JP2014006177A - Ultrasonic inspection device, and ultrasonic inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic inspection device, a nozzle attachment, and an ultrasonic inspection method by which stable inspection images can be obtained.SOLUTION: An ultrasonic inspection device includes: scanning means 1 and 2 capable of scanning in a horizontal direction; vertical height adjustment means 3 attached to the scanning means 1 and 2; a holder 5 attached to the height adjustment means 3; an ultrasonic probe 4 attached to the holder 5; a nozzle attachment 6 that flows out water from a nozzle to form a continuous water flow from the ultrasonic probe 4 to a workpiece 9; and gap adjustment means 6 attached to the height adjustment means 3 or the holder 5, and can move the nozzle attachment 6 in the vertical direction.

Description

  The present invention relates to an ultrasonic inspection apparatus, a nozzle attachment, and an ultrasonic inspection method.

  The ultrasonic inspection apparatus irradiates an inspection target (hereinafter referred to as “work”) with ultrasonic waves and receives the reflected or transmitted ultrasonic waves with an ultrasonic probe (hereinafter referred to as “probe”). It is a device that images.

  For example, when the workpiece is an electronic device, it is necessary to detect minute defects, and the ultrasonic inspection apparatus is required to have high resolution. In the ultrasonic inspection apparatus, the higher the frequency of the ultrasonic wave used, the higher the resolution is obtained. On the other hand, the higher the frequency of the ultrasonic wave used, the greater the attenuation and the lower the S / N ratio. Since water has a lower degree of attenuation of ultrasonic waves than air, a normal ultrasonic inspection apparatus performs ultrasonic inspection with the work immersed in water and the space between the probe tip and the work surface filled with water. It is like that. The ultrasonic inspection apparatus focuses on the interface to be observed inside the workpiece, and keeps the distance between the probe tip and the workpiece surface (hereinafter referred to as “water distance”) constant. The position and depth of the defect can be known by imaging the result obtained by scanning the probe.

  Here, when the work is an electronic device that dislikes water, or is a large-sized product or high-temperature object that is difficult to submerge, ultrasonic waves propagate by connecting the tip of the probe and the work surface with a water column. A local water immersion type ultrasonic inspection apparatus has been devised (see, for example, Patent Document 1).

Hei 2-17440

  Generally, in order to obtain a high position resolution, the ultrasonic inspection apparatus has a concave lens shape at the tip of the probe and focuses the ultrasonic wave at the observation position. In the case of a workpiece having a laminated structure inside, in order to observe a plurality of layer interfaces using one probe, it is necessary to measure by changing the water distance for each interface. For example, when observing a deep part of the work (side closer to the bottom of the work), the water distance is made smaller than when observing a shallow part of the work (side closer to the work surface).

  In the conventional ultrasonic inspection apparatus, an attachment for supplying water is directly attached to the housing of the probe, and in order to allow a large degree of freedom in the water distance, a water jet (hereinafter referred to as a nozzle). ) As close to the probe tip as possible. In this case, when the water distance is changed, the length of the water column extending from the nozzle to the workpiece surface changes.

  By the way, in order to acquire an inspection image by the ultrasonic inspection apparatus, it is necessary to scan the probe in the xy plane. For example, after scanning in the x direction, sending a predetermined pitch in the y direction, then scanning in the −x direction, and further sending in the y direction by a predetermined pitch are repeated. Scanning the probe in the x-direction or -x-direction includes an acceleration process from a speed of 0 to a desired speed, a constant speed process at a desired speed, and a deceleration process from a desired speed to a speed of 0.

  When the scanning direction of the probe changes, there is a problem that the water column is swung in the scanning direction of the original probe due to the law of inertia. This phenomenon is remarkable when the acceleration / deceleration of the probe is rapid, the flow rate of water is small, and the water column is long. When the water column is shaken, since ultrasonic waves are transmitted through the water column, there is a possibility that a reflected ultrasonic signal from a position deviated from directly below the probe is captured. In extreme cases, the water column may break into several drops. In this case, since the reflected signal from the first water-air interface as viewed from the probe side rather than from the observation location is taken in, accurate inspection data cannot be obtained.

  Conventionally, as a method for preventing such a phenomenon and obtaining a stable inspection image, a method of scanning a probe over a region wider than an area to be observed, a method of slowing acceleration / deceleration of the probe, and a method of increasing the flow rate of water There is a method of shortening the water column. However, both methods have problems.

  For example, in the method of scanning the probe over a region wider than the region to be observed or the method of slowing the acceleration / deceleration of the probe, the inspection time per work increases. Therefore, it is necessary to reduce the frequency of sampling inspection or increase the number of inspection devices. In the former case, since the probability that an abnormality can be detected is reduced, the reliability of the product is reduced. In the latter case, the manufacturing cost increases.

  In the method of increasing the flow rate of water, in the case of a local water immersion type ultrasonic inspection apparatus, when holding a work, it is necessary to improve the sealing property of the surface that dislikes water, and the cost increases.

Further, in the method of shortening the water column with the conventional ultrasonic inspection apparatus, the degree of freedom of the water distance is reduced and the number of layers that can be observed with one probe is limited. This is because the range in which the probe can be moved up and down is shortened because the water column is short.
Therefore, in the case of a workpiece having a multilayer structure, it is necessary to perform observation while exchanging several probes. This is a great labor for the operator and causes an increase in inspection time. In addition, since a probe is required for each workpiece structure, when a variety of products must be inspected, the number of probes increases, which is not realistic.

  Accordingly, an object of the present invention is to provide an ultrasonic inspection apparatus, a nozzle attachment, and an ultrasonic inspection method that can obtain a stable inspection image.

  In order to solve such a problem, the present invention comprises a scanning means capable of scanning in the horizontal direction, a vertical height adjusting means attached to the scanning means, a holder attached to the height adjusting means, An ultrasonic probe attached to the holder, a nozzle attachment for flowing water from a nozzle to form a continuous water flow from the ultrasonic probe to a workpiece, and attached to the height adjusting means or the holder. An ultrasonic inspection apparatus comprising: gap adjusting means capable of moving the nozzle attachment in a vertical direction.

  The present invention also provides a scanning means capable of scanning in the horizontal direction, a vertical height adjusting means attached to the scanning means, a holder attached to the height adjusting means, and an ultrasonic probe attached to the holder. A water supply path connecting portion for supplying water, a nozzle for discharging water to form a continuous water flow from the ultrasonic probe to the workpiece, and A nozzle attachment comprising: a height adjusting means or a gap adjusting means attached to the holder and movable in a vertical direction.

  Further, the present invention provides a step of forming a continuous water flow from the ultrasonic probe to the workpiece by supplying water to the nozzle attachment and causing the water to flow out from the nozzle, and the ultrasonic wave is adjusted by the height adjusting means. A step of adjusting the height of the probe and the workpiece, a step of adjusting a distance between the nozzle and the workpiece by a gap adjusting means, and an ultrasonic inspection of the workpiece by the ultrasonic probe. And an ultrasonic inspection method comprising: a step.

  According to the present invention, it is possible to provide an ultrasonic inspection apparatus, a nozzle attachment, and an ultrasonic inspection method capable of obtaining a stable inspection image.

It is a perspective view of the ultrasonic inspection apparatus concerning this embodiment. It is a schematic cross section of a probe and a nozzle attachment. It is a schematic cross section of a probe and a nozzle attachment when removing bubbles on the lens surface. (A) is a first example of a flow rate adjusting mechanism, and (b) is a second example of the flow rate adjusting mechanism. It is a schematic cross section of a probe and a nozzle attachment when scanning on a workpiece. It is a schematic cross section of a probe and a nozzle attachment when scanning a workpiece with a large gap. It is an experimental result of the relationship between a gap and the flow volume of water. It is a reflected echo waveform when the nozzle diameter is 7 mm for a probe having a lens diameter of 6 mm. It is a reflected echo waveform when the nozzle diameter is 6 mm with respect to a probe having a lens diameter of 6 mm. It is a reflected echo waveform when the nozzle diameter is 5 mm for a probe having a lens diameter of 6 mm. It is a figure which shows an example of the holding method of the workpiece | work by a workpiece holder. It is a flowchart of the process of the ultrasonic inspection using the ultrasonic inspection apparatus which concerns on this embodiment.

  Hereinafter, modes for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the drawings as appropriate. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.

≪Ultrasonic inspection equipment≫
An ultrasonic inspection apparatus S according to the present embodiment will be described with reference to FIG. FIG. 1 is a perspective view of an ultrasonic inspection apparatus S according to the present embodiment.
As shown in FIG. 1, the ultrasonic inspection apparatus S includes an x-direction scanning unit 1, a y-direction scanning unit 2, a height adjusting unit 3, a probe 4, a probe holder 5, a nozzle attachment 6, and a gap. The adjustment means 7, the water supply path 8, the work holder 10 holding the work 9, and the water receiving pan 11 in which the drain port 12 is formed are provided.

  The probe 4 can transmit ultrasonic waves and receive reflected ultrasonic waves (echoes).

  The probe 4 is fixed to the probe holder 5. The probe holder 5 is attached to the height adjusting means 3. The height adjusting means 3 is attached to the x-direction scanning means 1. The x-direction scanning unit 1 is attached to the y-direction scanning unit 2. The configuration of the probe 4 will be described later with reference to FIG.

  The nozzle attachment 6 causes the water supplied from the water supply path 8 to flow out from a nozzle 61 (see FIG. 2) which is an opening provided on the lower surface of the nozzle attachment 6, and forms a water column between the surface of the work 9. The propagation path of the ultrasonic wave formed and transmitted / received by the probe 4 can be secured.

  The nozzle attachment 6 is attached to the gap adjusting means 7. The gap adjusting means 7 is attached to the probe holder 5. The configuration of the nozzle attachment 6 will be described later with reference to FIG.

The gap adjusting means 7 can move the nozzle attachment 6 in the height direction (z direction). For example, an electric motor (not shown) as a drive source and a rotational movement of the electric motor are used. This can be realized by combining a ball screw mechanism (not shown) which is one of the rotation / linear motion conversion mechanisms for converting into linear motion.
Although the gap adjusting means 7 is described as being attached to the probe holder 5, the gap adjusting means 7 is not limited to this and may be attached to the height adjusting means 3.

  With this configuration, the ultrasonic inspection apparatus S can scan the probe 4 and the nozzle attachment 6 in the x direction by the x direction scanning unit 1, and the probe 4 and the nozzle by the y direction scanning unit 2. The attachment 6 can be scanned in the y direction.

  The scanning of the probe 4 and the nozzle attachment 6 is performed by the following procedure, for example. First, after the probe 4 and the nozzle attachment 6 are scanned in the + x direction (from left to right in FIG. 1) by the x direction scanning means 1, the y direction (from the back in FIG. 1) is scanned at a predetermined pitch by the y direction scanning means 2. Send to the front). Next, after the probe 4 and the nozzle attachment 6 are scanned in the −x direction (from right to left in FIG. 1) by the x direction scanning means 1, the y direction (in FIG. 1) is scanned at a predetermined pitch by the y direction scanning means 2. Send from the back to the front). Thereafter, these are repeated, and the entire region to be inspected is scanned.

  Incidentally, when the probe 4 and the nozzle attachment 6 are scanned in the + x direction or the −x direction by the x direction scanning means 1, an acceleration step for accelerating the probe 4 and the nozzle attachment 6 from a speed of 0 to a predetermined speed, and the probe 4 and the nozzle A constant speed step of moving the attachment 6 at a predetermined speed, and a deceleration step of decelerating from the predetermined speed to zero.

  The ultrasonic inspection apparatus S can adjust the height (z direction) of the probe 4 by the height adjusting means 3. That is, the height adjustment means 3 can adjust the water distance, which is the distance between the lens 41 (see FIG. 2) at the tip of the probe 4 and the surface of the work 9.

  The ultrasonic inspection apparatus S can adjust the height (z direction) of the nozzle attachment 6 by the height adjusting means 3 and the gap adjusting means 7. That is, the gap adjusting means 7 can adjust the distance between the nozzle 61 (see FIG. 2) and the surface of the workpiece 9 (gap 31 described later with reference to FIG. 5) independently of the water distance. It has become.

The ultrasonic inspection apparatus S according to the present embodiment is a local water immersion type ultrasonic inspection apparatus, and the work 9 may be wetted on one surface and side surface, but the other surface is allowed to be wetted. The case where it cannot be demonstrated is demonstrated to an example.
The work holder 10 has a mechanism for holding the work 9 to be inspected and preventing water flowing out from the nozzle 61 (see FIG. 2) from flowing around the lower surface of the work 9.

An example of a method of holding the workpiece 9 by the workpiece holder 10 is shown in FIG. For example, as shown in FIG. 9, the groove 10b in the region sandwiched between the double O-rings 10a is sealed with a double O-ring 10a provided between the lower surface 9a of the work 9 and the work holder 10. In this method, the inside is evacuated by a vacuum pump (not shown) connected via a vacuum pipe 10c (vacuum chuck system). By holding the workpiece 9 in this manner, water can be prevented from flowing around the lower surface 9 a of the workpiece 9.
Note that the work holder 10 shown in FIG. 9 is an example, and does not hinder the adoption of other methods.

Returning to FIG. 1, the bottom surface of the water pan 11 is arranged at a position lower than the holding position of the work 9 of the work holder 10. And so that the work holder 10 and the work 9 are not submerged by the water supplied from the nozzle 61 (see FIG. 2), the water can be drained from the drain port 12 formed on the bottom surface of the water receiving pan 11. ing.
In addition, the structure which returned to the water supply path 8 via the circulation pump and the flow controller may be sufficient as the water which flowed out from the drain port 12, and the structure discharged | emitted out of the ultrasonic inspection apparatus S may be sufficient as it is.

<Probe and nozzle attachment>
Next, the configuration of the probe and nozzle attachment included in the ultrasonic inspection apparatus S according to the present embodiment will be further described with reference to FIG. FIG. 2 is a schematic cross-sectional view of the probe 4 and the nozzle attachment 6.

  The probe 4 includes a lens 41 that is an ultrasonic radiation surface, a signal line 42, a piezoelectric element including an upper electrode 43, a piezoelectric body 44, and a lower electrode 45, and a ground line 46. 2, it is assumed that the signal line 42 is connected to the upper electrode 43 and the ground line 46 is connected to the lower electrode 45, but the ground wire is connected to the upper electrode 43. 46 may be connected, and the lower electrode 45 may be connected to the signal line 42.

Ultrasonic waves generated by applying a high frequency or pulse voltage to the piezoelectric body 44 using the upper electrode 43 and the lower electrode 45 are transmitted to the lens 41 directly or via some medium (not shown in FIG. 2). To the workpiece 9 (see FIG. 1).
In addition, the ultrasonic signal (echo) reflected by the surface of the work 9, the internal interface, defects, etc., follows the reverse path and reaches the piezoelectric element (upper electrode 43, piezoelectric body 44, lower electrode 45). , Converted into an electrical signal. Here, since the signal strength of the echoes returned differs depending on the material of the reflecting surface, the ultrasonic inspection apparatus S can know the positional information of the structure and defects by imaging this as a contrast. Yes.

  The nozzle attachment 6 is attached so as to cover the tip of the probe 4 (lens 41 which is an ultrasonic radiation surface), and a nozzle 61 which is an opening is formed in a portion corresponding to the lower portion of the lens 41. Further, water is supplied from the water supply path 8 to the nozzle attachment 6 via a water supply tube 80 through which water flows in the direction of flow indicated by the arrow 21. Accordingly, the inside of the nozzle attachment 6 is water-tight, and water is dropped from the nozzle 61 onto the surface of the work 9 (see FIG. 1), thereby ensuring an ultrasonic wave propagation path from the lens 41 to the surface of the work 9. It can be done.

  Here, as described above, the probe 4 is fixed to the probe holder 5, and the nozzle attachment 6 can adjust the height with respect to the probe holder 5 by the gap adjusting means 7. That is, the nozzle attachment 6 can be moved up and down with respect to the probe 4. In FIG. 2, the nozzle attachment 6 is shown as a reference. The lens 41 in a state where the nozzle attachment 6 is lowered (a state where the lens 41 and the nozzle 61 are separated) is shown by a solid line, and the nozzle attachment 6 is shown. The lens 41 in a raised state (a state in which the lens 41 and the nozzle 61 are brought close to each other) is illustrated by a broken line.

  It is desirable that the stroke in which the nozzle attachment 6 is moved up and down by the gap adjusting means 7 is approximately the same as the opening length d in the vertical direction of the connecting portion 8a of the water supply path 8. In addition, it is desirable that the attachment position of the water supply path 8 to the nozzle attachment 6 (position of the connecting portion 8a) can be approximately the same height as the lens 41 of the probe 4.

  In order to reduce the flow rate of water, it is desirable that the opening diameter D of the nozzle 61 is small. On the other hand, when the opening diameter D of the nozzle 61 is smaller than the lens diameter φ of the lens 41, the ultrasonic wave hits the nozzle 61 and is reflected, so that the ultrasonic signal reaching the portion to be observed is attenuated and the S / N ratio is small. In addition, unnecessary echoes may return to the piezoelectric element, affecting the measurement. Therefore, it is desirable that the opening diameter D of the nozzle 61 is equal to or larger than the lens diameter φ of the lens 41.

  Further, it is desirable that the opening of the nozzle 61 is provided with a taper 62 so that the lens 41 side is largely opened as shown in FIG. 2 and the work 9 (see FIG. 1) side is opened small. By providing the taper 62, unnecessary echoes can be prevented and the water flow from the nozzle 61 can be stabilized.

<Bubble removal operation>
Next, the removal of the bubbles 13 on the surface of the lens 41 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of the probe 4 and the nozzle attachment 6 when the bubbles 13 on the surface of the lens 41 are removed.

  The lens 41 is a concave lens so that the irradiated ultrasonic wave is focused, and the central part is higher than the outer peripheral part. For this reason, the bubbles 13 may remain on the surface of the lens 41. If the bubbles 13 remain on the surface of the lens 41, the ultrasonic waves are reflected by the bubbles 13, and unnecessary echoes are generated. At the same time, the ultrasonic signal reaching the part to be observed is attenuated and the S / N ratio is increased. Get smaller.

For this reason, the ultrasonic inspection apparatus S according to the present embodiment can remove the bubbles 13 on the surface of the lens 41.
Specifically, as described above, the attachment position of the water supply path 8 to the nozzle attachment 6 (position of the connecting portion 8a) is set to be substantially the same as the lens 41 of the probe 4.

  In such a state, by flowing a large amount of water from the water supply tube 80 in the direction of the arrow 21, the bubbles 13 ride on the water flow and move in the direction of the arrow 22 to be discharged from the nozzle attachment 6. Alternatively, it moves in the direction of the arrow 23 and accumulates on the upper part of the nozzle attachment 6 and is removed from the surface of the lens 41.

  In addition, when viewed in the height direction, the surface of the lens 41 is arranged between a position raised about 3 mm from the upper end of the connection portion 8a and a position lowered about 3 mm from the lower end of the connection portion 8a. The bubble removal effect from the surface of the lens 41 works effectively.

  In addition, when performing the ultrasonic inspection, if the height of the lens 41 is greatly deviated from the height of the connection portion 8a of the water supply path 8, there is a possibility that bubbles cannot be effectively removed. In such a case, the bubbles are removed by moving the lens 41 to a predetermined height after removing the bubbles by setting the position of the connection portion 8a to be approximately the same height as the lens 41 of the probe 4 in advance. Ultrasonography can be done with.

FIG. 4 shows an example of a flow rate adjusting mechanism that adjusts the flow rate of water supplied to the water supply path 8 via the water supply tube 80.
As a method of supplying a large flow rate of water during the bubble removal operation and adjusting to a predetermined flow rate during the ultrasonic inspection operation, for example, as shown in FIG. This can be achieved by setting the flow rate controller 82 at the maximum flow rate during the removal operation and adjusting the flow rate controller 82 to a predetermined flow rate during the ultrasonic inspection operation. As shown in FIG. 4B, the source stream 20 is branched into source streams 20a and 20b. The source stream 20a is provided with a shutoff valve 81a, and the source stream 20b is provided with a shutoff valve 81b and a flow rate controller 82. During the bubble removal operation, the shut-off valve 81a is opened and the shut-off valve 81b is closed to supply a large amount of water, and during the ultrasonic inspection operation, the shut-off valve 81a is closed and the shut-off valve 81b is opened to open the flow controller. 82 may be adjusted to a predetermined flow rate. In the following description, the ultrasonic inspection apparatus S will be described as including the flow rate adjusting mechanism shown in FIG.

<Ultrasonic inspection operation>
Next, the case of performing an ultrasonic inspection by scanning the workpiece 9 will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view of the probe 4 and the nozzle attachment 6 when scanning the workpiece 9.

  A gap 31 that is the distance between the nozzle 61 and the surface of the workpiece 9 is adjusted by the gap adjusting means 7. The height of the gap 31 is a height at which water rises by the surface tension on the surface of the workpiece 9, and specifically, it is desirable to set it to 3 mm or less as will be described later with reference to FIG. Further, the lower limit may be as long as the nozzle 61 does not hit the surface of the workpiece 9.

  As shown in FIG. 5, when the high-speed scanning of the probe 4 and the nozzle attachment 6 is turned from the left to the right (traveling direction 32) in the vicinity of the left end surface of the work 9, the water column is determined from the law of inertia and the ease of water flow. The shape is biased to the side opposite to the traveling direction 32, and water mainly flows in the direction of the arrow 25.

  Here, as described above, when the gap 31 is set below the height at which the water rises due to the surface tension, the water reservoir 24 in which a small amount of water accumulates in the traveling direction 32 of the nozzle 61 due to the surface tension and capillary action. The ultrasonic beam 30 can reach the work 9 by filling the propagation path of the ultrasonic beam 30 with water. Thereby, stable measurement is possible even when the probe 4 and the nozzle attachment 6 are scanned at high speed.

  Next, a state in which scanning is performed with a larger gap while keeping the distance (water distance) between the probe 4 and the workpiece 9 the same as in the example of FIG. 5 will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view of the probe 4 and the nozzle attachment 6 when the gap 9 is enlarged and scanned on the workpiece 9.

As shown in FIG. 6, the height of the gap 31 a is higher than the height at which water rises due to surface tension on the surface of the work 9.
When the high-speed scanning of the probe 4 and the nozzle attachment 6 is turned from left to right (traveling direction 32) in the vicinity of the left end surface of the work 9, the water column is opposite to the traveling direction 32 due to the law of inertia and the ease of water flow. The water flows mainly in the direction of the arrow 25a.

  In the case of FIG. 6, unlike the case of FIG. 5, the water reservoir 24 (see FIG. 5) due to capillary action is not formed on the water column side surface 24 a on the traveling direction 32 side. Due to the fluctuations, a part of the propagation path of the ultrasonic beam 30 may be detached from the water column, and stable measurement cannot be performed. Moreover, when the flow rate of water is small, the water column may be interrupted in the form of water droplets. This is considered to occur when the scanning speed is larger than the falling speed of water.

<Relationship between gap length and water flow rate>
FIG. 7 shows the experimental results of examining the flow rate of water and the gap length with which a stable inspection image can be obtained when the nozzle diameter is 9 mm and the scanning speed is 1000 mm / second. “◯” indicates a condition under which a stable inspection image was obtained, “×” indicates a condition under which only a partial inspection image was obtained, and “-” indicates that no experiment was performed.

As shown in FIG. 7, it can be seen that if the gap length is made larger than 3 mm, a stable image cannot be obtained no matter how the flow rate is changed. As shown in FIG. 6, when the scanning direction changes from right to left or from left to right, an air layer enters between the lens 41 and the work 9 by shaking the water column according to the law of inertia. It is thought to be because.
Further, when the flow rate was increased (when the flow rate was 1.0 (L / min), 1.4 (L / min)), a phenomenon that bubbles were formed on the surface of the work 9 was also observed.

  On the other hand, when the gap length is 3 mm or less, a stable inspection image can be obtained by appropriately setting the flow rate of water. It was also found that a stable image can be obtained with a smaller amount of water as the gap length becomes smaller.

<Relationship Between Aperture Diameter D of Nozzle 61 and Lens Diameter φ of Lens 41>
Next, reflected echo waveforms when the opening diameter D of the nozzle 61 is set to 7, 6, and 5 mm with respect to the probe 4 having a lens diameter φ of 6 mm are shown in FIGS. 8A to 8C.
FIG. 8A shows a case where the lens diameter φ is 6 mm and the nozzle opening diameter D is 7 mm, E ₁₁ is a reflected echo from the surface of the work 9, and E ₁₂ is a reflected echo from the interface where the ultrasonic waves are focused. . FIG. 8B shows a case where the lens diameter φ is 6 mm and the nozzle opening diameter D is 6 mm, E ₂₁ is a reflected echo from the surface of the work 9, and E ₂₂ is a reflected echo from the interface where the ultrasonic waves are focused. . FIG. 8C shows a case where the lens diameter φ is 6 mm and the nozzle opening diameter D is 5 mm, E ₃₁ is a reflected echo from the surface of the workpiece 9, and E ₃₂ is a reflected echo from the interface where the ultrasonic waves are focused. .

The reflection echo E ₃₂ with the nozzle opening diameter D = 5 mm has a smaller signal intensity and a lower S / N ratio than the reflection echoes E ₁₂ and E ₂₂ with the nozzle opening diameter D = 7 mm and 6 mm. I understand that. This is because a part of the ultrasonic wave is reflected by the edge of the nozzle 61 and the energy irradiated to the focal position is lowered. Therefore, it is desirable that the opening diameter D of the nozzle 61 is equal to or larger than the lens diameter φ of the lens 41.

≪Ultrasonic inspection device processing≫
An ultrasonic inspection process using the ultrasonic inspection apparatus S according to the present embodiment will be described with reference to FIG. FIG. 10 is a flowchart of ultrasonic inspection processing using the ultrasonic inspection apparatus S according to the present embodiment.

  In step S <b> 1, the inspector sets the workpiece 9 on the workpiece holder 10. At this time, the probe 4 is disposed at the origin position. If necessary, an appropriate probe 4 for observing the workpiece 9 is set in the probe holder 5.

  In step S2, the ultrasonic inspection apparatus S opens the shut-off valve 81 (see FIG. 4A) and supplies water from the water supply path 8 to the nozzle attachment 6 to form a water column.

In step S <b> 3, the ultrasonic inspection apparatus S controls the gap adjusting means 7 so that the position of the connection portion 8 a of the water supply path 8 is substantially the same as the lens 41 of the probe 4.
In step S4, the ultrasonic inspection apparatus S controls the flow rate controller 82 (see FIG. 4A) to make the flow rate of water larger than that during the ultrasonic inspection and remove the bubbles 13 on the surface of the lens 41. . When the removal of the bubbles 13 is completed, the flow rate controller 82 is controlled to set the flow rate of water to the flow rate at the time of ultrasonic inspection, and the process proceeds to step S5.

  In step S <b> 5, the ultrasonic inspection apparatus S controls the x-direction scanning unit 1 and the y-direction scanning unit 2 to move the probe 4 to the observation position of the workpiece 9. In order to prevent the nozzle 61 from coming into contact with the surface of the workpiece 9 during the movement, it is desirable to place the probe 4 and the nozzle attachment 6 at a high position by the height adjusting means 3.

  In step S <b> 6, the ultrasonic inspection apparatus S controls the height adjusting unit 3 to adjust the water distance, which is the distance between the probe 4 and the surface of the work 9, so Focus the ultrasound.

  In step S <b> 7, the ultrasonic inspection apparatus S controls the gap adjusting means 7 to adjust the gap 31 that is the distance between the nozzle 61 and the surface of the workpiece 9. Specifically, the gap 31 is adjusted to an appropriate position of 3 mm or less.

  In step S <b> 8, the ultrasonic inspection apparatus S controls the x-direction scanning unit 1 and the y-direction scanning unit 2 to perform ultrasonic inspection with the probe 4 while scanning the probe 4.

  In step S9, the ultrasonic inspection apparatus S controls the x-direction scanning unit 1 and the y-direction scanning unit 2 to move the probe 4 to the origin position. In order to prevent the nozzle 61 from coming into contact with the surface of the workpiece 9 during the movement, it is desirable to place the probe 4 and the nozzle attachment 6 at a high position by the height adjusting means 3.

  Thus, the ultrasonic inspection of the work 9 is finished. If necessary, the inspected work 9 is removed from the work holder 10, a new work 9 is set in the work holder 10, and a series of ultrasonic inspection processes are performed.

  In addition, although it demonstrated as what performs bubble removal operation | movement (S3, S4) in the origin position shown in FIG. 10, it is not restricted to this, A water column is formed in an origin position (S2), and the probe 4 is set to observation position. After moving to (S5), the bubble removal operation (S3, S4) may be performed. Further, after moving the probe 4 to the observation position (S5), a water column may be formed at the origin position (S2), and the bubble removing operation (S3, S4) may be performed.

<Action and effect>
As described above, according to the ultrasonic inspection apparatus S according to the present embodiment, even when the probe 4 is scanned at a high speed, the water reservoir 24 (see FIG. 5) is formed on the traveling direction side and a stable water column (super (Sound propagation path) is formed, and a stable inspection image can be obtained even if the flow rate of water is small. Moreover, since the height of the probe 4 and the nozzle attachment 6 can be adjusted independently, the height (water distance) of the probe 4 is not limited.
Further, since the flow rate of water can be reduced, a simple structure as shown in FIG. 9 is sufficient for the seal structure of the work holder 10 that protects the lower surface 9a of the work 9 from water.

  In addition, according to the ultrasonic inspection apparatus S according to the present embodiment, since the bubble removing operation for removing the bubbles 13 on the surface of the lens 41 can be performed, a stable inspection image can be obtained.

Ultrasonic inspection equipment S
1 x-direction scanning means (scanning means)
2 y-direction scanning means (scanning means)
3 Height adjustment means 4 Probe (ultrasonic probe)
5 Probe holder (holder)
6 Nozzle attachment 7 Gap adjustment means 9 Work piece 8 Water supply path 8a Connection part 31 Gap (distance between nozzle and work piece)
41 Lens 61 Nozzle 81, 81a, 81b Shut-off valve (flow rate adjusting means)
82 Flow rate controller (flow rate adjustment means)
D Aperture diameter φ Lens diameter

The present invention is an ultrasonic inspection device, Contact and relates to an ultrasonic inspection method.

Accordingly, the present invention is a stable ultrasonic inspection apparatus inspecting images is obtained, contact and, it is an object to provide an ultrasonic inspection method.

In order to solve such a problem, the present invention comprises a scanning means capable of scanning in the horizontal direction, a vertical height adjusting means attached to the scanning means, a holder attached to the height adjusting means, An ultrasonic probe attached to the holder, a nozzle attachment that flows out water from the nozzle to form a continuous water flow from a lens provided at the tip of the ultrasonic probe to the surface of the workpiece , and the height adjusting means or A gap adjusting unit attached to the holder and capable of moving the nozzle attachment in a vertical direction, and the height adjusting unit can adjust a distance between the lens and the surface of the workpiece, and the gap adjusting unit. By changing the position of the lens of the ultrasonic probe in the vertical direction inside the nozzle attachment, An ultrasonic inspection device, characterized in that adjustable distance between the facing surface and the surface of the workpiece and the workpiece of the nozzle.

The present invention also includes a scanning means capable of scanning in the horizontal direction, a vertical height adjusting means attached to the scanning means, a holder attached to the height adjusting means, an ultrasonic probe attached to the holder, and a nozzle. A nozzle attachment for flowing water to form a continuous water flow from the lens provided at the tip of the ultrasonic probe to the surface of the workpiece, and the nozzle attachment attached to the height adjusting means or the holder in the vertical direction an ultrasonic testing method of the ultrasonic inspection apparatus having a gap adjusting means, movable in, by supplying water to the nozzle attachment, by which water flows out from the nozzle, the surface of the workpiece from the lens forming a continuous water flow to, the lens and the workpiece by the height adjusting means And adjusting the height of the surface, and the step of adjusting the distance between the opposing surface and the surface of the workpiece and the workpiece of the nozzle by the gap adjusting means, ultrasonography of the work by the ultrasonic probe And a step of executing the ultrasonic inspection method.

According to the present invention, stable ultrasonic inspection apparatus inspecting images is obtained, contact and can provide an ultrasonic inspection method.

Claims (15)

Scanning means capable of scanning in the horizontal direction;
A vertical height adjusting means attached to the scanning means;
A holder attached to the height adjusting means;
An ultrasonic probe attached to the holder;
A nozzle attachment that flows water out of the nozzle to form a continuous water flow from the ultrasonic probe to the workpiece;
An ultrasonic inspection apparatus comprising: a gap adjusting unit attached to the height adjusting unit or the holder and capable of moving the nozzle attachment in a vertical direction. At the time of ultrasonic inspection, the gap adjusting means is
The ultrasonic inspection apparatus according to claim 1, wherein a distance between the nozzle and the workpiece is 3 mm or less. When removing bubbles on the lens surface of the ultrasonic probe, the gap adjusting means is
The ultrasonic inspection apparatus according to claim 1, wherein a water supply path connection portion of the nozzle attachment is substantially the same height as the lens. A flow rate adjusting means for adjusting a flow rate of water supplied to the nozzle attachment;
The flow rate adjusting means is
The ultrasonic inspection apparatus according to claim 3, wherein a flow rate supplied at the time of removing the bubbles is larger than a flow rate supplied at the time of the ultrasonic inspection. The ultrasonic inspection apparatus according to claim 1, wherein an opening diameter of the nozzle is equal to or larger than a lens diameter of a lens of the ultrasonic probe. Ultrasound comprising scanning means capable of scanning in the horizontal direction, vertical height adjusting means attached to the scanning means, a holder attached to the height adjusting means, and an ultrasonic probe attached to the holder A water supply path connection for connecting the inspection device and supplying water;
A nozzle that flows out water to form a continuous water flow from the ultrasonic probe to the workpiece;
A nozzle attachment comprising: a gap adjusting means attached to the height adjusting means or the holder and movable in a vertical direction. At the time of ultrasonic inspection, the gap adjusting means is
The nozzle attachment according to claim 6, wherein a distance between the nozzle and the workpiece is 3 mm or less. When removing bubbles on the lens surface of the ultrasonic probe, the gap adjusting means is
The nozzle attachment according to claim 6, wherein the water supply path connection portion has substantially the same height as the lens. Equipped with a flow rate adjusting means for adjusting the flow rate of water,
The flow rate adjusting means is
The nozzle attachment according to claim 8, wherein a flow rate supplied at the time of removing the bubbles is larger than a flow rate supplied at the time of the ultrasonic inspection. The nozzle attachment according to any one of claims 6 to 9, wherein an opening diameter of the nozzle is equal to or larger than a lens diameter of the lens of the ultrasonic probe. Forming a continuous water flow from the ultrasonic probe to the workpiece by supplying water to the nozzle attachment and causing the water to flow out of the nozzle;
Adjusting the height of the ultrasonic probe and the workpiece by a height adjusting means;
Adjusting the distance between the nozzle and the workpiece by a gap adjusting means;
Performing an ultrasonic inspection of the workpiece by the ultrasonic probe. An ultrasonic inspection method comprising: Adjusting the distance comprises:
The ultrasonic inspection method according to claim 11, wherein a distance between the nozzle and the workpiece is 3 mm or less. Forming the water stream comprises:
The ultrasonic wave according to claim 11, wherein bubbles are removed from the surface of the lens by setting the water supply path connection portion of the nozzle attachment to substantially the same height as the lens of the ultrasonic probe by the gap adjusting means. Inspection method. Forming the water stream comprises:
The ultrasonic inspection apparatus according to claim 13, wherein a flow rate of water supplied to the nozzle attachment is larger than a flow rate supplied during the step of executing the ultrasonic inspection. The ultrasonic inspection method according to claim 11, wherein an opening diameter of the nozzle is equal to or larger than a lens diameter of a lens of the ultrasonic probe.

Images