JPH05333009A - Ultrasonic flaw detecting apparatus - Google Patents

Abstract

PURPOSE:To obtain an ultrasonic flaw detecting apparatus, which can positively perform ultrasonic flaw detection at the narrow place at the bottom of an apparatus by easy handling operation with a simple constitution. CONSTITUTION:A running truck 10 is provided on rails 8 provided along a bottom part 1 of an apparatus. An elevation frame 13 is provided on the running truck 10. A parallel-link mechanism 19, which can be horizontally turned, is provided at the elevation frame 13. A gimbal mechanism 23, which is supported with a pushing spring 22 so as to push the mechanism 23 upward, is provided at the turning tip of the parallel-link mechanism 19. An attaching stag 29 having the ultrasonic probe is supported on the gimbal mechanism 23 so that the attaching stage 29 can be freely turned back and forth and right and left.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic flaw detector.

[0002]

2. Description of the Related Art As shown in FIGS. 6 and 7, a lower end plate (apparatus bottom part) 1 of the bottom of a pressure vessel such as a steam generator is provided with a nozzle 2 which vertically penetrates the inside and outside of the lower end plate 1. In some cases, a welding line 3 is provided on the bottom of the lower end plate 1 so as to pass between the nozzles 2.

A heat insulating material 4 is provided near the lower end plate 1 so as to pass through the nozzle 2 to prevent heat generated in the pressure vessel from escaping from the lower end plate 1.

Reference numeral 5 denotes a skirt provided on the base 6 so as to surround the lower mirror plate 1, and reference numeral 7 denotes an inspection opening formed between the base 6 and the heat insulating material 4 and having a size barely enough for a person to enter.

As described above, a large number of nozzles 2 and the like are arranged in the narrow space between the lower mirror plate 1 and the heat insulating material 4 at the bottom of the pressure vessel. Conventionally, a large number of such pipes are provided. There is no dedicated ultrasonic flaw detector capable of easily inspecting the welding line 3 of the lower mirror plate 1 existing in a narrow space.

[0006]

Therefore, it was very difficult to inspect the welding line 3 of the lower end plate 1 existing inside the narrow space provided with a large number of pipes.

In view of the above situation, the present invention is not limited to the spherical lower end plate of the bottom of the pressure vessel, but can be applied to general welding lines in a narrow space by an ultrasonic flaw detection with a simple structure and operation. It is an object of the present invention to provide an ultrasonic flaw detector capable of performing

[0008]

SUMMARY OF THE INVENTION The present invention provides an ultrasonic flaw detector for flaw detection of the bottom of an apparatus, a rail provided on the lower side along the bottom of the apparatus, a traveling carriage capable of traveling on the rail, The elevation frame is attached to the front side of the traveling carriage so that it can be elevated, the parallel link mechanism is attached horizontally to the front side of the elevation frame, and the parallel link mechanism can be pushed upward through the pressing spring at the turning tip of the parallel link mechanism. And a gimbal mechanism that rotatably supports the mounting base having an ultrasonic probe in the front-back and left-right directions.

[0009]

[Operation] When the elevation frame and the parallel link mechanism supported by the traveling carriage are rotated upward, the ultrasonic probe mounting base supported by the parallel link mechanism via the gimbal mechanism pushes the required pressing force by the pressing spring. The ultrasonic probe, which is pressed against the bottom of the device by and is attached to the mount by rotating the gimbal mechanism back and forth and left and right, reliably contacts the shape of the bottom of the device.

Therefore, the flaw detection of the bottom of the apparatus can be easily and surely carried out by a simple operation of only traveling the traveling carriage and horizontal turning of the parallel link mechanism.

[0011]

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

FIGS. 1 to 3 show an embodiment of the present invention. As an example, FIGS. 6 and 7 are used for ultrasonic flaw detection around the welding line 3 of the lower end plate (apparatus bottom) 1 of the bottom of the pressure vessel. It will be diverted and explained.

A curved rail 8 bent along the spherical surface of the lower mirror plate 1 is disposed below the lower mirror plate 1, and a rail drive 8 is provided on the rail 8 along the rail 8 by a traveling drive unit 9. A traveling carriage 10 having wheels 10 'that can travel in any direction is provided.

On the front side of the traveling carriage 10, the elevation drive unit 1 is provided.
1 is provided with a horizontal elevation shaft 12 that rotates in the B direction,
The elevation frame 13 is integrally attached to the elevation shaft 12.

A swivel arm 15, which is attached to the front side of the elevation frame 13 with a required space on the left and right, and is swung horizontally in the C direction by a swivel drive unit 14,
16 is provided, and the front end links 18 are connected between the tip end portions of the two swivel arms 15 and 16 via a pin 17, and the elevation frame 13, the swivel arms 15, 16 and the front end link 18 are provided.
The parallel link mechanism 19 is constructed.

Further, a roller stopper 20 is provided above the revolving arms 15 and 16 of the parallel link mechanism 19 for restricting the depression-improvement limit position of the revolving arms 15 and 16.

The front end link 18, which is the turning tip of the parallel link mechanism 19, is movable only in the vertical direction via a vertical guide 21, and is pressed upwards D by a pressing spring 22 and is rotatable back and forth and left and right. A gimbal mechanism 23 that supports the above is provided. Reference numeral 24 represents a stopper.

The gimbal mechanism 23 includes the vertical guide 21.
A support frame 26 that can move up and down along and has a left and right balance shaft 25 at the top, and is attached to the left and right balance shaft 25 so as to freely rotate in the left and right direction E for balance, and the left and right balance shaft 25. Left and right balance frame 2 having front and rear balance shafts 27 in the direction of 90 ° to
8 and has a mounting base 2 on the front and rear balance shaft 27.
9 is rotatably mounted in the front-rear direction F, whereby the mount 29 is supported so as to be freely rotatable in the front-rear direction and the left-right direction so as to be balanced.

A plurality of ultrasonic probes 30 for making ultrasonic waves incident on the welding line 3 and the like from various angles such as 0 °, 45 °, and 60 ° are attached to the mount 29.

FIG. 4 shows an example in which the curved rail 8 is arranged below the lower end plate 1.

A rail 8 which is bendable and expandable around a substantially central portion and has a curvature substantially equal to that of the lower mirror plate 1 is inserted from the inspection port 7 into a space between the lower mirror plate 1 and the heat insulating material 4 in a bent state. To be able to do so.

An H-shaped bracket 32 is pivotally attached to the tip of the rail 8 so as to swing up and down when viewed from the side, which holds a pair of upper and lower rolls 31 in two steps in the front and rear direction. Is provided with an electromagnet 33 that can be attracted to the lower end plate 1.

An ultrasonic flaw detector is installed on the rail 8 as shown in FIGS.

Next, the operation will be described.

1 to 3, the elevation drive section 11 is operated to rotate the elevation frame 13 upward so that the roller stopper 20 attached to the parallel link mechanism 19 always contacts the lower surface of the lower end plate 1. deep.

At this time, the pressing spring 22 supporting the gimbal mechanism 23 is compressed downward by a required amount, and the mounting base 29 having the ultrasonic probe 30 is pressed against the bottom surface of the lower end plate 1 by a required pressing force. It will be pressed stably with.

In this state, the traveling drive unit 9 is operated to cause the traveling carriage 10 to travel in the A direction, and the swinging drive unit 14 is further activated to horizontally swing the parallel link mechanism 19 in the C direction. Ultrasonic probe 30 provided in 29
Perform a flaw detection inspection by.

That is, as shown by the flaw detection locus X in FIG. 5, the position of the ultrasonic probe 30 is slightly advanced A (FIG. 1) along the rail 8 and then in the left-right direction C (FIG. 2, By advancing ultrasonic flaw detection while shaking in 3), it is possible to perform ultrasonic flaw detection in a wide range Y along the welding line 3 while avoiding the nozzle 2.

In the above, the pressing force of the mounting base 29 against the lower end plate 1 is always kept constant by the roller stopper 20 and the pressing spring 22, so that the elevation drive unit 11 simply pushes the elevation frame 13 upward. Therefore, it does not require any adjustment. Further, since the mounting base 29 is supported by the parallel link mechanism 19 via the gimbal mechanism 23, the ultrasonic probe 30 mounted on the mounting base 29 is surely brought into contact with the lower mirror plate 1 for accurate flaw detection inspection. It can be carried out.

Therefore, at the time of flaw detection, it is possible to easily carry out flaw detection of the narrow portion by a simple operation only by adjusting the traveling drive unit 9 and the turning drive unit 14.

The ultrasonic flaw detector of the present invention is not limited to the above-mentioned embodiment, but is applied to a place where a flaw inspection of various narrow spaces is required such as a boiler and a pressure vessel of a nuclear reactor. Of course, the roller stopper can be omitted, and various modifications can be made without departing from the scope of the invention.

[0032]

As described above, according to the ultrasonic flaw detector of the present invention, various excellent effects as described below can be obtained.

A traveling carriage is provided on a rail provided along the bottom of the device, and an ultrasonic probe is provided at the tip of the traveling carriage via a lifting frame, a parallel link mechanism, a gimbal mechanism having a pressing spring, and a mounting base. Since it is supported so that it can move back and forth, up and down, and left and right, for example, ultrasonic welding can be performed stably on the welding line and its surroundings formed in an extremely narrow space where a large number of nozzles, such as the lower mirror plate of a pressure vessel, are projected. can do.

Since the gimbal mechanism supported by the parallel link mechanism by the pressing spring is made to support the mounting base having the ultrasonic probe, the ultrasonic probe is made to correspond to the shape of the bottom of the device. Moreover, it is possible to make sure contact with a stable pressing force, which enables a reliable inspection, simplifies the configuration, and facilitates the position adjustment operation of the ultrasonic probe.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a mechanism diagram showing the operating principle of the embodiment of the present invention.

FIG. 4 is a side view showing an example of installation of curved rails.

FIG. 5 is a bottom view of the pressure vessel showing the inspection side of the welding line.

FIG. 6 is a side view showing a lower end plate of the pressure container.

7 is a view taken along the line VII-VII in FIG.

[Explanation of symbols]

 1 Lower End Plate (Bottom of Device) 8 Rail 10 Traveling Vehicle 13 Elevation Frame 19 Parallel Link Mechanism 22 Pressing Spring 23 Gimbal Mechanism 29 Mounting Base 30 Ultrasonic Transducer

[Procedure amendment]

[Submission date] September 24, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

As described above, a large number of nozzles 2 and the like are arranged in the narrow space between the lower mirror plate 1 and the heat insulating material 4 at the bottom of the pressure vessel. Conventionally, such a large number of nozzles are provided. There is no dedicated ultrasonic flaw detector capable of easily inspecting the welding line 3 of the lower mirror plate 1 existing in a narrow space.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

[0006]

Accordingly, the welding line 3 of the lower end plate 1 existing inside the narrow space provided with a large number of nozzles.
Was very difficult to inspect.

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Sasajima 8 Shinsita-cho, Isogo-ku, Yokohama-shi, Kanagawa Inside the Yokohama Works of Toshiba Corporation (72) Inventor Koji Ishiwata Shin-nakahara-cho, Isogo-ku, Yokohama, Kanagawa Prefecture Ishi Kawashima Harima Heavy Industries Co., Ltd.Yokohama No. 3 Factory (72) Inventor Riki Yagaki, Shin Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishi Kawashima Harima Heavy Industries Co., Ltd., Yokohama Works (72) Inventor Toshihiko Sasahara Isogo, Yokohama-shi, Kanagawa Prefecture No. 1 Shin-Nakahara-machi, Ishikawajima-Harima Heavy Industry Co., Ltd. Yokohama No. 1 Factory (72) Inventor Takaaki Sasaki No. 1, Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa Ishikawajima Harima Heavy Industry Co., Ltd. Yokohama No. 1 Factory

Claims (1)

[Claims] 1. An ultrasonic flaw detector for flaw detection on the bottom of an apparatus, comprising: a rail provided on the lower side along the bottom of the apparatus;
A traveling carriage that can travel on the rails, a rising / lowering frame that is attached to the front side of the traveling carriage so that it can be elevated, a parallel link mechanism that is horizontally swingably attached to the front side of the elevation frame, and a parallel link mechanism of the parallel link mechanism. An ultrasonic wave, comprising: a gimbal mechanism that is supported at the tip of the swivel so as to be able to be pressed upward via a pressing spring and that supports a mounting base having an ultrasonic probe so as to be rotatable back and forth and left and right. Flaw detector.