JPS644125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic fluoroscope suitable for, for example, inspecting the inside of a reactor vessel of a fast breeder reactor.

The reactor vessel of a fast breeder reactor contains liquid metal (mainly liquid sodium) as a coolant, and because the liquid metal is opaque, it is impossible to directly inspect the inside of the reactor vessel by visual inspection. Can not.
Therefore, ultrasonic fluoroscopy equipment has conventionally been used for such inspections inside the reactor vessel.

Figure 1 shows a conventional ultrasound fluoroscope.
A scanning arm 1 equipped with a plurality of ultrasonic transducers T ₁ , T ₂ , ...Tn is arranged horizontally in a reactor vessel 2 of, for example, a fast breeder reactor to be inspected, and is centered at one end by a drive mechanism 3 . Rotate and drive. The position of each ultrasonic transducer T ₁ , T ₂ , . . . Control 6. Further, the pulse oscillation circuit 7 applies a high voltage pulse to each ultrasonic transducer T ₁ , T ₂ , ...Tn via the switching circuit ₈ , and
T ₂ ,...Tn are sequentially driven. That is, the ultrasonic signals transmitted from each transducer pass through the liquid metal A in the reactor vessel 2, and reach the surface (ultrasonic reflecting surface) of the detected object B such as in-reactor equipment and core components.
The reflected signal is received by an arbitrary transducer, and the transducer outputs it as an echo signal. On the other hand, each transducer T ₁ , T ₂ ,
...An arbitrary echo signal among the echo signals output from Tn is applied to the peak value detection circuit 10 via the gate circuit 9, and the peak value of the echo signal detected by the peak value detection circuit 10 is determined by the luminance signal conversion circuit. The luminance signal is converted into a predetermined luminance signal. The outputs of this luminance signal conversion circuit and the position detection circuit 4 are processed as image signals in a signal processing circuit 12. Then, based on the output of the signal processing circuit 12, a perspective image is displayed on the CRT display 13, and from this image, objects to be detected B such as in-reactor equipment and core components in the reactor vessel 2 are displayed.
You can know the status of

Incidentally, when the density of the liquid metal A is uniform, the peak value of the echo signal detected by the peak value detection circuit 10 is determined by the distance from the ultrasonic transducer to the ultrasonic reflecting surface of the object to be detected (hereinafter referred to as (hereinafter referred to as the reflecting surface distance) varies depending on the inclination of the ultrasonic reflecting surface, surface roughness, and other surface conditions (hereinafter referred to as the reflecting surface condition). In other words, the perspective image based on the peak value obtained by sweeping is
This can be said to be a display that superimposes information on each other. Therefore,
For example, the brightness of the fluoroscopic image will decrease both when the reflective surface distance is long or when the ultrasonic reflective surface is tilted, so it is impossible to determine which cause of the brightness decrease occurred, and the object to be detected B It was not possible to accurately grasp the situation.

The present invention was made based on the above circumstances, and its purpose is to overcome the position, shape, etc. of an object (object to be detected) that is not directly visible inside a container filled with an opaque liquid. In an ultrasonic fluoroscopy device that uses sound waves to see through and display images, the distance from the ultrasonic transducer to the ultrasonic reflecting surface of the object to be detected and the surface condition of the ultrasonic reflecting surface are treated as separate information. Moreover, the object is to be displayed on the same screen so that the state of the object to be detected can be grasped accurately.

That is, as shown in FIG.
02 applies a driving voltage to the ultrasonic transducers to cause each transducer to send an ultrasonic signal toward the object to be detected, and the scanning means 101 sends a position signal corresponding to the position of each transducer. Also, when the ultrasonic signal reflected from the object to be detected is received by an arbitrary ultrasonic transducer and an echo signal is output from the ultrasonic transducer, the peak value of the echo signal is used as a luminance signal. The converting means 103 detects and converts the peak value into a predetermined luminance signal, and after applying a drive signal to each ultrasonic transducer, the echo signal output from the transducer is converted to a predetermined threshold. The echo time required to exceed the level is detected by the color signal converting means 104, and the echo time is converted into a color signal, and the position signal output from the scanning means 101 and the luminance output from the luminance signal converting means 103 are detected. Based on the signal and the color signal output from the color signal conversion means 104, the image display means 105 is configured to display an image with changes in brightness and hue.

Therefore, according to the ultrasonic fluoroscope according to the present invention, the position and shape of objects to be detected, such as in-reactor equipment and core components in a reactor vessel filled with liquid metal, can be displayed in brightness, and The distance from the ultrasonic transducer to the detected object can be displayed in different colors.

An embodiment of the present invention will be described below with reference to FIG. Note that the same parts as in FIG. 1 will be described with the same reference numerals.

The scanning means 101 is configured to rotate a scanning arm 1 to which a plurality of ultrasonic transducers T ₁ , T ₂ , . . . ₁ , _T2 ,
...The position of Tn is detected by the position detection circuit 4, and the position detection circuit 4 outputs a position signal to the control circuit 5, and the control circuit 5 controls the drive circuit 6 of the drive mechanism 3 based on the position signal. It is composed of The scanning arm 1 is disposed horizontally within a reactor vessel 2 of a fast breeder reactor, and is immersed in liquid metal A within the reactor vessel 2.

The driving means 102 applies high voltage pulses from the pulse generating circuit 7 to each of the ultrasonic transducers T ₁ , T ₂ , ...Tn via the switching circuit 8 to drive each of the transducers T ₁ , T ₂ , ...Tn. operate sequentially,
Each transducer is configured to transmit an ultrasonic signal toward the object B to be detected.

The luminance signal converting means 103 applies any signal among the echo signals outputted from each ultrasonic transducer T ₁ , T ₂ , ...Tn to the peak value detection circuit 10 via the gate circuit 9 and detects the peak value. The peak value of the echo signal output from the value detection circuit 10 is
The signal is configured to be output to a luminance signal conversion circuit 15 via a peak value/distance correction circuit 14 made up of an arithmetic/comparison circuit such as a microcomputer.

Further, the color signal conversion means ₁₀₄ converts any signal among the echo signals outputted from each of the ultrasonic transducers T ₁ , T _{2 ,} . , . . . 16 _-n and compares it with a different threshold level for each comparison circuit. Moreover, each comparison circuit 16 _-1 , 16 _-2 ,
A clock pulse is applied from the clock circuit ₁₈ to the counter circuits 17 _-1 , 17 _-2 , . . . 17 _-n provided corresponding to each counter circuit 16 -n. In each counter circuit 17 _-1 , 17 _-2 , . . . 17 _-n , the ultrasonic transducer T ₁ , T ₂ ,
...The clock pulses are counted from when a high voltage pulse is applied to Tn until the echo signal exceeds the threshold level in each comparator circuit 16 _-1 , 16 _-2 , ... 16 _-n , and each counter circuit 17
The outputs of _-1 , 17 _-2 , ...17 _-n are applied to the echo time detection circuit 19. The echo time detection circuit 19 detects the count value (echo time) from when the high voltage pulse is applied until the echo signal exceeds the highest threshold level, and sends this count value to the color signal conversion circuit 20. Apply and
It is configured to convert into color signals such as red, orange, etc. according to the count value.

Note that the count value (echo time) detected by the echo time detection circuit 19 is also sent to the peak value/distance correction circuit 14 , and in the peak value/distance correction circuit 14 , the count value (echo time) detected by the echo time detection circuit 19 is sent to the peak value/distance correction circuit 14 .
The peak value _{of the} echo signal input from ing.

The image display means 105 displays the position signals of the ultrasonic transducers T ₁ , T ₂ , . The signal is input to the signal processing circuit 21 and processed as an image signal, and the color CRT display 22 displays the shape and position of the detected object in brightness, as well as the distance from the ultrasonic transducer to the detected object in different colors. is configured to do so.

Note that the echo time detection in the color signal converting means 104 is performed as shown in FIG. 4, for example. That is, using four comparison circuits 16 _-1 to 16 _-4 , the threshold levels in each comparison circuit are set to SH1 to SH4, and each ultrasonic transducer
The echo time is the count value required until the echo signal exceeds the highest threshold level after the driving voltage is applied to T ₁ , T ₂ , . . . Tn.

However, the detection of echo time is not limited to the above method; for example, the echo signal is recorded digitally using a waveform memory, and a calculation/comparison circuit such as a microcomputer is used to calculate the peak value and the echo time until reaching the peak value. You may also ask for

Further, distance correction of the peak value in the peak value/distance correction circuit 14 is performed as shown in FIGS. 5A and 5B. In other words, Fig. 5 shows the relationship between the reflective surface distance (i.e., echo time) and the peak value of the echo signal, but from the relationship between the two in advance, the correction coefficient K = E / E _T = a _o · T ₀ +b _o /a _o・T+
Find b _o . However, E is an echo signal with distance correction, and _ET is an echo signal without distance correction.

With the above configuration, on the color CRT display 22, the state of the reflective surface of the object B to be detected is displayed in brightness, and the distance to the reflective surface is displayed by the hue, so that the position of the object B to be detected and the surface The inclination, surface roughness, etc. can be accurately grasped, and the desired effect can be achieved.

As described in detail above, according to the present invention, the shape and position of the object to be detected can be displayed in brightness, and the distance from the ultrasonic transducer to the object to be detected can be displayed in different colors. Therefore, it is possible to provide an ultrasonic fluoroscopy device that can accurately grasp the state of the object to be detected and is suitable for observing the state of in-reactor equipment, core components, etc. in the reactor vessel.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a conventional example, Fig. 2 is a block diagram showing the configuration of the present invention, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 is a color signal conversion in the same embodiment. FIG. 5 is a waveform diagram showing the echo time detection operation of the means, and FIG.
To explain the distance correction operation, Figure A is a graph diagram showing the relationship between the reflective surface distance and the peak value of the echo signal, and Figure B is a block diagram. T ₁ , T ₂ ,...Tn... Ultrasonic transducer,
2...Reactor vessel, A...Liquid metal, B...Detected object, 101...Scanning means, 102...Driving means, 103...Brightness signal conversion means, 104...Color signal conversion means, 105... ...Image display means.

Claims (1)

[Claims] 1 A scanning arm that is placed in a container in which an opaque liquid is stored and rotates around one end; Compares the receiving ultrasonic transducer and the echo signal received by this ultrasonic transducer with multiple preset threshold levels, and outputs a signal when the echo signal exceeds each threshold level. a comparator circuit; a counter circuit that receives the output signal from the comparator circuit and counts the time until the echo signal exceeds each threshold level; and a counter circuit that counts the time until the echo signal exceeds each threshold level; An echo time detection circuit that detects the time taken to reach the transducer, and converts the echo time detected by the echo time detection circuit into a color signal according to the distance between the ultrasonic transducer and the object to be detected. a color signal conversion circuit that outputs a color signal; a peak value detection circuit that detects the peak value of the echo signal received by the ultrasonic transducer; and a peak value detection circuit that detects the peak value of the echo signal received by the ultrasonic transducer; A peak value distance correction circuit that corrects based on the echo time detected by the peak value distance correction circuit, a brightness signal conversion circuit that converts the peak value corrected by this peak value distance correction circuit into a brightness signal and outputs it, and this brightness signal conversion circuit. An ultrasonic fluoroscopy apparatus comprising an image display unit receiving an output signal from the circuit and an output signal from the color signal conversion circuit and displaying an ultrasonic image of the object to be detected.