JP2809350B2 - Heat transfer tube plug stopper removal device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for removing a mechanical plug, that is, a stopper plug, attached to a heat exchanger tube of a heat exchanger or a steam generator from the heat exchanger tube.

[Related Art] In a nuclear power plant, a mandrel is generally closed by rotating a mandrel to remove a plug attached to an end of a heat transfer tube in a steam generator and closing the inside of the heat transfer tube from the heat transfer tube. After screwing into the stopper, the core push-up rod is advanced to push the core already mounted in the stopper into the back of the stopper, so that the stopper can be pulled out from the heat transfer tube, and then If the mandrel is retracted, the stopper can be pulled out.

Various types of closure stopper removing devices for automatically or manually performing such operations have been proposed.

That is, FIGS. 20 and 21 show representatively such a stopper removing device disclosed in Japanese Utility Model Laid-Open Publication No. 62-174838. The removal of the closure plug located at the end can be performed remotely.

The device is guided by a guide device (not shown) to the stopper removing position, and then the button X in the heat transfer tube b is pulled down by operating the clamp cylinder Z, and is fixed to the tube sheet a by the wedge action of the cutter Y.

As shown in FIG. 21, the removing portion of the stopper plug c mainly includes a cylinder B and a piston for pushing up the core d connected to the metal fitting A contacting the tube sheet a and pulling out the stopper plug c. D. The mandrel g inserted into the upper part of the piston D is fixed to the piston D by a pin E, is connected to a trigger F, and has a core push-up bar J inside. Core pushing rods J, as can screwed a threaded portion g ₁ of the mandrel tip regardless collapse or misalignment of the mandrel g the closed plug threaded portion c ₁ upon removal of the closure plug c, freely in clevis G joint Connected to H. Core d
Is of the push-up increases the piston D by introducing a pressure fluid into the cylinder B, carried out by raising the clevis G in the push-up surface D _1, its withdrawal is by the lowering of the piston D, the pin E, trigger Compound F And via a mandrel g. The upper end of the mandrel g is screwed into the stopper plug screw portion c ₁ , and the lower end is inserted into the gear V so as to be integrally rotatable in the circumferential direction and slidable in the axial direction. This is performed by rotating the angular axis I via the gear V. The rotation of the gear V is performed by driving a gear K meshing with the gear V by a motor L. Further, this device has a recovery device N for the stopper c after being pulled out, and the recovery device N turns and recovers under the control of a manipulator-like rotary actuator M.

[Problems to be Solved by the Invention] In the above-mentioned conventional automatic stopper removal device, the push-up stroke of the core d and the withdrawal stroke of the stopper c are added in series, so that the axial direction of the cylinder B is increased. The dimensions become longer.

Therefore, in a narrow space near the curved peripheral portion of the head plate (not shown) that defines the water chamber of the heat exchanger in cooperation with the tube sheet a,
The plug c in the heat transfer tube b cannot be pulled out. Therefore, the removal of the plug in the heat transfer tube in such a narrow space must rely on a manual removal device.
In particular, since the radioactivity level in the steam generator of a nuclear power plant is high, the above-described manual operation poses a problem for the safety and health of workers.

Further, when the length of the cylinder B becomes longer, the combined action of various members related to the cylinder B increases the weight of the entire stopper stopper removing device, which causes problems in terms of work efficiency and manufacturing cost.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an apparatus for removing a heat transfer tube plug from which a plug can be pulled out from a target heat transfer tube even in a narrow space with a short cylinder.

[Means for Solving the Problems] In order to achieve this object, a stopper inserted in the heat transfer tube is pushed up from a stopper holding position to a stopper releasing position by pushing a core inserted in the stopper. According to the present invention, there is provided a heat transfer tube closing plug removing device, which is removed by pulling out the heat transfer tube closing plug, wherein the mandrel is supported to be rotatable and vertically movable for screwing into the closing plug and pulling out the closing plug. A core push-up bar supported so as to be able to move up and down to push up the core from the closure-plug holding position to the closure-plug release position, and a core push-up and storage housing the mandrel and the core push-up bar.
A closing stopper pull-out cylinder, and the core pushing-up / closing stopper pulling-out cylinder so that a lifting force of the core pushing-up / closing stopper pulling-out cylinder is transmitted to the core lifting rod when the core is pushed up. A mandrel screw-in mechanism including a rotary actuator associated therewith so as to selectively bring the core push-up bar into an interlocked state, a mandrel elevating cylinder for elevating and lowering the mandrel, and rotating means for rotating the mandrel. And engages with the core pushing-up / closing stopper pull-out cylinder, and when pushing up the core, by the amount of the core pushing-up stroke,
A main body elevating mechanism including a main body elevating cylinder for lowering the stopper plug pulling cylinder downward, wherein the rotating means rotates from the side to the mandrel from the side via a universal joint below the core pushing up / closing plug pulling cylinder. Empowering.

[Operation] The removing device aligns the mandrel and the core push-up rod in the axial direction with the stopper to be removed and fits the heat transfer tube into which the stopper has not been inserted, so that the heat transfer tube or the tube sheet is fitted to the stopper. Supported.

First, the mandrel lifting cylinder is operated to raise the mandrel toward the stopper to be removed. Next, the turning means is operated to transmit the screwing rotational force to the mandrel via the universal joint, and the screw portion of the mandrel is screwed into the stopper. The rotating means is disposed on the lower side of the core pushing-up / closing stopper pulling-out cylinder, and gives a rotating force to the mandrel via a universal joint, so that the height of the removing device can be increased as much as possible. I am holding it down.

After screwing the mandrel into the stopper in this way,
The body lifting cylinder is operated to lower the core pushing-up / closing stopper pull-out cylinder by the core pushing-up stroke. Thereafter, the rotary actuator is operated to make the cylinder body of the core push-up / closing stopper pull-out cylinder and the core push-up bar in an interlocking state, and then a high-pressure fluid is introduced into the core push-up / closing stopper pull-out cylinder, The cylinder body and the core push-up rod are raised by the core pushing-up stroke with respect to the piston that is screwed into the stopper and transmits the reaction force to the mandrel in the hanging state, and the stopper is sealed in the heat transfer tube. The core that was tied up is pushed up and released.

As a result, the length of the core pushing-up / closing stopper pull-out cylinder is shortened by the core pushing-up stroke.

After the core is pushed up and released, the rotary actuator is released, and while holding the cylinder body of the core push-up / closing stopper pull-out cylinder with the body lifting cylinder, the high-pressure fluid And pull down the stopper by lowering the mandrel. The reaction force at this time acts on the tube sheet surface.

The withdrawn stopper plug releases the main body lifting / lowering cylinder and moves the whole core pushing / pulling stopper withdrawal cylinder down to define a space between the cylinder and the tube plate surface. Is introduced to move the piston and the mandrel upward, and the pulled out stopper plug projects into the space.
The projecting stopper can be collected by a stopper collecting mechanism.

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

1 to 8 are diagrams showing a detailed structure of the removing device 1 according to the present invention. In FIG. 1, a core pushing up / closing stopper pulling cylinder 2 of the removing device 1 is provided. A core push-up lock mechanism 3 using a pneumatically operated rotary actuator 4 for switching between a core push-up force and a closing plug pull-out force is provided, and the inside of the heat transfer tube b is closed via a mandrel 5. The plug c is pulled out, and the core d is pushed up through the core push-up rod 8 arranged coaxially in the mandrel 5.

The mandrel 5 has a threaded portion 5a to be screwed into engagement threaded portion c ₁ of the closure plug c in the outer circumference of the leading end portion. The mandrel screwing mechanism 10 has a mandrel raising / lowering cylinder 11 and a turning means 12 for screwing and feeding the mandrel 5.
The rotational torque from the screw 12 is transmitted to the mandrel 5 from the side via the universal joint 14 below the cylinder 2.

Further, the removing device 1 includes a main body lifting / lowering cylinder 16 that lowers the cylinder 2 by the core lifting stroke when the core d is raised, and a main body lifting / lowering lock cylinder 17 that reliably stops the lower movement of the cylinder 2 at a predetermined position. The main body lifting mechanism 15 having

The cylinder 2, the core push-up lock mechanism 3, the mandrel screwing mechanism 10, the main body elevating mechanism 15, and the like described above are held by the frame 30 together with the stopper collection mechanism 20. Also,
The frame 30 is also provided with a bracket 31 for mounting the tube sheet surface on a robot (not shown) running on its own, and a self-aligning means 32 of the removing device.

Detailed description of the structure of the removing device As shown in FIG. 2, the cylinder 2 is a piston rod of a pneumatic body lifting cylinder 16 fixed to a frame 30.
16a is connected via a connecting member shown in the drawing, and the pneumatic main body lifting / lowering lock cylinder 17 (FIG. 6) is locked and actuated accurately for the core pushing-up stroke before the core pushing-up operation. The stopper plug collecting mechanism 20 is lowered by the main body lifting cylinder 16 so as to allow the stopper stopper collecting mechanism 20 to operate before the stopper plug c is recovered.

As best shown in FIG. 1, inside the cylinder 2, a cylindrical piston 2a which is operated by supplying water pressure is disposed so as to be slidable up and down. As downward movement of the cylindrical piston 2a is restrained via the equal hardware 2d and mounting hardware 6a at the lower end of the piston 2a, screwed mandrel 5 screw portion 5a to the threaded portion c ₁ of the closure plug c In this case, the reaction force acting downward on the piston 2a when the stopper is pushed up is supported by the trigger 6 suspended from the lower shoulder 5b of the mandrel via the spherical seat 5c. Also,
The inner cylinder 2 'of the cylinder 2 extends inside the piston 2a, and the above-described mandrel 5 and trigger 6 can be rotated in the inner cylinder 2' in the circumferential direction and can be moved in the longitudinal direction. Is housed in

Push-up rod 8 extending axially through hollow mandrel 5
Has an upper part 8b and a lower part 8d interconnected by a universal joint 8c. The upper portion 8b has a cap 8a for retaining the mandrel 5 fixed at the top, and is restrained in a rotational direction with respect to the mandrel 5 by a key 5d, and slides in a longitudinal direction over a stroke sufficient to push up the core d. It is possible. Thus, the upper portion 8b is to transmit rotational force to the mandrel 5 by the engagement between the mandrel 5 by the key 5d, as the screw portion 5a of the mandrel 5 can be screwed into the screw portion c ₁ of the closure plug c I have to. After the core d is pushed up, the cylinder 2
The lock cylinder 17 is unlocked, high-pressure water is supplied above the piston 2a, and the mandrel 5 is largely lowered by the piston 2a to pull out the stopper c. At this time, the reaction force is applied to the tube sheet surface a.

The rotary actuator 4 operated by air pressure is
As shown in FIG. 1, a casing 4a fixed via a bracket 4e to a guide case 2f connected to a lower portion of the cylinder 2, a rotating link 4b attached to an actuator output shaft, and a pin connected to the rotating link 4b. And a locking link 4c coupled thereto. When the locking link 4c is lowered by a lifting stroke together with the cylinder 2 for pushing up the core, the locking link 4c is provided with a flange 8e provided on the lower portion 8d of the lifting rod. Engage with the lower surface. When the stopper is pulled out, the locking link 4c is made of a flange so that the piston 2a and the trigger 6 can secure a sufficient drawing stroke.
8e.

Mandrel lifting cylinder 11 shown in FIGS. 2 and 8
Is a cylinder body 11a fixed to a metal fitting 2d at a lower end of the piston 2a by a support 11c, a piston 11b operated by pressurized air, and an output portion of the piston 11b is connected to a mounting metal 6a of the trigger 6. And a connecting body 11d that
For screwing the mandrel 5 in the closed stopper c, to actuate the piston 11b so as pressing the screw portion 5a and c ₁ between it and the like to raise. Threaded portion 5a, when the c ₁ is brought into contact with each other, the mandrel 5 rotation means 12 (FIG. 1, FIG. 2)
, And is screwed into the stopper c by receiving the turning torque.

As shown in FIGS. 1 and 2, the rotating means 12 includes a rotational force transmitting gear train disposed obliquely below the push-up rod lower portion 8d in order to reduce the length of the removing device 1 in the vertical direction. 13, a reversible rotary motor 12a mounted on the frame 30 to input a rotational force to the gear train 13, and a universal joint 14 connecting the output portion of the gear train 13 and the lower end of the push-up rod lower portion 8d. It is composed of The gear box 13a accommodating the gear train 13 is supported by a support 13c on a sleeve 13b surrounding the lower end of the lower portion 8d so that the push-up rod 8 can rotate. The gear box 13a has an output shaft of the motor 12a
In the vertical direction, the motor 12 is prevented from moving up and down by the push-up bar 8.
It is slidable along the output shaft 12b of a. Rotating means
The rotational force transmitted to the lower portion 8d of the push-up bar 8 by 12 is:
The force is transmitted to the push-up bar upper portion 8b via the universal joint 8c, from which it is transmitted to the mandrel 5 which is slidable in the longitudinal direction, is restricted in the rotational direction, and is engaged with the push-up bar 8.

Various types of joints that change the rotation of one shaft at a right angle and transmit it to the other shaft are known in various types (for example, published by Gihodo Co., Ltd. on October 15, 1957. See also "Machine Motion Mechanism".) The universal joint 14 used in the embodiment of the present invention is formed in a parallelogram by links of the same length connected to each other by pins, and can also apply a rotational force to the mandrel 5. .

The main body elevating cylinder 16 and the main body elevating lock cylinder 17 have already been described in relation to the core pushing-up / closing stopper pull-out cylinder 2, so that further description is omitted here.

2 and 5 is a stopper which is pulled out via the mandrel 5 by the piston 2a being lowered to the bottom dead center by the high water pressure of the core pushing-up / closing stopper pulling cylinder 2. c is collected in the collecting cylinder 25, the main body elevating cylinder 16 is lowered to the stopper plug collecting position, and then the low pressure water is introduced below the piston 2a of the cylinder 2 to raise the mandrel 5, and the pipe sheet surface a Removal device 1
The plug c is pulled out in the space between the plug c and the plug c is exposed, and the plug c is gripped by the manipulator arm 21.

The arm turning cylinder 22 of the recovery mechanism 20 is fixed to the upper part of the cylinder 2, and is formed on a mounting hardware 22c of the L-shaped link 11b fixed to an output portion of the piston (not shown) during the extension operation. The arm 21 is turned through a pin 22d in the oblong hole. That is, the arm
21 pivotally supports the pin 22d with a protrusion at its proximal end,
With the extension operation of the piston, the piston is swung from the stopper collection position to the stopper grasping position through the base guide pin 21a along the guide slot 23a of the clevis 23 fixed to the top of the cylinder 2. It has become.

Further, the manipulator arm 21 is provided with a closure plug clamp cylinder 24 for extending the piston rod 24a at the closure plug gripping position and gripping the closure plug c at the distal end of the manipulator portion. When the manipulator arm 21 returns to the stopper stopper collection position, the collection cylinder 25 is opened below the manipulator portion at the distal end, and is attached to the side of the cylinder 2.

The operation confirmation of each operation member described above can be performed using, for example, a Hall element or a magnetic sensor.
This technique is known in sequence control, and a description thereof will be omitted.

Operation of Removal Device Next, the operation of the closure stopper removal device of the present invention having the above-described structure will be described with reference to FIGS. 9 to 19.

FIG. 9 shows a stand-by state. In this stand-by state, the piston of the mandrel elevating / lowering cylinder 11 is lowered to the start position of the stopper plug screw-in position, and the piston of the main body elevating / lowering cylinder 16 is raised to the stopper plug withdrawal position. The rotary actuator 4 for the core push-up lock and the main body lifting lock cylinder 17 are in the unlocked position.

To the completion status narrowing twisted mandrel shown in FIG. 10, the piston is rotated forward to and mandrel rotation motor 12a raises the mandrel lifting cylinder 11, the screw portion c ₁ of the threaded portion 5a of the mandrel 5 closing plug c Screwed into the core d
Is applied to the stopper c. Other cylinders 16, 17 and rotary actuator 4
Is the same as the standby state. Hereinafter, only the changed members will be described.

In order to start the core pushing-up operation shown in FIG. 11, the main body elevating lock cylinder 17 is operated to the lock position, and the main body elevating cylinder 16 is lowered by the core pushing-up stroke. Next, the rotary actuator 4 is locked and the core pushing-up / closing stopper pull-out cylinder 2 is in a state where the force for pushing up the core is transmitted to the push-up bar 8.

In order to make the core push-up completion state shown in FIG. 12, high-pressure water is supplied above the piston 2a of the core push-up / closing stopper pull-out cylinder 2 and the cylinder 2 is raised up to a position where it comes into contact with the tube sheet surface a. Drive and link the push-up rod 8 to the core d
Push up and release. In this case, the main body elevating cylinder 16 also returns to the standby position in conjunction with it.

The lock of the rotary actuator 4 is released in order to return the push-up rod to a state after the completion of pushing up the core shown in FIG. Further, the main body lifting / lowering rock cylinder 17 having completed its role is also returned to the release position.

In order to make the stopper plug pull-out completion state shown in FIG. 14,
Piston 2a of core pushing up / closing stopper pull-out cylinder 2
The piston 2a is driven downward by supplying high-pressure water to the upper part of the tube, and the plug c is pulled out from the heat transfer tube b. The reaction force at this time is received on the tube sheet surface a via the top surface of the cylinder 2.

In order to set the stand-by state for collecting the withdrawn stopper shown in FIG. 15, the piston rod 16a of the body lifting cylinder 16 is lowered to the stopper collecting position, and the core pushing up / closing stopper pulling cylinder 2 is lowered to close. A working space for the stopper collection mechanism 20 is secured.

In order to raise the pulled-out stopper plug shown in FIG. 16, low-pressure water is supplied below the piston 2a of the core pushing-up / stopper-pulling-out cylinder 2 with the body lifting / lowering cylinder 16 held at the stopper-plug recovery position. Then, the piston 2a is moved upward to expose the stopper c screwed to the mandrel 5.

In order to bring the stopper into the state shown in FIG. 17, the arm swivel cylinder 22 is operated from the stopper stopper collection position to the stopper stopper gripping position, and then the stopper stopper clamp cylinder 24 is moved from the stopper stopper unclamping position to the stopper stopper clamp. Activated to the position, the stopper c is clamped by the manipulator arm 21,
The mandrel rotation motor 14 is rotated in the reverse direction to remove the mandrel 5 from the stopper c.

In order to set the stopper plug collection completion state shown in FIG. 18, the piston of the mandrel lifting / lowering cylinder 11 is moved up to the stopper plug screwing start position, and the arm turning cylinder 22 is operated to the stopper plug recovery position to close the stopper plug clamp cylinder. The stopper 24 is operated to the stopper stopper unclamping position, and the stopper stopper c is dropped into the collection cylinder 25.

In order to enter the standby state after the completion of the stopper plug removal shown in FIG. 19, the piston of the main body lifting cylinder 16 is moved upward, and the core pushing-up / closing stopper pull-out cylinder 2 is moved to the standby state.

The above operation is performed for each heat transfer tube closed by the stopper.

[Effects of the Invention] As described above, according to the present invention, the device for removing a heat transfer tube plug is provided with a mandrel screwed into the plug, and then the main body elevating cylinder is actuated to push the core up and down. Lower the drawing cylinder by the core pushing-up stroke, and then operate the rotary actuator to make the cylinder body of the core pushing-up / closing stopper pulling-out cylinder and the core pushing-up rod interlock, then push up the core. A high-pressure fluid is introduced into the stopper plug withdrawal cylinder, and the cylinder body and the core push-up rod are raised by the push-up stroke with respect to a piston that is screwed into the stopper and transmits a reaction force to the hanging mandrel, It operates to push up and release the core, which had the closure plug secured inside the heat transfer tube in a sealed state. And the length of the core pushing-up / closing stopper pull-out cylinder is reduced accordingly.

In addition, since the rotating means applies a rotating force to the mandrel from the side using the universal joint below the core pushing-up / closing stopper pull-out cylinder, the overall height of the removing device can be shortened.

Such a reduction in the length of the cylinder and a reduction in the overall height of the removing device enable the automatic removal of the plug even for the heat transfer tube in a narrow space near the end plate, and concomitantly reduce the level of radioactivity to workers. From the high workplace.

[Brief description of the drawings]

FIG. 1 is a detailed sectional view of a heat transfer tube stopper according to the present invention, FIG. 2 is a side view of the remover of FIG. 1, FIG. 3 is a front view of the remover of FIG. 4 is a plan view of the removing device of FIG. 1, FIG. 5 is a sectional view taken along line VV of FIG. 3, and FIG. 6 is a sectional view taken along line VI-VI of FIG. , Seventh
FIG. 8 is a plan view of a rotary actuator, FIG. 8 is a cross-sectional view of a portion where a mandrel elevating cylinder is mounted, FIGS. 9 to 19 are operation explanatory views of the removing device of FIG. 1, and FIG. State, Fig. 10 is the mandrel screwing completed state, Fig. 11 is the core pushing up start state, Fig. 12 is the core pushing up completed state, Fig. 13 is the core pushing up rod return state after the core pushing up completion, FIG. 14 shows the state in which the stopper is completely pulled out, FIG. 15 shows a state in which the withdrawn stopper is recovered, FIG. 16 shows a state in which the stopper is pulled out, FIG. 17 shows a state in which the stopper is being recovered, and FIG. FIG. 19 shows a stand-by state after completion of closure plug removal, FIG. 19 shows a standby state after completion of closure plug removal, FIG. 20 is a front view of a conventional removal apparatus, and FIG. 21 is a view of the removal apparatus of FIG. It is sectional drawing. DESCRIPTION OF SYMBOLS 1 ... Removal device of heat transfer tube stopper 2 ... Core pushing-up / closing stopper pull-out cylinder 4 ... Rotary actuator 5 ... Mandrel, 8 ... Core push-up bar 10 ... Mandrel screw-in mechanism 11 ... Mandrel lifting / lowering Cylinder 12 ... Rotating means, 14 ... Universal joint 15 ... Main body elevating mechanism, 16 ... Main body elevating cylinder b ... Heat transfer tube, c ... Closing stopper

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23P 19/04 B23P 21/00 301

Claims (1)

(57) [Claims] 1. A device for removing a stopper fitted in a heat transfer tube by pushing up a core inserted in the stopper from a stopper holding position to a stopper releasing position and then withdrawing the core. A mandrel rotatably and vertically liftably supported for screwing into the stopper and pulling out the stopper, and elevating and lowering to push the core from the stopper holding position to the stopper opening position. A core pushing-up rod supported, a core pushing-up / closing stopper pull-out cylinder accommodating the mandrel and the core pushing-up rod, and a lifting force of the core pushing-up / closing stopper pulling-out cylinder when pushing up the core. And a rotary actuator associated therewith so as to selectively bring the core push-up / close plug withdrawal cylinder and the core push-up rod into an interlocking state so that the core push-up bar is transmitted to the core push-up bar. A mandrel screwing mechanism including a mandrel elevating cylinder for elevating and lowering the mandrel and a rotating means for rotating, and a core pushing-up / closing stopper pulling-out cylinder engaged with the core for pushing up the core; A lifting / lowering mechanism including a body lifting / lowering cylinder for lowering the core pushing / upping / closing stopper pulling cylinder downward for the pushing-up stroke, wherein the rotating means includes a universal joint below the core pushing / upping / closing stopper pulling cylinder. A device for removing a heat transfer tube stopper from the side through which a rotational force is applied to the mandrel.