JPH0690362B2 - Fiberscope - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a fiberscope used when a tip probe is moved along a dark and elongated gap and the inside of the gap is optically observed.

[0002]

2. Description of the Related Art Conventionally, as such a fiberscope, an image guide and a light guide are gathered in one outer tube, and in the probe at the tip, the image guide is provided with a side view portion and the light guide is provided with a light projecting portion. Are known.

The point of use is to illuminate the observation object from the light projecting portion through the light guide through the light guide, and to transmit the reflected light from the side viewing portion to the eyepiece through the image guide.

FIG. 1 shows a projection range and a visual field range in the fiberscope.

Light is projected at a projection angle α '(usually up to 60 °) from the projection part of the light guide l'and observed from the side-view part of the image guide i'at a viewing angle α' (usually up to 45 °). ing.

However, when the observation distance h'when observing with the fiberscope is large (for example, several hundred mm),
The observation width d'is sufficiently projected.

[0007]

By the way, in order to observe, for example, a nuclear fuel assembly in a cooling pool with the above fiberscope, a tip probe is inserted into a gap between fuel rods (spacing is several mm). It is then necessary to slide the probe left and right.

However, in this case, the observation distance is 2.0 mm or less, and if this observation distance is Δh 'in FIG.
Even if the light from the light guide l ′ is tilted as much as possible, the light can only be projected onto a part Δw ′ of the original observation width w ′, the observation range becomes narrow, and the observation efficiency is reduced. It is impossible to avoid a significant decrease in

Further, since the image guide and the light guide are arranged in one outer tube, this outer tube becomes an obstacle, and there is a problem that it is difficult to perform super close observation. Furthermore
As described above, attach the tip probe between the fuel rods.
It is necessary to insert and slide it in the gap of
In a fiberscope, the tip probe is flexible
Therefore, it was extremely difficult to insert and slide.

The invention, together with the observation distance is adapted to the proximity observations, and securely inserted into the gap of the small dimension between the fuel rods scan
To provide a fiberscope that can be used for riding
It

[0011]

The present invention is an image guide.
Do not place the light guide tips on either side of the
The outer end of each guide is covered with an outer tube to form a flat-type scope part that can be inserted into an elongated gap and has high rigidity, and the flat-type scope part is used as a tip probe and an eyepiece. Side image guide and light guide
A flexible insert in a state excluding the upper Symbol outer tube into the tube of round cross-section having a round scope of bendable eyepiece side
It is a fiberscope.

[0012]

The tip probe is a flat scope part, and its thickness dimension is equal to the dimension of the outer tube of one image guide or light guide, so that it is an elongated gap such as between nuclear fuel assemblies. Is also easy to insert.

In accordance with the movement of the tip probe, the round scope portion on the base end side (eyepiece side) has flexibility and moves flexibly following it.

[0014]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments.

2 to 7 show an embodiment of the fiberscope according to the present invention.

2 to 7, 1 is a tip probe, 2 is a bendable portion, 3 is an eyepiece, and 4 is a light guide connector.

I is an image guide and l and l are two light guides. In the tip probe 1, as shown in FIG.
1 are arrayed to form a flat scope part.

The arrangement in the other portions can be appropriately arranged, for example, in a bundle as shown in FIG.

Each guide ( tip ) in the tip probe 1
The tip of the image guide i and the tip of the light guide l
As shown in FIGS. 6 and 7 , the end portion is covered with a metal pipe 5 (for example, a stainless pipe) as an outer pipe, and the mutual pipes are integrated by brazing or the like.

As described above, the tip probe 1 forms a flat scope having a high rigidity.

The stainless pipe 5 is brazed to the guide arrangement box 6 (stainless steel).

As shown in FIG. 2, the bendable portion 2 between the box 6 and the eyepiece mount portion P is covered with a flexible metal armored tube 7 such as a spiral metal tube shown by 7 in FIG. An outer cover 8 made of rubber, plastic, or the like is placed on the mounting pipe 7.

In other words, on the eyepiece side of the fiberscope of the present invention, the image guide i and the light guides 1 and 1 are inserted into a flexible tube having a round cross section with the metal tube 5 removed. Then, the bendable round scope part is formed.

In the eyepiece mount P, the image guide i and the light guide 1 are separated, the image guide i is connected to the eyepiece 3, and the light guide 1 is connected to the light guide connector 4 connected to the light source. There is.

In FIG. 2 or 3, l ₀ is a light projecting portion provided in the light guide l of the probe, i ₀ is a side view portion provided in the image guide i of the probe, and these are in the longitudinal direction of the guide. It exists in the same position.

In this side-view portion i ₀ , as shown in FIG. 6, an objective lens 71 and a mirror or prism 72 are arranged at the tip of the image guide i, a side-view hole 51 is provided in the metal tube 5, and a lens, A mirror or the like is fixed by an adhesive 73.

In the light projecting section l ₀ , as shown in FIG. 7, a mirror or prism 74 is arranged at the tip of the light guide l, a light transmission side hole 52 is provided in the metal tube 5, and a lens, a mirror and the like are bonded. It is fixed by the agent 73.

FIG. 8 shows an observation procedure of the nuclear fuel assemblies b, b ...
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The clearance between the fuel rods b, b ... Is 1.6 to 4
Therefore, the outer diameter of the tip probe 1 (outer diameter of the metal tube 5) is slightly smaller than this clearance dimension (
1.5 to 3.0 mm).

Further, glass having excellent radiation resistance, for example, glass fiber core materials for light guides and image guides, lenses, mirrors, and prisms for the side-view portion and the light-projecting portion, for example, a purity of 90% by weight or more, preferably 99.9% by weight % Or more of quartz glass is used.

In the observation of the above nuclear fuel rod, the distance between the probe and the surface of the fuel rod, that is, the observation distance is 2 mm or less, but in the tip probe 1 consisting of the flat scope part, both sides of the image guide i are observed. The light guide 1 is arranged in the light guide section 1 and the light projecting sections l ₀ and l ₀ of the two light guides 1 and 1 are, when viewed from the longitudinal direction, as shown in FIG.
The center extension lines 11 and 11 are arranged in an inclined shape so as to gradually approach the center extension line 13 of the side view portion i ₀ of the central image guide i.

With this structure, the observation distance Δ
Since light projection from the light guides 1 and 1 can be applied to almost the entire visual field width w of the image guide i under h (2 mm or less), the observation range of the image guide can be maximized under its visibility capability.

FIG. 10 shows another embodiment.

That is, the units u ₁ , u ₂ , u each consisting of one image guide i and two light guides l, l
₃ ... The combined plurality箇集arranges all the units u _1, u ₂ ... a in a horizontal row at the distal end probe 1.

In each unit u ₁ , u ₂ ... Light guides 1, 1 are arranged on both sides of the image guide i, and between each unit, a light projecting / side-viewing part q ₁ , q ₂ ( _{2 for} each). Of the light guides 1 and 1 and the light projecting portions l ₀ and l ₀ of the image guide i and the side view portion i ₀ of the image guide i).

The shift distance t is 1 to 4 mm.

The viewing angle of each unit is usually the same,
You can make them different.

In the fiberscope of FIG. 10, when the tip probe 1 is moved along the length direction of the nuclear fuel rod, the observation range in the circumferential direction of the nuclear fuel rod b can be widened as shown in FIG.

Of course, in the probe of each unit,
Since the light guides are arranged on both sides of the image guide, the viewing range of the image guide can be maximized based on its visibility.

The structure of one probe in FIG. 10 is the same as that described with reference to FIGS.

In FIG. 10, reference numeral 6 denotes a guide arrangement box, and the rear end side of the box 6 is, like the case of FIG. 2, in a flexible tube having a round cross section, with the outer tube removed. By inserting the image guides i ... And the light guides 1 ..., a bendable portion 2--a round scope portion--is formed.

In the above, when the probe is moved along the length direction of the nuclear fuel rod, it is safe if the obstacle can be observed when there is something that hinders the movement of the probe. It is desirable to provide an auxiliary scope on one or both sides of the.

In this auxiliary scope, as shown in FIG.
It is possible to use a single image guide i ″ (i ₀ ″ is an m-direction side view portion) and light guides l ″ and l ″ (l ₀ ″ is an n-direction light emitting portion) on both sides of the guide. I can.

Further, in the present invention, as shown in FIGS. 10 and 11, the three projecting / side-viewing portions q ₁ , q ₂ , q ₃ are displaced so that the surface of one nuclear fuel rod can be observed from three positions. However, this can be shifted so that the surface of each of the three nuclear fuel rods is observed at one location.

As described above, the fiberscope according to the present invention can maximize the observation range of the side-viewing fiberscope even when the observation distance is 2 mm or less.

Particularly, in the fiberscope of the embodiment shown in FIGS. 10 to 12, the observation range in the length direction of the probe can be widened. As described above, in the fiberscope according to the present invention, it is possible to observe a wide range by running the probe once.

[0047]

EFFECT OF THE INVENTION The tip probe 1 is a flat type probe having high rigidity.
It is a corp, and its thickness is one image guide.
Since it is equal to the size of the outer tube of do i or light guide 1,
Even the elongated slot, such as between the fuel assemblies, while maintaining the straightness and inserted into easy to Tsu Do and can be observed. Also,
Areas that could not be projected by one light guide l
Light can be projected by the light guide l of
It will be possible.

Further, following the movement of the tip probe 1, the other portion (on the eyepiece side) formed from the bendable round scope portion moves smoothly, and the entire fiberscope is moved to the desired location. Easy, quick and reliable operation.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a conventional fiberscope.

FIG. 2 is an overall sectional view showing an embodiment of the present invention.

FIG. 3 is an enlarged view showing the inside of the dotted line frame in FIG.

4 is an enlarged cross-sectional view taken along line CC of FIG.

5 is an enlarged cross-sectional view taken along line DD of FIG.

FIG. 6 is an enlarged sectional view of a main part.

FIG. 7 is an enlarged sectional view of a main part.

FIG. 8 is an explanatory diagram of a usage state.

FIG. 9 is an explanatory diagram showing an observation range.

FIG. 10 is a side view of a main portion showing another embodiment.

FIG. 11 is an explanatory diagram showing an observation range.

FIG. 12 is a side view showing a modified example.

[Explanation of symbols]

 1 Tip probe 2 Flexible part i Image guide l Light guide

Front page continued (72) Inventor Atsushi Utsumi 3-4-1, Marunouchi, Chiyoda-ku, Tokyo Inside Dainichi Nippon Electric Cable Co., Ltd. (72) Inventor Toshiyuki Nakajima 3-4-1 Marunouchi, Chiyoda-ku, Tokyo Dai Nippon Electric Cable Co., Ltd., Tokyo Office (72) Inventor Kohei Morisaki 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Takamatsu, Masatoshi Hyogo, Kobe, Hyogo Prefecture 1-1 Wadazakicho, Ward, Mitsubishi Heavy Industries Ltd., Kobe Shipyard (72) Inventor Shoichi Hamada 1-1-1, Wadasakicho, Hyogo-ku, Hyogo Prefecture Mitsubishi Heavy Industries Ltd., Kobe Shipyard (72) Invention Junji Nakayama 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd., Kobe Shipyard (72) Inventor Yoshiaki Kondo 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Sanryo Heavy Industries Co., Ltd. ( 56) References JP-A-56-117208 (JP, A) JP-A-55-118733 (JP, A) Actually opened 48-14085 (JP, U) Actually opened 56-133802 (JP, U)

Claims (1)

[Claims] 1. Lights on both sides of the tip of the image guide
Line up the guide tips and attach them to each guide tip.
It s covered with a outer tube, which can be inserted into the elongated slot in and form a large flat scope of the rigid, flat type scope
The part serves as a tip probe and the eyepiece side image
Characterized in that the Jigaido and light guide, flexible insert in a state of excluding the upper Symbol outer tube into the tube of round cross-section with, and the ocular side and bending <br/> song freely round scope section And a fiberscope.