JPS5987422A - Inner observation device - Google Patents

Abstract

PURPOSE:To prevent an image from the reduction of contrast and a window plate from the adhesion of dust or the like by arranging slantly the window plate on the point surface of an optical fiber and forming a nozzle hole on the fixing point of the window plate. CONSTITUTION:A light guide 8 consisting of the optical fiber flux 7 transmits illumination light and irradiates the light from the point to an object, and an image guide 9 transmits the picture of the object irrdiated by the illumination light. If the point surface of the optical fiber flux 7 and the window plate 15 are separated by a prescribed distance and paralleled each other, the bright point 27b of the illumination light on the point surface of the light guide 8 is displayed as the bright point 27a due to the reflection of the back side M1 of the window plate and the bright point 27b due to the reflection of the front side M2 of the window plate, and the bright point 27b due to the reflection of the front side M2 of the window plate out of these bright points is made incident to the visual field theta of the image theta guide 9. When the bright point 27 is observed in the visual field of the image guide 9, the contrast of the image is reduced due to the entry of the illumination light. Even if the window plate 15 parallel to the point surface of the optical fiber flux 7 is adhered to the end surface of the optical fiber flux 7, the bright point 27 is not projected outside the visual field theta. If the window plate 15 is inclined to one direction, the bright point 27 is removed from the visual field theta. Since air curtain flow is made flow from one direction along the window plate 15, dust can be effectively purged.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a device for visually observing the inside of a blast furnace.

2. Description of the Related Art Conventionally, there has been known a device for visually observing the inside of a furnace by inserting an image guide made of an optical fiber into the furnace. Utility Model Application Publication No. 55-1718, which disclosed these prior art
52, JP-A-57-45515, etc.

An internal device using an original fiber stores the optical fiber in a protective cylinder, and transmits the state inside the furnace to the outside through the optical fiber and observes it through a glass window or lens at the tip of the cylinder. The state of descent of the contents in the furnace, the rate of descent, and the flow! 1
111 phenomenon, mixed layer formation state, layer thickness, furnace wall immobile layer formation state, powdering state, particle size, position and behavior of the softened melt zone, etc., and still spectroscopically analyze the extracted light. This is used to measure temperature, components, etc.

However, in this type of conventional wedding ceremony device, the illumination light emitted from the tip of the optical fiber is reflected on the window plate at the tip of the cylinder, which obstructs observation. In addition, dust from inside the furnace adhered to the window panels, making it difficult to observe them.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a family gift device that solves the above problems, and its features are that a transparent window plate is attached to the tip, and the original fiber is attached to one of the protective cylinders. In the held endoscopic device, the window plate is tilted with respect to the optical fiber tip surface so that the bright spot reflected by the window plate of the illumination light emitted from the tip of the light guide is positioned 16' outside the field of view of the image guide. A nozzle hole is provided in the window plate mounting portion to allow a curtain flow to flow in one direction from the peripheral edge side of the window plate along the front surface of the window plate.

Hereinafter, practical examples of the present invention will be explained in detail based on the drawings.

In FIG. 1, il) is a protective cylinder, which is formed into a double cylinder consisting of a concentric inner cylinder (2) and an outer cylinder (3). The gap between the inner cylinder (2) and the outer cylinder (3) is closed by a front wall (4) at the tip of the cylinder 11). Inner cylinder (2)
A partition cylinder (5) is inserted into the gap between the outer cylinder (3) and the outer cylinder (3) at a predetermined interval from both cylinders [2+ +31, and the partition cylinder (5)
) A predetermined gap is formed between the tip of the front wall (4) and the front wall (4).

A cooling medium made of water or gas is circulated between the inner cylinder (2) and the outer cylinder (3) via a partition cylinder (5) in the direction of arrow a in the figure. The flow of the cooling medium may be opposite to the direction shown.

The inner cylinder (2) and the outer cylinder (3) are welded together to facilitate manufacturing and to use different materials.

That is, the front end of the cylinder m is made of a material with good thermal conductivity in order to enhance the cooling effect of the cooling medium.

Both ends of the inner hole (6) of the inner oil (2) are open, and the inner hole (6)
An optical fiber bundle ('7) is inserted and held on the inner surface with a predetermined gap maintained. This optical fiber bundle (7) consists of a light guide (light guide) and an image guide (9). Inner hole (6
) The tip part is formed to have a small diameter in order to tightly fit and hold the optical fiber bundle (7), and the small diameter part (10) is provided with a sulin (II) located in the ml111 direction as shown in Fig. 2. The inside and outside of the inner hole (6) are communicated with each other. Optical fiber bundle (7
) protrudes from the end of the inner hole (6).

Purge gas is supplied between the upper gc2 optical fiber bundle (7) and the inner hole (6) in the direction of the arrow. Thus, the slit (11) supports both the optical fiber bundle (7) and the cooling effect of the purge gas flow.

At the tip of the cylinder (1), the outer cylinder (3) has a front wall (4
) protrudes further forward and forms a recess with a front opening.

A screw (12) is provided on the inner surface of this recess.
) is screwed onto the window plate holder (1 camphor). (14) is the backing provided at the bottom of the screw.

The window plate holder (13) is formed into a ring shape, and a window plate (15) made of transparent heat-resistant glass is attached to the inner hole of the window plate holder (13). The window plate 05) is fitted into the inner hole of the holder (13), and is axially moved by the holder (an oak screwed into the inner hole of the Japanese cypress) through the retainer θ and the stopper (17). being held in place.

A plug (09) made of an elastic material is provided on the end face of the oak (oak) H, and presses the stopper (17) via the plug (19).

The opposing surfaces of the receiving plate (17) are parallel inclined surfaces, and hold the window plate (15) in an inclined manner with respect to the cylinder axis.This window plate holder (1→ and Receiver (16) are in communication with each other, and the sulin) (
11) is provided with a flow path communicating with the flow path, and the flow path is
It communicates with the nozzle hole (2I) that opens at the front of the window plate (lower end).

As shown in Fig. 3, the nozzle hole (2++) is the window plate (
1 Along the front of the unit, install the support plate θ (2) and the window plate (15) so that a curtain flow of purge gas flows upward from the bottom end.
There is an opening in between. Therefore, the purge gas is ejected from the nozzle 1) through the inner cylinder inner hole (6), through the surin (II) and the flow path (E), and blows off the dust adhering to the front surface of the window plate (16). As shown in Fig. 4, the window plate θ
The purge gas is blown out from the periphery of the pipe, and multiple blowouts are made from the same direction toward the center as shown in Figure 5(a).
Alternatively, if a swirling flow is created as shown in FIG. 5(b), stagnation occurs in the center of the window plate (15y), and dust (2 odors, etc.) tends to adhere.However, in the present invention, as shown in FIG. ), since the air curtain flow is from one direction, dust does not accumulate on the window plate (10).

In addition, +23i and +24i are positioning bins, and the receiver (
1 odor and holder (13), and cash (17) and holder 0
3) Provided between
) are held so that their slopes are parallel.

CI! The clasp is a tip protection cap, which is fitted on the window plate holder (kuni tip).This cap (to) has a cone shape to reduce resistance to insertion into the furnace, and is attached to the holder (la) with an intermediate fit. Heat IF UJ after being fitted and inserted into the furnace
% difference and the pressure of purge gas from the nozzle (21),
Holder (1 detached from the tip.

Next, the inclination of the window plate 0 will be explained based on FIG.

The light guide (8) of the optical fiber bundle (7) transmits illumination light and irradiates the object from its tip, and the image guide (9) displays an image of the object illuminated by the illumination light. It is something that is transmitted. If the tip end face of the optical fiber bundle (7) and the window plate (15) are parallel to each other and separated by a predetermined distance, as shown in FIG. The point □□□ appears as a bright spot (2,'7b) due to reflection from the rear surface of the window plate (Ml) (2γa bright spot (2, '7b) due to reflection from the front surface of the window plate (M2), and in the example shown, among these bright spots, Bright spot (2'i'b) due to reflection from the front surface of the window board (M2)
) comes within the field of view (θ) of the image guide (9). In this way, if a bright spot array is seen within the image guide (9) ψf (θ), the contrast of the image will deteriorate due to the wraparound of the illumination light.

Even if the window plate (15) parallel to the tip direction of the optical fiber bundle (7) is brought into close contact with the end face of the optical fiber bundle (7) as shown in FIG. 6(b), the bright spot (271 is the field of view (θ)) I never go outside.

Even if the core plate 05) is tilted in the direction shown in FIG. 6(C), the bright spot is still within the field of view (θ) of η.

Therefore, when the window plate (I5) is tilted in the direction shown in FIG. 6(d), the bright spot .eta. moves out of the field of view (.theta.), and the above-mentioned problem is solved.

This will be explained in more detail with reference to FIG. The symbols in the figure are: l; distance between the fiber end face and the core plate; thickness of the window plate h; distance θ between the image guide and the light guide; viewing angle θ of the image guide; bright spot of the light guide light from the image guide. Viewed angle (beam angle) θb; Normal angle n of the window plate; Refractive index no of the window plate; Assuming the refractive index of the atmosphere, (1) The core plate (15) is parallel to the optical fiber bundle (7) In this case, (a) the position of the reflective bright spot (27) at +nj (j4)-c after the window plate and the same bright spot (2 points) using the image guide (9).
) The relationship with the angle (θ) seen from ) is (21-d)tanθ+dtan(sin'((,)s
inθ) )=h However, if l≧d, then 7? tanθ11tan (sin '((%')
sin θ))=h provided that f<d.

(b) Reflection bright spot (2η) on the front surface of the window plate (M2) and angle (
The relationship with θ) is (21+d) tanθ+am (sin ((-j
T ) sin θ])=h.

(11) When the window plate θ0 is tilted, the above (a) and (b)
) is obtained by substituting (l + dsin Ob) for l in the equation, and θ', which is obtained by θ' = θ + θb, is obtained from the image guide (9) to the bright spot (
2 This is the angle at which the force is viewed.

From the above relationship, the viewing angle (θ) of the image guide (9)
In order to prevent bright spots from entering inside the window plate (
The inclination angle (θb) of 15) may be set to satisfy 0·I>%.

Next, the results obtained by substituting numerical values into the above equation are shown in the graphs of FIGS. 8 and 9.

In Figure 8, h = 1 mm, d'' = 5 mm
This shows the relationship between l and θ when the (sapphire window) is used parallel to the end face of the optical fiber (7), and the fiber (7) light 11^ and core plate 05 are closely attached (1 = o
), the bright spot (2) on the front surface of the window plate (M2) is in the field of view (
/2) Figure 9 shows h:1. ,, (1: This is the case where the window plate θ0 between 'i' is tilted (θ). For example, if l = 2 mm and the viewing angle (0/2) is 30°, the window plate 05) is θb = 15
It can be seen that by tilting the lens by more than 1°, the bright spot tzi will be out of the field of view.

, ■Figure 10 is a graph showing the relationship between the inclination of the window plate 0 (θO) and transmittance.The inclination of the window plate (I5) increases the reflection at the rear surface of the window plate (M2) and reduces the transmittance. However, as is clear from this graph, θb
If the angle is within -45°, the decrease in transmittance poses no practical problem.

Therefore, h=1mm, '3-='/mmmm11=2
, when n = 30°, the window plate inclination angle (θb) is 15° to 4
If the angle is set within the range of 5°, the bright spot hi can be brought out of the field of view and illuminated without reducing the transmittance.

As described above, according to the persimmon example of the present invention, ■ Protective barrel 1
Since the tip of 1) is made of a material with good thermal conductivity, the cooling effect of the cooling medium can be reduced, and it can be used in a high-temperature atmosphere such as a blast furnace.

(2) Since the optical fiber (7) is supported by providing a sulin (II) at the tip of the inner cylinder (2), it is possible to support both the fiber (7) and the cooling effect by the gas flow.

■ Since the air curtain flow is applied to the window plate (15) from one direction, it is possible to effectively purge dust that tends to adhere to the window plate.

■ Since the window plate (15) is tilted, the bright spot of the illumination light (2
It is possible to prevent η from entering the field of view of the image guide (θ), and to prevent a reduction in image contrast due to the wraparound of illumination light.

■ Since a cap is attached to the tip of the cylinder body, the tip will not be damaged when inserted into the furnace.Moreover, this cap (20 is automatically inserted after 1 hour) It's convenient because you can leave it.

etc. will be effective.

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

According to the present invention, it is possible to prevent a decrease in the contrast of the image, and since dust and the like do not adhere to the window, endoscopic observation becomes easier.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing an embodiment of the present invention, Fig. 2 is a perspective view of the inner cylinder and the pipe taken along the line ■-■ in Fig. 1, and Fig. 3 is a perspective view of the inner cylinder and the
The figures are a sectional view taken along the line 111-II in FIG. 1, FIG. 4 is a sectional view showing a comparative example, FIGS. 5(a) and 5(b) are front views showing a comparative example, and FIG. Fig. 6 and 7 are explanatory diagrams showing the relationship between the window plate inclination and the bright spot position, and Fig. 8 shows the relationship between the distance between the fiber tip and the window plate and the beam angle. FIG. 9 is a graph showing the relationship between the window plate inclination angle and beam angle, and FIG. 1θ is a graph showing the relationship between the R8 plate inclination angle and transmittance. +++...Protective cylinder, (7)...Optical fiber, (8
)...Light guide, (9)...Image guide,
θ5)...Window plate, 1)...Nozzle hole, (271・
...Reflection bright spot, (θG...Window plate inclination angle, (θ)...
field of view. Patent applicant Kobe Steel, Ltd. Figure 1 III 11 7UA Figure 8 ) Figure 10

Claims (1)

[Claims] 1. In a private device in which an optical fiber is held internally in a protective cylinder with a transparent window plate attached to the tip, the bright spot reflected by the window plate of the illumination light emitted from the tip of the light guide is outside the field of view of the image guide. The window plate is provided at an angle with respect to the tip surface of the optical fiber, and a nozzle hole is provided that directs a curtain flow from the edge of the window plate in one direction onto the front surface of the window plate. A family celebration device characterized by being installed in the wearing part.