JPH0219751A - X-ray radiographing inspecting method for cv cable - Google Patents

Abstract

PURPOSE:To improve the accuracy for inspecting a defect by placing a part to be inspected of a CV cable in a radiographing part which has been surrounded by an X-ray shielding body, on the side face which has excluded the X-ray radiating direction and the passing direction of the CV cable and covering other surface than the part to be inspected with lead. CONSTITUTION:A connecting part 1 being a part to be inspected of a CV cable is positioned in an X-ray shielding body 2 of a radiographing part. This shielding body 2 consists of lead, etc., opened in the lengthwise direction of the cable, and has larger width than necessary width of an X-ray radiographing use film 5. This film 5 is provided on the opposite side to an X-ray generating device by placing the connecting part 1 between. Also, on the shielding body 2, a mask 4 for prescribing an X-ray radiating range is provided, and the mask 4 is controlled so that an X-ray radiation line coincides with the outside diame ter of the connecting part 1. In such a way, when the mask 4 coincides with the outside diameter of the connecting part 1, indistinctness of an image caused by an overexposure in the film 5 can be decreased remarkably, and the visibility of the image can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a Cv cable, and mainly to an X-ray photographic inspection method for its connection portion.

[Conventional technology]

CV cables made of cross-linked polyethylene insulators are
It has been put into practical use as an ultra-super high voltage cable of 154KV to 275Kv. In particular, CV cables do not require a lubricating device and are easy to maintain and inspect, so 275K
It is about to be used as a V-length underground power transmission line. on the other hand,
The CV cable connection is mainly made of polyolefin, which is the same material as the cable insulator, but since it is assembled on-site, X-ray photography is the most suitable on-site inspection method. It is important to establish this testing method.

In conventional X-ray inspection, an X-ray generator is placed opposite a photographic film placed in a flat plate across the CV cable to be inspected.

[Issue 8 to be solved by the invention] However, in the past, the area around the inspection device was a concrete wall, and the thickness of the space between the X-ray film and the object was large between the inner diameter and the outer diameter of the circular connection insulator. Since the X-ray film is affected by diffuse reflection of X-rays, the resolution of the X-ray film after development is poor, and it is often difficult to detect minute defects in the photographic film.

For this reason, there was a need for an inspection method that would reduce the blurring of the image after shading of the X-ray bottle imaging film.

The purpose of the present invention is to solve the conventional problems caused by X-ray inspection,
An object of the present invention is to provide an X-ray inspection method for making images clear.

[Means and effects for solving the problem] The gist of the present invention is to provide an X-ray shield around the part to be inspected of the CV cable,
A mask for regulating the X-ray irradiation range is placed on the shield to prevent unnecessary X-ray irradiation and diffuse reflection, thereby making the X-ray film photographed image clearer.

That is, the above-mentioned object of the present invention is to place the part of the CV cable to be inspected in an imaging section whose side surfaces except for the direction of X-ray irradiation and the direction of passage of the CV cable are surrounded by an X-ray shield, and to cover the surface other than the part to be inspected. Cover with a lead-based mask and apply X to the area to be inspected.
This is achieved by an X-ray photographic inspection method for Cv cables, which is characterized by irradiating and photographing a Cv cable.

In the present invention, placing the part of the Cv cable to be inspected in the imaging area whose sides are surrounded by X&* shields except for the direction of X-ray irradiation and the direction of passage of the CV cable means that the length of the CV cable is The direction is such that the cable can be moved and passed through.For example, the connection part to be inspected is installed in the imaging section, and in that case, the side of the cable connection part of the inspection part is surrounded by an X-ray shield. This means that When the X-ray generator is installed at the top, the imaging section is U-shaped and surrounded by an X-ray shield, and when the X-ray generator is installed horizontally, the X-ray shield of the imaging section is U-shaped. Therefore, by moving the cable as necessary and installing the part that requires inspection in the imaging section, other cable parts can be inspected.

Lead/concrete is used as the X-ray shield in the present invention, but since the part of the cable to be inspected is mainly constructed on-site and to prevent diffuse reflection, a shield mainly made of lead is used. is preferred.

In the present invention, covering surfaces other than the inspected area with a mask mainly made of lead means that X-rays are irradiated to areas other than the inspected area, and the X-rays are repeatedly reflected diffusely, making the image of the inspected area unclear. The purpose is to use a mask that has a shielding plate mainly made of lead, and the shielding part can be adjusted arbitrarily. As for the format of the mask, one using two plates is preferable.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to this embodiment.

Connecting part l, which is the part to be inspected of the CV cable, is
It is located within the line shield 2'.゛The X-ray shield 2 is a metal body such as lead that has high X-ray absorption, is open in the length direction of the cable, and has a width larger than the required width of the X-ray film 5. have. The X-ray photographing film 5 is provided on the side opposite to the X-ray generator across the connection portion, which is the portion to be inspected, of the Cv cable. In this case, in order to reduce the influence of X-ray scattering on the connection part, which is the part to be inspected, of the Cv cable, the distance between the Cv cable connection part 1 and the X-ray photographic film 5 should be set 20 to 100 degrees apart. The other end of the X-ray shield 2 is connected to the X-ray irradiation port of the XvA generator 3, and can be positioned dimensionally fixed. The X-ray shield 2 is provided with a mask 4 that defines the X-ray irradiation range. The mask 4 is also made of a metal body mainly made of lead, which is the same material as the X-ray shielding body 2. The mask 4 is adjusted in such a way that the X-ray radiation is particularly directed to the outer diameter of the CV cable connection l. When the mask 4 is completely matched with the outer diameter of the Cv cable connection portion 1, blurring of the image due to overexposure on the X-ray photographic film 5 can be significantly reduced, and the clarity of the image can be improved.

Since the width of the X-ray shield 2 is approximately 50c+a, which is about the width of the X-ray imaging film 5, C'■ Cable connection part 1
To take an X-ray image of the entire area, the X-ray shield 2 is moved a predetermined distance or a cable is moved.

This X-ray imaging inspection method can prevent blurring of images due to scattering from concrete walls, etc. due to X-ray irradiation, and can also prevent X-ray imaging due to differences in X-ray irradiation at the outer diameter of the connection part. It is possible to reduce blurring of the image due to overexposed portions of the film.

(Effects of the Invention) By using the Cv cape and X-ray imaging inspection method of the present invention, parts to be inspected assembled on site, such as connections, can be inspected easily and safely to the human body. The X-ray image of the part to be inspected can now be seen more clearly than before, making it possible to improve the accuracy of defect inspection in insulators.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of a vertical photographing section showing an embodiment of the present invention, and FIG. 2 is a perspective view of a horizontal IRS shadow section of the present invention. 1... Part to be inspected of CV cable 2... X-ray shield 3... X-ray generator 4... Mask 5... Film for X-ray photography

Claims (1)

[Claims] 1. Place the part of the CV cable to be inspected in the imaging area whose sides, except for the direction of X-ray irradiation and the direction of passage of the CV cable, are surrounded by an X-ray shield, and cover the other side with a mask mainly made of lead. An X-ray photographic inspection method for a CV cable, characterized by covering the part to be inspected, and irradiating and photographing the part to be inspected with X-rays.