JPH07244032A - Weld inspection device - Google Patents

Abstract

(57) [Summary] [Purpose] To enable ultrasonic flaw detection of the welded part of the lower end plate in the reactor pressure vessel from the inside of the reactor pressure vessel. [Arrangement] An arm 10 having an ultrasonic probe 11 for ultrasonically flaw-detecting a welded portion of a lower end plate on the tip end side is vertically mounted on a horizontal shaft 8 which can be moved up and down along left and right guide rails. The arm elevating wire 2 which is externally fitted so as to be rotatable, and drives the arm elevating wire winding shaft 15 to wind or unwind to move the horizontal shaft 8 and the arm 10 up and down.
3 is connected to the horizontal shaft 8, and the arm rotating wire winding shaft 14
The arm rotating wire 22 for rotating the arm 10 up and down by driving and winding or unwinding is connected to the arm 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weld inspection device.

[0002]

2. Description of the Related Art A linear welded portion 3 of a lower end plate 2 of a reactor pressure vessel 1 as shown in FIGS. 10 and 11 needs to be regularly ultrasonically inspected by remotely operating a welded portion inspection device. There is. In addition, in FIG. 10, 42 is an upper lid.

[0003]

However, under the outer surface of the lower end plate 2, a large number of tubular control rod drive mechanism housings 4 are vertically projected at intervals of about 300 to 500 mm, and the heat insulating material 5 and the like are provided. Since it is provided, it is difficult to perform ultrasonic flaw detection on the welded portion 3 from the outer surface of the lower end plate 2.

Although the control rod drive mechanism housing 4 also protrudes from the inner surface of the reactor pressure vessel 1, since there is no interfering substance above the reactor pressure vessel 1, the control rod drive mechanism housing 4 is located above the reactor pressure vessel 1. It is conceivable to bring the welding line inspection device close to the welding portion 3 of the lower end plate 2, but such a device has not been realized so far.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to easily, promptly and safely perform ultrasonic flaw detection on a welded portion of a lower end plate of a reactor pressure vessel from within the reactor pressure vessel. It was done.

[0006]

According to the present invention, the base end side is externally fitted to a horizontal shaft 8 which can be moved up and down along the left and right guide rails 7 extending vertically, and the welded portion 3 of the lower end plate 2 is used. Of the ultrasonic probe 11 provided on the tip side of the lower end plate 2 for performing the ultrasonic flaw detection of the above, and an arm rotating wire winding shaft 14 for winding or arm rotating wire. An arm rotating wire 22 configured to rotate the arm 10 up and down by unwinding from the winding shaft 14,
The arm 10 can be wound around the arm lifting wire winding shaft 15 or by being unwound from the arm lifting wire winding shaft 15.
The arm elevating wire 23 is configured to be elevated and lowered together with the horizontal shaft 8.

Further, according to the present invention, a bracket 37 having a top portion formed in a polygonal pyramid shape facing upward and provided with a dovetail groove 38 diagonally upward and downward along an inclined surface 37a, and a bracket 37 which can be raised and lowered by an actuator 36, If the rear end of the slide rod 40 is engaged with the dovetail groove 38 of the bracket 37, and the fixed pad 41 is provided at the tip of the fixed rod 41, which is capable of contacting the columnar body 4 protruding upward of the lower end plate 2, the slide rod 40 is movable forward and backward. good.

Further, according to the present invention, an actuator 32 for pushing the arm 10 forward may be provided.

Furthermore, the present invention may be provided with means 34 for fixing the arm 10 stopped in a substantially vertical position.

Further, according to the present invention, the ultrasonic probe 11 may be a phased array type.

[0011]

In the present invention, the arm rotating wire 22 is wound by driving the arm rotating wire winding shaft 14, and the arm 10 held substantially vertically with the horizontal shaft 8 facing upward is moved to the horizontal shaft 8. Is used as a reference to turn the arm turning wire 22 and the arm raising / lowering wire 23 by driving the arm turning wire winding shaft 14 and the arm raising / lowering wire winding shaft 15. While keeping the horizontal state, the ultrasonic probe 11 is lowered along the guide rail 7 to position the ultrasonic probe 11 from the upper surface of the lower end plate 2 to the vicinity of the welded portion 3, and the arm elevating wire winding shaft 15 is driven to move the arm elevating wire. 23 is wound up, the base end side of the arm 10 is raised along the guide rail 7, and the tip end side of the arm 10 is moved along the welded portion 3, and the arm rotating wire winding shaft 14 Winding so as not driven to cause slack in the arm rotating wire 22, performing ultrasonic flaw detection of the welded portion 3 while moving along the ultrasonic probe 11 to the welding portion 3.

According to the present invention, the ultrasonic flaw inspection of the welded portion 3 of the lower mirror plate 2 of the container can be performed easily, quickly and safely from inside the container.

Further, according to the present invention, the actuator 36 is driven to raise the bracket 37 so that each slide rod 4 is moved.
When 0 is advanced and the fixing pad 41 is brought into contact with the columnar body 4 to securely support the device on the columnar body 4, ultrasonic flaw detection can be performed more easily, quickly and safely.

Further, the arm 10 stopped in a vertical state.
By pushing the arm 10 forward by the actuator 32 when rotating the arm 1 upward,
0 can be swung quickly.

Further, when the inspection is not carried out, the device 10 can be easily transported and set by fixing the arm 10 by the means 34 for fixing the arm 10.

Furthermore, when the ultrasonic probe 11 is of the phased array type, it is possible to accurately and surely perform ultrasonic flaw detection even if the welded portion 3 is not linear.

[0017]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 9 show an embodiment of the present invention.

The welded portion inspection apparatus of the present invention is provided with a vertically long frame 6 having a C-shaped plane and a front surface which is large enough to be housed in a space surrounded by four control rod drive mechanism housings 4. On the inner surfaces of the left and right side plates 6a of the frame 6, vertically oriented guide rails 7 are provided close to the opening 6b side.
Is installed.

A frame 6 is provided between the left and right guide rails 7, 7.
A horizontal shaft 8 is arranged so as to extend in the width direction of the roller. Rollers 9 are provided at both longitudinal ends of the horizontal shaft 8 so as to be vertically rollable along the guide rails 7, 7. Between the right and left rollers 9 and 9 of the horizontal shaft 8, the base end side of the arm 10 that is rotatable with respect to the horizontal shaft 8 is externally fitted. When the horizontal axis 8 is located at the upper limit and the arm 10 is vertically stored in the frame 6, the arm 10 is formed to have a length such that the lower end does not protrude below the frame 6, and the frame at the lower end of the arm 10 is provided. An ultrasonic probe 11 of a phased array type is pivotally attached to the inner surface of the plate 6 via a pin 12 arranged parallel to the horizontal axis 8.

An arm rotating wire winding shaft 14 and an arm elevating wire winding shaft 15 are rotatably supported by the bracket 13 installed in the frame 6 in parallel with the horizontal shaft 8, and the bracket 13 is mounted on the bracket 13. Bevel gears 18, 1 externally fitted and fixed to the output shafts of the arranged vertical reduction motors 16, 17
Reference numeral 9 denotes bevel gears 20 and 21 externally fitted and fixed to the arm rotating wire winding shaft 14 and the arm elevating wire winding shaft 15.
Meshes with.

Two arm rotating wires 22 are wound around both ends of the arm rotating wire winding shaft 14 in the longitudinal direction, and the ends thereof are fixed to the arm rotating wire winding shaft 14. An arm elevating wire 23 is wound around a central portion in the longitudinal direction of the arm elevating wire winding shaft 15, and an end portion of the arm elevating wire 23 is fixed to the arm elevating wire winding shaft 15.

On the upper surface of the frame 6, there is installed a frame 24 whose plane size is substantially the same as that of the frame 6 and whose front surface is opened similarly to the frame 6, and two frames 2 are provided on both sides in the width direction in the frame 24. A plurality of brackets 25 are arranged, and a bracket 26 is arranged at the center in the width direction of the frame 24. The brackets 25, 26 are parallel to the arm rotating wire winding shaft 14 and the arm elevating wire winding shaft 15. Support shafts 27 and 28 are attached to the support shafts 27 and 28, respectively.
Pulleys 29 and 30 are rotatably fitted on the outer circumference 28. Also, the arm rotating wire 22 and the arm lifting wire 2
3 extends upward from the arm rotating wire winding shaft 14 and the arm elevating wire winding shaft 15, is wound around the pulleys 29 and 30 and extends downward, and the lower end of the arm rotating wire 22 is near the lower end of the arm 10. The lower end of the arm elevating wire 23 is fixed to the horizontal shaft 8.

A fluid pressure cylinder 32 is horizontally arranged on a bracket 31 disposed inside the lower end of the frame 6, and the tip of a piston rod 32a of the fluid pressure cylinder 32 is mounted on the arm 10 via a block 33 fixed to the arm 10. The lower end can be pushed forward. The bracket 31 has a magnet 34 alongside the fluid pressure cylinder 32.
Are arranged, and when the arm 10 is vertically stored in the frame 6 as shown by the solid line in FIG. 2, the arm 10 is attracted and fixed by the magnet 34 so that the arm 10 does not move.

On the upper surface of the frame 24, as shown in FIG. 4, the planar size of which is substantially the same as that of the frame 6, and a cylindrical frame 35 having a substantially octagonal planar shape is provided. A quadrangular pyramid-shaped bracket 37 is attached to the upper end of the piston rod 36a of the installed fluid pressure cylinder 36 with its top portion facing upward. Thus, the bracket 37
A dovetail groove 38 is formed on each of the inclined surfaces 37a so as to extend obliquely up and down along the inclined surface 37a.

In the circumferential direction of the frame 35, cylindrical horizontal slide bearings 39 are provided at four positions at intervals of approximately 90 degrees when seen in a plan view, and each slide bearing 39 can move back and forth in the horizontal direction. The slide rod 40 is slidably fitted. A fixed pad 41 is attached to the outer end of the frame 35 of the slide rod 40 so as to contact the outer periphery of the control rod drive mechanism housing 4 to position and fix the device at a predetermined position. A projection 40a formed on the inner rear end of the frame 35 of 40 is slidably engaged with a dovetail groove 38 formed on the oblique side of the bracket 37.

Next, the operation of this embodiment will be described with reference to FIGS.
The explanation will be made by also referring to.

When ultrasonically detecting the welded portion 3 of the lower end plate 2, the upper lid 42 of the reactor pressure vessel 1 shown in FIG. 10 is removed, and the arm 10 is vertically framed as shown in FIG. 6, the welding part inspection device in a state where it is stored in the magnet 6 and attracted to the magnet 34 and the slide rod 40 is retracted is hung by a crane or the like, and the welding part inspection device is placed in the reactor pressure vessel 1 containing water. The control rod drive mechanism housing 4 is lowered from the opening of the reactor pressure vessel 1 so as not to interfere with the control rod drive mechanism housing 4, and the lower end surface of the frame 6 is seated on the upper surface of the lower end plate 2.

When the lower end surface of the frame 6 comes into contact with the upper surface of the lower end plate 2, the fluid pressure cylinder 36 is operated to raise the piston rod 36a. Then, the slide rod 40 rises, so that the slide rod 4
0 is pushed in the horizontal direction and pushed out of the frame 35,
As a result of the four fixing pads 41 coming into contact with the outer circumferences of the different control rod drive mechanism housings 4, the weld inspection device is set at a predetermined position in the reactor pressure vessel 1.

When the weld inspection device is set at a predetermined position, the fluid pressure cylinder 32 is operated to operate the piston rod 3
2a is projected, and the lower end of the arm 10 is pushed forward via the block 33. Therefore, the arm 10 is released from the attraction by the magnet 34, and the arm 10 is centered on the horizontal shaft 8 in FIG.
It slightly rotates counterclockwise as shown by the imaginary line.

When the vertical reduction motor 17 is driven in this state, the arm rotating wire winding shaft 14 is rotated via the bevel gears 18 and 20, and the arm rotating wire 22 is wound, so that the arm 10 is rotated. It rotates in the counterclockwise direction of FIG. 2 with respect to the horizontal shaft 8 to a position where it becomes substantially horizontal. Therefore, the arm 10 becomes horizontal and stops at the upper limit position (see FIG. 6).

Next, the vertical reduction motor 16 is driven to rotate the arm rotating wire winding shaft 14 in the reverse direction, and the vertical reduction motor 17 is driven to rotate the arm lifting wire winding shaft 15 to rotate the arm rotating wire winding shaft. Rotate in the same direction as the shaft 14,
Both the arm rotating wire 22 and the arm elevating wire 23 are repeated at a speed that satisfies a predetermined relationship. For this reason,
The roller 9 rolls with respect to the guide rail 7 so that the arm 10 maintains a substantially horizontal state.
The ultrasonic probe 11 is located near the welded portion 3 of the lower mirror plate 2 (see FIG. 7).

Rotational speed N of the arm rotating wire winding shaft 14 when the arm 10 is lowered while being maintained in a substantially horizontal state.
_As shown in FIG. 9, the relationship between ₁ and the rotation number N ₂ of the arm lifting wire winding shaft 15 is as follows: the length of the arm 10 is S, the initial length of the arm rotating wire 22 is L _1O , and the arm lifting wire 23. Initial length L _2O , the length of the arm rotating wire 22 after t seconds from the initial is L _1t , the length of the arm elevating wire 23 after t seconds from the initial is L _2t , and the arm rotating wire 22.
Is V ₁ , the feeding speed of the arm elevating wire 23 is V ₂ , the radius of the arm rotating wire winding shaft 14 is R ₁ ,
When the radius of the arm lifting wire winding shaft 15 is R ₂ ,
It looks like this:

That is, as shown in FIG. 9, in the initial stage,

[ _Equation 1] (L _2O ) ² + S ² = (L _1O ) ² (i) holds, and in order to descend the arm 10 while maintaining the horizontal state after t seconds have passed from the initial stage,

[Equation 2] (L _2t ) ² + S ² = (L _2O ) ² (ii) must be satisfied.

Further, the initial length L of the arm rotating wire 22 is
_{Between 10} and the length L _1t after t seconds have passed,

## _EQU3 ## The relationship of L _1t = L _1O + V _1t (iii) is established, and the initial length L of the arm lifting wire 23 is L.
_{Between 20} and the length L _2t after t seconds have passed,

The relationship of L _2t = L _2O + V _2t (iv) holds.

Substituting equations (iii) and (iv) into equation (ii) and rearranging using equation (i)

## EQU5 ## V ₂ = {(2L ₁₀ + t) / (2L ₂₀ + t)} V ₁ (v) is obtained.

On the other hand, the feeding speed V of the arm rotating wire 22
₁ and the relationship between the rotational speed N ₁ of the arm rotating wire take-up shaft 14

## EQU6 ## V ₁ = 2πR ₁ N ₁ (vi), and similarly, the relationship between the feed speed V ₂ of the arm lifting wire 23 and the rotation speed N ₂ of the arm lifting wire winding shaft 15 is

## EQU7 ## V ₂ = 2πR ₂ N ₂ (vii), and from the equations (v) (vi) (vii),

N ₂ = {(2L ₁₀ + t) / (2L ₂₀ + t)} (R ₁ / R ₂ ) N ₁ (viii) is obtained. Therefore, if the vertical reduction motors 17 and 16 are driven so that the equation (viii) is established, the arm 1
0 descends while maintaining the horizontal state.

When the arm 10 maintains the horizontal state and descends to the lower limit, the phased array type ultrasonic probe 11 contacts the welded portion 3 or is located in the vicinity of the welded portion 3. Therefore, by driving the vertical reduction motors 17 and 16, the arm elevating wire winding shaft 15 and the arm rotating wire winding shaft 14 are rotated in the opposite direction to the case where the arm 10 is lowered.

At this time, the winding speed of the arm elevating wire 23 is set so that ultrasonic flaw detection can be carried out smoothly.
The winding speed of the arm rotating wire 22 is set such that the tip side of the arm 10 does not move upward and the arm rotating wire 22 does not sag. Therefore, the arm 1
The base end side of 0 moves upward due to the roller 9 rolling on the guide rail 7, but the ultrasonic probe 1 of the arm 10
The tip side to which 1 is attached does not rise, and therefore the ultrasonic probe 11 moves along the welded portion 3 of the lower mirror plate 2 (see FIG. 8), and ultrasonic flaw inspection is performed.

When the arm 10 stands upright and approaches the vertical state, the ultrasonic probe 11 approaches the frame 6 side, and the ultrasonic flaw inspection of the welded portion 3 becomes difficult, but in this case, the arm 10 Stored in the frame 6 and attracted to the magnet 34, the bracket 37 is lowered to retract the fixed pad 41, the device is hoisted, transported, and lowered again at a predetermined position to set the weld inspection device. The position is changed, and the ultrasonic flaw detection of the welded portion 3 is performed according to the procedure described above.

By using the weld inspection apparatus as in this embodiment, the ultrasonic flaw inspection of the weld 3 can be performed even from within the reactor pressure vessel 1 which is narrow due to the control rod drive mechanism housing 4. It can be done easily, quickly and safely.

In the embodiment of the present invention, the case where the weld inspection device is applied to the ultrasonic flaw inspection of the welded portion of the lower end plate of the reactor pressure vessel has been described. Not only, it can be applied to ultrasonic flaw inspection of the welded part of the lower end plate of various containers, and others,
Of course, various changes can be made without departing from the scope of the present invention.

[0043]

According to the first aspect of the present invention, there is provided a welded portion inspection apparatus.
According to this, the ultrasonic flaw detection of the welded portion 3 of the lower end plate 2 can be easily, quickly and safely performed from the inside of the container. According to claim 2, the apparatus can be reliably set at a predetermined position. Therefore, the ultrasonic flaw detection can be performed more easily, quickly, and safely. According to claim 3, the arm 10 can be easily rotated at the start of the inspection. According to the fifth aspect, it is possible to easily and quickly carry and set the device, and according to the fifth aspect, it is possible to accurately and surely perform ultrasonic flaw detection even when the welding portion 3 is not linear. Various excellent effects can be obtained.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a welded portion inspection device of the present invention.

FIG. 2 is a view taken along the line II-II in FIG.

3 is a III-III direction arrow view of FIG. 1. FIG.

FIG. 4 is a view taken along the line IV-IV in FIG.

5 is a view taken in the direction of the arrows VV in FIG.

FIG. 6 is a side view for explaining the operation of the welded portion inspection apparatus of the present invention, and is a side view showing a state in which the arm rotates upward and becomes horizontal.

FIG. 7 is a side view for explaining the operation of the welding portion inspection apparatus of the present invention, and is a side view showing a state where the arm is lowered to the lower limit position while maintaining the horizontal state.

FIG. 8 is a side view for explaining the operation of the welded portion inspection apparatus of the present invention, and is a side view in which ultrasonic flaw detection inspection is performed while raising the arm base end side.

FIG. 9 is a conceptual diagram for obtaining the relationship between the payout speed of the arm rotating wire and the payout speed of the arm elevating wire when the arm is lowered while keeping the arm horizontal in the welding portion inspection apparatus of the present invention.

FIG. 10 is a vertical cross-sectional view of a reactor pressure vessel to which the welding portion inspection device of the present invention is applied.

11 is a plan view of a lower mirror plate of the reactor pressure vessel shown in FIG.

[Explanation of symbols]

 2 Lower end plate 3 Welded portion 4 Control rod drive mechanism housing (columnar body) 7 Guide rail 8 Horizontal shaft 11 Ultrasonic probe 14 Arm rotating wire winding shaft 15 Arm lifting wire winding shaft 22 Arm rotating wire 23 Arm Lifting wire 32 Fluid pressure cylinder (actuator) 34 Magnet (means for fixing arm) 36 Fluid pressure cylinder (actuator) 37 Bracket 37a Inclined surface 38 Dovetail groove 40 Slide rod 41 Fixed pad

Claims (5)

[Claims] 1. Left and right guide rails (7) extending vertically
The base end side is externally fitted to a horizontal shaft (8) that can be moved up and down along the ultrasonic axis, and ultrasonic flaw detection of the welded portion (3) of the lower mirror plate (2) can be performed from the upper surface side of the lower lens plate (2). (10) provided with the ultrasonic probe (11) on the tip side
And an arm rotation wire (22) configured to rotate the arm (10) up and down by winding the arm rotation wire winding shaft (14) or unwinding the arm rotation wire winding shaft (14). ) And an arm lifting wire winding shaft (1
5) Winding or arm lifting wire winding shaft (15)
A welding part inspection device comprising an arm elevating wire 23 adapted to elevate and lower the arm (10) together with the horizontal shaft (8) by feeding the arm (10) out of the arm. 2. A dovetail groove (3) whose top portion is formed in the shape of a polygonal pyramid facing upward and which extends obliquely up and down along the inclined surface (37a).
8) provided with a bracket (37) which can be moved up and down by an actuator (36), and a rear end of which is engaged with a dovetail groove (38) of the bracket (37) and protrudes upward of the lower end plate (2). The welded portion inspection device according to claim 1, further comprising a slide rod (40) having a fixed pad (41) capable of abutting against the columnar body (4) provided at a tip thereof and capable of moving forward and backward. 3. The weld inspection device according to claim 1, further comprising an actuator (32) for pushing the arm (10) forward. 4. An arm (1) stopped in a substantially vertical state.
0) with means (34) for fixing 0),
The weld inspection device according to 2 or 3. 5. The weld inspection device according to claim 1, 2, 3 or 4, wherein the ultrasonic probe (11) is of a phased array type.