JPS63122938A - Automatic flange surface inspector - Google Patents

Abstract

PURPOSE:To enable labor saving for inspection work and a higher operation factor of a plant, by turning a rotary arm with the base end thereof pivoted at the center of the undersurface of a fixed beam to move a luminaire at the tip of the arm and an ITV camera to a desired position. CONSTITUTION:Stud bolts 3 are erected on a flange surface 2 of a nuclear reactor pressure vessel (RPV)1 as distributed circumferentially at an equal interval. In the inspection, first, the apparatus is hoisted with a crane to gel the engaging section 4b of the top member 4a of a stationary beam 4 engaged with a desired bolt 3 and a clamp 9 is operated to fix the apparatus on the RPV1. Here, a rotary arm 5 is driven to photograph a flange surface 2. An image signal thus obtained is processed with an image processor to check for flaws and dust. The rotation and stoppage of the arm 5 and the operation of the clamp 9 are automatically performed with a controller by remote operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an inspection device for automatically inspecting a flange surface of, for example, a nuclear reactor pressure vessel.

(Prior Art) In recent years, in nuclear power plants, automation of various inspections during normal operation or periodic inspections has been progressing in order to reduce radiation exposure of inspectors and improve plant availability.

One of the above-mentioned inspection operations that should be automated is inspection for flaws on the flange seal surface of the reactor pressure vessel (RPV) during periodic inspections. Conventionally, this flaw inspection has been carried out by an inspector visually detecting the presence of flaws and dirt. However, this flaw inspection involved wearing a full-face mask in an area with relatively high radiation levels, which not only placed a heavy mental and physical burden on the working tools, but also did not provide good work performance.

In order to solve the above-mentioned problems, an ITV camera and an opening device are mounted on a vehicle that freely runs on the seal surface.
It has been considered to image the seal surface. In this means, features are extracted from images captured by an ITV camera using an image processing device.

Highly reliable flaw inspection can be performed by determining the presence or absence of flaws.

(Problems to be Solved by the Invention) However, in the automatic inspection using the traveling vehicle, various cables are required for supplying power to the traveling vehicle, sending and receiving control signals, and transmitting image signals, and the traveling vehicle is When traveling, the various cables mentioned above have to be dragged while traveling, which has the disadvantage of making the traveling unstable. To prevent this, it is necessary to perform some kind of cable processing, but RPV
Stud bolts are provided on the flange, making it difficult to handle the cable from the side.

Additionally, since the vehicle runs on the flange surface, there is always a risk of falling, but since a steam dryer (dryer) is installed in the RPV close to the flange, there is no risk of damage to the dryer due to falling. It is necessary to take some kind of fall prevention measures to prevent this from happening.

However, similar to the cable treatment described above, this fall prevention measure is also difficult to implement.

The present invention has been developed based on the above circumstances, and allows for easy cable processing, no fear of falling into the RPV, and damage to the flange seal surface, and is robust and allows inspection with high positional accuracy. The objective is to obtain an automatic flange surface inspection device that can perform the following tasks.

[Structure of the Invention] (Means for Solving the Problems) The flange surface automatic inspection device of the present invention has a gate shape and engages stud bolts erected on the flange surface of a pressure vessel at both ends of its upper surface member. a fixed beam having an engaging portion that allows the
a clamp for fixing the fixed beam to the pressure vessel by pressing the stud bolt engaged with the engaging portion; and a clamp having a base end pivoted at the center of the lower surface of the fixed beam, and a lighting device and an ITV camera on the lower surface of the distal end. Equipped with a rotating arm.

A control device that controls the drive of the rotary arm, blinking of the lighting device, operation of the clamp, etc., and a control device that processes image signals from the ITV camera to eliminate scratches on the flange surface.

The apparatus is characterized by comprising means for determining the presence or absence of garbage.

(Function) In the flange surface automatic inspection device of the present invention, the rotating arm whose base end is pivoted at the center of the lower surface of the fixed beam is rotated to move the illumination device and the mechanical TV camera at the tip of the arm to a desired position. I can do it. Since the motor driving the rotary arm is mounted on a fixed beam, the cable supplying power to the motor is not twisted by the rotation of the rotary arm. Furthermore, if the cables for supplying power to the lighting device and ITV camera, controlling them, and transmitting and receiving signals are fixed near the base end of the rotary arm, they will not be dragged along as the rotary arm rotates.

Further, since the device of the present invention is fixed to the pressure vessel by pressing the stud bolt engaged with the engagement portion with a clamp, it will not fall into the pressure vessel.

(Embodiment) FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is a plan view thereof. In these figures, the flange face 2 of the RPVI
Stud bolts 3 are planted at equal intervals in the circumferential direction. The automatic flange surface inspection device of the present invention has a gate shape, and includes engaging portions 4b at both ends of a gate-shaped upper surface member 4a that engage with those located on the same diameter of the flange surface 2 of the stud bolt 3. a fixed beam 4, a rotary arm 5 having one end pivoted at the center of the lower surface of the upper surface member 4a and having a length extending to the flange surface 2, a lighting bag gE6 and an ITV camera 7 attached to the lower surface of the tip of this arm 5. has. On the other hand, a motor 8 for driving the rotating arm 5 is provided at the center of the upper surface of the upper surface member 4a. Also, fixed beam 4
One side member 4c has an engaging portion 4b of the side member.
A clamp 9 is provided for fixing the position of the device of the present invention by pressing the stud bolt 3 engaged with the clamp 9. Further, on the upper surface of the upper surface member 4a of the fixed beam 4, a wire rope 11 from a crane hook 10 is attached at a symmetrical position with respect to the center thereof.
A wire hook 12 for hanging is provided.

The flange surface is inspected in the following manner using the apparatus of the present invention having the above configuration. First, the device of the present invention is lifted up by a crane, the engaging portion 4b of the upper surface member 4a of the fixed beam 4 is engaged with an arbitrary stud bolt, and the clamp 9 is operated to fix the device of the present invention to the RPvl. Here, the arm 5 is driven once to take an image of the flange surface 2. The image signal obtained by this imaging is processed by an image processing device (not shown) to determine the presence or absence of scratches and dust. Note that the rotation and stopping of the rotating beam 5 and the operation of the clamp 9 are automatically performed by remote control by a control device III (not shown).

In the device of the invention described above, since the motor 8 is installed on the fixed beam, the cable for supplying power to this motor is independent of the rotation of the rotary arm. In addition, if other types of cables are fixed to the base of the rotating arm 5, the rotating arm 5 will not rotate due to dragging of the cables, and the rotation range of the rotating arm 5 is reciprocating rotation within 360 degrees Celsius. There is almost no need to worry about the twist imparted to the cable by the rotation of the arm 5.

Furthermore, since the apparatus of the present invention inspects the flange surface without contacting it, there is no risk of damaging the integrity of the flange surface. In addition, there is no risk of falling, so the inspection can be carried out safely.

Note that the present invention is not limited to the above embodiments.

For example, there may be three or more engagement portions tt with stud bolts.

[Effects of the Invention] As is clear from the above, according to the apparatus of the present invention, the inspection of the flange surface can be automatically performed without visual inspection by the inspector, so that the amount of radiation exposure of the inspector can be significantly reduced. I can do it. Furthermore, since the flange surface can be inspected automatically, quickly, and reliably, it is possible to save labor in inspection work and improve the operating rate of the plant.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is a plan view thereof.

Claims (1)

[Claims] A fixed beam having a gate shape and having engaging portions at both ends of its upper surface member for engaging stud bolts erected on the flange surface of the pressure vessel, and pressing the stud bolts engaged with the engaging portions. a clamp for fixing the fixed beam to the pressure vessel; a rotating arm having a base end pivoted at the center of the lower surface of the fixed beam and an illumination device and an ITV camera mounted on the lower surface of the distal end; and driving the rotating arm; A control device that controls blinking of the lighting device and operation of the clamp, etc., and a control device that processes the image signal of the ITV camera to eliminate scratches on the flange surface.
1. A flange surface automatic inspection device comprising means for determining the presence or absence of dust.