flaw detection method can inspect the surface layer portion of a metal material, it has a problem that it is difficult to discriminate defects in detection results because it detects structural changes and magnetic changes other than defects.
Therefore, in general, an ultrasonic surface flaw detection method as shown in Patent Document 1 is often used. The ultrasonic flaw detection method sends out ultrasonic waves that become surface waves from the ultrasonic probe into the body to be inspected, and receives the ultrasonic waves reflected back from the body under inspection by the ultrasonic probe. It detects a surface defect and a surface subcutaneous defect of an object to be inspected. At this time, if there is a contact medium used by the ultrasonic probe in the ultrasonic propagation path in the flaw detection area, or if water droplets or dust adheres, the contact medium or deposits that are not defects Since the ultrasonic waves are reflected, the contact medium or deposits in the flaw detection area are blown off with an air blower or removed with a wiper. Such an ultrasonic surface flaw detection method has the advantage that the defect detection accuracy is good and the workability for the inspection worker is also good.

  FIG. 10 is a diagram showing the configuration of the cylindrical body surface inspection apparatus disclosed in Patent Document 1. As shown in FIG. In FIG. 10A, a probe 101 is arranged on the surface of a cylindrical body 100, and this propagation is in the propagation direction of ultrasonic waves along the circumferential direction of the cylindrical body (the direction indicated by the solid line arrow). An air nozzle 102 for injecting air onto the surface of the cylindrical body is disposed along the direction. In FIG. 10 (b), the deposits indicated by oblique lines on the surface of the cylindrical body 100 are contact media used by the ultrasonic probe, and the cylindrical body 100 rotates clockwise toward the paper surface, Is blowing air toward the cylindrical body 100. With such a configuration, the contact medium does not exist in the flaw detection area indicated by the broken line in FIG.

JP 2003-98160 A

In the ultrasonic flaw detection method, if the contact medium or surface deposit used for propagating ultrasonic waves from the ultrasonic probe into the body to be inspected remains in the propagation path without being completely removed, the contact medium or surface attachment Since the reflected signal of the ultrasonic wave is returned from the kimono, there is a problem that the reflected signal from the surface deposit that is not a defect is detected.
Therefore, as disclosed in Japanese Patent Application Laid-Open No. H10-228688, a means is adopted in which the contact medium and surface deposits are blown off by an air nozzle so as not to enter the propagation path of the flaw detection area. In the method disclosed in Patent Document 1, air is jetted in the direction opposite to the rotation direction while rotating the object to be inspected so that the contact medium does not enter the flaw detection area. However, in this method, the contact medium and surface deposits that have been removed or cannot be removed from the flaw detection area always exist in the propagation direction of the ultrasonic waves, resulting in disturbance. As a result, as shown by a broken line in FIG. 10B, only a part of the area where the contact medium can be removed can be inspected, and a flaw detection area where a defect can be detected by one inspection is only a part of the inspection object. It is limited to. Therefore, the circumferential inspection of the object to be inspected must be performed in several degrees, and the problem that the object to be inspected cannot be moved in the length direction of the object to be inspected until the circumferential inspection is finished. is there.

In addition, even when the contact medium or surface deposits are removed using a wiper, the wiper itself is in the ultrasonic wave propagation path, so that there is a problem that it is detected as a defect pseudo signal.
Therefore, the present invention has been made in view of the above problems, and by appropriately setting each of the material passing direction of the inspection object to be inspected, the propagation direction of the surface wave, the position of the air nozzle and the injection direction, the ultrasonic wave It is an object of the present invention to provide a detection device and a method for detecting a surface defect and a surface subcutaneous defect that can detect the entire surface of the object to be inspected by making one surface wave of the surface to be inspected in the circumferential direction and reduce reflected waves from other than the defect. .

In order to achieve the above-described object, the present invention takes the following technical means.
That is, the surface defect and the surface subcutaneous defect detection apparatus according to the present invention includes at least one of the transmitted ultrasonic wave and the transmitted ultrasonic wave that transmits the ultrasonic wave propagating directly under the surface of the test object to the test object. A probe having a receiving unit for receiving ultrasonic waves reflected and returned by a defect in the inspected object, and a surface deposit on the inspected object in the propagation direction of the ultrasonic waves transmitted from the transmitting unit, Removing means for removing in a direction substantially perpendicular to the propagation direction.

Further, the surface defect and subcutaneous surface defect detection apparatus according to the present invention is arranged such that when the object to be inspected is a long object, the probe transmits ultrasonic waves in the circumferential direction of the object to be inspected. The removing means is provided over the entire circumference of the object to be inspected.
Further, the surface defect and subcutaneous surface defect detection apparatus according to the present invention has the two probes, and the two probes are arranged at different positions in the longitudinal direction of the inspection object, Ultrasonic waves are transmitted in directions opposite to each other in the circumferential direction of the object to be inspected.

Here, the removing unit may be an air ejecting unit that ejects air in a direction substantially perpendicular to a propagation direction of an ultrasonic wave transmitted from the probe with respect to a flaw detection range to be inspected.
A surface defect and subcutaneous surface defect detection method according to the present invention is a method for detecting a defect in an inspected body using ultrasonic waves, and the surface deposit on the inspected object in the propagation direction of ultrasonic waves The ultrasonic wave propagating directly below the surface of the object to be inspected is transmitted to the object to be inspected, and at least of the ultrasonic waves sent to the object to be inspected. The ultrasonic wave reflected by the defect is received.

Moreover, the surface defect and the surface subcutaneous defect detection method according to the present invention, when the object to be inspected is a long object, send ultrasonic waves in the circumferential direction of the object to be inspected, and simultaneously over the entire circumference of the object to be inspected. Surface deposits are removed in a direction substantially perpendicular to the propagation direction.
Further, the surface defect and subcutaneous surface defect detection method according to the present invention is characterized in that the flaw detection range existing ahead in the propagation direction on the object to be inspected starts to be transmitted in the longitudinal direction of the object to be inspected. To do.

In addition, the surface defect and subcutaneous surface defect detection method according to the present invention is characterized in that ultrasonic waves are transmitted from different positions in the longitudinal direction of the object to be inspected toward each other in the circumferential direction of the object to be inspected.
Here, air may be injected into the flaw detection range to be inspected so as to be in a direction substantially perpendicular to the propagation direction of the ultrasonic waves.

  According to the apparatus and method for detecting a surface defect and a surface subcutaneous defect according to the present invention, reflected waves from other than the defect can be reduced, the material passing direction of the inspection object to be inspected, the propagation direction of the surface wave, the air blower By appropriately setting each of the position and the jetting direction, it is possible to detect the entire surface by making one round of the surface wave of the ultrasonic wave in the circumferential direction of the object to be inspected, and to reduce the reflected wave from other than the defect .

It is a figure showing the structure of the detection apparatus of the surface defect by the 1st Embodiment of this invention, and a surface subcutaneous defect. It is sectional drawing which shows the structure of a sensor head. (A) is a perspective view which shows arrangement | positioning of the sensor head with respect to a to-be-inspected object, and the air blower mentioned later, (b) is the structure shown to Fig.2 (a) from the upstream of the material passing direction of a to-be-inspected object. It is a figure which shows a state when it sees. (A) is a figure showing the state which has arrange | positioned the air blower to the sensor material direction downstream with respect to a sensor head, (b) represents the state which has arrange | positioned the air blower to the sensor material upstream in the material direction. FIG. (A) is a figure which shows arrangement | positioning and a structure of an air blower with respect to a to-be-inspected object, (b) is a figure which shows arrangement | positioning and a structure of an air blower with respect to a to-be-inspected object. It is a figure which shows the state which installed the detection apparatus of the surface defect and the surface subcutaneous defect in the same line in the downstream of a magnetic particle flaw detector. It is a figure which shows the state which installed the detection apparatus of the surface defect and the surface subcutaneous defect in the upstream of the magnetic particle flaw detector in the same line. (A) is a figure which shows the structure which has arrange | positioned one set of the combination of an air blower and a sensor head on the test | inspection surface adjacent to a to-be-inspected object, (b) is the same combination of an air blower and a sensor head of a to-be-inspected object. It is a figure which shows the structure arrange | positioned so that two sets may be followed on a test | inspection surface in a material passing direction. It is a figure which shows the state which provided two sensor heads on the same test | inspection surface of a to-be-tested object which has a defect, and sent the surface wave to the direction which opposes, respectively. (A) is a perspective view showing schematic structure of a cylindrical body surface inspection apparatus, (b) is AA arrow sectional drawing in (a).

Hereinafter, embodiments of a detection apparatus for surface defects and surface subcutaneous defects according to the present invention will be described with reference to the drawings.
The surface defect and surface subcutaneous defect detection apparatus 1a according to the present invention includes a transmitter that transmits ultrasonic waves propagating directly under the surface of the inspection object 2 to the inspection object 2 such as a steel bar or a steel piece, which is a metal material. Among the transmitted ultrasonic waves, at least a probe 10 including a receiving unit that receives ultrasonic waves reflected and returned by a defect in the inspection object 2, and a propagation direction of the ultrasonic waves transmitted from the transmitting unit And removing means 3a for removing the deposit on the surface of the object 2 to be inspected in a direction substantially perpendicular to the propagation direction.
[First Embodiment]
With reference to FIG. 1, the structure of the detection apparatus 1a of a surface defect and a surface subcutaneous defect is demonstrated. FIG. 1 is a schematic diagram showing the configuration and arrangement of a surface defect and subcutaneous surface defect detection device 1a and a device under test 2 according to a first embodiment of the present invention.

An apparatus 1a for detecting surface defects and subsurface defects includes an air blower 3a as a removing means, a sensor head 15 comprising a probe 10 and a sensor holder 4, a factory air supply unit 5, a contact medium supply / recovery unit 6, an ultrasonic flaw detector. 7 and a signal recording processing device 8.
The detection device 1a for surface defects and surface subcutaneous defects is fixed and installed in a production line for the object 2 to be inspected, which is a substantially square bar steel.

First, the configuration of the sensor head 15 used for detecting surface defects and surface subcutaneous defects will be described. A sensor head 15 shown in FIG. 1 includes a probe 10 and a sensor holder 4 that holds the probe 10.
The sensor holder 4 is, for example, a box-shaped housing that is substantially cubic and has an open bottom, and has a probe 10 that transmits and receives surface waves (Rayleigh waves) that are ultrasonic waves inside the box. Further, the sensor holder 4 includes a contact medium supply pipe 11 for supplying a contact medium that transmits ultrasonic waves between the probe 10 and the inspection object 2, and a contact medium collection pipe for collecting the contact medium. 12.

  Although not shown, the probe 10 is, for example, a probe using a piezoelectric element. An electromagnetic ultrasonic sensor such as a Lorentzian transverse wave generating sensor has a transmission coil that is a transmission unit that transmits surface waves, and a reception coil that is a reception unit that receives the transmitted surface waves. The electromagnetic ultrasonic sensor does not require a contact medium. However, in the embodiment of the present invention, a probe using a piezoelectric element suitable for detecting surface defects and surface subcutaneous defects is used. Here, the surface wave is an ultrasonic wave that propagates on the surface of the inspection object or directly below the surface.

Next, the configuration of the sensor head 15 will be described in more detail with reference to FIG.
FIG. 2 is a cross-sectional view showing the configuration of the sensor head 15. In the sensor holder 4 of the sensor head 15 arranged on the side surface (inspection surface) of the inspection object 2, the probe 10 provides a predetermined space between the inspection object 2 and the inspection object 2 as shown in FIG. It is provided so as to be secured. That is, in the sensor holder 4 that is in contact with the inspection object 2, the probe 10 is separated upward from the inspection object 2 by a predetermined distance.

The side wall of the sensor holder 4 surrounds the probe 10, and the probe 10 is in a space formed by the sensor holder 4.
When detecting a defect, the contact medium is supplied into the space from the contact medium supply pipe 11, and the supplied contact medium is recovered to the contact medium recovery pipe 12.
The contact medium supply / recovery unit 6 shown in FIG. 1 supplies the contact medium used in the sensor head 15 to the space in the sensor holder 4 through the contact medium supply pipe 11 of the sensor holder 4 and also recovers the contact medium of the sensor holder 4. The contact medium is recovered from the space in the sensor holder 4 through the tube 12. Therefore, the contact medium supply / recovery unit 6 is connected to the contact medium supply pipe 11 and the contact medium recovery pipe 12 of the sensor holder 4. Here, the contact medium is a substance that transmits ultrasonic waves, such as water, glycerin paste, and oil.

With reference to FIG. 3, the arrangement of the sensor head 15 in which the probe 10 is built will be described. In the drawing, the direction in which the device under test 2 moves is indicated by an arrow as the material passing direction.
The inspection object 2 moves from the start end of the arrow indicating the material passing direction toward the end. In the present embodiment, the starting end side of this arrow is referred to as the upstream side, and the terminal end side is referred to as the downstream side.
FIG. 3A is a perspective view showing the arrangement of the sensor head 15 and an air blower 3a, which will be described later, with respect to the inspection object 2, and FIG. 3B shows the configuration shown in FIG. It is a figure which shows a state when it sees from the upstream of the material passing direction.

  As shown in FIG. 3A, the sensor head 15 has a surface wave so that the lower end surface or the lower end side of the side wall of the lower open surface of the sensor holder 4 is in contact with the position on the one end side of the inspection surface of the inspection object 2. The delivery direction is arranged in the circumferential direction of the device under test 2. Accordingly, the sensor head 15 sends a surface wave from one point on the side surface of the device under test 2 toward the circumferential direction of the device under test 2 as indicated by an arrow. In the drawing, the region sandwiched between two thin lines drawn over the entire circumference in the circumferential direction of the inspection object 2 in the width of the sensor head 15 in the material passing direction indicates the propagation range of the transmitted surface wave. The surface wave transmitted from the sensor head 15 propagates around the entire surface of the device under test 2. This propagation range is the inspection range of surface defects and surface subcutaneous defects.

The inspection object 2 moves in the material passing direction, but the sensor head 15 is provided in the surface defect and surface subcutaneous defect detection device 1a and does not move in the material passing direction. Therefore, it moves to the upstream side.
The ultrasonic flaw detector 7 shown in FIG. 1 controls transmission of a pulse current to the transmission coil of the probe 10 and reception of the pulse current from the reception coil, and is connected to the sensor head 15. . By adjusting the pulse current with the ultrasonic flaw detector 7, it is possible to generate an ultrasonic wave having an intensity that propagates over the entire circumference of the inspection object 2.

The signal recording processing device 8 shown in FIG. 1 is based on an echo (reflected wave) signal obtained from the receiving coil of the probe 10 via the ultrasonic flaw detector 7, the arrival time of the echo, that is, the position of the defect, etc. Is connected to the ultrasonic flaw detector 7. The signal recording processing device 8 is constituted by, for example, a PC (personal computer).
Next, the configuration of the air blower 3a as a removing unit in the surface defect and surface subcutaneous defect detection device 1a will be described. The air blower 3a includes a substantially rectangular parallelepiped housing having substantially the same width as the side surface of the object 2 to be inspected, a plurality of air nozzles 9 provided along the longitudinal direction of the housing, and an air inlet (not shown). ). 3 has seven air nozzles 9. The air blower 3a shown in FIG.

  As shown in FIG. 3, the air blower 3 a is disposed on the inspection surface on which the sensor head 15 is disposed at a downstream position away from the sensor head 15 by a predetermined distance. At this time, the air blower 3a is arranged in a state of being lifted with a predetermined distance between the air blower 3a and the side surface so as not to generate large friction with the side surface. Further, at such a position, the air blower 3 a is arranged with the air nozzle 9 directed toward the propagation range of the surface wave along the circumferential direction of the device under test 2.

As shown in FIG. 3B, when the arrangement of the sensor head 15 and the air blower 3a as described above is viewed from the upstream side of the device under test 2, the sensor head 15 and the air blower 3a are arranged so as to overlap each other.
At this time, two air blowers 3a are arranged in FIG. 3A so that the jet direction of the air nozzle 9 is substantially perpendicular to the propagation direction of the surface wave from the downstream side to the upstream side in the material passing direction. It is arrange | positioned so that air may be injected from the downstream to the upstream including the propagation range pinched | interposed by this thin line.

The factory air supply unit 5 is a factory pressure pipe, a compressor, or the like that supplies air for use in the entire factory where the detection device 1a for surface defects and surface subcutaneous defects is installed. The factory air supply unit 5 is connected to the air inlet of the air blower 3a and supplies air.
When air is supplied from the factory air supply unit 5 to the air blower 3a configured and arranged as described above, the air blower 3a is supplied with air supplied to the air inlet as shown by an arrow in FIG. Are ejected from a plurality of air nozzles 9 from the downstream side to the upstream side in the material passing direction as indicated by arrows in the figure.

  As shown in FIGS. 3A and 3B, the size of the sensor head 15 is relatively small with respect to the longitudinal width of the air blower 3a. However, as shown in FIG. 3B, since the arrangement of the two overlaps in the air injection direction, when air is injected from the air blower 3a toward the sensor head 15, the air is also blown to the sensor head 15. It is done. At this time, the sensor holder 4 surrounding the space provided between the probe 10 and the inspection object 2 plays a role of windshield, so that the contact medium in the space is blown off together with the air from the air blower 3a. There is no. In addition, the contact medium in the immediate vicinity of the sensor holder 4 can be surely removed by blowing air to the sensor head 15.

A part of the contact medium in the space is not recovered to the contact medium recovery pipe 12 and leaks to the outside of the sensor holder 4 as indicated by the arrow from the portion where the sensor holder 4 and the inspected object 2 are in contact with each other. The minute is blown away by the air from the air blower 3a and does not remain in the surface wave propagation range.
The surface defect and subsurface defect detection apparatus 1a having such a configuration allows the inspection object 2 to pass through without rotating, propagates surface waves from the sensor head 15 in the circumferential direction of the inspection object 2, and Air is injected from the air blower 3a in the direction opposite to the material passing direction of the inspection body 2.

  By doing so, the contact medium within the propagation range of the surface wave can be removed in a direction substantially perpendicular to the propagation direction and out of the propagation range, and adhesion of dust and the like in the factory can be prevented. It is possible to reduce false detection of defects and surface subcutaneous defects. In addition, since the propagation direction of the surface wave is the circumferential direction of the object to be inspected 2 and the air injection direction from the air blower 3a is substantially perpendicular to the propagation direction of the surface wave, unnecessary contact with the surface wave propagation range is achieved. Since no medium is present, the entire circumference in the width direction of the inspection object 2 can be detected by a single flaw detection without dividing the entire periphery of the inspection object 2 as in the prior art. If such a flaw detection inspection is continuously performed while moving the inspection object 2 in the material direction, continuous inspection over the entire length of the inspection object 2 becomes possible, and the time required for flaw detection can be shortened. Therefore, the flaw detection efficiency is improved.

In the above description, as shown in FIG. 4 (a), the air blower 3a is arranged on the downstream side in the material passing direction with respect to the sensor head 15, but as shown in FIG. 4 (b), the air blower 3a is You may arrange | position so that the air nozzle 9 may face the upstream in the upstream of a material passing direction with respect to the sensor head 15. FIG. Also at this time, the air blower 3a is arranged such that the air nozzle 9 is jetted from the downstream side to the upstream side in the material passing direction, and the air is jetted onto the surface of the inspection object 2. Even with this arrangement, it is possible to detect the entire circumference in the width direction of the inspected object 2 with a single flaw detection so that the contact medium and dust do not adhere to the propagation range of the surface wave. Further, since the sensor head 15 is not affected by the wind from the air blower 3 a at all, the probe 10 can be exposed without being housed in the sensor holder 4.
[Second Embodiment]
Next, a surface defect and surface subcutaneous defect detection device 1b according to a second embodiment of the present invention will be described with reference to FIG.

  The surface defect and surface subcutaneous defect detection device 1b of the present embodiment corresponds to the four inspection surfaces of the inspected object 2 instead of the air blower 3a in the surface defect and surface subcutaneous defect detection device 1a of the first embodiment. The four air blowers 3b to 3e that are the first to fourth removing means are employed. The configuration other than the air blowers 3b to 3e is the same as that of the surface defect and surface subcutaneous defect detection device 1a of the first embodiment.

FIG. 5A shows the arrangement of the air blowers 3b to 3e and the sensor head 15 of the surface defect and surface subcutaneous defect detection device 1b according to the second embodiment of the present invention, and the upstream side in the material direction. It is the figure seen from.
The air blowers 3b to 3e have the same configuration as the air blower 3a described in the first embodiment, and are connected to the factory air supply unit 5 described in the first embodiment.

Further, the contact medium supply / recovery unit 6, the ultrasonic flaw detector 7, and the signal recording processing device 8 described in the first embodiment are connected to the sensor head 15.
In the same manner as in the first embodiment, the sensor head 15 is disposed on the inspection surface of the inspection object 2, and the air blowers 3 b to 3 e are disposed downstream of the sensor head 15 in the material passing direction. As shown in FIG. 5A, each of the air blowers 3b to 3e is disposed so as to surround the device under test 2 in the circumferential direction at a position away from the surface wave propagation range by a predetermined distance. In addition, each of the air blowers 3b to 3e floats away from the inspection surface of the object 2 to be inspected at a predetermined interval, and the injection direction of the air nozzle 9 propagates surface waves from the downstream side to the upstream side in the material passing direction. It is arranged so that air is jetted from the downstream side to the upstream side so as to be substantially perpendicular to the direction and including the propagation range of the surface wave.

In such an arrangement, the sensor head 15 transmits a surface wave, and the transmitted surface wave propagates in the direction of a substantially circular arrow indicated on the device under test 2. At the same time, the air blowers 3a to 3d eject air along the ejection direction indicated by the arrows, and remove contact medium and dust in the propagation range of the transmitted surface wave.
As described above, by arranging the air blowers 3a to 3d around the entire periphery of the inspection object 2 so as to correspond to the inspection surface of the inspection object 2, dust and the like in the propagation range of the surface wave can be removed over the entire periphery of the inspection object 2. Therefore, the reflected wave from dust etc. other than defects can be reduced.

With reference to FIG.5 (b), the detection apparatus 1c of the surface defect which is a modification of 2nd Embodiment, and a surface subcutaneous defect is demonstrated.
The surface defect and surface subcutaneous defect detection device 1c in the present modification employs an air blower 3f instead of the four air blowers 3b to 3e in the surface defect and surface subcutaneous defect detection device 1b according to the second embodiment of the present invention. It has the structure. In this modification, the inspection object 2b is a columnar steel bar.

In the surface defect and surface subcutaneous defect detection device 1c, the components other than the air blower 3f have the same configuration as the surface defect and surface subcutaneous defect detection device 1b according to the second embodiment.
As shown in FIG. 5B, the air blower 3f has an annular casing having an opening through which the device under test 2b passes, has an air inlet (not shown), and A plurality of air nozzles 9 are provided on an annular plane of the housing. In FIG. 5B, 22 air nozzles 9 are shown. The air blower 3f injects the air supplied to the air inlet from a plurality of air nozzles 9 as indicated by arrows in the figure.

  Such an air blower 3f is arranged on the downstream side in the material passing direction of the inspection object 2 with the air nozzle 9 facing the sensor head 15. Since the air blower 3f allows the inspection object 2b to pass through the opening, as shown in FIG. 5B, the air blower 3f is spaced from the side surface of the inspection object 2 at a predetermined distance from the sensor head 15. A space is provided so as to surround the object 2b in the circumferential direction.

Further, at such a position, the air blower 3f is arranged with the air nozzle 9 facing the surface wave propagation range along the circumferential direction of the inspection object 2b.
At this time, the air blower 3f is disposed on the downstream side so that the injection direction of the air nozzle 9 is substantially perpendicular to the propagation direction of the surface wave from the downstream side to the upstream side in the material passing direction and includes the propagation range. It is arrange | positioned so that air may be injected to the upstream from.

As shown in FIG. 5B, when the arrangement of the sensor head 15 and the air blower 3f as described above is viewed from the upstream side of the device under test 2b, the sensor head 15 and the air blower 3f are arranged so as to overlap each other. .
In such an arrangement, the sensor head 15 transmits a surface wave, and the transmitted surface wave propagates in the direction of a substantially circular arrow shown on the device under test 2b. At the same time, the air blower 3f injects air in the injection direction indicated by the arrow, and removes the contact medium and dust in the propagation range of the transmitted surface wave.

Thus, by arranging the air blower 3f so as to surround the entire circumference of the inspection object 2b, not only unnecessary contact medium on the inspection object 2b but also adhesion of dust in the factory can be removed. Therefore, it is possible to reduce the reflected wave from dust or the like other than the defect in the surface wave propagation range over the entire circumference of the inspection object 2b.
In this modification, the inspection object 2b is a columnar steel bar. However, even if the inspection object 2b is a substantially square pole steel bar similar to the inspection object 2a, the inspection object 2b extends over the entire circumference of the inspection object 2a. Dust and the like in the surface wave propagation range can be removed.

By the way, the surface defect and surface subcutaneous defect detection apparatus according to the first and second embodiments of the present invention detects the surface defect and the surface subcutaneous defect of the inspected object 2. When performing flaw detection, the magnetic particle flaw detector 14 and an internal defect flaw detector that sends out ultrasonic waves vertically and obliquely to detect internal defects may be installed on the same line.
In the magnetic particle flaw detection method, first, the object to be inspected 2 is magnetized by a predetermined method, and a magnetic powder liquid in which magnetic particles having fluorescent properties are dispersed is sprayed on the object 2 to be inspected, and leakage leaks from surface defects of the object 2 to be inspected. Magnetic powder is attracted by magnetic flux. Thereafter, the magnetic particles aggregated around the surface defect are irradiated with an ultraviolet light source to emit fluorescence, and the magnetic particle indicating pattern is observed to detect the surface defect.

  For example, as shown in FIG. 6, when the surface defect and surface subcutaneous defect detection device 1a according to the first embodiment of the present invention is installed on the downstream side of the magnetic particle flaw detector 14, the magnetic powder liquid used in the magnetic particle flaw detector is inspected. It adheres over the entire length and circumference of the body 2. Further, when the surface defect and surface subcutaneous defect detection device 1a according to the first embodiment of the present invention is installed on the downstream side of the internal defect inspection device, the contact medium used for transmitting the ultrasonic wave is the total length of the object 2 to be inspected. And adheres all around. Since it is impossible to know where these magnetic powders and contact media are attached to the object 2 to be inspected, the surface defect and surface subcutaneous defect detection device 1a of the first embodiment is inspected after these inspections. However, if only the air blower 3a is provided, the magnetic powder liquid or the like attached over the entire circumference of the inspection object 2 cannot be removed. In this case, a large number of signals reflected from the magnetic powder liquid and the contact medium are detected, so that the position of the defect cannot be accurately detected.

  Therefore, using the surface defect and surface subcutaneous defect detection device 1b of the second embodiment as shown in FIG. 5A, the air blowers 3b to 3e correspond to each inspection surface over the entire circumference of the inspection object 2. If installed in such a way, it is possible to detect surface defects and surface subcutaneous defects by removing them without waiting for the magnetic powder solution or contact medium to dry, thus reducing the time required for inspection and detecting efficiency. Along with the improvement, productivity of the production line will also improve. Furthermore, since water droplets can also be removed over the entire length and the entire circumference of the device under test 2, rusting of the device under test 2 can be prevented.

As shown in FIG. 7, when the surface defect and surface subcutaneous defect detection device 1 a according to the first embodiment of the present invention is installed on the upstream side of the magnetic particle flaw detection device 14, the entire circumference of the inspected object 2 is not necessarily required. It is not necessary to install an air blower over the entire surface, but by arranging the air blowers 3a to 3d so as to correspond to each inspection surface over the entire circumference of the inspection object 2, the propagation range of the surface wave over the entire periphery of the inspection object 2 In addition to the unnecessary contact medium in the factory, it is possible to remove the adhesion of dust in the factory, etc., so that it is possible to reduce the reflected wave from dust other than defects.
[Third Embodiment]
Next, a surface defect and surface subcutaneous defect detection device 1d according to a third embodiment of the present invention will be described with reference to FIG. The surface defect and surface subcutaneous defect detection device 1d of the present embodiment has a configuration in which two air blowers 3a and two sensor heads 15 in the surface defect and surface subcutaneous defect detection device 1a of the first embodiment are employed. ing.

  FIG. 8A shows a configuration in which a combination of the air blower 3a and the sensor head 15 is arranged on the inspection surface adjacent to the inspection object 2 one by one. The arrangement configuration of the air blower 3a and the sensor head 15 in one combination is the same as that described in the first embodiment, and the air blower 3a has the air nozzle 9 injecting direction from the downstream side to the upstream side in the material passing direction. Thus, the air is arranged so as to be substantially perpendicular to the propagation direction of the surface wave and so that air is injected from the downstream side to the upstream side including the propagation range.

In addition, the air wave blower 3a and the sensor head 15 are arranged so that the surface wave transmission directions of the two sensor heads 15 are opposite to each other in the circumferential direction of the device under test 2 and the propagation ranges of the surface waves do not overlap. Deploy each combination of.
FIG. 8B shows a configuration in which two combinations of the air blower 3a and the sensor head 15 are arranged on the same inspection surface of the inspection object 2 so as to be continuous in the material passing direction. The arrangement of the air blower 3a and the sensor head 15 in one combination is the same as that described in the first embodiment, and the air blower 3a has an injection direction of the air blower 3a from the downstream side to the upstream side in the material passing direction. Thus, the air is arranged so as to be substantially perpendicular to the propagation direction of the surface wave and so that air is injected from the downstream side to the upstream side including the propagation range.

In addition, the two sensor heads 15 are arranged so that the surface wave sending directions are opposite in the circumferential direction of the device under test 2.
When the two sensor heads 15 arranged in this way each transmit a surface wave, a defect that cannot be detected when only one sensor head 15 is used can be detected. The reason for this will be described with reference to FIG.

FIG. 9 is a diagram illustrating a state in which two sensor heads 15 are provided on the same inspection surface of the inspection object 2 having the defect 13 and surface waves are transmitted in opposite directions. In the figure, an arrow shown under the subject 2 indicates a surface wave sent from the sensor head 15.
As shown in FIG. 9, the defect 13 inclined from the upper right to the lower left of the page reflects the surface wave transmitted by the sensor head 15 on the right side of the page toward the inside of the inspection object 2. It is difficult for the head 15 to detect the defect 13. However, since the surface wave transmitted from the sensor head 15 on the left side of the paper is reflected in a direction to be confined to the defect 13 and the surface of the inspection object 2, the surface wave travels along the surface of the inspection object 2 and returns to the sensor head 15. As a result, the left sensor head 15 can detect the defect 13.

As described above, since the shape of the defect is complicated, even if the defect has a small scattering cross section effective with respect to the propagation direction of the surface wave or is a defect inclined as described above, the two sensor heads 15 According to the surface defect and surface subcutaneous defect detection device 1d that sends surface waves in the opposite directions, the defect can be reliably detected.
At that time, by placing a probe on the surface of the object to be inspected 2 that is transported in a rhombus shape, the contact medium can be prevented from entering the surface wave propagation direction. Therefore, the detection effect becomes higher. The rhombus conveyance means that one diagonal line in the cross section perpendicular to the material passing direction of the object to be inspected 2 is horizontal and the surface facing downward is supported by a pinch roller or the like so as to form a rhombus shape in cross section. It is a method of transporting the inspection body 2.

  As mentioned above, although the detection apparatus of the surface defect and the surface subcutaneous defect of this invention has been demonstrated from 1st Embodiment to 3rd Embodiment, each embodiment can be combined suitably. For example, the arrangement of the air blower 3a and the sensor head 15 shown in FIG. 4B in the first embodiment can be applied to the second and third embodiments. That is, the air blowers 3b to 3e in the second embodiment can be arranged upstream of the sensor head 15 in the material passing direction without changing the air injection direction. Moreover, the two air blowers 3a in 3rd Embodiment can also be arrange | positioned in the upstream of the material passing direction with respect to the sensor head 15 which is a group, without changing the injection direction of those air.

  Moreover, the air blowers 3b to 3e and the air blower 3f shown in FIGS. 5A and 5B in the second embodiment can be applied to the third embodiment. That is, instead of the two air blowers 3a in the third embodiment, the air blowers 3b to 3e in the second embodiment can be arranged so as to correspond to each inspection surface over the entire circumference of the object 2 to be inspected. At this time, the air blowers 3b to 3e are arranged so that the air injection direction is the same as that of the two air blowers 3a and is directed from the downstream side to the upstream side in the material passing direction. Further, instead of the two air blowers 3a in the third embodiment, the air blowers 3f in the second embodiment can be arranged downstream of the two sensor heads 15 in the material passing direction. At this time, the air blower 3f is arranged so that the air injection direction is the same direction as the two air blowers 3a and is directed from the downstream side to the upstream side in the material passing direction.

As a result, in the third embodiment, as in the second embodiment, dust and the like in the propagation range of the surface wave can be removed over the entire circumference of the inspection object 2, and reflected waves from dust and the like other than defects can be removed. Can be reduced.
Furthermore, in each embodiment, steel slabs and steel bars are disclosed as examples of the object to be inspected 2. However, the present invention is not limited to this, and any material that can propagate surface waves can be used. It can be applied as the inspection object 2.

DESCRIPTION OF SYMBOLS 1 Detection apparatus of surface defect and surface subcutaneous defect 2 Test object 3a-3e Air blower 4 Sensor holder 5 Factory air supply part 6 Contact medium supply collection part 7 Ultrasonic flaw detector 8 Signal recording processing apparatus 9 Air nozzle 10 Defect 11 Contact medium Supply pipe 12 Contact medium recovery pipe 13 Defect 14 Magnetic particle flaw detector 15 Sensor head

Claims (9)

A transmitter that transmits ultrasonic waves propagating directly under the surface of the object to be inspected, and reception of ultrasonic waves that are reflected and returned by at least a defect in the object to be inspected. A probe with a section,
A surface defect comprising: removal means for removing surface deposits on the object in the direction of propagation of the ultrasonic wave transmitted from the transmitter in a direction substantially perpendicular to the direction of propagation; and Detection device for surface subcutaneous defects. When the object to be inspected is a long object,
The probe is arranged to send ultrasonic waves in the circumferential direction of the object to be inspected,
The apparatus for detecting a surface defect and a surface subcutaneous defect according to claim 1, wherein the removing unit is provided over the entire circumference of the object to be inspected. Having two of the probes,
The two probes are arranged at different positions in the longitudinal direction of the object to be inspected, and transmit ultrasonic waves in directions opposite to each other in the circumferential direction of the object to be inspected. An apparatus for detecting surface defects and surface subcutaneous defects according to claim 1.   The removal means is an air injection means for injecting air in a direction substantially perpendicular to a propagation direction of an ultrasonic wave transmitted from the probe with respect to a flaw detection range to be inspected. Item 4. The apparatus for detecting a surface defect and a surface subcutaneous defect according to any one of Items 1 to 3. A method for detecting defects in an inspected body using ultrasound,
The surface deposit on the object to be inspected in the ultrasonic propagation direction is removed in a direction substantially perpendicular to the propagation direction,
Sending ultrasonic waves propagating directly under the surface of the object to be inspected,
A method for detecting a surface defect and a surface subcutaneous defect, comprising: receiving at least an ultrasonic wave reflected by a defect in a body to be inspected among ultrasonic waves transmitted to the body to be inspected. When the object to be inspected is a long object,
Sends out ultrasonic waves in the circumferential direction of the test object,
6. The surface defect and surface subcutaneous defect detection method according to claim 5, wherein surface deposits are removed in a direction substantially perpendicular to the propagation direction simultaneously over the entire circumference of the object to be inspected.   7. The surface defect and surface subcutaneous defect detection method according to claim 6, wherein a flaw detection range existing in front of a propagation direction on an inspection object where transmission of ultrasonic waves is started is moved in a longitudinal direction of the inspection object.   The surface defect and the surface subcutaneous defect according to any one of claims 5 to 7, wherein ultrasonic waves are transmitted from different positions in the longitudinal direction of the inspection object in directions opposite to each other in the circumferential direction of the inspection object. Detection method.   The surface defect and the surface subcutaneous defect detection according to claim 5, wherein air is jetted to a flaw detection range of an inspection target so as to be substantially perpendicular to a propagation direction of ultrasonic waves. Method.

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