JPH04276511A - Ultrasonic wave measuring apparatus - Google Patents

Abstract

PURPOSE:To reduce the contact range with a liquid metal cooling material and to perform disassembling and maintenance work readily and efficiently by making the apparatus compact, readily moving the apparatus in the narrow working space, making the access to an object easy, and providing the tightly closed gas atmosphere structure inside the casing of a main body. CONSTITUTION:This apparatus has a tubular main body casing 20 and the parts having the following functions. A transducer 22 is attached to the tip part of a main body casing 20 through an expansion bellows 21 and transmits and receives ultrasonic waves. A drive shaft 25 drives a motor housed in the main body casing 20. A link mechanism 27 is attached to the drive shaft 25 so that the mechanism is rotated as a unitary body, and a play shaft 28 is provided at the tip. A link driving device 30 drives the link mechanism 27 so that the play shaft 28 is moved back and forth in the direction of the diameter of the drive shaft 25. The transducer 22 is provided at the play shaft 28 so that the transducer is rotated freely and spiral motion is performed in this constitution.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Industrial Application Field] The present invention relates to an ultrasonic measuring device for measuring the shape and contour of an article using ultrasonic waves, and is particularly suitable for measuring objects under the liquid surface of a liquid metal cooled nuclear reactor. It relates to an ultrasonic measuring device.

0003

[Prior Art] A fast breeder reactor, which is a liquid metal cooled nuclear reactor, has a reactor core housed in a reactor vessel, and an intermediate heat exchanger and circulation pump are installed around the reactor core. It has a structure. Because the inside of the reactor vessel is filled with liquid metal sodium, which is a liquid metal coolant, it is difficult to observe the inside of the reactor, unlike in light water reactors that use water as a coolant.

Even in fast breeder reactors that use liquid metal sodium as a coolant, it is necessary to observe, maintain, and inspect the reactor internal structures and reactor equipment below the sodium liquid level. There is an ultrasonic measuring device that uses ultrasonic waves as a device for observing and measuring the reactor internal structures, reactor equipment, and the like.

[0005] This ultrasonic measurement device transmits ultrasonic waves to an object under the sodium liquid level, and applies spiral motion to a transducer that receives the reflected waves to obtain an ultrasonic image of the object. It has become.

[0006]

[Problems to be Solved by the Invention] However, in conventional ultrasonic measurement devices, in order to give spiral motion to the transducer that transmits and receives ultrasonic waves, it is necessary to combine rotational motion in the circumferential direction and motion in the radial direction of the transducer. It is necessary to grant the For this reason, conventional ultrasonic measurement devices are equipped with an inner cylinder that houses a transducer, and a drive mechanism that provides rotational motion to the inner cylinder and a drive mechanism that drives the transducer housed in the inner cylinder in the radial direction. However, in order to give the transducer spiral motion using two independent drive sources, or to make the transducer spiral motion using a single-axis drive device, a complicated gear mechanism is required, and in either case, the ultrasonic measurement device is There was a problem with increasing the size.

By the way, in a nuclear reactor such as a fast breeder reactor, the reactor internal structures and reactor equipment are arranged in a complicated manner in and around the reactor core, so it is difficult to take up a large working space, and the work space is limited. Maintenance, inspection, and maintenance work must be carried out in a narrow space, and it is difficult to access objects such as equipment inside the reactor using large ultrasonic measurement equipment.

In addition, in conventional ultrasonic measurement devices, each drive mechanism that drives the transducer comes into contact with liquid metal coolant, so when performing maintenance work, disassembly and inspection are not easy due to the adhesion of coolant. There was a problem.

The present invention has been made in consideration of the above-mentioned circumstances, and provides a small and compact ultrasonic measuring device that can be easily moved even in a narrow working space, provides easy access to an object, and is small and compact. The purpose is to provide

Another object of the present invention is to configure the inside of the main body casing to have a sealed gas atmosphere structure to reduce the area that comes into contact with the liquid metal coolant, so that disassembly and maintenance work can be performed easily and efficiently. An object of the present invention is to provide an ultrasonic measuring device according to the present invention. [Structure of the invention]

[0011]

[Means for Solving the Problems] In order to solve the above-mentioned problems, an ultrasonic measuring device according to the present invention includes a cylindrical main body casing and a liquid-tight attachment to the tip of the main body casing via a telescopic bellows. a transducer that transmits and receives ultrasonic waves; a motor-driven drive shaft housed in the main body casing; a link mechanism that is rotatably attached to the drive shaft and has a floating shaft at its tip; and a link drive device that drives the link mechanism to move the shaft forward and backward in the radial direction of the drive shaft, and the transducer is rotatably provided on the floating shaft and configured to perform spiral motion.

Further, in order to solve the above-mentioned problems, the ultrasonic measuring device according to the present invention includes a link drive device that is housed in a main body casing, and includes a reducer to which rotational driving force of a drive shaft is input; This reduction gear has a slide spool provided on the output side and slidably fitted to the drive shaft in a free rotation manner, and a drive ring provided outside the slide spool in a free rotation manner,
The driving side of the link mechanism is connected to the drive ring, and the inside of the main body casing is configured to have a gas atmosphere such as an inert gas.

[0013]

[Function] The ultrasonic measuring device of the present invention has a transducer liquid-tightly attached to the tip of a cylindrical main body casing via an extensible bellows, and a device (drive shaft, link mechanism) for spirally moving the transducer within the main body casing. , link drive device), making it compact and compact.
Because it is compact, it is possible to access objects smoothly and easily even in narrow spaces.

[0014] Furthermore, the inside of the main body casing is configured to have a hermetically sealed gas atmosphere such as an inert gas, and the driving device of the transducer housed inside can be isolated from the surrounding fluid. The area that comes into contact with the fluid is minimized, allowing for efficient and easy disassembly and maintenance work.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ultrasonic measuring device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing an example of a tank type fast breeder reactor as a liquid metal cooled nuclear reactor equipped with this ultrasonic measuring device. A reactor safety vessel 2 is provided, and a reactor vessel 3 is housed within this safety vessel 2. The reactor vessel 3 includes a core 4 loaded with nuclear fuel, and is divided into an upper plenum 6 and a lower plenum 7 with a core support structure 5 that supports the core 4 as a boundary. 6 and 7 are filled with sodium coolant 8, which is a liquid metal coolant.

Further, around the reactor core 4, there is an intermediate heat exchanger 10 for exchanging heat between the primary sodium coolant and the secondary sodium coolant, and a circulation system for forcibly circulating the primary sodium coolant within the reactor vessel 3. A pump 11 is provided. The intermediate heat exchanger 10 and the circulation pump 11 are installed vertically on an upper lid 12 and a roof slab 13 that cover the upper opening of the reactor vessel 3.

A rotary plug 14 is rotatably supported on the roof slab 13, and a small rotary plug 15 is provided on the rotary plug 14 so as to be eccentrically rotatable. This small rotation plug 1
5 is a control rod drive mechanism (
(not shown), etc., is provided.
The ultrasonic measuring device 18 shown in FIG.
is provided. This ultrasonic measuring device 18 may be removably installed outside the core upper mechanism 16. Specifically, a cylindrical body of a measuring device is installed in the rotating plug or fixed plug of a fast breeder reactor, and the cylindrical body of the measuring device is inserted through the plug, and ultrasonic measurement is carried out at the tip of the cylindrical body via an extendable and retractable multi-jointed bellows. A device may also be provided. The cylindrical body may be telescopic or rotatable. Note that the reference numeral 19 is a cover gas space filled with an inert gas or the like.

The ultrasonic measuring device 18 is used to observe the surface condition of the reactor internal structures and equipment, the presence or absence of bolts and nuts falling off, the presence or absence of abnormal deformation, etc. It has a cylindrical main body casing 20. A metal extensible bellows 21 is provided at the tip of the main body casing 20, and a transducer 2 that emits ultrasonic waves at the tip of the bellows 21 and receives reflected waves of the emitted ultrasonic waves.
2 is mounted in a liquid-tight manner.

[0020] Also, a motor 24 is provided inside the main casing 20.
is installed, and the drive shaft 2 is driven by this motor.
5 is driven to rotate. The drive shaft 25 extends inside the main body casing 20 toward the distal end, and a large diameter portion 25a is formed at the distal end of the drive shaft 25, and a four-bar link or the like is inserted into a slit 26 formed in the large diameter portion 25a. The constituting link mechanism 27 is attached to rotate integrally. The link mechanism 27 has a floating shaft 28 parallel to the drive shaft 25 (may have a predetermined angle),
It is supported so as to be swingable around a fulcrum P, so that the floating shaft 28 is moved forward and backward in the radial direction A of the drive shaft 25. The transducer 22 is rotatably engaged with the floating shaft 28 .

On the other hand, the link mechanism 27 is connected to the link drive device 3.
It is driven by 0. This link drive device 30 is housed in the main body casing 20, inputs the rotational driving force of the drive shaft 25, and receives the rotational driving force of the drive shaft 25.
A reduction gear 31 having a common shaft with the reduction gear 31, a slide spool 33 that rotatably engages with a low-speed sleeve 32 provided on the output side of this reduction gear 31, and a drive provided outside of this slide spool 33 so as to be free to rotate. The drive ring 34 is connected to the driving side of the link mechanism 27 via a connecting link 35, for example, the ring arm 27a.
is pin-coupled to one end of the

The slide spool 33 is screwed to a support 37 fixed to the main body casing 20 so as to be raised and lowered, and is fitted onto the drive shaft 25 so as to be freely rotatable and slidable. Slide spool 3
A low-speed sleeve 32 that rotationally engages with the drive shaft 25 is also loosely fitted to the drive shaft 25.

As described above, the link drive device 30 that drives the link mechanism 27 has a component that is the drive shaft 2.
Since this link drive device 30 does not require a complicated gear mechanism, it can be compact and weighed, and the main body casing 20
It can be stored efficiently and compactly inside. By arranging the link drive device 30 so as to have a common axis with the drive shaft 25, the diameter of the main body casing 20 can be reduced without increasing the diameter, and the overall size can be made smaller and more compact.

Further, the main body casing 20 is filled with an inert gas (helium, argon, etc.) to create a sealed gas atmosphere structure, and the main body casing 20 is isolated from the external fluid. Therefore, the link mechanism 27 housed in the main body casing 20 and its drive device 30 are reliably prevented from coming into contact with the sodium coolant.

Next, the operation of the ultrasonic measuring device 18 will be explained.

The ultrasonic measuring device 18 is capable of accessing objects such as the reactor core and in-reactor equipment in the reactor vessel 3 attached to the upper core mechanism 16 of a fast breeder reactor, for example.

With the ultrasonic measurement device 18 accessing the target object, the motor 24 is driven and the drive shaft 2
Rotate 5. As the drive shaft 25 rotates, the link mechanism 27 also rotates integrally, and the floating shaft 28 of the link mechanism 27 pivots around the drive shaft 25 in the circumferential direction. As the floating shaft 28 pivots, the transducer 22, which is rotatably attached to the floating shaft 28, also pivots. At this time, the floating shaft 28 rotates on its own axis while revolving around it due to the rotation of the drive shaft 25, but since the transducer 22 is fixed to the telescopic bellows 21, its rotation is suppressed and it only revolves around its axis.

On the other hand, the drive shaft 25 is connected to a reducer 31 of the link drive device 27.
1, the speed is decelerated at a constant ratio and output to the low speed sleeve 32. A slide spool 33 is attached to the low speed sleeve 32.
are rotatably connected and can slide freely in the axial direction. When the slide spool 33 rotates, the slide spool 33 slides in the axial direction by a screw connection of a bolt and nut mechanism.

A drive ring 34 is rotatably coupled to the slide spool 33, and a connecting link 35 is pin-coupled to this drive ring 34, and the other end of this connecting link 35 is connected to the drive side of the link mechanism 27, for example. It is pin-coupled to one end of the link arm 27a. Due to this connection, when the slide spool 33 slides, the floating shaft 28 of the link mechanism 27 is moved forward and backward in the radial direction A.

In this manner, the ultrasonic measuring device 18 uses the rotational driving force transmitted to the drive shaft 25 by the motor drive to rotate the floating shaft 28 via the link mechanism 27.
While the transducer 22 revolves in the circumferential direction, the slide spool 33 is slid in the axial direction of the drive shaft 25 by the driving force input to the reducer 31 of the link drive device 30, and the idle shaft 28 is moved through the link mechanism 27.
causes a radial movement. As a result, the floating shaft 28
moves in the radial direction while turning in the circumferential direction, and the tip of the floating shaft 28 can draw a constant spiral locus.

In this case, since the transducer 22 is attached to the telescopic bellows 21 and is coupled to the floating shaft 28 in a free-rotation manner, it draws a spiral locus as the floating shaft 28 moves, but its rotation is restricted. Further, since the transducer 22 is attached to the telescopic bellows 21 in a liquid-tight manner, internal sealing performance can be ensured, and the driving portion of the transducer 22 can be isolated from the surrounding fluid.

[0032] In this manner, the transducer 22 is given a spiral motion and the ultrasonic waves are emitted from the transducer 22 toward the object. The emitted ultrasonic waves hit an object and are reflected, and the transducer 22 receives the reflected waves. The received signal is sent to a processing device such as an image processing device via a signal cable (not shown) and subjected to signal processing. Through this signal processing, the shape, contour, etc. of the object can be confirmed in the image.

In this case, the transducer 22 attached to the telescopic bellows 21 revolves, but does not rotate, so that the cables connected to the transducer 22 can be easily routed, improving maintainability.

[0034]

As described above, the ultrasonic measuring device according to the present invention has a transducer that is fluid-tightly attached to the tip of the cylindrical main body casing via the telescopic bellows, and the transducer is mounted inside the main body casing. Since the drive shaft for spiral movement, the link mechanism, and the link drive device are efficiently housed, it can be made smaller and more compact, and the object can be accessed smoothly and easily even in a narrow space.

Furthermore, the inside of the main body casing is constructed with a sealed gas atmosphere such as an inert gas, and the driving device of the transducer housed inside can be isolated from the surrounding fluid such as liquid metal. The contact area can be minimized, and disassembly and maintenance work can be performed efficiently and easily.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a liquid metal cooled nuclear reactor equipped with an ultrasonic measuring device of the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of the ultrasonic measuring device according to the present invention.

[Explanation of symbols]

1 Reactor building 3 Reactor vessel 4 Reactor core 6 Upper plenum 7 Lower plenum 10 Intermediate heat exchanger 11 Circulation pump 13 Roof slab 14 Rotating plug 16 Upper core mechanism 18 Ultrasonic measurement device 20 Main body casing 21　Extendable bellows 22 Transducer 24 Motor 25 Drive shaft 26 slit 27 Link mechanism 28 Idle axis 30 Link drive mechanism 31　Reducer 33 Slide spool 34 Drive ring 35 Connecting link

Claims (2)

[Claims] 1. A cylindrical main body casing; a transducer that is fluid-tightly attached to the tip of the main body casing via a telescopic bellows and that transmits and receives ultrasonic waves;
A motor-driven drive shaft housed in the main body casing, a link mechanism rotatably attached to the drive shaft and having a floating shaft at its tip, and a link mechanism configured to move the floating shaft forward and backward in the radial direction of the drive shaft. a link drive device for driving the link mechanism, the transducer being rotatably provided on an idle shaft;
An ultrasonic measurement device characterized in that it is configured to have a spiral motion. 2. The link drive device includes a reducer housed in the main body casing, into which the rotational driving force of the drive shaft is input, and a link drive device provided on the output side of the reducer so as to be able to freely rotate and slide on the drive shaft. It has a slide spool that fits into the slide spool, and a drive ring that is rotatably provided on the outside of the slide spool. 2. The ultrasonic measuring device according to claim 1, wherein the ultrasonic measuring device has a gas atmosphere structure.