JPS5928863B2 - Automatic flaw detection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an automatic flaw detection device that automatically inspects heat exchanger tubes and the like of a steam generator.

Steam generators used in nuclear power plants need to be inspected periodically, and in the past, this periodic inspection was carried out by workers entering the main body of the steam generator. It is extremely dangerous for workers to enter and inspect this area.

Therefore, the present applicant has already proposed an automatic flaw detection device shown in FIGS. 1 to 6 for automatically inspecting heat exchanger tubes of a steam generator. This automatic flaw detection device will be explained with reference to the same figures. In Fig. 1, 1 is the water chamber of the steam generator;
2 is the partition wall, 3 is the tube plate of the steam generator, 2nd and 5th
4 in the figure is a large number of heat exchanger tubes arranged at equal intervals in the X and Y directions on the tube sheet 3, and 5 in FIGS. 2 to 5 is an automatic flaw detection device, and the automatic flaw detection device 5 is directly below the tube sheet 3. The heat exchanger tubes 4 are inspected by automatically walking in the X and Y directions.
Next, the automatic flaw detection device 5 will be described in detail with reference to FIGS. 3, 4, 5, and 6. Reference numeral 6 denotes a U-shaped frame in plan view, 8 an outer plate, and 9 both sides 6a of the frame 6. , 6a and both ends of the outer plate 8, a part of which serves as a feed screw shaft. 10 is each guide shaft 9
A frame body having a U-shaped planar shape with both side parts 10a and 10a is used to drive a drive motor (not shown) in the negative direction, while also connecting the drive motor and the guide shaft 9 (feed screw shaft). When an electromagnetic clutch (not shown) for the frame 10 is inserted into a power transmission mechanism (not shown) between (Y, one) direction,
Further, when the electromagnetic clutch is engaged while driving the drive motor in the forward direction, the frame body 10 moves between the frame body 6 and the outer plate 8 in the (Y, +) direction. .

Note that the frames 6, 10 have side plates 6a, 6a, 10a, 1
Back plate 6b connecting 0a. 6b, and are facing each other. 11 is the upper and lower parts 2 attached at both ends to the side plates 6a, 6a.
Book guide shafts 12 are two upper and lower guide shafts whose ends are attached to the side plates 10a, 10a, and each of them is entirely or partially used as a feed screw shaft.

13 is a carrier attached to the guide shaft 11, and 14 is another carrier attached to the guide shaft 12, which drives the drive motor in the negative direction and connects the drive motor with the guide shaft 10 (the feed screw shaft). ), the carrier 13 moves between the stoppers 15 and 16 (X, - ) direction, and while driving the drive motor in the forward direction, when the electromagnetic clutch is engaged,
The same carrier 13 moves between stoppers 15 and 16 (X, +)
A power transmission mechanism (not shown) between the drive motor and the guide shaft 12 (feed screw shaft) drives the drive motor in the negative direction. When an electromagnetic clutch (not shown) for the carrier 14 provided therein is engaged, the carrier 14 drives the drive motor in the (X, 1) direction between the stoppers 17 and 18 in the forward direction. On the other hand, when the electromagnetic clutch is engaged, the carrier 14 moves between the stoppers 17 and 18 (X
, +) directions, respectively.

In the case of the figure, the walking distance of the frame 10 along the Y direction and the walking distance of the carrier 14 along the x direction are equal to the distance between the centers of adjacent heat exchanger tubes 4. In contrast, the walking distance of the carrier 13 along the x direction has tripled. The reason why the walking distance of the carrier 13 is tripled in this way is that the walking speed in the X direction is increased by walking across two consecutive holes (two adjacent heat transfer tubes 4) that are already blocked. It's for a reason. Above, the frame 6, 10 carrier 13,
14, the lifting and lowering of the tap shafts 19, 20 provided on the carrier 13, the tap shafts 21, 22 provided on the carrier 14, and the clamp/unclamp mechanism are shown in FIG. 5 (see FIG. 3). This will be explained with reference to FIG. 6 (one longitudinal side view taken along the line shown in FIG. 5) and FIG. 6 (the other side view taken along the line shown in FIG. The tap shaft 19 is slidably inserted into the vertical hole 23 provided in the tap shaft 19, and 24 in FIG.
An inner hole 25 in FIG. 5 is provided vertically through the tap shaft 19, and the middle part has a smaller diameter than the upper and lower parts, and 26 slides into the middle part of the inner hole 25. A clamp shaft 27 that can be inserted into the clamp shaft 27 is a key groove that allows the clamp shaft 26 to move only in the axial direction. 29 is another skew gear that meshes with the skew gear 28; 30 and 30 are bearings that rotatably support the skew gear 28 in the tap shaft 19; and 31 is slidable on the upper part of the clamp shaft 26. A compression spring 32 is housed in the upper part of the inner hole 25, and a tap 33 supports the housing 31 so as to be movable in the axial direction and limits the upper limit position of the housing 31. The nut 26a on the shaft 19 side is a tapered portion 34 provided at the upper end of the clamp shaft 26.
is arranged around the tapered portion 26a and is mounted on the housing 31; 35 is a worm gear; 36 is a worm meshing with the worm gear 35; 37;
is the worm gear meshing with the same worm 36, 3 in Fig. 6
8 is a pinion provided on the worm gear 37, 39 is a rack on the tap shaft 19 side that meshes with the pinion 38,
A power transmission mechanism (not shown) between the drive motor and the worm gear 35 while driving the drive motor in the negative direction.
When an electromagnetic clutch (not shown) for the tap shaft 19 provided therein is engaged, the rotation of the drive motor is transmitted to the tap shaft 19 through the worm gear 35, the worm 36, the worm gear 37, the pinion 38, and the rack 39. Same tap axis 1
9 is starting to rise 0 and tap axis 19
rises, the collet 34 enters the heat exchanger tube 4, and when the stopper 19a provided at its lower end comes into contact with the bottom surface 13a of the carrier 13, a limit switch (not shown) provided at that position is activated. . On the other hand, even if the stopper 19a hits the bottom surface 13a as described above and the tap shaft 19 cannot rise relative to the carrier 13, the first drive motor does not stop rotating and transmits rotation to the power transmission mechanism. As a result, a skew gear (not shown) provided in the same power transmitting mechanism escapes against the spring, and this movement is transmitted to another limit switch provided near the skew gear, which operates the same limit switch. When the two limit switches are actuated in this way, the signals obtained at that time are transmitted to the electromagnetic clutch, which disengages.
The lifting of the tap shaft 19 is now completed. While the drive motor is rotated in the negative direction as described above, an electromagnetic clutch (see figure) for the clamp shaft 26 provided in a power transmission mechanism (not shown) between the drive motor and the skew gear 29 is connected. (not shown), the rotation of the drive motor will be
The force is transmitted to the clamp shaft 26 via the skew gears 29 and 28, and the clamp shaft 26 begins to descend, and the collet 34 is pushed and expanded by the tapered portion 26a of the clamp shaft 26.
The clamp shaft 26 is in close contact with the inner surface of the heat exchanger tube 4, making it impossible to lower the clamp shaft 26. However, since the rotation of the drive motor continues, the subsequent rotation of the skew gear 29 causes the skew gear 28 to rise along the clamp shaft 26 (threaded shaft), and the tap shaft 19 and carrier 13 are connected to the compression spring 32.
The upper end of the tap shaft 19 comes into contact with the tube plate 3. After that, it becomes impossible for the tap shaft 19 and the carrier 13 to rise, but since the drive motor continues to rotate, an abnormally large force is applied to the skew gear 29. In other words, fluctuations in rotational torque occur, but this is detected, and the signal obtained at that time is sent to the electromagnetic clutch of the clamp shaft 26, which disengages and stops the skew gear 29, completing the clamping. It's summery. Further, while driving the drive motor in the forward direction, if the electromagnetic clutch of the tap shaft 19 and the electromagnetic clutch of the clamp shaft 26 are engaged in the reverse order, the clamp shaft 26 rises and the collet 3
4 is released from the inner surface of the heat tube 4, the tap shaft 19 is lowered, the collet 34 comes out from the heat tube 4, and unclamping is performed.
9 has been described above, the other tap shaft 20 provided on the carrier 13 has a similar mechanism, and lifts and lowers, and clamps and unclamps, in synchronization with the tap shaft 19. I'm starting to do it. Also, two tap shafts 21 provided on the carrier 14
, 22 are the same 0 and 40 in Figures 2 and 3 is the arm,
41 is an arm support portion that supports the base end portion 40a of the arm 40 so as to be rotatable on the outer surface of both side portions 6a, 6a of the frame body 6;
40b is the distal end of the arm 40 on which an inspection device for inspecting the heat exchanger tube 4 is mounted; 42 and 43 are stoppers;
It can be rotated 0 or 180 degrees as required. Next, the operation of the automatic flaw detection device 5 will be explained. (1)
When the device 5 is moved one pitch in the (X, -) direction, the clamp shafts 26 of the tap shafts 21 and 22 are raised, the respective collects 34 are separated from the inner surfaces of the adjacent heat tubes 4, and the taps are moved again. The shafts 21 and 22 are lowered, and the respective collects 34 are taken out from the insides of the heat exchanger tubes 4, and the tap shafts 2 are removed.
Unclamp steps 1 and 22. Next, the carrier 14 is moved from the position shown in FIGS. 3 and 4 in the (X, -) direction until it comes into contact with the stopper 17. At this time, the tap shafts 21, 22
The collector 34 moves one pitch relative to each of the heat exchanger tubes 4 and faces directly below the adjacent heat exchanger tubes 4, 4. Next, the tap shafts 21 and 22 are raised, and the respective collects 34 are inserted into the respective heat transfer tubes 4, and the clamp shafts 26 of the tap shafts 21 and 22 are lowered, and the respective collects 34 are inserted into the respective heat transfer tubes 4. and clamps the tap shafts 21 and 22. Next, tap shaft 19,
20 clamp shafts 26 are raised to separate the respective collects 34 from the inner surfaces of the adjacent heat exchanger tubes 4, and the tap shafts 19 and 20 are lowered to take out the respective collects 34 from the respective heat exchanger tubes 4, The tap shafts 19 and 20 are unclamped.Next, the drive motor is driven in the forward direction while the electromagnetic clutch of the carrier 14 is engaged. In that case, the tap shafts 21 and 22 are clamped, and the carrier 1
4 does not move, the frames 6, 10, etc. move in the (X, -) direction, move one pitch, and stop when the stopper 18 comes into contact with the carrier 14. At this time, the tap shafts 19, 20
The collector 34 also moves one pitch in the (X, -) direction,
It faces directly below the adjacent heat exchanger tube 4. Next, the tap shafts 19 and 20 are raised, and the respective collects 34 are
is inserted into the heat exchanger tube 4, and the clamp shafts 26 of the tap shafts 19 and 20 are lowered to bring the respective collects 34 into close contact with the inner surfaces of the heat exchanger tubes 4, thereby clamping the tap shafts 19 and 20. . The device 5 thus returns to the state shown in FIG. 3 and completes the one-pitch walking operation in the (X, -) direction. (
1) When the device 5 is to be moved one pitch in the (X, +) direction, the tap shafts 19 and 20 are unclamped, and then the drive motor is driven in the negative direction, while the electromagnetic clutch of the carrier 14 is engaged. . In that case, the tap shaft 21,
22 is clamped and the carrier 14 does not move.
The frames 6, 10, etc. move in the (X, +) direction, move one pitch, and stop when the stopper 17 comes into contact with the carrier 14. At this time, the collection 34 of the tap shafts 19, 20
Move one pitch in the (X, +) direction and move to the adjacent heat tube 4.
You will be facing the position directly below. Next, tap shafts 19, 2
0 and unclamp the tap shafts 21 and 22 in sequence, and then move the carrier 14 in the (X, +) direction until it comes into contact with the head stopper 18.
Perform the clamp. The device 5 thus returns to the state shown in FIG. 3 and completes the one-pitch walking operation in the (X, +) direction.
(n]) When the device 5 is to be moved three pitches in the (X, -) direction, the operation is the same as described in (1), except that starting from unclamping the tap shafts 19 and 20, the device 5 is
It is only necessary to move 3 pitches in the (X, 1) direction. (IV
) To move the device 5 three pitches in the (X,
All you have to do is move it 3 pitches in the +) direction. (When moving the device 5 one pitch in the (Y, -) direction, follow the same procedure as described in (4) or (I[), but start by unclamping the tap shafts 19, 20, of(
It suffices to move it one pitch in the Y, 1) direction. (7) When making the device 5 walk one pitch in the (Y, +) direction,
In the same manner as described in (1) or (1), however, it is sufficient to start by unclamping the tap shafts 21 and 22 and move the device 5 one pitch in the (Y, +) direction. The tap shafts 19, 20, 21, 22 are alternately clamped by the clamp shaft 26 as shown in FIG.
14 in the X direction, and the frames 6 and 10 in the Y direction,
Walking in the (X, -) (X, +) (Y, -) (Y, +) direction. Also, when you finish walking and stop, arm 4
0 is rotated 90'' or 180°, and the heat exchanger tube 4 is inspected by an inspection device attached to the tip. If one tap shaft is used, a plurality of tap shafts 19 to 22 are used because the weight balance will be poor and the mechanical strength will be insufficient.

However, since there are manufacturing tolerances on the inner surface of the heat tube 4 and the absolute dimensions are different, the clamp shafts 26 of the tap shafts 19 and 20 also differ.
If the clamp shafts 26 of the tap shafts 21 and 22 are also driven by one drive shaft, there will be a difference in the clamp force, and in extreme cases, even if one clamp shaft 26 is clamped, the other clamp shafts 26 will not be clamped at all. cause problems.
The present invention addresses the above-mentioned problems and includes a tap shaft that ascends to insert the collet into the hole to be inspected, and a clamp shaft that descends within the tap shaft to bring the collet into close contact with the inner surface of the hole to be inspected. A ramp shaft elevating drive mechanism is provided in which a plurality of drive shafts are attached to each of the first and second carriers, and the rotation of the drive shaft is simultaneously transmitted to the plurality of clamp shafts to raise and lower each of the clamp shafts. It is attached to each of the first and second carriers, and the carriers are attached to the first and second frames so that they can be moved in one direction, and the frames are also moved in the other direction orthogonal to the above direction. In an automatic flaw detection device in which an inspection device for inspecting the hole to be inspected is attached to the same frame, each of the clamp shafts descends and the collet comes into close contact with the inner surface of the hole to be inspected, and the clamp For axis lifting 5
A clutch mechanism is provided between the drive shaft and the drive mechanism for lifting the clamp shaft, which moves backward and stops transmitting the rotation of the drive shaft to the drive mechanism for lifting the clamp shaft when the load torque of the drive mechanism increases. The purpose of the automatic flaw detection device is to connect multiple clamp shafts to one
An object of the present invention is to provide an improved automatic flaw detection device that does not cause any difference in clamp force even when raised and lowered by two drive shafts.

Next, the automatic flaw detection apparatus of the present invention will be explained with reference to an embodiment shown in FIGS. 7, 8, 9, and 10.
Among the parts shown in FIGS. 6 to 6, common parts will be described using the same reference numerals.

50 in FIGS. 8 and 9 is a drive shaft provided in the carrier 13;
51 is a tortoise-magnetic clutch that connects and disconnects between the drive shaft 50 and the drive motor; 52 is an annular body that is loosened to the drive shaft 50 by a key 53; and 54 is movable on the drive shaft 50 in the axial direction. a tenth annular body, 55 a slide piece interposed between the annular bodies 52 and 54, and 56 a tension spring interposed between the slide piece 55 and the annular body 54;
, 52a and 55a in the figure are claws provided on the opposing edges of each of the annular bodies 52 and the slide piece 55, 29 is a worm (skew gear) loosely fitted and supported by the annular bodies 52 and 54, and the tap shaft At the same time, the spline provided in the inner hole fits into the spline groove provided on the outer surface of the slide piece 55. In addition, 57 in FIG. 8 is a bearing mounted so as to be movable in the axial direction on the drive shaft 50 and adjacent to the annular body 54, 59 is a cylindrical body fixed to the carrier 13, and 58 is the same cylindrical body 59. If this is the drive system for the tap shaft 19 (clamp shaft 26) using the slide piece interposed between the bearing 57, similar drive mechanisms 5-
5Ff is also arranged on the left side sandwiching the cylinder 59, (
Same drive mechanism 5i~5 tap shaft 20C laja v axis 26)
It is used in the drive system of A compression spring 60 is interposed between each of the slide pieces 58, 5, and the compression spring 60 pushes the slide piece 58, bearing 57, annular body 54, and slide piece 55 to the right. The slide piece 5 and the bearing 5V are arranged so that the claw 55a is pressed against the annular body 52.
The slide piece 5go is pushed to the left and comes into pressure contact with the claw 55a of the slide piece 5da or the annular body 5g. Next, the operation of the automatic flaw detection apparatus will be explained.The operation until the lifting of the zero tap shaft 19 is completed is as described above.

That is, while driving the drive motor in the negative direction, an electromagnetic clutch (not shown) for the tap shaft 19 provided in the power transmission mechanism (not shown) between the motor and the worm gear 35 is engaged. Then, the rotation of the drive motor is transmitted to the tap shaft 19 via the worm gear 35, worm 36, worm gear 37, pinion 38, and rack 39.
begins to rise. When the tap shaft 19 rises and the collector 34 enters the heat exchanger tube 4, and the stopper 19a provided at its lower end contacts the bottom surface 13a of the carrier 13, a limit switch (not shown) provided at that position is activated. 19) is activated.Meanwhile, the drive motor is operated by the stopper 19.
Even if the tap shaft 19 cannot rise relative to the carrier 13 due to abutting the bottom surface 13a as described above, the rotation is not stopped and the rotation is transmitted to the power transmission mechanism. As a result, a skew gear (not shown) provided in the same power transmission mechanism escapes against the spring, and this movement is transmitted to another limit switch provided near the skew gear, which is activated. When the two limit switches are actuated in this manner, the signals obtained at that time are applied to the electromagnetic clutch, which is disengaged and the lifting of the tap shaft 19 is completed (see FIG. 7). Another tap shaft 20 provided on the carrier 13 has a similar mechanism, and is synchronized with the tap shaft 19 to complete the lift. Even in this state, the drive motor continues to rotate in the negative direction. continuing.
If the electromagnetic clutch 51 on the tap shaft 19 side is engaged from the above state and the drive shaft 50 shown in FIGS. The body 52 also rotates in the same direction. This annular body 5
2 and the slide piece 55 are the claws 52a in FIGS. 10 and 11.
, 55a. Moreover, the compression spring 60 in FIG. 8 pushes the slide piece 58 bearing 57 annular body 54 slide piece 55 to the right (in the direction of the annular body 52),
The claw 55a of the slide piece 55 is in pressure contact with the claw 52a of the annular body 52, and a frictional force is generated between them.
Therefore, the slide piece 55 also rotates in the same direction as the annular body 52, and the spline grooves formed on the outer peripheral surface of the slide piece 55 allow the skew gear 29 shown in FIG. 9 and the skew gear 28 shown in FIG. rotates, and the clamp shaft 26 of the tap shaft 19 begins to descend. Also, when this clamp shaft 26 begins to descend, the collet 34
is pushed and expanded by the tapered portion 26a of the clamp shaft 26, and comes into close contact with the inner surface of the heat-generating tube 4. The force (clamp force) that brings the collet 34 into close contact with the inner surface of the heat exchanger tube 4 is exerted by the compression spring 60.
It is determined by the spring force, that is, the frictional force between the claw 55a of the slide piece 55 and the claw 52a of the annular body 52. Collection 34
When the clamping force becomes larger than the frictional force between the claws 55a and 52a, the claw 55a of the slide piece 55 slides along the slope of the claw 52a of the annular body 52, and the slide piece 55 moves in the direction of arrow b in FIG. At this time, the annular body 54 bearing 57 slide piece 58 also retreats in the same direction (to the left in FIG. 8) against the compression spring 60, and when the amount of retreat exceeds the height of the pawl 52a of the annular body 52, the drive The rotation of the shaft 50 is no longer transmitted to the slide piece 55, skew gears 29, 28, and the clamp shaft 26, and the clamp shaft 26 stops descending. Further, when the slide piece 58 retreats to the left in FIG. 8 as described above, a limit switch (not shown) is activated and the completion of the clamping operation on the clamp shaft 26 of the tap shaft 19 is detected. One drive shaft 50
The rotation is performed by similar mechanisms 5i to 55 shown on the left side of FIG.
It is also extended to the clamp shaft 26 of the tap shaft 20 via the skew gear 2 go and the second gear (the second gear is not shown), and the same clamping operation as described above is performed on the tap shaft 20 side as well.
However, in this system, the clamper of the collet 34 is connected to the claw 55.
a: When the friction force becomes larger than 521, the slide piece 55' annular body 5 e bearing 57' slide piece 5
When the slide piece retreats against the compression spring 60 to the right in FIG. 5. When the gear 2 and 2 are no longer transmitted to the clamp shaft 26, the clamp shaft 26 stops descending, and when the slide piece 58' retreats to the right in FIG. 8 as described above, the limit switch (not shown) is activated. ) is activated, and the tap shaft 20
It is detected that the clamping operation has been completed at the clamp shaft 26 of. Further, when the clamping operation is completed on both tap shafts 19 and 20 and the two limit switches are activated, the electromagnetic clutch 51 is disengaged and the drive shaft 50 is stopped. The clamping operation of the tap shafts 19 and 20 provided on the frame body 13 has been described above, but the clamping operation of the tap shafts 21 and 22 provided on the other frame body 14 is also the same. Further, the unclamping operation of these tap shafts 19, 20, 21, 22 may be performed by rotating the drive shaft 50 in the unclamping direction opposite to the clamping direction. In this way, in the automatic flaw detection apparatus of the present invention, the clamp shaft 26 is lowered, the collet 34 is brought into close contact with the inner surface of the hole 4 to be inspected, and the drive mechanisms 29, 28 and 29', 28' for raising and lowering the clamp shafts are moved.
When the load torque of the drive shaft 50 increases, the drive shaft 50 moves backward.
The rotation of the lifting mechanism 29, 28 and 29', 2
8', the clutch mechanisms 52 to 60 to 5i are connected to the same drive shaft 50, the same lifting drive mechanisms 29, 28, and 2 go, 2.
d, so the tap shafts 19, 20 (or 2
1 and 22) are applied to the inner surface of the hole 4 to be inspected (compression spring 60), regardless of variations in the inner dimensions of the hole 4 to be inspected.
This allows the claws 55a, 55a of the slide pieces 55, 55 to be brought into close contact with the claws 52a, 52a of the annular bodies 52, 52 (frictional force generated when the claws 55a, 55a of the slide pieces 55, 55 are brought into pressure contact with the claws 52a, 52a of the annular bodies 52, 52).

Therefore, even if one clamp shaft 26 is clamped, the problem that the other clamp shafts 26 are not clamped can be solved. However, the present invention is not limited to the above, and various design modifications may be made without departing from the spirit of the present invention.

For example, if a cleaning tool or the like is attached to the tip 40b of the arm 40, it is possible to clean the heat transfer tube 4.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the outline of the steam generator, Fig. 2 is a bottom view showing the state of use of the automatic flaw detection device already proposed, Fig. 3 is its top view, Fig. 4 is its perspective view, and Fig. 4 is its perspective view. 5 is a vertical cross-sectional side view taken along the line V- in FIG. 3, FIG. 6 is a vertical cross-sectional side view taken along the line shown in FIG. A longitudinal side view showing an embodiment,
Figure 8 is a longitudinal cross-sectional view along the line shown in Figure 7, Figure 9 is an enlarged vertical cross-sectional view of the main part, Figure 10 is an enlarged cross-sectional view of the main part, and Figure 11 is a side view of the same part. Enlarged side view from the side, No. 12
The figure is a sectional view taken along the arrow line in FIG. 8. 4... Hole to be inspected, 5... Force flaw detection device,
6...First frame, 10...Second frame, 13...First carrier, 14...
・Second carrier, 19-22...Tap shaft,
26... gangway shaft, 28, 29, 28', 2
9'... Drive mechanism for lifting and lowering the clamp shaft, 34...
...Collection chuck, 50...Drive shaft,
52~60~5i...Clutch mechanism.

Claims (1)

[Claims] 1. A tap shaft that rises to insert the collet into the hole to be inspected, and a clamp shaft that descends within the tap shaft to bring the collet into close contact with the inner surface of the hole to be inspected are attached to the first and second carriers, respectively. Each of the first and second carriers is equipped with a drive shaft and a drive mechanism for lifting and lowering the clamp shafts, which simultaneously transmits the rotation of the drive shaft to the plurality of clamp shafts and raises and lowers each of the clamp shafts. The respective carriers are attached to the first and second frames so as to be movable in one direction, and the respective frames are assembled so as to be movable in the other direction perpendicular to the above-mentioned direction, and the above-mentioned holes to be inspected are inspected. In an automatic flaw detection device in which inspection equipment to be inspected is attached to the same frame, each of the clamp shafts is lowered, the collet is brought into close contact with the inner surface of the hole to be inspected, and the load torque of the drive mechanism for raising and lowering the clamp shafts is increased. At times, a clutch mechanism is provided between the drive shaft and the clamp shaft elevating drive mechanism for retracting and disabling rotation of the drive shaft from being transmitted to the clamp shaft elevating drive mechanism. Automatic flaw detection equipment.