JPS60155907A - Ultrasonic measuring apparatus - Google Patents

Abstract

PURPOSE:To accurately measure a distance without receiving the influence of the change in the temp. of a medium, by measuring the distance from an article to be measured on the basis of the input output time difference of a pair of ultrasonic sensors respectively present at positions spaced apart from said article to be measured over certain distances according to a specific operation formula. CONSTITUTION:A surface plate part 7b, to which a large number of ultrasonic sensors 2 are arranged in longitudinal and lateral directions, is movable only over a distance L0 with respect to attachment parts 7a for supporting the upper and lower ends of an article 1 to be measured. When a time interval, wherein an ultrasonic wave is emitted from each sensor 2 to be reflected from the article 1 to be measured and again inputted to said sensor 2, is set to T, the distance L1 between the sensor and the article 1 to be measured and the distance L2 between both of them after the surface plate part 7 moved over a distance L0 are calculated from respectively measured time intervals T1, T2 according to formula. However, because this formula receives no influence of the change in the temp. of an ultrasonic wave transmitting medium, accurate distances L1, L2 can be operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an ultrasonic measuring device used, for example, in measuring distortion, deformation, etc. of a long columnar body.

[Technical background of the invention and its problems] When measuring the distortion and deformation of long columnar bodies such as fuel assemblies and channel boxes used in nuclear power plants, it is necessary to is mounted on a standard loading platform (surface plate) with almost no distortion, and the distance from the loading platform is measured at multiple points using a contact or non-contact measuring device, and the amount of distortion and deformation of the columnar body is determined from the distribution of the measured distances. is being carried out.

Here, contact-type measuring devices include electric micrometers and pneumatic micrometers, but non-contact types are usually used because they may damage the surface of the object to be measured. ing.

Typical non-contact measuring devices include those that use eddy current sensors and those that use ultrasonic sensors.

Eddy current sensors measure the distance to a measured object (metal) based on the amount of change in coil impedance due to eddy current loss, but if the measured object is a metal that has been left in water for a long time, The drawback is that large measurement errors occur due to rust attached to the surface.

On the other hand, when using an ultrasonic sensor, measurement can be performed without any problem even if rust is attached to the surface, so it is suitable for measuring distortion and deformation of a columnar body left in water for a long period of time.

FIG. 1 shows the basic configuration of an ultrasonic measuring device. In the figure, an ultrasonic sensor 2 is installed facing an object to be measured 1, and water 3 is placed in a gap therebetween as an ultrasonic transmission medium. An amplifier 4 is connected to the ultrasonic sensor 2, and a signal generator 5 and a signal processing device 6 are connected to the amplifier 4.

In the ultrasonic measuring device having such a configuration, a pulse signal oscillated from the signal generator 5 is input to the ultrasonic sensor 2, converted into an ultrasonic signal, and emitted toward the object to be measured 1. The emitted ultrasonic signal is reflected on the surface of the object to be measured 1 and input to the ultrasonic sensor 2 . The ultrasonic signal input to the ultrasonic sensor 2 is converted into an electrical signal, and then sent to the amplifier 4.
is input.

Here, the signal generated from the signal generator 5 and the signal detected by reflection are input to the amplifier 4, and an output signal as shown in FIG. 2 is input to the signal processing device 6.

This signal processing device 6 is equipped with a circuit for detecting the time between the two signals and a converting circuit to a distance corresponding to the time 1, and is capable of displaying the distance.

Here, if the ultrasonic transmission speed is 9, the time difference between the two signals is T, and the distance from the ultrasonic sensor 2 to the object to be measured 1 is L, then L is expressed by the following equation.

L-(V-T)/2・・・・・・・・・・・・・・・
(1) A large number of ultrasonic sensors 2 that can measure the distance from the ultrasonic sensor to the object to be measured based on the above principle are arranged on the standard loading platform 7 as shown in Fig. 3. , by attaching the object to be measured 1 to the standard loading platform,
The distance between the ultrasonic sensor 2 at the position where the ultrasonic sensor 2 is arranged and the object to be measured 1 is fixed, and deformation and distortion of the object to be measured 1 can be detected from measurement data of each distance.

FIG. 4 shows a specific example in which an ultrasonic sensor 2° is attached to a standard loading platform 7.

In an ultrasonic measurement device having such a configuration, temperature changes in the water 3 pose a problem.

That is, when the water temperature changes from, for example, 20°C to 25°C, the velocity V of ultrasonic waves in water is 1482.66 m/S.
It will change from ee to 1497.00m+/sec, and as the water temperature increases by 5℃, the ratio shown in the following formula (1497,00-1482,66)/1482.66
= 0.97%・・・・・・・・・・・・・・・・・・
・Old: Old: (2) is faster, and the distance measured by equation (1) has an error of 0.91% 15°C,
Accurate distance measurement becomes impossible.

[Object of the invention] The present invention eliminates the above-mentioned problems in the background art,
An object of the present invention is to provide an ultrasonic measurement device that can accurately measure an object to be measured or a medium between it and an ultrasonic sensor.

[Summary of the invention] In other words, the ultrasonic measuring device of the present invention uses ultrasonic waves, a sensor h
In an ultrasonic measuring device that transmits an ultrasonic signal toward an object to be measured, receives the reflected signal, and measures the distance based on the time difference between them, the ultrasonic measuring device is configured to transmit an ultrasonic signal toward an object to be measured, receive the reflected signal, and measure the distance based on the time difference between them. Based on the input/output time difference T1, T2 of a pair of ultrasonic sensors located at the same position, one of the following formulas L+ = (T+ ・Lo)/(T2-T+)L
2 = (T2 ・Lo) / (T2-T+) However, L2-Lo, +L+ (here, Lo is a known value) is calculated, and the distance L from the ultrasonic sensor to the object to be measured is calculated.
+, Lz.

[Embodiments of the Invention] Hereinafter, embodiments of the present invention and their operations will be described with reference to FIGS. 5 to 9. In these figures, the same members as in FIGS. 1 and 3 are given the same reference numerals.

In FIG. 5, the standard loading platform 7 is composed of mounting portions 7a that support the upper and lower ends of the object to be measured 1, and a surface plate portion 7b that connects these mounting portions.

The surface plate part 7b, on which a large number of ultrasonic sensors 2 are arranged and fixed at predetermined intervals in the vertical and horizontal directions, is at a distance L from the mounting part 7a.
It is connected to the mounting portion 7a via a moving mechanism (not shown) so that it can be moved by o.

FIG. 6 shows an example in which, contrary to the case in FIG. 5, the reference carrier 7 is a U-shaped fixed base, and the object to be measured 1 can be moved relative to it. Guide racks 8 are fixed to both side surfaces of the mounting portions 7a formed at both the upper and lower ends. Rectangular cylindrical mounting bases 9 are fixed to the upper and lower ends of the object to be measured 1, and these mounting bases are fitted into the mounting portions 7a and are driven by a drive motor (not shown) via drive wires 10. It is pulled and moves in the longitudinal direction of the attachment part 7a. Further, a part of the gear 11 rotatably attached to both sides of the mounting base 9 protrudes inward of the mounting base 9 through a window 9a formed on the side surface of the mounting base 9, and meshes with the guide rack 8. A protrusion 8a without teeth is provided at both ends of the guide rack 8, and when the gear 11 rides on the protrusion 8a, further movement of the mounting base 9 is blocked.

FIG. 7 shows the basic configuration of the ultrasonic measuring device of the present invention. As in FIG. 1, pulses from the signal generator 5 are input to the ultrasonic sensor 2 through the amplifier 4, and the ultrasonic signal 3 to occur. This ultrasonic signal is reflected on the surface of the object to be measured 1 and is input to the ultrasonic sensor 2 as a reflected wave. The ultrasonic sensor 1 converts the reflected wave into an electrical signal and transmits it to the signal processing device 6 through the transducer 4.

The signal processing device 6 stores the transmission time of the ultrasonic signal and the reception time of the reflected wave, and performs the calculation of equation (1). In the embodiment of the present invention, this storage calculation processing is performed by the ultrasonic sensor 2 If the distance of the object to be measured 1 is Ll, then the object to be measured 1 moves a preset distance L'o and Gj, and the distance between them becomes 1.
If the number is 2, it will be executed twice.

If the distance from the ultrasonic sensor 2 to the object 1 changes from 11 to 12 when the object 1 is moved to 1', the signal input from the amplifier 4 to the signal processing device 6 is As shown in FIG. 8, the time interval between the signal transmitted from the signal generator 5 and the signal reflected from the object to be measured 1 also changes from T1 to T2.

Here, 11 and Ll are LI −(v −T+ )/2 from equation (1).
......(3) Ll = (V-T2)/2...
・・・・・・・・・・・・・・・・It is expressed as (4),
Due to the relationship Ll = Lo +1+, LI, Ll is LI = (T+ ・Lo)/(T2-T+ 1"
(5) Ll = (T-2・Lo)/(T2-T
+ )・= (6).

Here, the calculations of equations (5) and (6) are executed in the signal processing device 6 for each ultrasonic sensor 2, but T I , T
Since 2 is a measured value and LO is a constant value,
Ll and Ll are determined only by measured values and are unrelated to the ultrasonic velocity V in equation (1), and are unrelated to physical changes such as changes in water temperature. Therefore, such a measurement is determined by the accuracy of Lo moving a certain distance and the measurement precision of the times T1 and T2 with the transmitted signal.

In the above embodiments, C represents the reference loading platform 7 and the object to be measured 1.
We have explained an example in which one of the detectors is moved and measurements are taken twice before and after the movement. However, it is also possible to move the detector itself without changing the positions of the reference carrier 7 and the object to be measured 1. Good too.

Further, the present invention can be modified as shown in FIG.

In the figure, the ultrasonic sensors 2a, 2b are fixed on the standard loading platform 7 with their positions shifted so that the distance to the object to be measured 1 differs by LO; in this case, the ultrasonic sensors 2a, 2. b
It is possible to simultaneously emit ultrasonic signals from the 1st object and to calculate the equations (5) and (6) based on the arrival time difference of the reflected waves. 7 or an advantage that the moving mechanism for the ultrasonic sensor 2a12b can be omitted.

[Effects of the Invention] As described above, in the ultrasonic measuring device of the present invention, ultrasonic signals are transmitted from the ultrasonic sensors located at positions different from the object to be measured by a known distance Lo, and the time difference between the reflected waves is calculated by (5 )
Since the distance to the object to be measured is calculated using equations (6) and (6), even if the ultrasonic transmission medium, such as the heat trace of water, changes, it will not be affected by the change and will be accurate. It is possible to perform accurate measurements.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the basic configuration of a conventional ultrasonic measuring device, Fig. 2 is an explanatory diagram of its operation, Fig. 3 is an exploded perspective view illustrating a conventional ultrasonic measuring device, and Fig. 4 is an ultrasonic measuring device. FIG. 5 is an exploded perspective view showing an embodiment of the present invention; FIG. 6 is an exploded perspective view showing another embodiment of the invention; FIG. 7 is an exploded perspective view showing an embodiment of the present invention; FIG. 8 is a block diagram showing the basic configuration of the acoustic wave measuring device, FIG. 8 is an explanatory diagram of its operation, and FIG. 9 is an explanatory diagram showing still another embodiment of the present invention. 1.1'...Object to be measured 2.2a, 2b...Ultrasonic sensor 3...Medium 4...Amplifier 5...... Signal generator 6...
...... Signal processing device 7 ......
Standard loading platform 7a...Mounting section 7b...Surface plate section 8...Guide rack 8a...
...Protrusion 9 ...Mounting base 9a ... Window 10 ... Drive wire 11・・・・・・
...Gear Agent Patent Attorney Sa Suyama - Figure 1 Figure 2 Time Figure 3 Figure 4 Figure 5 Figure 6 Tomiki Figure 8 Time

Claims (1)

[Scope of Claims] (1) In an ultrasonic measurement device that transmits an ultrasonic signal from an ultrasonic sensor toward an object to be measured, receives the reflected signal, and measures a distance based on the time difference between the ultrasonic signals, Based on the input/output time difference TI and T2 of a pair of ultrasonic sensors located at distances L1 and L2 from the object to be measured, respectively, L+ = (T+ ・Lo)/(T2-T+)1
2 = (T2 · Lo) / (T2 - T+)
However, L2 = Lo +L+ (Here, Lo is a known value)
1. An ultrasonic measuring device characterized in that it is configured to measure a distance ml, L2 from the ultrasonic sensor to the object to be measured. (2) The ultrasonic measuring device according to claim 1, wherein the ultrasonic sensor has a mounting number attached to the standard loading platform. (3) The reference loading platform is composed of a mounting portion and a surface plate portion that is mounted so as to be movable with respect to the mounting portion, and an ultrasonic sensor is attached to the surface plate portion. Claim 2
The ultrasonic measuring device described in Section 1.