JP3152607B2 - Micro sample collection apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-sample collecting apparatus and a micro-sample collecting method for collecting minute members from the surface of a structural material such as a power plant by electric discharge machining, and for collecting a sample of a desired shape.

[0002]

2. Description of the Related Art As a conventional technique for collecting a surface layer of a metal material, as described in, for example, Japanese Patent Application Laid-Open No. 63-231238, a U-shaped electric discharge machining electrode is inserted into a previously cut groove. It is also known to extract the material by means of lowering it and moving it parallel to the metal surface. In this example, a weir is provided around the processing part, and the processing liquid is filled therein.

[0003] As a conventional technique for collecting a surface layer of another metal material, there is disclosed a thermal nuclear power generation, Vol.
3, No. As shown in No. 4 ", there is also known a method in which a groove is formed by die discharge and a sample is cut by die discharge to collect a material. In this example, the production of a test piece for evaluating the soundness of a structure was performed by welding and working after the material was sampled.

Further, as another known example, Japanese Patent Application Laid-Open No.
The invention described in No. 9295 is also known. The present invention rotatably supports a boat-shaped mold electrode having a concave inner surface, rotates the mold electrode in an insulating liquid, and allows the electrode to enter from the surface of the metal material to the inside by electric discharge machining. It is configured to cut out a part of the metal material.

[0005]

However, in the above-mentioned prior art, since the mold electrode is used for all the processing, an extra sample is added from the metal (structure) to be collected by the thickness of the mold electrode. Had to be collected. Also,
Since the sample collected by the mold electrode contains a very thick altered layer on the sample surface compared to the sample collected by wire electric discharge machining, there is substantially less usable healthy sample part, and therefore the amount of the altered layer is further increased. Extra sampling had to be done in anticipation. In addition, since the sampling portion is not fixed in the final stage of material sampling, the discharge becomes unstable and the discharge machining may not proceed.

Further, when these methods are applied to a plant such as a nuclear reactor, there is no problem that a mechanism for holding the collected material is not provided, so that the material cannot be taken out. Furthermore, when this method is applied to the collection of test pieces for evaluating the integrity of reactor internals, after collecting the material activated in the reactor, cutting, cutting, etc. It is necessary to process, and it is necessary to consider the reduction of exposure of workers and the processing of activated processing powder, and to apply to parts that require remote operation such as material sampling from reactor internals In order to achieve this, it was necessary to further promote integration and miniaturization of the entire apparatus.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances of the prior art, and an object of the present invention is to provide an apparatus and a method for collecting a micro sample capable of minimizing a dead portion caused by electric discharge machining. It is in.

Another object of the present invention is to provide a micro sample collecting apparatus and method capable of collecting a material having as large a volume as possible with respect to a machining mark of a portion to be machined having the same size by minimizing a machining waste portion caused by the electric discharge machining. Is to do.

It is still another object of the present invention to provide an apparatus and a method for sampling a micro-sample, in which electric discharge machining can be performed smoothly to the end by preventing the material of the sampling section from moving during machining.

It is still another object of the present invention to provide an apparatus and a method for collecting a micro sample which can take out the collected material to the outside without dropping the material.

[0011] Still another object is to provide a small sample which can reduce the man-hour for preparing a test piece when it is necessary to prepare a test piece by collecting a material which is difficult to handle such as activated in a nuclear reactor. It is an object of the present invention to provide a sampling device and a method.

[0012]

Means for Solving the Problems To achieve the above object, a first means is to provide a small sample collecting apparatus for collecting a small test piece from the surface of a metal immersed in pure water or oil. A mold electrode for machining, a means for moving the mold electrode and forming a groove corresponding to the mold electrode on the metal surface, a wire for electric discharge machining, and supporting the wire and forming the wire on the metal surface Means for moving in the formed groove to cut out a metal portion between the opposing grooves by the wire.

In this case, it is preferable to provide a post-processing electrode for re-discharge machining a groove formed by cutting the wire. Further, in addition to the post-processing electrode, a means for finishing a surface cut by the wire may be further provided. Further, it is desirable to provide a means for fixing the entire apparatus to the sample collection surface. Further, means for holding the sampled material at the sample collection site and taking out the sampled material after sampling may be further provided. The cutting means may include a wire supply mechanism for supplying a new wire and a wire winding mechanism for winding the wire once used for processing.

[0014] To achieve the above object, the second means comprises:
In a micro sample collecting method for collecting a small test piece from a surface of a metal immersed in pure water or oil, a first step of attaching a suction means for holding to a surface of a sampling target site, and focusing on the suction means A second step of arranging two EDM electrodes in parallel with a gap therebetween, and a third step of driving the mold electrodes downward to enter the metal by supplying current to the mold electrodes. A fourth step of stopping electric discharge machining when the mold electrode reaches a target depth, a fifth step of lifting the mold electrode upward, and a wire supporting and feeding member in a groove created by electric discharge machining. A sixth step in which the wire support feed member is inserted into the groove on the structure surface while supplying a current to the wire for electric discharge machining by lowering the wire, and a new slit is formed so that the slit end is connected; The depth of A seventh step of changing the driving direction of the wire to a direction parallel to the surface of the structure, driving the wire supporting and feeding member along the slit formed by the mold electrode, and cutting the lower surface of the sampling site by wire electric discharge machining, An eighth step of driving the wire supporting / feeding member upward when the supporting / feeding member reaches the slit end surface to cut the last remaining surface.

At this time, between the fifth and sixth steps, a cylindrical shape of the electric discharge machining mold having a desired shape as a sample is further obtained from the metal surface between the grooves formed by the two mold electrodes. It is also possible to provide a step of driving the electrode downward to form a groove having the shape of the cylindrical mold electrode, and obtain a columnar micro sample in the seventh step. Further, the electric discharge machining mold electrode is formed in a shape along the planar two-dimensional shape of the test piece to be used for the sampled material, and a slit or a donut-shaped groove is formed using the mold electrode, The driving of the wire supporting and feeding member in accordance with the shape of the test piece in the thickness direction may be controlled to collect a minute sample. Further, after the eighth step, the surface on which the sample was sampled was subjected to electric discharge machining using a post-processing electrode having a shape that alleviates stress concentration, or the portion subjected to electric discharge machining by the post-processing electrode was further subjected to heat treatment. Is also good. It is desired that the mold electrode and the wire supporting feed member are driven by a hydraulic piston or a motor and controlled by remote control.

According to the above configuration, first, the suction means is attached to the surface of the sampling target site, and two mold electrodes are arranged on the upper surface of the sampling site with the gap centered on the suction device. The distance between the two mold electrodes is adapted to the size of the required sampling material. An electrode driving mechanism is provided above the mold electrode, and can drive the mold electrode vertically. While supplying a current to the mold electrode, the mold electrode is driven downward, and the electrode is made to enter the inside of the material while performing a servo drive of electric discharge machining. When the electrode reaches the sampling depth, the electric discharge machining is stopped and the electrode is pulled up. At this time, a slit-shaped groove is formed on the surface of the structure. The wire support feed member is lowered into this groove. There are at least two wire supporting feed members, each having a mechanism such as a pulley for supporting and supplying the electric discharge machining wire. In sampling from two parallel slits, a new slit that connects the slit ends is formed by inserting the wire support feed member into the groove on the structure surface while supplying current to the wire. When the wire reaches a predetermined depth, the driving direction of the wire is changed to a direction parallel to the structure surface. When the wire supporting and feeding member is driven along the slit formed by the mold electrode, the lower surface of the sampling site can be cut by wire electric discharge machining.

In the conventional method, this lower surface is also cut off by the mold electrode. However, by using wire discharge, the cutting allowance can be greatly reduced. When the wire support feed member reaches the slit end surface, the wire support feed member is driven upward to cut the last remaining surface. When there is no holding member for the sampled material, when the uncut portion slightly remains, the sampled portion is shaken, the electric discharge becomes unstable, and machining can no longer be performed. However, since the collection site is held, the discharge proceeds stably until the cutting is completed, and the material can be reliably collected. When the material is collected,
If the material is not retained, the collected material will fall and cannot be recovered depending on the application location.
However, in this method, since the holding is performed, the material can be reliably collected after the cutting is completed.

As described above, in the above method, first, a groove for driving the wire supporting / feeding member is formed using the mold electrode, and the doughnut-like shape is formed using the planar two-dimensional mold electrode of the test piece to be used. Are formed between the driving grooves of the wire supporting and feeding member. Next, when the driving of the wire supporting and feeding member is controlled in accordance with the shape in the thickness direction of the test piece, a donut-shaped test piece is immediately formed by the series of mold discharge and wire discharge. When it is necessary to reduce the surface roughness or to remove the electric discharge machining affected layer, the desired object can be obtained only by polishing the surface of the obtained test piece.

The first electrode for forming a groove for driving the wire supporting and feeding member is formed into a shape corresponding to, for example, the shape of a tensile test piece, and a groove for driving the wire supporting and transmitting member is formed. When the driving of the member is controlled in accordance with the shape in the thickness direction of the test piece, a test piece in the form of a tensile test piece can be immediately formed by a series of such mold discharge and wire discharge.

[0020]

The electric discharge machining groove including the altered layer formed on the structure is subjected to a heat treatment with a laser beam or the like. By dissolving the altered layer on the surface once, the altered layer on the surface is modified into an unused material state.

If the mold electrode and the wire support feed member are driven by a hydraulic piston system, remote control can be easily performed simply by pulling the hydraulic hose far away. In addition, the drive mechanism can be made relatively small, and since the mechanism is simple, there is no fear of failure.

The drive of the mold electrode and the wire supporting feed member may be of a motor type instead of the hydraulic piston type. In this case, the power supply wire is pulled far and remote control is performed.

The mold electrode, the drive mechanism for the mold electrode, the wire supply mechanism, the wire support / feed member, the wire support / feed member drive mechanism, and the holding mechanism for the collected material are housed in one container.
Integration and miniaturization. By attaching this to the tip of a robot, for example, it can be used where space is limited and remote control is required, such as in a nuclear reactor.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of the micro sample collecting apparatus according to this embodiment as viewed from the front, and FIG. 2 is a cross sectional view of the micro sample collecting apparatus as viewed from the side. As can be seen from these figures, all the mechanisms of the micro sample collection device are contained in the device container 14. The micro sample collection device is a robot connection unit 15
And can be attached to a robot. Driving the robot, immersing the equipment container 14 in pure water in the reactor,
The apparatus container 14 is pressed against the target structure 4 for collecting the material. At this time, the apparatus container 14 is loaded by the robot via the robot connection unit 15 and is stably held by the structure 4. Sampling target site 19 on the surface of structure 4
Is provided with a suction type holding mechanism 3, and the suction type holding mechanism 3 is evacuated through a vacuum tube 17.
The suction type holding mechanism 3 is completely in close contact with the sampling target site 19.

Inside the apparatus container 14, a mold electrode 1, a hemispherical post-treatment electrode 22, an electrode changeover switch 23 for exchanging the mold electrode 1 with the post-treatment electrode 22, and an electrode changeover between the mold electrode 1, the post-treatment electrode 22 and the electrode A type electrode driving mechanism 6 for holding and driving the switch 23 is provided. In addition, a circular electrode 24 and a tensile test type electrode 25 are connected to an electrode switch 23 according to the purpose of use. Also, instead of the electrodes switched by the electrode changeover switch 23 according to the processing purpose, a processing finishing mechanism 37 is used.
(FIG. 7) can also be attached.

The mold electrode drive mechanism 6 uses a hydraulic cylinder, and the vertical movement of the mold electrode 1 can be accurately performed by controlling the hydraulic pressure of the hydraulic hose 20 through the hydraulic hose tube 16. A wire support feed member 2 for driving the electric discharge machining wire 13 for wire electric discharge machining and a hydraulic wire support feed member driving mechanism 5 for driving the wire support feed member 2 are provided inside the apparatus container 14.
Are provided so that the wire supporting and feeding member 2 can be accurately driven in the vertical and horizontal directions. In addition, a wire supply shaft 11 for supplying an electric discharge machining wire 13 and a wire feed shaft 11 for passing through a machining portion are provided on the opposite side of the wire support feed member drive mechanism 5 and the mold electrode drive mechanism 6 in FIG. And a wire take-up shaft 21 for taking up the electric discharge machining wire 13 (FIG. 2). The tension of the electric discharge machining wire 13 can be kept constant by being pulled downward by a predetermined elastic force by the wire tension adjusting mechanism 12. A current is supplied to the mold electrode 1 and the post-processing electrode 22 by the electrode current supply wire 7, and a current is supplied to the electric discharge wire 13 from the wire electric discharge current supply wire 8 via the power supply plate 10. . Further, the ground wire 9 is connected to the device container 14 which is a conductor. Mold electrode current supply wire 7, EDM wire current supply wire 8, and ground wire 9
Are connected to a power source outside the reactor through a power cable 18.

FIG. 3 is a flowchart showing a processing procedure when a minute test piece is collected.

In the figure, first, the small volume sampling device is fixed at the sampling position as described above (step 101), and it is determined whether or not the shape of the small test piece is determined (step 102). FIG. 4 shows an example in which the shape of the minute test piece is not determined, and the procedure shown in the flowchart will be described with reference to FIG. That is, when the shape of the minute test piece is not determined, first, the apparatus container 14 is fixed to the target position of the structure (collected material) 4. The suction type holding mechanism 3 is arranged at the collection target site 19 and the vacuum tube 17
Is evacuated to completely contact the sampling target site 19. Next, the pattern electrode 1 is made to face the sampling material 4 by the electrode changeover switch 23 (step 103).

Then, a current is supplied to the plate-shaped mold electrode 1 from the electrode current supply wire 7, and the mold electrode driving mechanism 6 causes the mold electrode 1 to enter the inside of the structure 4. At this time, servo drive of the mold electrode 1 is performed so that electric discharge machining proceeds stably. The mold electrode groove 26 is formed as the electric discharge machining proceeds (step 104). When the mold electrode groove 26 is introduced to a predetermined depth, the driving of the mold electrode 1 is temporarily stopped, and then the mold electrode 1 is moved in the opposite direction (step 105-FIG. 4A). The mold electrode 1 is returned to a position higher than the wire supporting and feeding member 2, and the supply of current from the mold electrode current supply wire 7 to the mold electrode 1 is stopped. After the mold electrode 1 has returned above the wire support feed member 2, the wire support feed member 2 is moved by the wire support feed member driving mechanism 5 to an upper portion of the end of the mold electrode groove 26, and the wire electric discharge machining current is reduced. An electric current is supplied to the electric discharge machining wire 13 via the supply wire 8 and the power supply plate 10. At the same time, the wire supply shaft 11 and the wire take-up shaft 21 rotate, and the electric discharge wire 13 is connected to the wire supply shaft 1.
1 moves in the direction of the wire winding shaft 21. And
The wire support / feed member 2 is inserted into the mold electrode groove 26 by the wire support / feed member drive mechanism 5 (step 106-FIG. 4B). The electric discharge machining wire 13 has two mold electrode grooves 2
Pressed between 6.

While maintaining a constant tension by the wire tension adjusting mechanism 12, the electric discharge machining wire 13 is used for both electrode grooves 2.
6, wire electric discharge machining grooves 27 are formed. At this time, the wire is wound while being supplied by the wire supply shaft 11 and the wire winding shaft 21. This allows
Since the electric discharge machining wire 13 on the wire electric discharge machining surface is always new, the wire electric discharge machining speed is high and the electric discharge machining surface can be cleaned. In addition, since the cutting chips generated during wire electric discharge machining are removed at the same time as the electric discharge machining wire 13 is moved, the wire electric discharge machining can be performed smoothly. The wire for electric discharge machining 13 is the mold electrode groove 2
6 (step 107), the scanning direction of the wire support / feed member 2 is changed from the direction perpendicular to the surface of the structure 4 to the horizontal direction by the wire support / feed member driving mechanism 5 (step 108-FIG. 4 (c)). When the electric discharge machining wire 13 reaches the opposite end of the mold electrode groove 26, the scanning direction of the wire supporting and feeding member 2 is changed from the horizontal direction to the vertical direction with respect to the surface of the structure 4 by the wire supporting and feeding member driving mechanism 5. (Step 109-FIG. 4D). When the wire electric discharge machining is continued vertically upward, the sampling material 28 and the structure 4 are connected to each other with only a small area. At this time, the sampling material 28 tends to unstablely vibrate under the influence of heat and pressure fluctuations of the electric discharge machining. However, since the sampling material 28 is completely held by the suction-type holding mechanism 3, no vibration occurs. Therefore, the electric discharge machining proceeds stably, and the sampling material 28 can be reliably cut off. The structure 4 has two parallel mold electrode grooves 26,
The U-shaped wire electric discharge machining groove 3 is formed, and the sampling material 28 is formed.
Is disconnected.

FIG. 5 is an explanatory view showing a method of taking out the sampling material 28. The suction holding mechanism 3 used for holding the sampling target portion 19 during the electric discharge machining is in close contact with the suction holding mechanism 3. The collected material 28 is taken out (step 110). For example, in the case of performing a sampling process in a nuclear reactor, this method can reliably carry out the sampling material 28 out of the reactor without dropping the sampled material 28 into the reactor.

FIG. 6 shows a mold electrode groove 26 formed by the post-processing electrode 22.
FIG. 4 is an explanatory view showing a method of repairing the electrode.
3 switches the electrode facing the structure 4 from the pattern electrode 1 to the post-processing electrode 22. In this embodiment, as can be seen from FIG. 1, the mold electrode 1 and the post-processing electrode 22 are vertically
Rotate to switch. Thereafter, a current is supplied to the post-processing electrode 22 from the electrode current supply wire 7, and the post-processing electrode 22 is caused to enter the inside of the pattern electrode groove 26 by the pattern electrode driving mechanism 6 (FIG. 6A). Also at this time, the servo drive of the post-processing electrode 22 is performed so that the electric discharge machining proceeds stably. As the electric discharge machining proceeds, the post-processing electrode grooves 34 are formed.
When the post-processing electrode groove 34 is introduced to a predetermined depth, the driving of the post-processing electrode 22 is stopped and the post-processing electrode 22 is moved in the opposite direction (step 120). The post-processing electrode groove 34 formed by the post-processing electric discharge machining has a hemispherical shape (FIG. 6B). Therefore, the stress concentration coefficient is small, and the influence on the structure even after collecting the minute test piece is small. When a deteriorated layer due to electric discharge machining on the surface becomes a problem, a machining finish mechanism 36 is attached to the attachment portion of the jig which is controlled by the electrode changeover switch 23 as shown in FIG. After the processing, the heat treatment of the affected layer is performed by switching with the switch 23. A laser beam is used for this heat treatment. Specifically, the metal surface is heat-treated by irradiating a laser beam along the surface of the post-treatment electrode groove 34. When the repair is completed in this manner, the load applied by the robot is released, and the apparatus container 14 is removed from the sampling surface of the structure 4 (step 12).
1) Take it out of the reactor and end the process (step 122).

When the shape of the test piece is not determined,
By using the square electrode 29 shown in FIG. 8, the machining allowance by electric discharge machining is increased, but the process of machining the structure 4 by the electric discharge wire 13 in the vertical direction can be reduced. Further, a pair of parallel arc-shaped electrode grooves 31 are formed by using the arc-shaped electrode 30 shown in FIG. 9, and the wire supporting / feeding member driving mechanism 5 is not formed in a U-shape but in the arc-shaped electrode groove 31 of the arc-shaped electrode 30. , The post-processing electrode groove can be formed by the post-processing electrode 22 in a short time.
In FIGS. 7 to 9, parts that are not particularly described are denoted by the same reference numerals as in FIGS. 1 and 2, and redundant description is omitted.

Next, step 1 in the flowchart of FIG.
The case where it is determined that the shape of the minute test piece is determined in 02 will be described.

When the shape of the minute test piece is determined as described above, for example, when a test piece having a circular hole shape as shown in FIG. 10 is collected, first, the apparatus container 14 is fixed to the target position of the sample material 4. Then, the pattern electrode 1 is made to face the sampling material 4 by the electrode changeover switch 23. A current is supplied to the plate-shaped mold electrode 1 from an electrode current supply wire 7, and a mold electrode driving mechanism 6 is provided.
The mold electrode 1 is caused to enter the inside of the structure 4. At this time, servo drive of the mold electrode 1 is performed so that electric discharge machining proceeds stably. As the electric discharge machining progresses, the mold electrode groove 26 is formed. When the mold electrode groove 26 is introduced to a predetermined depth, the drive of the mold electrode 1 is temporarily stopped and then moved in the opposite direction (FIG. 10A). Here, the suction-type holding mechanism 3 is arranged at the collection target site 19, and is evacuated through the vacuum tube 17, so as to be completely adhered to the collection target site 19. Next, the electrode facing the structure 4 is changed to the cylindrical electrode 24 by the electrode changeover switch 23. Cylindrical electrode 2
Current is supplied to the electrode 4 from the electrode current supply wire 7, and the cylindrical electrode 24 is caused to enter the inside of the structure 4 by the pattern electrode drive mechanism 6. At this time, the cylindrical electrode 24 is servo-driven so that the electric discharge machining proceeds stably. As the electric discharge machining progresses, a circular electrode groove 32 is formed (step 11).
1).

When the circular electrode groove 32 is formed to a predetermined depth, the driving of the cylindrical electrode 24 is temporarily stopped, and the cylindrical electrode 24 is moved in the opposite direction (step 112-FIG. 10 (b)). As long as the cylindrical electrode 24 is small in size and the circular electrode groove 32 fits between the mold electrode grooves 26, a large number of circular electrode grooves 32 can be formed as necessary. The cylindrical electrode 24 is returned to a position higher than the wire support feed member 2, and stops supplying current to the cylindrical electrode 24 from the mold electrode current supply wire 7.

After the cylindrical electrode 24 has returned to a position above the wire support feed member 2, the wire support feed member 2 is driven by the wire support feed member driving mechanism 5 to cause the die electrode groove 2 to move.
6 to the top of the end. Next, the micro test piece holding mechanism 3 is attached to the micro test piece collection site 19, and is fixed by vacuuming. A current is supplied to the electric discharge machining wire 13 through the wire 8 for supplying electric current for wire electric discharge and the power supply plate 10, and at the same time, the wire supply shaft 11 and the wire winding shaft 21 are provided.
Is rotated to connect the electric discharge wire 13 to the wire supply shaft 11.
The wire support / feed member 2 is inserted into the mold electrode groove 26 by the wire support / feed member drive mechanism 5 while moving from the direction of the wire winding shaft 21 (step 114-FIG. 10).
(C)). The electric discharge wire 13 has two mold electrode grooves 26.
The wire electric discharge machining groove 27 is formed between the mold electrode grooves 26 while maintaining a constant tension by the wire tension adjusting mechanism 12. When the electric discharge machining wire 13 reaches the target depth (step 115), the wire supporting / feeding member 2 is driven by the wire supporting / feeding member driving mechanism 5.
Is changed from the vertical direction to the horizontal direction with respect to the surface of the structure 4 (step 116-FIG. 10).
(D)). When the electric discharge machining wire 13 reaches the opposite end of the mold electrode groove 26, the scanning direction of the wire supporting and feeding member 2 is changed from the horizontal direction to the vertical direction with respect to the surface of the structure 4 by the wire supporting and feeding member driving mechanism 5. (Step 117). The structure 4 has two parallel mold electrode grooves 2.
6, a U-shaped wire electric discharge machining groove 3 and a circular electrode groove 32 are formed, and a cylindrical test piece 33 is collected. At this time, the columnar test piece 33 is taken out to the outside while being kept in close contact with the suction cup holding mechanism 3 used for holding the sampling target portion 19 during the electric discharge machining (step 118). This is repeated until a necessary number is collected (step 119).
The post-processing is the same as the case where the test piece shape is not determined (steps 120, 121, 122).

Next, another example in which the shape of the minute test piece in the flowchart of FIG. 3 is determined is shown in FIG.
This will be described with reference to FIG. In this example, a tensile test piece is collected. In FIG. 11, the device container 14 is fixed to the target position of the sampled material 4. The suction-type holding mechanism 3 is arranged at the collection target site 19, and is evacuated via the vacuum tube 17, so as to be completely adhered to the collection target site 19. The electrode facing the structure 4 by the electrode changeover switch 23 is
It replaces with the tension type electrode 25. An electric current is supplied to the tension type electrode 25 from the electrode current supply wire 7 and the type electrode driving mechanism 6
Thereby, the tension type electrode 25 enters the inside of the structure 4. At this time, servo drive of the tension type electrode 25 is performed so that the electric discharge machining proceeds stably. As the electric discharge machining progresses, the tension type electrode groove 35 is formed.
FIG. 11 (a)). Pull-type electrode groove 28 to a predetermined depth
Is inserted, the driving of the tension type electrode 25 is temporarily stopped, and the tension type electrode 25 is moved in the opposite direction (step 112). The pull-type electrode 25 is returned to a position above the wire supporting / feeding member 2, and the pull-type electrode 25 from the wire 7
Stop supplying current to the After the tension type electrode 25 returns to above the wire supporting and feeding member 2, the tensile test specimen 37 is cut out by the electric discharge machining wire 13 in the same manner as in the case of the circular test specimen, and is taken out by the suction holding mechanism 3. (Steps 113, 114, 115, 116, 117,
118-FIG. 11 (b), (c)).

As described above, when the shape of the test piece is determined, for example, the tension type electrode 2 is adjusted to the shape.
5. For example, by using an electrode having a compact tension test piece shape, for example, an electrode having a circular compact tension test piece shape, for example, a rectangular electrode or the like, the number of steps for processing the test piece can be reduced.

As described above, according to the present embodiment, the cutting of the sampled material, which has been conventionally performed by the mold electric discharge machining, is mostly replaced by the wire electric discharge machining, thereby minimizing the waste portion of the material sampling. Becomes possible. In addition, by making the specimen sampling surface spherical by post-processing, a specimen effective for reliability evaluation can be obtained without affecting the soundness of the structure. By using this method, a highly accurate soundness diagnosis can be performed, and the reliability of the plant can be improved. In addition, since the specimen shape can be formed by the primary sampling process, it is necessary to reduce the time and effort required to manufacture the specimen when applying it to reactor internal structures where it is necessary to collect activated material. And no or minimal worker exposure is required. Also, the problem of removing activated processing powder is released.

[0043]

As is apparent from the above description, according to the present invention, by using the electric discharge machining with the wire together, it is possible to reduce the machining waste caused by the electric discharge machining as much as possible.

In addition, since the machining wasted portion generated by the electric discharge machining can be reduced as much as possible, it is possible to collect a material having as large a volume as possible with respect to a machining mark of a portion to be machined having the same size.

Further, since the material of the sampling portion is kept from moving during machining by the fixing means, electric discharge machining can be performed smoothly and accurately to the end.

Further, since the means for holding the collected material and taking out the collected material after the collection is provided, the collected material can be reliably taken out without dropping.

Further, a groove is formed by a mold electrode formed in a shape conforming to a desired test piece shape, and the groove is cut out by an electric discharge machining wire using the groove. Even when it is necessary to produce a test piece by collecting a material that is difficult to handle, the test piece can be cut out to the extent that almost no post-process is required, and the man-hour for producing the test piece can be reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing the internal structure of a micro sample collecting apparatus according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view as viewed from the side of FIG.

FIG. 3 is a flowchart showing a processing procedure when a minute sample is collected.

FIG. 4 is a schematic view showing a procedure for collecting a test piece when the shape of the test piece is not determined.

FIG. 5 is a diagram showing a state in which a collected test piece is picked up using a suction cup type holding mechanism.

FIG. 6 is a diagram showing a state when the surface of a structure is repaired using a post-treatment electrode.

FIG. 7 is a cross-sectional view of a micro sample collecting apparatus provided with a laser beam irradiation mechanism for performing a heat treatment.

FIG. 8 is a schematic diagram showing a state when a test piece is collected using a square electrode.

FIG. 9 is a schematic diagram showing a state when a test piece is collected using an arc-shaped electrode.

FIG. 10 is a schematic diagram showing a state when a circular test piece is collected.

FIG. 11 is a schematic diagram showing a state when a tensile test specimen is collected.

[Explanation of symbols]

 Reference Signs List 1 type electrode 2 wire support feed member 3 suction type holding mechanism 4 structure 5 wire support feed member drive mechanism 6 type electrode drive mechanism 7 type electrode current supply wire 8 discharge machining wire current supply wire 9 ground wire 10 power supply plate power supply Plate 11 Wire supply shaft 12 Wire tension adjustment mechanism 13 Electric discharge machining wire 14 Equipment container 15 Robot connection 16 Hydraulic hose tube 17 Vacuum tube 18 Power cable 19 Sampling target site 20 Hydraulic hose 21 Wire winding shaft 22 Post-processing electrode 23 Electrode Changeover switch 24 Cylindrical electrode 25 Tensile test type electrode 26 Type electrode groove 27 Wire electric discharge machining groove 28 Collecting material 29 Square type electrode 30 Circular electrode 31 Circular electrode groove 32 Circular electrode groove 33 Cylindrical test piece 34 Post-processing electrode Groove 35 Tension type electrode groove 36 Finishing mechanism 37 Tension test Test specimen

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Nario Hattori 3-1-1, Sachimachi, Hitachi-shi, Ibaraki Pref. Hitachi, Ltd. Hitachi Plant (72) Inventor Takahiko Kato 3-1-1, Sachimachi, Hitachi-shi, Ibaraki No. 1 Hitachi, Ltd. Hitachi Plant (56) References JP-A-63-231238 (JP, A) JP-A-6-160251 (JP, A) JP-A-9-150318 (JP, A) 7-159295 (JP, A) JP-A-5-332896 (JP, A) JP-A-4-286935 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 1/00 -1/34 G01N 3/00-3/62 G21C 17/00 JICST file (JOIS)

Claims (9)

(57) [Claims] 1. A micro sample collecting apparatus for collecting a small test piece from a surface of a metal immersed in pure water or oil, comprising: a mold electrode for electric discharge machining; moving the mold electrode; Means for forming a corresponding groove in the metal surface; a wire for electric discharge machining; and a metal portion between the grooves which support the wire and move in the groove formed in the metal surface to be opposed by the wire. And a means for cutting out a micro sample. 2. The micro sample collecting apparatus according to claim 1, further comprising a post-processing electrode for re-discharge machining a groove formed by cutting the wire. 3. The micro-sampler according to claim 1, further comprising means for finishing a surface cut by the wire. 4. The micro-sampler according to claim 3, wherein said finishing means comprises a device for heat-treating the altered layer on the metal surface formed by electric discharge machining. 5. The micro sample collecting apparatus according to claim 1, further comprising means for holding the sample material at the sample collection site and taking out the sample material after the sample collection. 6. The micro sample according to claim 1, wherein said cutting means includes a wire feeding mechanism for feeding a new wire and a wire winding mechanism for winding a wire once used for processing. Sampling equipment. 7. A method for collecting a minute test piece from a surface of a metal immersed in pure water or oil, comprising: a first step of attaching a suction means for holding to a surface of a collection target portion; A second step of arranging two electric discharge machining mold electrodes in parallel with a gap centered on the suction means, and driving the mold electrodes downward while supplying current to the mold electrodes to form a metal. A third step of entering the inside, a fourth step of stopping electric discharge machining when the mold electrode reaches a target depth, a fifth step of pulling up the mold electrode, A sixth step of lowering the wire support feed member into the groove and inserting the wire support feed member into the groove on the surface of the structure while supplying current to the wire for electric discharge machining, and forming a new slit to connect the slit end. And the wa Ya is changed in a direction parallel to the driving direction of the wire reaches the predetermined depth in the structure surface, said wire support feed members the driven along the slit formed in the mold electrode,
7th cutout of the lower surface of the sampling site by wire electric discharge machining
And an eighth step of, when the wire support / feed member reaches the slit end face, driving the wire support / feed member upward to cut the last remaining surface. Micro sampling method. 8. The method according to claim 5, further comprising the steps of:
A step of driving a cylindrical electric discharge machining mold electrode downward from a metal surface between the grooves formed by the two mold electrodes to form a groove having the shape of the cylindrical mold electrode; 7. A method of collecting a micro sample according to the control device 7, wherein a column-shaped micro sample is obtained in the step of 7. 9. The method according to claim 7, wherein after the eighth step, the surface on which the sample has been sampled is subjected to electrical discharge machining using a post-treatment electrode having a shape for alleviating stress concentration.