JPS61245011A - Ultrasonic thickness gauge - Google Patents

Abstract

PURPOSE:To always present information required most for analyzing a result of measurement by extracting the maximum thickness and the minimum thickness from the stored thickness data, and displaying them visually. CONSTITUTION:An electric pulse for driving an ultrasonic probe 104 is outputted from an ultrasonic wave generating circuit 152, by which through a route (h) from a transmitting part (g) of the probe 104, an ultrasonic wave is made incident on the inside of a body to be inspected 105 through a medium 160. Also, the ultrasonic wave which has been reflected by the reverse side is inputted to a receiving part (i) of the probe 104, converted to an electrical signal and sent to a centralized controlling circuit 151. On the other hand, a part of the ultrasonic wave generated by the probe 104 is reflected by the surface of the body to be inspected 105 and inputted to the receiving part (i). Subsequently, by a controlling circuit 151, an input time difference of the respective echo signals from the surface and the reverse side of the body to be inspected 105 is measured, and a thickness of the body to be inspected 105 is calculated. Moreover, from a data which has been stored in a storage device 156, the maximum thickness and the minimum thickness are extracted and displayed visually, and information required most for analyzing a result of measurement is always presented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention generally relates to an ultrasonic inspection device, and more specifically to an ultrasonic thickness inspection device that measures the thickness of an object using ultrasonic waves. This is related to the meter.

[Prior Art] Conventionally, a hand-held ultrasonic thickness gage uses an ultrasonic probe that is pressed against the surface of an object to be inspected, such as a steel plate, through a medium liquid (couplant) and brought into contact. The thickness of the specimen was measured by numerically displaying the thickness to the back surface of the specimen, or the thickness at several specific points was measured to estimate the corrosion state of the back surface. According to this method, even if the specimen has different thicknesses within a narrow range, is locally corroded, or has internal defects, it is often impossible to detect these. Furthermore, since the data display displays the thickness of the measurement point as a numerical value, it is difficult to continuously grasp the condition of the back surface of the object.

[Problems to be Solved by the Invention] The purpose of the present invention is to solve the above-mentioned problem of overlooking changes in thickness due to measurement of discontinuous points or the presence of internal defects, and to solve the problem of overlooking the presence of internal defects. The object of the present invention is to solve the problem that it is difficult to grasp the condition of the back side by displaying only the numerical value of the size.

The purpose of this invention is to detect continuous changes in thickness by continuous measurement according to the present invention, and to display the measured data on a visually appealing graphic display to show the continuous connection of thickness, that is, a cross-sectional view of the object. This is achieved by making it possible to automatically obtain the information such as the back surface condition of the object and the distribution condition of internal defects, etc.

In particular, in the present invention, the maximum thickness and minimum thickness are extracted from the stored thickness data and visually displayed, thereby constantly presenting the information required for analysis of the measurement results. The aim is to achieve the following goals.

[Means for Solving the Problems] That is, the ultrasonic thickness gauge of the present invention includes: a sound velocity input means; a graphic display device; an ultrasonic probe: an ultrasonic generator connected to the ultrasonic probe; circuit; an ultrasonic receiving circuit connected to the ultrasonic probe and receiving an echo signal from the subject directly under the ultrasonic probe; and to the sound velocity input means and the ultrasonic receiving circuit; means for calculating the thickness of the object from the echo signal, means for storing position data of the object and corresponding thickness data, and means for reading out the position data and thickness data of the object. A central control circuit including means for presenting a cross-sectional view on the graphic display device, and means for reading the maximum thickness and minimum thickness from the stored thickness data and presenting it on the graphic display device. Features.

[Operation] The thickness of steel materials, etc. is measured by bringing an ultrasonic probe into contact with it.
This measurement is performed not only at the stationary contact part of the probe, but also by storing the thickness data at each position as numerical values when the probe is continuously moved while maintaining the contact state, and by obtaining multiple consecutive thickness data. An image display that shows a cross-sectional view directly below the moving route is also performed.

Particularly, in the present invention, the maximum thickness and minimum thickness are extracted from the stored thickness data and visually displayed, so that information required for analysis of measurement results is constantly presented.

[Example] FIG. 1 is a perspective view of an ultrasonic thickness gauge according to an example of the present invention. 1 is the main body of the ultrasonic thickness gauge with a graphic display device, 2 is a battery box that stores batteries as a power source, 3 is a power switch that controls the power supply to the load, and 4 is an ultrasonic probe that measures the thickness. It is electrically connected to the needle body 1 by a flexible cable. The ultrasonic probe 4 is generally divided into two parts, one for transmitting and one for receiving, and converts the amount of electricity transmitted from the thick needle body into ultrasonic waves, which are incident and propagated inside the subject 5. The ultrasonic waves reflected from the bottom surface of the subject are received again by the probe 4 and converted into electrical signals. This electrical signal is guided to the thickness needle body, and thickness data is obtained from this received information. The graphic display panel 6 not only displays the data from the probe 4, but also displays the sound speed from 0 to
Input and display using 10 numerical keys (numeric keypad) 8 of 9. In addition to the numeric keys, the keyboard 7 also has an erase or CLR key 9 for erasing old data from the graphic display panel 6, a unit changeover switch 10 for the thickness direction, and a position for confirming the thickness at a desired position. A left movement switch 11 and a right movement switch 12 are provided to move the mark.

Furthermore, the display panel 6 allows the probe 4 to move along the linear scanner 13 and inputs the position signal of the probe 4 to the thickness needle body 1 through a flexible cable.
Using this probe position information and the above-mentioned thickness information, a cross-sectional view is obtained in which the position of the portion where the probe has moved is plotted on the vertical axis and the thickness on the horizontal axis, and this is displayed on the display panel 6. do. Also, the distance to the back surface closest to the surface of the object in this cross-sectional view,
That is, the minimum thickness and the distance from the front surface of the object to the farthest back surface, that is, the maximum thickness are automatically searched for, and these are displayed as numerical data in sections a and b. Furthermore, the thickness of the object at the position indicated by the moving mark is also displayed in the 0 section. 14 is a correction volume for measurement data, which will be described later with reference numeral 1 in Fig. 2.
Corresponds to 14. Note that the cables of the probe 4 and the scanner 13 are connected to the thickness needle body by connectors d, e, and f, respectively.

FIG. 2 is an electrical block diagram showing an embodiment of the present invention. Reference numeral 102 denotes a power supply battery with a voltage of 18, and 103 a power switch. When the power switch 103 is turned on, a DC-DC converter 150 operates to generate a required power supply voltage. For example, the power supply Vc is a power supply for the central control circuit 151 and the like, and is +5V, the power supply Vo is a power supply for driving the display panel 106 and is -8V, and the power supply VE is a power supply for the ultrasonic generation circuit 152 and is +100V.

Electric pulses that drive the ultrasonic probe 104 are output from the ultrasonic generation circuit 152 at a repetition frequency of 1 kHz. The ultrasonic wave enters the inside of the subject 105 via a medium 160 such as an oil film, and the ultrasonic wave reflected from the back surface enters the wave receiving part i of the probe 104. The electrical signal converted here is amplified and shaped by the receiving circuit 153 and sent to the central control circuit 151.

A part of the ultrasonic waves emitted from the ultrasonic probe 104 is route j
is reflected from the surface of the subject 105 and enters the delivery section i.

The centralized control circuit 151 calculates the thickness of the object by measuring the difference in time between input of the echo signals from the back side and the front side of the object. The formula for calculating the thickness is shown below.

to −Vo For details, see "Transistor Technology" July 1982 issue, 3
(See page 16, “Basics of Ultrasonic Sensors and Applications to Flaw Detectors and Thickness Gauges.”) Set the sound velocity of the object in advance and press numeric key 8 on the keyboard 107.
Please enter the following information. 1 For example, steel is 5900■/sec
For aluminum, it is 6320+a/sec, so for steel, the key force is El, El, 9 times. If this value disappears when the power switch 103 is turned off, it will be necessary to input it every time the switch 103 is turned on. To avoid this inconvenience, the sound speed data is stored in the low power consumption memory 154. That's convenient. The memory 154 is supplied with the voltage VB of the battery 102 without going through the switch 103, so as long as the battery 102 exists and maintains a predetermined voltage, it can hold the sound speed data, and can measure objects made of the same material. In some cases, there is no need to re-enter the information.

The thickness gauge according to the present invention repeatedly acquires thickness data at a frequency of 1 kHz, but at the same time, the probe 104 is continuously moved and the position signal is transmitted from the scanner 113 to the encoder 1.
The signal is input to the central control circuit 151 via 55.

For example, if the scanner 113 can linearly scan 70 m and obtain position signals every 0.21 m during that time, 350 pieces of position data and accompanying thickness data can be stored in the storage device 156 in the control circuit. .

At the same time, this numerical thickness data is converted into display length data for displaying a cross-sectional view. These location data,
The display length data is sent to the display drive circuit 151 along with other data.
The cross-sectional view is displayed on the graphic display panel 106 as shown in FIG.

When performing the next measurement, the erase key 109 on the keyboard 107 is pressed to erase unnecessary portions of the display screen.

In FIG. 3, the graphic display panel 106 is composed of, for example, a dot matrix type liquid crystal display panel, and key manual data of the speed of sound is displayed on the speed of sound display section J. Also, m is a moving mark, and when the left or right movement switch 111 or 112 is pressed, the mark moves to the left or right on the straight line n, and the thickness of this mark position is displayed on the mark position thickness display section C. Ru. At this time, a line perpendicular to the surface may be displayed in order to better understand the position of the bottom surface in the cross-sectional view. The minimum and maximum thickness values obtained by comparing all the thickness data stored in the storage device 156 are displayed on the minimum and maximum thickness display sections a and b, respectively.

The marks q and r representing the minimum and maximum may be represented by letters like q'r' in FIG.

Further, the thickness scale 0 can be set to, for example, X 1 m, X 10 m, X 1100 a by the thickness unit changeover switch 110.
The magnification is switched. At the same time, thickness display parts a, b, c
For example, in the case of ×1, each of
．． 65 shoes), up to 1st place for X10 (16,5 shoes),
When the value is 100, the display method of the thickness value may be switched to an integer (eg 165).

If the unit changeover switch 110 is erroneously set to a small unit and large thickness data is input, it will be convenient for the user if the section display becomes impossible and the OF table display indicating overflow lights up. For example, when the changeover switch 110 is set to the x10 position and data indicating a thickness of 1100a or more is input from the probe 104, an alarm is issued.

Reference numeral 114 in FIG. 2 is a measurement data correction means, which corrects when the measurement data is adversely affected by temperature changes or when the waveguide plastic part is worn out due to multiple scans of the probe 104. For example, if a 5-shoe-thick object is measured to be 5.25 m, this volume is used to correct it to 5.00 m.

In this embodiment, a split type probe is used as the ultrasonic probe, but a probe that integrates transmitting and receiving functions may also be used.

Furthermore, although it has been described that the speed of sound is entered using a numeric keypad, a four-digit thumbwheel switch may also be used, for example.

In the embodiment, a linear probe scanner has been described, but a curved scanner is the same in that continuous scanning is performed, and the scanner does not need to be present.

In this case, the probe is manually moved for a certain period of time, for example, one second, and a cross-sectional view of the scanned part is automatically drawn during that period.

In this case, time information is used as the horizontal axis of the cross-sectional view instead of position information.

In addition, although a liquid crystal panel is used as a graphic display device in the embodiment, a fluorescent display tube or a plasma display panel may be used, and a printer may also be used in order to leave a record.

[Effects of the Invention] As is clear from the above description, continuous thickness measurement is possible with a simple configuration in which a graphic display panel that displays a cross-sectional view is attached to an ultrasonic thickness gauge, and the thickness of the object to be examined is measured discontinuously. Problems such as overlooking defective parts have been resolved. It is also a great convenience to be able to visually clearly understand, for example, the corroded state of the bottom surface.

Furthermore, upon analysis of the measurement results, the required maximum and minimum thicknesses can be extracted and visually displayed.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an ultrasonic thickness gauge according to the present invention, FIG. 2 is an electrical block diagram of an ultrasonic thickness gauge according to the present invention, and FIG. 3 is an example of a graphical display format of an ultrasonic thickness gauge according to the present invention. , and FIG. 4 show examples of other graphical display formats, respectively. In the figure: 1: Ultrasonic thickness needle body, 2: Battery box, 3: Power switch, 4: Ultrasonic probe, 5: Subject, 6: Graphic display panel, 7: Keyboard, 8: Numeric keys, 9: Clear key, 10: Thickness unit selector switch, 11:
Position mark left movement switch, 12: Position mark right movement switch, 13: Linear scanner, 14: Data correction volume.

Claims (1)

[Claims] Sound velocity input means; Graphic display device; Ultrasonic probe; Ultrasonic generating circuit connected to the ultrasonic probe; an ultrasonic receiving circuit that receives an echo signal from the subject directly under the tentacle; and is connected to the sound velocity input means and the ultrasonic receiving circuit, and calculates the thickness of the subject from the echo signal. means for storing positional data of the subject and thickness data corresponding thereto; means for reading the positional data and thickness data and presenting a cross-sectional view of the subject on the graphic display device; 1. An ultrasonic thickness gage characterized by comprising a central control circuit including means for reading the maximum thickness and minimum thickness from the thickness data and presenting them on the above-mentioned graphical display device.