JPS62245107A - Ultrasonic thickness meter - Google Patents

Abstract

PURPOSE:To display an almost continuous change in a thickness and to enable the simple alteration of a scanning range, by combining the time data of a timer means generating only a predetermined number of timing signals at every predetermined time with the thickness data of an object to be inspected. CONSTITUTION:A probe 104 is pressed by a hand to be moved on the surface of an object 105 to be inspected through an inclusion 160 such as oil. Thickness data is taken in by a method wherein the probe 104 is set to the measuring start position of the object 105 to be inspected and a start key 113 is pushed to generate a timing pulse only for the scanning time (e.g., 7sec) prescribed by a timer circuit 155. If it is assumed that thickness data is obtained at every 0.02sec, 350 pieces of time data and thickness data corresponding thereto are stored in a memory device 156 and, at the same time, converted to display length data. These time data and display length data are sent to a display driving circuit 157 along with other data to be displayed on a figure display panel 106 as a cross-section on real time. Herein, if the probe 104 moves over 70mm almost uniformly within the prescribed time (7sec), thickness data is obtained at every 0.2mm.

Description

[Detailed Description of the Invention] [Field of Industrial Application] 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 gauge has been designed to press an ultrasonic probe against the surface of an object to be examined, such as a steel plate, through a medium liquid (couplant). Measure the thickness of the specimen to the back surface at several specific locations (for example, 30 cm).
The thickness of the object to be inspected was measured by displaying a numerical value at each time, or the corrosion state of the back surface was estimated by measuring the thickness at several specific points. 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 grasp the condition of the back surface of the object almost continuously.

By the way, as shown in FIG.
The position of the probe Z is changed via the link mechanism P, and the thickness data from the probe Z and the thickness data of the probe Z via the link mechanism P are changed.
A large-sized ultrasonic flaw detector is known that calculates scanning position data using a controller Q and displays a cross-sectional view on a monitor R.

However, in the apparatus shown in FIG. 4, the link mechanism Q for scanning the probe Z is large, making it inconvenient for ultrasonic flaw detection in a narrow space.

In addition, when changing the scanning range, for example, when expanding the scanning range, a larger link mechanism Q with longer arms is required, resulting in an increase in the size of the apparatus.

[Problems to be solved by the invention and means for solving them]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ultrasonic thickness gauge that can display substantially continuous changes in thickness and can easily change the scanning range.

A further object of the present invention is to provide an ultrasonic thickness gauge that can display predetermined thickness data as well as a substantially continuous change in thickness.

The purpose of this is to use an ultrasonic thickness gage that includes an ultrasonic probe, an ultrasonic generation circuit connected to the ultrasonic probe, and an ultrasonic generator circuit connected to the ultrasonic probe that generates an echo signal from the subject. an ultrasonic receiving circuit for receiving, a measurement start input means, a timer means for generating a predetermined number of timing signals at predetermined time intervals after starting the tlli constant, and means for changing the generation interval of the timing signal of the timer means; This is achieved by providing a display means for displaying a cross-sectional view of the object based on the time data of the timer means and the thickness data of the ultrasonic receiving circuit.

〔Example〕

FIG. 1 is a perspective view of an ultrasonic thickness gauge according to an embodiment of the present invention. 1 is the main body of an ultrasonic thickness gauge with a graphic display device, which is covered with a portable case. 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; 4 is an ultrasonic probe that is electrically connected to the thick needle body 1 by a flexible cable. combined. The ultrasonic probe 4 is generally divided into two parts, a transmitter and a receiver, and converts the amount of electricity transmitted from the thick needle body into an ultrasonic wave, which enters and propagates 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.

This thickness data is displayed on the graphic display panel 6 as numerical data and a cross-sectional diagram. The graphic display panel 6 not only displays the data from the probe 4, but also inputs and displays the sound speed of each type of object 5 from the keyboard 7 using ten numerical keys (numeric keys) 8 from O to 9. do. In addition to the numeric keypad, the keyboard 7 also includes a CLR (clear) key 9 for erasing old data from the graphic display panel 6, a unit changeover switch 10 for the display scale in the thickness direction, and a switch 10 for checking the thickness at the desired position. Move the position mark m to the left,
A left moving switch 11 and a right moving switch 12 are provided for moving rightward.

After pressing the start switch 13, a certain scanning time to
When the probe 4 is manually scanned in one direction over the object within (pulse generation interval x number of pulse generation), thickness data can be obtained every unit time. That is, thickness data of the portion where the probe moves over the subject can be obtained substantially continuously. If this thickness data is taken as the vertical axis and time is taken as the horizontal axis, a cross-sectional view of the portion where the probe 9 has moved is obtained, and this is displayed on the graphic display panel 6. 23a is a scanning range expansion key m=2°3.
-1--, This is used in conjunction with each numeric key of 9 to expand the pulse generation interval by m times without changing the number of pulses generated in the timing signal.If the scanning speed is assumed to be constant, the scanning range is expanded by m times. can. Similarly, 23b is the scanning range reduction key, m=
2.3. -----． Used in conjunction with each numeric key of 9 to change the pulse generation interval by 1 without changing the number of pulse generation of the timing signal.
Reduce the size by 7 m. Note that when the CLR key 9 is pressed, the pulse generation interval is restored to its original state (m=1).

In addition, 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 surface of the object to the back surface furthest, that is, the maximum thickness, are automatically found, and these are converted into numerical data. , displayed in section b. Further, the thickness of the object at the position indicated by the moving mark m is also displayed in the 0 section. 14 is a correction volume for measurement data, which will be described later. Note that the cables of the probe 4 are connected to the thickness needle body through connectors d and e, respectively.

FIG. 2 shows an electrical block diagram of 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 the power supply for the central control circuit 151 and the like, and the power supply v0 is the power supply for driving the display panel 106 and is 18V, and the power supply Vε is the power supply for the ultrasonic wave 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 1KH2, and are thereby transmitted from the wave transmitting section g of the split type ultrasonic probe 104 made of piezoelectric elements to the route. 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 wave receiving 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 = VOX (Ta - Ts) / 2■o: Sound velocity of the object TB: Time of entry of the echo from the back surface into the probe T,:
The input time of the echo from the surface to the probe (details of the circuit for determining the thickness can be found in "Transistor Technology 4, July 1982 issue,
(See page 316, "Basics of ultrasonic sensors and applications to flaw detectors and thickness gauges")
Input using the numeric key 8. For example, steel is 5900
In m/sec, aluminum is 6320 m/sec, so in the case of steel, (9) key manual force is 1 time and 9 times. If this value disappears when the power switch 103 is turned off, it will be necessary to enter it manually 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 connects the voltage v1 of the battery 102 to the switch 10.
3, and therefore the battery 102
exists and a predetermined voltage is maintained, sonic velocity data can be retained, and re-input is not required when measuring objects made of the same material.

In the thickness gage according to the present invention, the probe 104 is held down by hand and moved over the surface of the object through an inclusion such as oil. To take in the thickness data, set the probe 104 to the measurement start position on the surface of the object, press the start key 113 on the keyboard 107, and then use the central control circuit 151.
The scanning time To specified by the timer circuit 155 in
(for example, 7 seconds) by generating timing pulses at regular intervals.

In general, if there are no scratches inside the specimen, the thickness of the specimen is approximately constant, so the scanning speed does not need to be constant to detect the absence of scratches, and manual scanning of the probe is sufficient. . Further, in the normal case where the scanning speed of manual scanning is approximately constant, it is possible to detect the flaw position although the accuracy is low.

By the way, assuming that thickness data during scanning can be obtained every 0.02 seconds, 350 pieces of time data and accompanying thickness data are 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 time data and display length data are sent to the display drive circuit 15 along with other data.
7 and displayed in real time on the graphic display panel 106 as a cross-sectional view as shown in FIG. Note that the data may be stored in the storage device 156 once and read out and displayed at a later stage.

Here, if the probe 104 moves almost uniformly for 7 parts mmfJ within the specified time (7 seconds), the thickness data is 0.2 mm.
This means that we were able to obtain it every time.

In addition, when performing two-dimensional scanning by shifting one-dimensional scanning multiple times in the direction perpendicular to the scanning direction, cross-sectional views from each scanning can be displayed overlapping each other. In this case, the presence or absence of flaws can be detected two-dimensionally. can.

Note that when a series of measurements is completed and the next measurement is to be performed, unnecessary portions of the display screen can be erased by pressing the erase key 109 on the keyboard 107.

In FIG. 3, the graphic display panel 106 is constituted by, for example, a dot matrix type liquid crystal display panel, and the key manual data of the speed of sound is displayed on the speed of sound display section 1. Also, m is a moving mark, and when the left and right movement switches 111 and 112 are 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. be done. 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 thicknesses are the minimum and maximum values obtained by comparing all the thickness data stored in the storage device 156, respectively. Marks v indicating the minimum and maximum thickness are shown in the minimum and maximum thickness display sections a and b, respectively. , w or the characters MIN and MAX indicating the minimum and maximum.

If the minimum or maximum value exceeds a predetermined value, it will be easier to determine if an alarm is displayed (for example, the marks v and w are lit or blinking, the 0 part data is blinking, or a warning sound or voice is displayed). .

Furthermore, the thickness scale 0 is determined by the thickness unit changeover switch 110, for example, X 1 am, x 10 mm.

The magnification is changed to 100 mm. At the same time, each of the thickness display parts a, b, and c also has two decimal places when it is x1.
(Example 1.65mm), up to 1st position when xlO (Example 1
6.5mm), an integer when xlOO (example: 165mm)
You may change the display method of the thickness value.

If the unit selection 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 is lit. For example, when the changeover switch 110 is set to the X10mm position and data indicating a thickness of 100mm 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 is used when the waveguide plastic part is worn out due to temperature changes or multiple scans of the probe 104.

This is a volume to correct when there is a negative influence on the measurement data. For example, when measuring something with a thickness of exactly 5 mm, and when it is measured as 5.25 mm, this volume is used to correct it to 5.00 am. It is.

In the above embodiments, 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.

Further, 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 store the information as a memory.

(Effects of the Invention) As described above, the present invention provides an ultrasonic thickness gauge that can display substantially continuous thickness changes, easily change the scanning range, and further display predetermined thickness data. be able to.

[Brief explanation of drawings]

1 and 2 are perspective views and electrical block diagrams of a first embodiment of an ultrasonic thickness gauge according to the present invention, FIG. 3 is a diagram showing an example of a graphic display format, and FIG. 4 is a diagram of a conventional example. Explanatory diagram. In the figure, 4 is an ultrasonic probe, 6 is a graphic display panel, 13 is a start switch, 23a and 23b are scanning range enlargement keys, and scanning range reduction key 155 is a timer circuit.

Claims (7)

[Claims] (1) An ultrasonic probe, an ultrasonic generating circuit connected to the ultrasonic probe, and an ultrasonic receiving circuit connected to the ultrasonic probe and receiving echo signals from a subject. , measurement start input means; timer means for generating a predetermined number of timing signals at predetermined intervals after the start of measurement; means for changing the generation interval of the timing signal of the timer means; time data of the timer means and the An ultrasonic thickness gage comprising a display means for displaying a cross-sectional view of a subject based on thickness data of an ultrasonic receiving circuit. (2) The ultrasonic thickness gauge according to claim 1, wherein the cross-sectional view is displayed in real time. (3) The ultrasonic thickness gauge according to claim 1, wherein the cross-sectional view is displayed after the time data and thickness data are stored in a storage means. (4) The ultrasonic thickness gauge according to claim 1, wherein the main body is covered with a portable case. (5) The ultrasonic thickness gauge according to claim 1, wherein the display means is capable of displaying predetermined thickness data. (6) The ultrasonic thickness gauge according to claim 1, wherein the display means is capable of displaying a minimum thickness or a maximum thickness. (7) The ultrasonic thickness gage according to claim 5, further comprising a mark indicating in the sectional view a portion where thickness data is displayed.