KR102528648B1 - Novel Steam Generator Heat Exchanger Tube Flexible Incision Tool Applying Electric Discharge Machining Method - Google Patents

Abstract

To facilitate the cutting machining of a boundary area between a bent pipe part and a straight pipe part, and the bent pipe part, provided is a flexible electric discharge cutting tool for a heat transfer pipe of a steam generator, comprising: a rotating body formed to be able to be inserted into a heat transfer pipe of a steam generator; a head installed on one side of the rotating body to guide the forward movement of the rotating body inside the heat transfer pipe of the steam generator; an electric discharge electrode installed on one side of the rotating body and inducing a spark discharge between the heat transfer pipe of the steam generator and the electric discharge electrode to perform electric discharge machining on the heat transfer pipe; an electrode moving means for moving the electric discharge electrode away from the central part of the heat transfer pipe of the steam generator or moving toward the central part; a fixing means for fixing the rotating body to the inside of the heat transfer pipe of the steam generator; and a rotating means for rotating the rotating body.

Description

Novel Steam Generator Heat Exchanger Tube Flexible Incision Tool Applying Electric Discharge Machining Method}

The present invention relates to an articulated electric discharge machining cutting tool for steam generator heat transfer tubes, in which electric discharge machining technology with electrodes optimized by reflecting the curvature, inner diameter and outer surface shape of steam generator heat transfer tubes of various specifications is applied, and the bent pipe and The boundary area of the straight pipe and the curved pipe are moved to the desired opening incision angle and incision position with a single device insertion, applying the positioning system and the electric discharge machining technique using ultrapure water without applying the load and stress generated by the processing to the heat transfer pipe of the steam generator. It relates to a new articulating electrical discharge machining cutting tool for steam generator heat pipes that precisely implements the minimum necessary foreign material recovery passage according to the size of each foreign material.

The steam generator installed in a nuclear power plant is a type of heat exchanger that uses high-temperature and high-pressure cooling water heated by the nuclear fuel fission reaction of a nuclear reactor and a working fluid that operates a turbine generator on the primary and secondary sides, respectively. It is one of the main facilities of a nuclear power plant located at the boundary between the cooling water (primary side) and the clean system outside the reactor (secondary side).

The shape of the primary side heat pipe of the Korean Standard Nuclear Power Plant (KSNP) steam generator consists of a U-BEND shape, a bent pipe part bent twice at a 90° angle and a specific curvature, and a straight pipe part. The material of the heat pipe for heat exchange is composed of Alloy 690. Inside the primary heat transfer pipe of the steam generator, water flows irregularly at high temperature and high pressure.

Inside the steam generator, the size, size, and number of installed heat pipes are very diverse according to the purpose, and the bundle structure of straight and bent pipes is made of materials such as Inconel, stainless steel, copper alloy, and titanium, which usually have a thickness of 0.7 to 2.0 mm. The number of heat transfer tubes inside the furnace steam generator varies from 1,000 to 13,000 depending on the purpose.

Currently, as the soundness and service life of steam generators increase, the damage to the heat pipe is pointed out as the biggest problem among the defects occurring in steam generators, and the stress on the primary and secondary sides caused by the use environment such as high temperature and high pressure cooling water Various damages occur due to stress corrosion cracking (SCC), fluid-induced flow, and structural characteristics of steam generators. In addition, such damage is caused by a complex action of water chemical treatment, thermodynamic design, material selection, manufacturing method, and operation method.

Steam generator maintenance is performed regularly, and due to the development of inspection technology, cases of foreign matter found inside steam generators are increasing. According to a report by the Nuclear Safety Council (a regional organization of the Nuclear Safety and Security Commission), various foreign objects such as wires, bolts, and hammers exist inside the steam generator. At that time, foreign substances remained due to human resources caused by omission of inspection and negligence in management during steam generator production.

These foreign substances may move inside the steam generator by the fluid-induced flow generated inside the steam generator, wear the outside of the heat transfer pipe of the steam generator, and consequently break the heat transfer pipe to create a hole.

If a metal object exists inside the steam generator and hits the heat pipe wall with a thickness of about 1 mm, and a heat pipe breakage occurs, the radioactive material in the primary coolant is in the reactor containment, in the secondary side of the steam generator, or in the generator turbine. The integrity of the heat pipe must always be maintained because it can leak.

If the foreign matter continuously breaks the outer wall of the heat transfer pipe of the steam generator and moves to the inside of the steam generator without being detected, safety damage and financial damage may continue to occur due to wear of another heat transfer pipe. When a steam generator heat pipe is damaged by a foreign substance during power generation in a nuclear power plant, it can spread to a serious accident. This is because when the heat transfer pipe is damaged during power generation, a large amount of cooling water leaks through the fractured portion of the heat transfer tube of the steam generator in a short time, and radioactivity leaks out to the secondary side. In the worst case, radioactive material moves from the primary system to the secondary system through the damaged heat pipe and then moves along the pipe, releasing a large amount of radioactivity into the atmosphere through the steam generator safety valve or atmospheric release valve. In addition, from an economic point of view, if the nuclear power plant does not produce electricity due to a foreign substance in the steam generator, a loss of about 2 billion won is incurred every day, and it is impossible to remove the foreign substance permanently, so when replacing the steam generator, the cost of replacing one steam generator costs hundreds of billions of won. Occurs.

Even at Westinghouse, which has the world's best nuclear power maintenance technology, it is known that it is impossible to recover foreign substances that exist around the bends of steam generator heat transfer pipes with current technology.

Publication No. 10-2013-0023443 (2013. 03. 08.)

The present invention has been made in view of the above points, and the electric discharge machining technology equipped with electrodes optimized by reflecting the curvature, inner diameter and outer surface shape of steam generator heat transfer pipes of various specifications is applied, and the boundary area of the bent pipe part and the straight pipe part and the bent pipe are transferred to the desired opening incision angle and incision position with a single device insertion, and the localization system and the electrical discharge machining technique using ultrapure water are applied without applying the load and stress generated by processing the heat transfer pipe of the steam generator. Its purpose is to provide a new articulating electrical discharge machining cutting tool for steam generator heat pipes that precisely implements the minimum necessary foreign matter recovery passage.

A new articulated electric discharge machining cutting tool for a steam generator heat pipe proposed by the present invention includes a rotating body that is formed to be inserted into the heat pipe of a steam generator, and is installed on one side of the rotating body to rotate inside the heat pipe of the steam generator. A head for guiding the forward movement of the body, a discharge electrode installed on one side of the rotating body and performing electrical discharge processing of the heat transfer tube by inducing a spark discharge between the heat transfer tube of the steam generator, and the discharge electrode is connected to the steam generator. Electrode moving means for moving the heat transfer pipe of the generator in a direction away from the center of the pipe or moving in a direction closer to the center of the pipe, a fixing means for fixing the rotating body inside the heat pipe of the steam generator, and the other side of the rotating body It is installed on and includes a rotating means for rotating the rotating body.

The rotation body is arranged side by side with cylindrical unit rotation bodies arranged side by side at regular intervals, and alternately with the unit rotation bodies, It is flexible in that its shape is deformed by an external force and is formed so that it can return to its original state when the external force is removed. It includes a plurality of unit elastic bodies.

The head is flexible in shape deformed by an external force and is formed to return to its original state when the external force is removed, and is characterized in that it is naturally bent in response to the bent shape of the bend region of the heat transfer pipe.

The electrode moving means includes a moving motor supported by the rotating body, a transfer shaft rotated positively and reversely by the moving motor, an electrode moving rod supported by the rotating body so as to be movable forward and backward and moved forward and backward when the transfer shaft rotates forward and backward, and , A cable connecting the electrode moving rod and the discharge electrode, pushing the discharge electrode when the electrode moving rod moves forward and pulling the discharge electrode when the electrode moving rod moves backward, and a cable installed on the rotating body and pulling the discharge electrode when the cable pulls the discharge electrode, and an electrode moving guide for guiding the discharge electrode so that when the cable pushes the discharge electrode away from the center of the conduit, the discharge electrode approaches the center of the conduit of the heat transfer pipe.

The fixing means includes a fixed motor supported by the rotating body and capable of normal and reverse rotation, a transfer shaft rotated forward and reverse by the fixed motor, a forward and backward movement cam coupled to the transfer shaft and moved forward and backward when the transfer shaft rotates, and A plurality of rotation levers, one side of which is hinged to the three-rotation body and rotates outward when the forward and backward movement cam moves forward, and a plurality of rotation levers installed around the other side of the rotation lever to increase the size when the forward and backward movement cam rotates outward, and to the tube wall of the heat transfer pipe It is made including a rubber ring that is in close contact.

The rotation means includes a rotation support body, a rotation motor supported by the rotation support body, a driving gear coupled to a shaft of the rotation motor, and a driven gear engaged with the rotation gear and fixed to the rotation body. It is done.

According to the articulated electric discharge machining cutting tool for steam generator heat pipe according to an embodiment of the present invention, since the discharge electrode can rotate, move forward and backward, and move left and right within the heat pipe, various positions of the heat pipe can be easily discharged.

In addition, according to the articulated electric discharge machining tool for steam generator heat pipe according to an embodiment of the present invention, since the rotating body and head can be flexibly bent and have elasticity, the electrode can easily enter the bend of the heat pipe and the entire area of the bend. It is possible to process and prevents flow during electric discharge machining.

1 is a side view of a steam generator according to an embodiment of the present invention.
2 is a side view showing an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
3 is a cross-sectional side view showing a first rotating body and a second rotating body in an articulated electric discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
4 is a cross-sectional side view showing a third rotational body in an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
5 is a perspective view showing an elastic body in an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
6 is a side view showing an elastic body in an articulated electric discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
7 is a side view showing a head in an articulated electric discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
8 is a side view illustrating a state in which a head is inserted into a bent portion of a heat exchanger pipe in an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
8A and 8B are side views illustrating a state in which a head having a cutting edge moves a bent portion of a heat transfer pipe.
9 is a perspective view showing an electrode of an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
10 is a cross-sectional view showing an electrode in an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
11 is a side cross-sectional view showing an electrode moving means in an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
12 is a cross-sectional view showing an electrode moving guide of an electrode moving means in an articulated electrical discharge machining incision tool for a steam generator heat pipe according to an embodiment of the present invention.
12a and 12b are side views illustrating a state in which the articulating electric discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention is recovered when power is lost.
13 is a cross-sectional side view showing a fixing means in an articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.
14 is a cross-sectional side view showing a rotating means in the articulated electrical discharge machining cutting tool for a steam generator heat pipe according to an embodiment of the present invention.

Next, a preferred embodiment of a new articulating electric discharge machining cutting tool for a steam generator heat pipe according to the present invention will be described in detail with reference to the drawings.

Hereinafter, the same reference numerals are used for technical elements that perform the same function, and repeated detailed descriptions are omitted to avoid redundant description.

In addition, the embodiments described below are shown by way of example to effectively show preferred embodiments of the present invention, and should not be construed to limit the scope of the present invention.

As shown in FIGS. 1 to 4, a new articulating electric discharge machining cutting tool 10 for a steam generator heat pipe according to an embodiment of the present invention is installed so that it can be inserted into the heat pipe 4 of the steam generator 2 A rotating body 100, and a head 200 installed in front of the rotating body 100 to guide the forward movement of the rotating body 100 inside the heat transfer pipe 4 of the steam generator 2, A discharge electrode 300 in which electric discharge processing of the heat pipe 4 is performed by inducing a spark discharge between the steam generator 2 and the heat pipe 4, and the discharge electrode 300 is connected to the steam generator 2 The electrode moving means 320 for moving the heat transfer tube 4 of the tube in a direction away from the center of the tube or in a direction closer to the center of the tube, and the rotating body 100 are connected to the heat transfer tube 4 of the steam generator 2 It includes a fixing means 400 for fixing to the inside and a rotating means 500 for rotating the rotating body 100.

The rotary body 100 is formed in a substantially bar shape and is inserted into the heat transfer pipe 4 to be flexibly bent along the shape of the bend pipe 5 when entering the bend pipe 5.

The rotation body 100 is formed of unit rotation bodies 101 arranged side by side at regular intervals, and the approximately cylindrical shape and is alternately disposed with the unit rotation bodies 101, It is flexible in that its shape is deformed by an external force and is formed so that it can return to its original state when the external force is removed. It includes a plurality of unit elastic bodies (160).

Here, the unit rotation bodies 101 are formed in a substantially cylindrical shape, and the first rotation body 110, the second rotation body 120, and the third rotation body 130 are formed according to the order in which they are inserted into the heat transfer pipe 4. made including

Also, the unit elastic bodies 160 are formed in a substantially cylindrical shape, and the first elastic body 161, the second elastic body 170, and the third elastic body 180 are inserted in the order of being inserted into the heat pipe 4. ), including

An electrode moving guide 330 of an electrode moving means 320 to be described later is installed on the first rotating body 110 .

A moving motor 321 of an electrode moving means 320 to be described later is supported by the second rotating body 120 .

The first elastic body 161 has one side coupled to one side of the first rotating body 110 and the other side coupled to one side of the second rotating body 120, and a cable of an electrode moving means 320 to be described later inside. (328) is installed.

The third rotating body 130 is fixed to or released from the tube wall of the heat transfer pipe 4 by the fixing means 400, and the fixing means 400 will be described in more detail below.

The second elastic body 170 has one side coupled to the other side of the second rotation body 120 and the other side coupled to one side of the third rotation body 130 .

The third elastic body 180 has one side coupled to the other side of the third rotation body 130 and the other side coupled to the rotation body 500 to be described later.

Referring to FIGS. 5 and 6 , the elastic bodies 160 have a hollow structure and have cutouts 164 at regular intervals along the longitudinal direction.

The cutout 164 is formed by alternating a pair of first cutouts 165 formed on the left and right sides and a pair of second cutouts 166 formed on the upper and lower sides alternately.

The head 200 is installed at the front end of the rotating body 100 configured as described above, that is, the first rotating body 110, and the head 200 has the rotating body 100 inside the heat pipe 4. When inserted, it is inserted into the heat transfer pipe 4 before the rotating body 100.

The head 200 can be implemented in the same configuration as the elastic body.

That is, referring to FIGS. 7 and 8 , the head 200 is formed in a substantially cylindrical shape and is flexible in shape deformed by an external force and can be returned to its original state when the external force is removed, so that the heat transfer pipe 4 In the area of the curved pipe 5, it leads the rotating body 100 while being naturally bent in response to the curved shape of the curved pipe 5.

Here, the head 200 is made of a hollow structure and has cutouts 210 at regular intervals along the longitudinal direction.

The cutout 210 is formed by alternating a pair of first cutouts 211 formed on the left and right sides and second cutouts 212 formed on the upper and lower sides alternately.

Referring to FIGS. 8A and 8B , the head 200 may also have a tip 220 having one side formed of an inclined surface.

When the tip 220 is provided on the head 200, the rotating body 100 escapes from the heat pipe 4 through the opening 7 pre-formed in the heat pipe 4 when the rotating body 100 moves forward. can prevent

That is, for electrical discharge machining of the heat transfer pipe 4 in which the opening 7 is already formed in front of the position to be electrical discharge machining, the articulated electrical discharge machining tool 10 according to an embodiment of the present invention is inserted into the heat transfer pipe 4 It moves forward to the target point. At this time, even if the head 200 interferes with the edge of the opening 7, it naturally moves forward while interfering with the inclined surface of the tip 220, and the heat transfer pipe 4 passes through the opening 7. Guide them so they don't stray outside.

The first rotating body 110 coupled to the head 200 has an electrode arrangement groove 112 on one side of which the discharge electrode 300 is disposed.

Referring to FIGS. 9 and 10, the discharge electrode 300 has a processing part 302 having a circumferential surface 303 corresponding to the inner circumferential surface of the heat transfer tube 4 on one side, and the processing part 302 on the other side It is formed in and includes a connection portion 306 connected to the cable 328 of the electrode moving means 320 to be described later.

The processing part 302 is formed in a substantially semi-cylindrical shape, and as it is installed on one side of the electrode support 112 of the first rotating body 110, it forms a cylindrical shape together with the first rotating body 110.

Here, the distance between the circumferential surface 303 of the discharge electrode 300 and the tube wall of the nearby heat transfer tube 4 can be changed by the electrode moving means 320 . That is, when the electric discharge machining of the heat exchanger tube 4 is performed, the circumferential surface 303 of the discharge electrode 300 is moved closer to the tube wall of the heat exchanger tube 4, and when the electric discharge machining is not performed, the circumferential surface 303 of the discharge electrode 300 is moved. ) can be moved away from the tube wall of the heat transfer tube 4.

As shown in FIGS. 11 and 12 , the electrode moving means 320 includes a moving motor 321 supported by the second rotating body 120 of the rotating body 100 and the moving motor 321. A feed shaft 324 rotated forward and backward, an electrode moving rod 326 supported by the second rotation body 120 so as to be movable back and forth and moved forward and backward when the feed shaft 324 rotated forward and backward, and the first elastic It is disposed inside the body 161 and connects the connection part 306 of the electric moving rod 326 and the discharge electrode 300, and when the electrode moving rod 326 moves forward, the discharge electrode 300 is pushed and the electrode moving rod ( 326) A cable 328 pulling the discharge electrode 300 when moving backward and installed on the first rotating body 110, and when the cable 328 pulls the discharge electrode 300, the discharge electrode 300 moves the heat transfer pipe 4 ) and when the cable 328 pushes the discharge electrode 300 away from the center of the conduit, the electrode moving guide guides the movement of the discharge electrode 300 so that the discharge electrode 300 approaches the center of the conduit of the heat transfer pipe 4 ( 330).

The moving motor 321 is composed of a motor equipped with a rotary encoder to measure the rotation angle of the motor shaft.

A transfer screw is formed on the transfer shaft 324 and the electrode moving rod 326 . That is, the transfer shaft 324 has a male screw, and the electrode moving rod 326 has a female screw engaged with the male screw.

The cable 328 is formed to be energized so that power for electrical discharge machining can be applied to the discharge electrode 300 .

The electrode movement guide 330 is provided with a guide groove 332 in an oblique direction, and is assembled to the guide groove 332 at the connecting portion 306 of the electrode 300 to move along the guide groove 332. A protrusion 310 is formed.

The electrode moving means 320 configured as described above is an electrical discharge machining cutting tool ( 10) can be easily recovered.

That is, nuclear power plants frequently experience power loss due to power outages or power outages due to their characteristics. Even in such power loss situations, a function capable of recovering the electric discharge cutting cutting tool 10 is desperately needed.

Accordingly, as shown in FIGS. 12A and 12B, the present invention pulls the moving cable 20 from the outside of the steam generator 2 when power is lost during electrical discharge machining to move the electrical discharge cutting cutting tool 10 backward, the discharge electrode ( 300) becomes caught on the edge of the electrical discharge machining opening 8, and the cable 328 is cut after being tensed while only the cable 328 moves backward, and when the electrical discharge machining cutting tool 10 continues to move backward, the discharge electrode 300 While moving to the center of the heat pipe 4 along the guide groove 332 of the silver electrode moving guide 330, the jamming is released, and the electric discharge machining cutting tool 10 including the discharge electrode 300 is pulled out of the heat pipe 4, recovery is possible.

Here, the yield stress of the cable 328 can be installed weaker than other parts of the electric discharge machining cutting tool 10 .

That is, when a certain load (tensile force) is applied to the cable 328 by continuously moving the electric discharge cutting cutting tool 10 backward while the discharge electrode 300 is caught on the edge of the discharge machined opening 8, the cable 328 is cut. form to be

Meanwhile, in the discharge electrode 300 moved by the electrode moving means 320, the electrode moving rod 326 and the cable 328 move backward so that the moving protrusion 310 is at one end of the guide groove 332. When located at , the circumferential surface 302 of the discharge electrode 300 is far from the center of the pipe of the heat transfer pipe 4, enabling electrical discharge machining (see FIGS. 11 and 12), and the electrode moving rod 326 and the cable 328 ) is advanced and the moving protrusion 310 is positioned at the other end of the guide groove 332, the circumferential surface 302 becomes closer to the center of the pipe of the heat transfer pipe 4, and at this time, electrical discharge machining is not performed (FIG. 3 and FIG. see 10).

The discharge electrode 300 can precisely perform electrical discharge machining position setting and electrical discharge machining by the electrode moving means 320 in a state in which the rotary body 100 is fixed, and the rotary body 100 can perform the It is fixed to or released from the pipe wall of the heat transfer pipe 4 by the fixing means 400 .

Referring back to FIG. 1 , a moving cable 20 may be connected to the rear end of the rotation support body 510 .

Here, the moving cable 20 moves back and forth as a transfer roller (not shown) installed outside the steam generator 2 rotates while holding the moving cable 20, and accordingly, the rotation support body 501 moves the heat transfer pipe 4 ) can be moved back and forth along the longitudinal direction of

As shown in FIG. 13, the fixing means 400 includes a fixing motor 401 supported by the third rotation body 130 and capable of normal and reverse rotation, and a feed shaft rotated forward and reverse by the fixing motor 401 ( 410), a forward and backward moving cam 420 coupled to the feed shaft 410 and moving back and forth when the feed shaft 410 rotates, and one side hinged to the third rotating body 130 and the forward and backward moving cam A plurality of rotary levers 430 rotated outward when the 420 moves forward, and a front and rear moving cam 420 installed around the other side of the rotary lever 430 moves forward so that the rotary lever 430 rotates outward. It is increased in size and includes a rubber ring 440 that is in close contact with the wall of the heat transfer pipe 4.

The fixed motor 401 is composed of a motor equipped with a rotary encoder to measure the rotation angle of the motor shaft.

Feed screws are formed on the feed shaft 410 and the forward/backward movement cam 420 . That is, the feed shaft 410 has a male screw, and the forward/backward movement cam 420 has a female screw engaged with the male screw.

The forward/backward moving cam 420 moves forward when the feed shaft 410 rotates forward and moves backward when the feed shaft 410 rotates backward.

The rotation lever 430 may be rotated inward when the forward/backward movement cam 420 moves backward and return to its original state.

The rubber ring 440 is separated from the tube wall of the heat transfer pipe 4 while being restored to its original state by being reduced in size as the rotary lever 430 rotates inwardly and returns to its original state.

When the rubber ring 440 is separated from the tube wall of the heat transfer tube 4, the rotation body 100 is also unfixed.

The rotation body 100 can be rotated through the rotation means 500.

As shown in FIG. 14, the rotation means 500 includes a rotation support body 510, a rotation motor 520 supported by the rotation support body 510, and a shaft 522 of the rotation motor 520. It includes a driving gear 530 coupled with, and a driven gear 540 engaged with the driving gear 530 and installed and fixed to the third elastic body 180 of the rotating body 100.

The rotary motor 520 is composed of a motor equipped with a rotary encoder 524 so that the rotation angle of the motor shaft 522 can be measured.

The motive gear 530 and the driven gear 540 may be made of internal gears.

That is, the driven gear 530 is installed inside the driven gear 540, the driven gear 540 has gear teeth on its inner circumference, and the driven gear 530 has gear teeth on its inner circumference.

The rotating means 500 configured as described above rotates the rotating body 100 so that the discharge electrode 300 is rotated, thereby enabling the electrical discharge machining position to be set.

Referring back to FIG. 1 , a moving cable 20 may be connected to the rear end of the rotation support body 510 .

Here, the moving cable 20 moves back and forth as a transfer roller (not shown) installed outside the steam generator 2 rotates while holding the moving cable 20, and accordingly, the rotation support body 501 moves the heat transfer pipe 4 ) can be moved back and forth along the longitudinal direction of

Wires for supplying power and transmitting and receiving control signals may be installed inside the moving cable 20 .

The transfer cable 20 may be inserted into the heat transfer tube 4 through a cable moving inner tube 30 connecting one end of the heat transfer tube 4 to the outside, and the other end of the heat transfer tube 4. As the discharge liquid supply cable 40 can be inserted.

The discharge liquid is transferred to the inside of the discharge liquid supply cable 40, and the discharge liquid is discharged from the front end during electrical discharge machining, and the discharge liquid is sprayed between the electrode 300 and the heat transfer pipe 4.

In the above, the preferred embodiment of the articulated electric discharge machining cutting tool for steam generator heat pipe according to the present invention has been described, but the present invention is not limited thereto, and various modifications are made within the scope of the claims and detailed description of the invention and the accompanying drawings. Modifications and implementations are possible, and this also falls within the scope of the present invention.

2: steam generator 4: heat pipe
6: bend part
10: Articulated electric discharge machining cutting tool for new steam generator heat pipe
100: rotation body 101: unit rotation body
110: first rotation body 120: second rotation body
130: third rotation body 160: elastic body
161: unit elastic body 162: first elastic body
170: second elastic body 180: third elastic body
200: head 300: discharge electrode
302: processing part 306: connection part
310: guide protrusion 320: electrode moving means
321: movement motor 324: transfer axis
326: electrode moving rod 328: cable
330: guide 400: fixing means
401: fixed motor 410: transfer axis
420: forward and backward movement cam 430: rotation lever
440: rubber ring 500: rotation means
510: rotation support body 520: rotation motor
530: driving gear 540: driving gear

Claims (9)

A rotating body formed to be inserted into the heat transfer pipe of the steam generator;
A head installed on one side of the rotating body to guide the forward movement of the rotating body inside the heat transfer pipe of the steam generator;
A discharge electrode installed on one side of the rotating body to perform electrical discharge processing of the heat transfer tube by inducing a spark discharge between the heat transfer tube and the steam generator;
Electrode moving means for moving the discharge electrode in a direction away from the center of the pipe of the heat transfer pipe of the steam generator or in a direction closer to the center of the pipe;
Fixing means for fixing the rotary body to the inside of the heat transfer pipe of the steam generator;
Includes a rotating means for rotating the rotating body,
the head,
New steam characterized in that it is formed in a cylindrical shape and is flexible in shape deformed by an external force and can be returned to its original state when the external force is removed, so that it is naturally bent in response to the bent shape of the bend in the bend area of the heat transfer pipe. Articulated electric discharge machining cutting tool for generator heating tubes. delete The method of claim 1,
The head is a new refractory electrical discharge machining cutting tool for a steam generator heat pipe having a tip having one side made of an inclined surface. The method of claim 1,
The electrode moving means,
A moving motor supported by the rotating body, a transfer shaft rotated positively and reversely by the moving motor, an electrode-moving rod supported by the rotation body so as to be movable back and forth and moved forward and backward when the transfer shaft rotates forward and backward, the electrode-moving rod and a cable connecting the discharge electrode, pushing the discharge electrode when the electrode moving rod moves forward and pulling the discharge electrode when the electrode moving rod moves backward, and installed on the rotating body, and when the cable pulls the discharge electrode, the discharge electrode is far from the center of the pipe of the heat transfer pipe A new articulated electrical discharge machining cutting tool for a steam generator heat pipe including an electrode moving guide for guiding the electrode so that the discharge electrode comes closer to the center of the pipe of the heat pipe when the cable pushes the discharge electrode. The method of claim 4,
The discharge electrode is
It includes a processing part having a circumferential surface on one side and a connection part formed on the other side of the processing part and connected to the cable of the electrode moving means,
The electrode movement guide has a guide groove in an oblique direction,
A new articulated electrical discharge machining cutting tool for steam generator heat pipe, characterized in that a moving protrusion assembled in the guide groove and movable along the guide groove is formed at the connection part of the discharge electrode. The method of claim 1,
The rotation means,
A new steam generator electric row including a rotation support body, a rotation motor supported by the rotation support body, a motive gear coupled to the shaft of the rotation motor, and a driven gear rotated in mesh with the motive gear and fixed to the rotation body. Conventional Articulated EDM Cutting Tool. delete The method of claim 1,
The rotating body,
Cylindrical unit rotation bodies arranged side by side at regular intervals, and arranged alternately with the unit rotation bodies, It is flexible in that its shape is deformed by an external force and is formed so that it can return to its original state when the external force is removed. Articulated electric discharge machining cutting tool for new steam generator heat pipe including a plurality of unit elastic bodies. The method of claim 8,
The unit rotation bodies,
Including a first rotating body, a second rotating body and a third rotating body disposed at regular intervals according to the order of insertion into the heat pipe,
The unit elastic bodies,
A new bendable electric discharge machining cutting tool for a steam generator heat pipe including a first elastic body, a second elastic body, and a third elastic body disposed at regular intervals in the order of insertion into the heat pipe.

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