JPH09196713A - Jig for mounting/exchanging acoustic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mounting jig which enables mounting of an acoustic sensor of an ultrasonic probe or the like used to detect a leak, etc., of a nuclear plant with the use of a minimum equipment at an area, for example, where people cannot enter, and achieves instrumentation at places where the instrumentation is conventionally impossible. SOLUTION: An acoustic sensor 2 is fitted at a front end of this jig, with a flexible tube 4 coupled thereafter. A plurality of bosses 6 are interposed at a middle position of the flexible tube 4. Moreover, a lead wire 5 is arranged at an inner central part of the flexible tube 4. A leading end of the lead wire 5 is connected to a rear part of the acoustic sensor 2. A coil spring 3 is set between a rear end face of the acoustic sensor 2 and the forefront of the bosses 6, elastically urging and eventually pressing the acoustic sensor 2 to a measuring point by a reactive force. The jig can move even in a guide tube 1 with a bend tube owing to the expansion/compression of the flexible tube 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for installation / replacement of an ultrasonic flaw detector for an accelerometer, an ultrasonic flow meter, and a void meter used for leak detection and loose parts monitor of a nuclear power plant.

[0002]

2. Description of the Related Art Conventionally, acoustic sensors (accelerometers, ultrasonic flaw detectors) have been mounted by a worker's hand pressing from above onto an object to be inspected or by welding onto the object to be inspected. Was commonly known, and it was necessary for a worker to approach the mounting position.

Further, a method of remotely attaching and replacing the ultrasonic flaw detector using a multi-joint manipulator has been considered.

[0004]

By the way, in the former method as described above, in the former method, since it is necessary for the worker to approach the mounting position of the acoustic sensor, for example, in the case of a reactor vessel chamber of a fast breeder reactor. There is a problem that the ultrasonic flaw detector cannot be attached or replaced in a place where it is difficult for workers to enter.

In the latter method, equipment for an articulated manipulator is required. However, in a narrow space such as the reactor vessel chamber of a fast breeder reactor, reactor vessels, pipes, structures, instrumentation parts, etc. are installed. In order to install equipment for an articulated manipulator at a place arranged in close proximity, interference with other equipment must be taken into consideration, which causes a problem that the entire equipment becomes complicated.

[0006] Further, it is not economically suitable for the cost increase for the construction and operation of the nuclear power plant due to the flow meter and the void meter.

Therefore, it has been necessary to develop a device which can be replaced by attaching an acoustic sensor to a place where it is difficult for a worker to approach it, and which has a function of pressing an ultrasonic flaw detector.

The present invention solves the above-mentioned disadvantages of the prior art and provides a new acoustic sensor installation / replacement jig having a function of mounting and exchanging an acoustic sensor and pressing an ultrasonic flaw detector in a narrow working space. Has an aim.

[0009]

As a structure for achieving the above object, the acoustic sensor installation / replacement jig of the present invention is inserted into a guide tube and is used for remote inspection to perform flaw detection or measurement at a measurement point of an object to be inspected. In the jig to be performed, an acoustic sensor such as an accelerometer or a flow meter or an ultrasonic sensor such as an ultrasonic flaw detector is attached to the tip of the jig, and this is connected to a flexible tube. A boss is interveningly connected, and a lead wire is stretched in the flexible tube from the rear center of the acoustic sensor via the boss. Further, a coil spring is attached to the rear end surface of the acoustic sensor so as to be elastically resilient. Inserted from outside the guide tube by remote control,
It is characterized in that it can be removed and installed remotely and the acoustic sensor can be pressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is an external view of an acoustic sensor installation jig according to an example of the present invention, FIGS. 2A and 2B are explanatory views of a state in which the acoustic sensor is inserted into a guide tube, and FIG. 3 is an acoustic sensor installation. FIG. 4 is an explanatory diagram showing a state, and FIG. 4 is an explanatory diagram of an example when applied to a nuclear reactor plant.

First, in FIGS. 1 to 3, 1 is a guide tube,
The jig is inserted into the guide tube.

Reference numeral 2 is an acoustic sensor which is attached to the tip of the jig.
A flexible tube 4 is connected to the rear of the sensor.

Bosses 6 are connected and interposed at a plurality of intermediate positions of the flexible tube 4, and a lead wire 5 is arranged at the center of the flexible tube 4.
The tip of the lead wire 5 is connected and fixed to the rear portion of the acoustic sensor 2.

A coil spring 3 is interposed between the rear end surface of the acoustic sensor 2 and the boss 6 located at the frontmost portion of the plurality of bosses, and supports the acoustic sensor 2 in a resilient state. ing.

As shown in FIGS. 2 and 3, when the rear end of the jig of the present invention is pressed, the jig advances in the guide tube 1 while shrinking the flexible tube 4 (state of FIG. 2 (a)). Then, as shown in FIG. 2 (b), after passing through the curved pipe portion, the flexible tube 4 extends while advancing and reaches the measurement point of the inspection object.

The jig can be sufficiently advanced even in a guide tube having a curved tube by expanding and contracting the flexible tube.

Since it is necessary to press the acoustic sensor 2 against the measuring point when the acoustic sensor 2 reaches the measuring point, the acoustic sensor 2 is pressed against the measuring point by the deflection of the lead wire 5 and the reaction force of the coil spring 3. .

Since the lead wire 5 is pressed at the jig insertion start position as shown in FIG. 3, the acoustic sensor 2 is continuously pressed.

When replacing the acoustic sensor 2, it is possible to remove it at a remote position by pulling out the lead wire 5.

The arrival of the acoustic sensor 2 at the measurement point and the confirmation of the pressing of the acoustic sensor 2 are carried out by utilizing the fact that the reaction force from the acoustic sensor installation jig is applied to the insertion drum 8 shown in FIG. It is detected by the load cell 7.

Next, an example in which the present invention is applied to an FBR plant (fast breeder reactor) will be described with reference to FIG. FIG. 4 is an explanatory view of a state in which the present invention is applied to an ultrasonic flowmeter for top entry piping of a fast breeder reactor.

In FIG. 4, an ultrasonic flaw detector for an ultrasonic flowmeter is inserted into the guide tube 1 by a jig inserting / pulling device 14 installed on a roof deck portion 15, and the jig of the present invention (FIG.
It is installed on the horizontal portion 12 of the top entry pipe, which is the measurement point.

The ultrasonic flaw detector is replaced by the insertion / extraction device 14
By winding the jig.

Reference numeral 10 indicates an upper core mechanism, and 11 indicates a nuclear reactor.

[0025]

According to the jig of the present invention, it is possible to install the acoustic sensor in the inaccessible area of the worker using the minimum equipment, and thus the cost for installing the acoustic sensor is reduced.

Further, since it is possible to measure a portion which cannot be measured conventionally, the reliability of the plant is improved.

Further, when used in an area which is accessible but has a high radiation dose, the exposure of workers is reduced and the safety of work is improved.

[Brief description of drawings]

FIG. 1 is an external view of an acoustic sensor installation jig that is an example of an embodiment of the present invention.

2 (a) and 2 (b) are explanatory views of a state in which an acoustic sensor is inserted into a guide tube.

FIG. 3 is an explanatory view showing an installed state of the acoustic sensor of the present invention.

FIG. 4 is an explanatory diagram when the present invention is applied to a nuclear reactor plant.

[Explanation of symbols]

 1 Guide tube 2 Acoustic sensor 3 Coil spring 4 Flexible tube 5 Lead wire 6 Boss 7 Load cell 8 Insertion drum 10 Core upper mechanism 11 Reactor 12 Top entry piping 14 Jig insertion / extraction device 15 Roof deck section

Claims (1)

[Claims] 1. A jig which is inserted into a guide tube and is used for flaw detection or measurement at a measurement point of an inspection object by remote control,
An accelerometer, a flow meter, or other acoustic sensor, or an acoustic sensor, such as an ultrasonic flaw detector, is attached to the end of the jig, and this is connected to a flexible tube, and a plurality of bosses are connected in the middle of the tube. In addition, a lead wire is stretched in the flexible tube from the center of the rear part of the acoustic sensor via the boss, and a coil spring is elastically attached to the rear end surface of the acoustic sensor, and these are guided by remote control. An acoustic sensor installation / replacement jig characterized in that it can be installed / removed from the outside of the pipe to enable remote installation / replacement and pressing of the acoustic sensor.