JP2612351B2 - Ultrasonic inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ultrasonic inspection apparatus for inspecting a test material for defects using ultrasonic waves.

[Conventional technology]

An ultrasonic inspection device can inspect the presence or absence of a defect inside a test material without destroying the test material, and is used in many fields. The inspection for the presence / absence of a defect inside the test material is performed by scanning the surface of the test material with ultrasonic waves. There are various methods for scanning by such an ultrasonic wave. Among these methods, an ultrasonic inspection apparatus using an array probe is excellent in that it can perform ultrasonic scanning in a short time. I have. Hereinafter, such an ultrasonic inspection apparatus will be described with reference to the drawings.
Since it is known from Japanese Patent Application Laid-Open No. 197649 or the like, its description is merely a brief description.

FIG. 4 is a block diagram of a conventional ultrasonic inspection apparatus.
In the figure, reference numeral 1 denotes an array probe that emits an ultrasonic wave and receives its reflected wave. The array probe 1 will be described in more detail with reference to FIG. Reference numeral 2 denotes a control circuit that emits ultrasonic waves from the array probe 1 in a predetermined mode and processes the reflected waves. Reference numeral 3 denotes a motor for moving the array probe 1 in a predetermined direction, and reference numeral 4 denotes an encoder for detecting a rotation amount of the motor 3. Reference numeral 5 denotes a CPU (microprocessor unit) for performing various controls of the ultrasonic inspection apparatus, which is constituted by a micro computer. Reference numeral 6 denotes a keyboard for inputting necessary commands to the CPU 5, and reference numeral 7 denotes an interface used to exchange signals between the CPU 5 and the outside. Reference numeral 8 denotes an image memory that stores data obtained from the ultrasonic reflected waves as data of an ultrasonic image, and 9 denotes a display unit that displays data of the image memory 8.

FIG. 5 is a side view of the array probe shown in FIG.
Reference numeral 1 denotes an array probe shown in FIG. 4, and reference numeral 11 denotes a support arm for supporting the array probe 1. A _{1 to An} are array transducers arranged in a row in a predetermined direction below the array probe 1. A piezoelectric element is used for each of these array transducer A ₁ to A _n.

Now, when the array transducers A _{1 to} A ₈ are selected as a group and a pulse voltage having a predetermined delay time is applied to each of the array transducers, the ultrasonic beam B shown in FIG. ₁ is emitted. The delay time is a delay time for the array transducer A ₁ to A ₈ When t ₁ ~t ₈ respectively, the _{t 1 = t 8 <t 2} = t 7 <t 3 = t 6 <t 4 = t 5 Selected. Incidentally, the focal point of the delay reducing the time (larger) Then ultrasonic beams B ₁ is longer (shorter), thereby to select the depth of the inspection surface of the material being tested.

Next, the array transducer is shifted by one, and array transducers A ₂ to
When a new group of A ₉ is selected and given a pulse voltage with a delay time of the same pattern as above, a new ultrasonic beam B ₂ identical to the ultrasonic beam B ₁ is output from the ultrasonic probe 1.
(Indicated by dashed lines) are emitted.

Continuing with this process, from the array probe 1, it becomes possible ultrasonic beam B ₁ ~B _n-7 Yuku are sequentially emitted, since the selection switching of these array transducer is carried out electronically, compared to those of method of performing scanning mechanically transition the probe emits a single beam will be sequential transition of the ultrasonic beam B ₁ ~B _n-7 (scanning) is carried out at high speed, Inspection time can be significantly reduced. In addition,
In FIG. 5, AP indicates an array oscillator pitch, SP indicates a sampling pitch, and both are the same pitch.

FIG. 6 is an explanatory diagram of an inspection method for inspecting a test material using the array probe shown in FIG. 1 is an array probe,
A _{1 to An} are array transducers, and 13 is a test material. X and Y indicate coordinate axes. Usually, the array probe 1 and the test material 13 are opposed to each other via water, and the ultrasonic beam is transmitted and received using water as a medium. In the figure, each black point indicates a sampling point by an ultrasonic beam, and its position is represented by X and Y coordinates. X
The scanning in the axial direction is performed electronically as described above, and the scanning in the Y-axis direction is mechanically performed by driving a motor in accordance with a command from the CPU 5 to move the array probe 1 in the Y-axis direction.

The reflected wave of the ultrasonic beam at each sampling point is
The ultrasonic beam is received by each array transducer of the array transducer group that has emitted the ultrasonic beam, and is converted into an electric signal. Each of these electrical signals is added to one by being given a delay time in the relationship described above. The added signal is fetched by the CPU 5 through processes such as amplification, detection, peak value detection, and A / D conversion in the control circuit 2, and is stored in the image memory 8 as ultrasonic image data at the sampling point. .
When the display is instructed by the keyboard 6 after the scanning of all the sampling points is completed, an ultrasonic image based on the data stored in the image memory 8 is displayed on the display unit 9, and the presence or absence of a defect is inspected by looking at the ultrasonic image. You.

[Problems to be solved by the invention]

The ultrasonic inspection apparatus using the above-described array probe 1 has the advantage of being able to perform quick scanning and greatly reducing the inspection time as described above, but has the following problems.

As shown in FIG. 5, the sampling pitch SP of the ultrasonic beam in the array transducer array direction (the X-axis direction in FIG. 6) by the array probe 1 is equal to the pitch AP of each array transducer. AP is determined by the size of the array transducer. By the way, when observing the ultrasonic image displayed on the display unit 9, there is a case where a more precise ultrasonic image is required. Such a fine ultrasonic image can be obtained by selecting a smaller sampling pitch in the X-axis direction and the Y-axis direction. In this case, the sampling pitch in the Y-axis direction can be made very small by controlling the motor 3, but the sampling in the X-axis direction is determined by the size of the array vibrator as described above, so that it is made smaller. It is impossible to obtain a fine ultrasound image after all.

In order to make the sampling pitch variable, the number of array transducers involved in the generation of the ultrasonic beam is made variable or given to each selected array transducer as described in, for example, JP-A-54-162811. Means for changing the delay time have been proposed. However, the number of pitches obtained by this method is not only limited, but also the apparatus becomes complicated.

An object of the present invention is to solve the above-mentioned problems in the conventional technology and to provide an ultrasonic inspection apparatus capable of easily obtaining a fine ultrasonic image using an array probe.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an array probe having a large number of array transducers arranged thereon, and a specific number of adjacent array transducers which are sequentially shifted to excite the array transducer. A control unit that performs scanning of the ultrasonic beam in the arrangement direction, a moving mechanism that moves at least one of the array probe and the inspection object in a direction orthogonal to the arrangement direction, and is sampled by the ultrasonic beam. Storage unit that stores the data stored therein, and a display unit that displays an ultrasonic image based on the data stored in the storage unit, an ultrasonic inspection apparatus including: A specific ultrasonic beam generating means for repeatedly generating an ultrasonic beam using only a specific array transducer, and at least one of the array probe and the object to be inspected are arranged in the arrangement; Characterized by providing the other moving mechanism for moving at any pitch in the direction.

According to still another aspect of the present invention, in addition to the above aspect, an area indicating means for displaying an arbitrary area on the display unit, and only the real area on the inspection object corresponding to the area displayed by the area indicating means is subjected to ultrasonic wave A drive control unit that drives each of the moving mechanisms to scan, and an enlarged display unit that displays an enlarged ultrasonic image of the real area on the display unit based on data obtained by ultrasonic scanning of the real area. Is provided.

(Operation)

In the array probe, first, a plurality of specific array transducers are selected, and one ultrasonic beam is repeatedly generated using these array transducers. Then, the array probe is moved by pitches of an arbitrary size in the arrangement direction of the array transducers, thereby scanning in the arrangement direction with the one ultrasonic beam.

According to another aspect of the invention, when performing the above-described scanning, a scanning region of the test material is designated on the display of the display unit, only this scanning region is scanned, and an ultrasonic wave in that region is scanned based on the obtained data. The image is enlarged and displayed on the display unit.

〔Example〕

 Hereinafter, the present invention will be described with reference to the illustrated embodiments.

FIG. 1 is a block diagram of an ultrasonic inspection apparatus according to an embodiment of the present invention. In the figure, the same or equivalent parts as those shown in FIG. Reference numeral 15 denotes a motor that moves the array probe 1 in the array direction (X-axis direction) of the array transducers, and 16 denotes an encoder that detects the amount of rotation of the motor 15. Usually, an ultrasonic inspection apparatus using an array probe is configured such that a test material is placed in a water tank filled with water, guides extending in the Y-axis direction on both sides of the water tank, and movably mounted on both guides. The support arm 11 shown in FIG. 5 is attached to a position facing the test material on the arm. The motor 3 is for moving the arm in the Y-axis direction along the guide.
The array probe also moves in the Y-axis direction integrally with the arm. The motor 15 is for moving the support arm 11 in the X-axis direction along the arm, whereby the array probe can also move in the X-axis direction integrally with the support arm 11. it can.

Next, the operation of the present embodiment will be described with reference to the front view of the display unit 9 shown in FIGS. 2A to 2C and the side view of the array probe shown in FIG. FIG. 2A is a diagram in which data obtained by a conventional method of scanning electronically in the X-axis direction and mechanically scanning in the Y-axis direction is displayed on the display unit 9. At this time, the array probe has returned to its original position since all scanning has been completed. In FIG. 2 (a), 9a the display surface of the display unit 9, C ₁ is a pop box cursor displayed on the display surface 9a. 13P denotes an ultrasonic image of the test material 13 (a test material different from the test material shown in FIG. 6), and F denotes a defective portion of the test material 13.

When observing the above image, it may be necessary to know the state of the defective portion more precisely. In this case, the viewer is first a region to be observed finely, and instructs to display the second pop box cursor C ₂ on a display screen 9a, as shown in FIG. 2 (b) by a key scanning of the keyboard 6 . Incidentally, the breadth of the region can be determined by inputting the magnification by the keyboard 6, and may be indicated by the position keyboards 6 of pop box cursor C _2.

Next, the observer instructs “start the enlargement scan” by scanning the keys of the keyboard 6. In this case, the scanning start position S is set to the box cursor as shown in FIG.
The upper-left corner of the C _2. Here, since the address of the image memory 8 and each pixel constituting the display surface 9a are associated with each other on a one-to-one basis, the coordinates (x _i , y _j) of the start position S on the XY plane which is the scanning plane are used. Is immediately judged by the CPU 5. CPU5 Based on this determination, selects an i-th array transducer so as to generate an ultrasonic beam B _i in the array probe 1.

FIG. 3 shows the generation of the ultrasonic beam B _i (B ₆ ) when i = 6. In this case, the array transducer A ₆ to A ₁₃ is selected, a pulse is applied by the same delay pattern and previously described. The ultrasonic beam B _i is being caused to repeatedly occur. Further, the CPU 5 drives the motor 3 to move the array probe 1 by (j × SP) in the Y-axis direction. As a result, the ultrasonic beams B _i will move to the actual position corresponding to the start position S.

Next, the CPU 5 fixes the selection of the array transducer, that is, fixes the emission position of the ultrasonic beam from the array probe 1,
In a state in which the ultrasonic beam was repeatedly generated to drive the motor 3, 15 based on the magnification instructed previously, to scan the actual area corresponding to the indicated area in pop box cursor C ₂ . For example, if the magnification is instructed threefold, motor 15 moves the X-axis direction to the actual position corresponding to an array probe 1 to the right end of the pop box cursor C ₂ in pitch of 1/3 of the pitch AP And then motor 3
Moves the array probe 1 in the Y-axis direction by 1/3 of the pitch AP, and then the motor 15 moves the array probe 1 in the X-axis reverse direction with the same pitch. Scan of the actual area corresponding with the repetition of this operation in a region designated by a pop box cursor C ₂ is performed. Data obtained by this scanning is stored at a predetermined address of the image memory 8.

FIG. 2 (c) shows an enlarged ultrasonic image displayed on the display surface 9a based on the data obtained by the above scanning. In the example where the magnification is 3 times, the ultrasonic image is magnified 3 times both vertically and horizontally, so that the defective portion F is displayed finely.

As described above, in the present embodiment, the position where the ultrasonic beam is generated from the array probe is fixed, and the array probe can be moved in the X-axis direction while repeatedly generating the ultrasonic beam. A fine ultrasonic image can be obtained for the apparatus without losing the original function of the array probe of high-speed scanning in a normal state.

In addition, the characteristics of each array oscillator and the characteristics of their transmission / reception circuits are not uniform, and even if sensitivity adjustment is performed by any means, avoid the existence of uneven sensitivity among channels of each array oscillator. Therefore, if means for changing the selection of the array transducer is used, image noise due to uneven sensitivity will be mixed in the ultrasonic image, especially when a fine ultrasonic image is to be observed. Is inconvenient.
However, in the present embodiment, since the ultrasonic beam is generated using only the selected specific array transducer, the above-described problem of the sensitivity unevenness does not occur. A sound image can be obtained.

Further, since no means such as changing the number of array transducers to be selected or changing the delay time of the selected array transducers is used and only a specific array transducer is selected, the apparatus is extremely simple. Can be configured.

In the description of the above-described embodiment, an example has been described in which the ultrasonic beam (i-th ultrasonic beam) corresponding to the upper left corner of the box cursor is generated. Obviously it is good.
Also, an example has been described in which only the predetermined area is mechanically scanned. However, after mechanically scanning the entire area, data may be displayed using the data of the predetermined area. Further, although a 1/3 pitch has been illustrated as an example, the pitch can be freely selected in each of the X-axis direction and the Y-axis direction. Furthermore,
In the description of the above embodiment, an example in which the array probe is moved in the X-axis direction has been described. However, the test material may be moved, or both may be moved.

〔The invention's effect〕

As described above, in the present invention, in a state where the generation position of the ultrasonic beam from the array probe is fixed and the ultrasonic beam is repeatedly generated, scanning in the array direction of the array transducer is performed by the ultrasonic beam. Since the operation is performed mechanically, a fine ultrasonic image can be obtained without losing the original function of the array probe, that is, high-speed scanning in a normal state. Further, since an ultrasonic beam is generated using only the selected specific array transducer, there is no unevenness in sensitivity, and a fine ultrasonic image can be obtained from this plane. Further, the means of changing the number of array transducers to be selected, or changing the delay time of the selected array transducers is not used,
Since only a specific array transducer is selected, the device can be configured very simply.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ultrasonic inspection apparatus according to an embodiment of the present invention, FIGS. 2 (a), (b) and (c) are front views of the display unit shown in FIG. 1, respectively. FIG. 4 is a side view of an array probe, FIG. 4 is a block diagram of a conventional ultrasonic inspection apparatus, and FIG.
FIG. 6 is a side view of the array probe, and FIG. 6 is an explanatory view of an inspection method of the apparatus shown in FIG. 1 ... array probe, 2 ... control circuit, 3, 15 ... motor, 5 ... CPU, 6 ... keyboard, 8 ... image memory, 9 ... display unit.

Claims (2)

(57) [Claims] An array probe having a large number of array transducers arranged thereon and an adjacent specific number of the array transducers are sequentially shifted to be excited to generate an ultrasonic beam in an array direction of the array transducers. A control unit for performing scanning, a moving mechanism for moving at least one of the array probe and the inspection object in a direction orthogonal to the arrangement direction, and a storage unit for storing data sampled by the ultrasonic beam And an ultrasonic inspection apparatus including a display unit that displays an ultrasonic image based on the data stored in the storage unit, wherein only a plurality of specific array transducers selected from the array transducers are displayed. A specific ultrasonic beam generating means for generating an ultrasonic beam by using at least one of the array probe and the inspection object at an arbitrary pitch in the arrangement direction; That other mobile mechanism and ultrasonic inspection apparatus characterized in that a. 2. An ultrasonic inspection apparatus according to claim 1, wherein: an area indicating means for displaying an arbitrary area on said display unit; and an area on the inspection object corresponding to the area displayed by said area indicating means. A drive control unit that drives each of the moving mechanisms so as to ultrasonically scan only the real region, and an enlarged ultrasonic image of the real region on the display unit based on data obtained by ultrasonic scanning of the real region. An ultrasonic inspection apparatus, comprising: an enlarged display means for displaying.