JPS60119497A - Stoppering device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for plugging a mechanical plug into a pipe or a hole, and is particularly suitable for use in repair work of a heat transfer tube inside a steam generator of a nuclear power plant. It is suitable.

One of the most important pieces of equipment in a pressurized water power reactor is a steam generator that generates steam to rotate turbine blades. This steam generator, like other nuclear power-related equipment, is subject to very strict maintenance and inspection management, and various inspections and associated repairs are performed periodically even during operation. One of the repair works for heat exchanger tubes in steam generators is to install mechanical plugs inside the heat exchanger tubes.

FIG. 1 shows a partially cutaway side view of a mechanical plug fully inserted into a heat exchanger tube using a conventional manual plugging device, and FIG. 2 shows a detailed cross-section of the mechanical plug.

A mandrel 2 is provided to extend through the hydraulic cylinder 1, and the mandrel 2 can reciprocate in its longitudinal direction by the operation of the hydraulic cylinder 1. A bearing 3 is attached to one end of the hydraulic cylinder 1, and the mandrel 2 passes through it rotatably. A plug installation position detector 4 is attached to the bearing 3 via a base 4ai, and a stroke detector 5 is attached to the bearing 3 via its measuring spindle 5.
A plate 7 is attached via a bearing 6 to the opposite end of the end that is supported by a bearing 3 with the mandrel 2 da 1 in the direction of expansion and contraction of a. When the plate 7 moves, it always comes into contact with the tip of the measuring spindle 5a of the stroke detector 5.

That is, when the mandrel 2 moves due to the operation of the hydraulic cylinder 1, the stroke detector 5 detects the amount of movement.

A screw is machined at the tip of the mandrel 2 on the bearing 3 side, and the cone 0 of the mechanical plug 01 to be inserted into the heat transfer tube
It is designed to be screwed together with the screw machined in 2.

The plug body 01 of the mechanical plug 03 has a cylindrical shape with one end open, and the inside has a tapered shape that widens from the opening toward the back.
2 has been inserted.

Therefore, the mechanical plug 03 is attached to the mandrel 2 via the cone 02.

Conventionally, when plugging a mechanical plug, an operator enters into the water chamber of a steam generator while holding a manual plugging device having the above-mentioned structure in his/her hand.

First, the cone 02 of the mechanical plug 03 and the mandrel 2 of the mechanical plug 03i are inserted into the heat exchanger tube. The heat exchanger tube and the mechanical plug o3 are made to face each other, and the hydraulic cylinder 1 is operated to move the mandrel 2 in the direction in which it is pulled out from the heat exchanger tube. When the cone 02 is moved in the direction to be pulled out in conjunction with the movement of the mandrel 2, the plug body 0
1 is expanded and the heat transfer tube is plugged. Completion of the plugging is detected by a plugging position detector, and when the plugging is completed, the screw connection between the cone 02 and the mandrel 2 is removed using a tool (not shown), and the mechanical plug 03 and the manual plugging device are separated.

These operations are carried out in the water chamber through which the primary water passes, but because the downstream water is connected to the reactor, the interior of this water chamber is often contaminated with radiation, so it is manual work and Separating the tool and the plug required a separate tool, so there was a risk that the worker would be exposed to a large amount of radiation.

The present invention has been made in view of the above-mentioned situation, and provides a valve locking device that can automatically lock the valve by remote control in dangerous or narrow places where it is difficult for people to enter, thereby improving the safety of workers. In particular, when repairing steam generator heat exchanger tubes in nuclear power plants, where mechanical plugs are installed inside the heat exchanger tubes, it is possible to connect the heat exchanger tubes by remote control without the need for workers to enter or exit the water chamber. The purpose is to reduce the amount of radiation exposure by making it possible to plug the water and eliminating the need for workers to direct water.

The structure of the present invention that achieves this object includes a mandrel that holds a mechanical plug inserted into a pipe or a hole, a mandrel moving mechanism that reciprocates the mandrel in its longitudinal direction, and a mandrel that removes the mandrel from the mechanical plug. A mandrel detachment mechanism, a holding member for holding the mandrel moving mechanism and the mandrel detachment mechanism, and a holding member moving mechanism for reciprocating the holding member in a direction parallel to the longitudinal direction of the mandrel. shall be.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plugging device according to the present invention will be described in detail below with reference to the drawings.

FIG. 3 shows a partially cutaway side view of a state in which a mechanical plug is inserted into a heat exchanger tube using the plugging device according to the present invention. In addition, the same reference numerals are given to the same members as those of the conventional manual stoppering device, and detailed description thereof will be omitted.

Casing 6 connected to a tool supply device (not shown)
An elevating cylinder 7, which is a holding member moving mechanism, is attached to the holder, and a piston rod 7a, which is a movable part thereof, is extendable and retractable. The casing 6 has a lifting cylinder 7
A guide shaft 8 is fixed parallel to the piston rod 7a, and a base plate 9, which is a holding member, passes through the guide shaft and is fixed to the tip of the piston rod a.

The base plate 9 moves along the guide shaft 8 by the operation of the lifting cylinder 7.

A plug installation position detector 4 for detecting the insertion position of the plug is attached to the opposite end of the base plate 9 to the end fixed to the piston door a. Further, a guide shaft 10 is attached to a part of the base plate 9 in parallel with the elevation guide shaft 8, and a stroke detector 5 is attached with the measuring spindle 5a extending and contracting in parallel with the elevation guide shaft 8. A hydraulic cylinder 1, which is a mandrel moving mechanism, is attached to the vicinity of the center of the base plate 9 via a bearing 3. The mandrel 2 is provided so as to pass through the mandrel 2, and the mandrel 2 can be moved back and forth in the longitudinal direction by the operation of the hydraulic cylinder 1.

A guide plate 11 is attached to the opposite side of the mandrel 2 from the base plate 9 across the hydraulic cylinder 1 so that the mandrel 2 passes through it via a bearing 12, and a guide shaft 10 passes through a part of the guide plate 11. Even if the mandrel 2 rotates, the guide plate 11
are prevented from rotating together by the guide shaft 10. One end of the guide plate 11 is adapted to always come into contact with the tip of the measuring spindle 5a of the stroke detector 5 when it moves with the reciprocating movement of the mandrel 2. A gear 13, which is one of the mandrel detachment mechanisms, is attached to the end of the mandrel 2 on the side where the guide plate 11 is attached. 14 drive gears 15
It meshes with the.

When the lift cylinder 7 operates, the base 49 to which the hydraulic cylinder 1, plug installation position detector 4, stroke detector 5, guide shaft 10, motor 14, etc. are attached reciprocates along the lift guide shaft. The actuation of the hydraulic cylinder 1 moves the mandrel 2 to which the guide plate 11 and the gear 13 are attached in the longitudinal direction, and the drive of the motor 14 causes the mandrel 2 to rotate via the gears 13 and 15.

A screw is machined at the tip of the mandrel 2 on the bearing 3 side, and the cone 0 of the mechanical plug 03 is inserted into the heat transfer tube.
It is designed to be screwed together with 2.

The operation of plugging a mechanical plug into a heat exchanger tube using the plugging device having the first configuration is performed as follows.

The operator attaches the mechanical plug 03 to the tip of the mandrel 2 of the plugging device near the manhole outside the water chamber of the steam generator. The plugging device is carried into the water chamber by a tool feeding device (not shown) and positioned at a position where the mechanical plug 03 and the heat transfer tube face each other. When the positioning is completed, the lifting cylinder 7 is activated, and the base plate 9 holding the hydraulic cylinder 1 etc. moves once along the lifting guide shaft 8, and the mechanical plug screwed onto the mandrel 2 via the cone 02. 03 is inserted into the heat exchanger tube. Mechanical plug 03
When the plug is inserted at a predetermined position, the plug installation position detector 4 detects this, the operation of the lifting cylinder 7 is stopped, the hydraulic cylinder 1 is activated, and the mandrel 2 to which the cone 02 is screwed is transferred. It is moved in the direction of pulling it out from the heat tube. As the mandrel 2 moves, the cone 02 moves inside the tapered plug body 01, and the plug body 01 moves into the cone 02.
The valve is expanded and plugged. When the mandrel 2 is pulled out from the heat exchanger tube to the stoppered position, it is detected by the stroke detector 5 via the idle plate 11 while the mandrel 2 is being held, and the hydraulic cylinder 1 is stopped. is driven by gear 15.13
The cone 02 and the mandrel 2 are separated from each other by rotating the mandrel 2 through the threaded connection. When the separation of the cone 02 and the mandrel 2 is completed, the lifting cylinder 7 is operated, the mandrel 2 is completely pulled out from the heat exchanger tube, and the plugging device is moved to the vicinity of the operator who is remotely operating it outside the water chamber using a tool supply device (not shown). be returned.

In the above embodiment, a plug installation position detector and a stroke detector are independently provided on the base plate, but various detection mechanisms may be provided on the elevating cylinder or the hydraulic cylinder. 1. Although the base plate and mandrel were moved using a cylinder, it is also possible to use a communication mechanism such as a combination of a feed screw and a motor.

As explained above, when the above-mentioned plugging system # is used to plug the steam generator heat transfer tubes, it becomes possible for the operator to plug the heat transfer tubes by remote control without having to go in and out of the dangerous water chamber. The radiation exposure of people has been significantly reduced.

The above-mentioned embodiment was used for repair work on heat exchanger tubes of a steam generator in an atomic couplant, but of course it can also be used for plugging pipes and holes in other dangerous or narrow places.

As described above in detail based on one embodiment, according to the plugging device according to the present invention, plugging work in dangerous or narrow places where it is difficult for people to enter can now be performed by remote control. By using devices, manipulators, etc., it has become possible to eliminate the need for workers to enter dangerous or narrow spaces to plug the plugs, and the danger to workers has been greatly reduced.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of a mechanical plug being inserted into a heat exchanger tube using a conventional manual plugging device, Fig. 2 is a detailed sectional view of the mechanical plug, and Fig. 3 is a partially cutaway side view of a mechanical plug being inserted into a heat exchanger tube using a conventional manual plugging device. A partially cutaway side view of the mechanical plug inserted into the heat exchanger tube is shown. In the drawings, 1 is a hydraulic cylinder, 2 is a mandrel, 7 is a lifting cylinder, 9 is a base plate, 1a and 15 are gears 1. 14 is a motor, 01 is a plug body, 02 is a cone, and 03 is a mechanical plug. Patent applicant: Mitsubishi Heavy Industries, Ltd. Patent attorney: Shibu Mitsuishi (and one other person)

Claims (1)

[Claims] A mandrel that holds all the mechanical plugs inserted into and plugged into pipes or holes, a mandrel moving mechanism that reciprocates the mandrel in its longitudinal direction, a mandrel detachment mechanism that detaches the mandrel from the mechanical plug, and a mandrel moving mechanism. A plugging device comprising: a holding member that holds the mandrel detachment mechanism; and a holding member moving mechanism that causes all of the holding members to reciprocate in a direction parallel to the longitudinal direction of the mandrel.