JPH0510647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a tube inner surface inspection device for observing the presence or absence of scratches on the tube inner surface and the condition of the inner surface.

Prior Art In recent years, endoscopes have been widely used for medical and industrial purposes.

For example, in the above-mentioned industrial fields, endoscopes are used to inspect the inner surfaces of tubes in boilers, chemical plants, etc., and various improvements to these endoscopes have been proposed.

For example, in the conventional example disclosed in Japanese Utility Model Application Publication No. 54-146282, a light source for illuminating the inner surface of the tube is disposed on the tip side of the tube through a slit formed in the tube, and the inside of the illuminated tube is It is constructed so that the surface is bent through a prism and imaged with an objective lens for observation.

However, in this conventional example, the illumination direction and the viewing direction of the observation optical system are approximately the same direction, so even if there are damaged areas such as unevenness on the inner surface of the tube,
It has the disadvantage that it is difficult to distinguish images because contrast is not easily formed in the observed images.

On the other hand, in the conventional example disclosed in Japanese Utility Model Application Publication No. 56-95207, a plurality of illumination ports are provided on the distal end side of the endoscope insertion part, so that the object to be observed can be illuminated from the side. There is.

However, since the illumination port is formed around the objective optical system in the endoscope insertion section,
There were problems in that it became difficult to illuminate from a direction that was significantly different from the viewing direction, and furthermore, it became difficult to achieve a good contrast due to the spread caused by the light guide illumination.

Furthermore, in order to solve the above-mentioned drawback that the contrast is not sharp, a device as shown in Figs.
No. 19775).

That is, an inspection device 2 for observing the inner surface of the tube 1 is inserted into the tube 1 with an endoscope 3 for observation, a light guide cable 4 for illumination, and the endoscope 3 and light guide cable 4 fixed. and a scope fixing member 5. As shown in the cross-sectional view of the distal end side in FIG. 2, the light guide cable 4 is inclined so that the distal end thereof faces the inner surface of the tube 1.

However, the light intensity distribution in the observation range of the inner surface of the tube 1 in the conventional example described above is a distribution in which the light intensity increases only in a certain narrow range, and the light intensity around that area rapidly decreases, as shown by curve A in Fig. 2. becomes. In other words, although the contrast is high, the light amount distribution has a problem in that only a specific narrow range is bright and the surrounding area is dark.

Purpose The purpose of the present invention is to provide an inspection device for the inner surface of a tube that has a high contrast and can obtain bright and uniform illumination light.

Overview This invention provides a scope fixing member that is movable within a tubular member, and includes an illumination means consisting of an endoscope having a side-view observation optical system facing the inner surface of the tube and a light guide cable, and a light guide cable at the tip of the illumination means. Uniform illumination is achieved by providing a semi-cylindrical reflecting member that directs illumination light toward the viewing direction.

Embodiment FIGS. 3 to 6 are diagrams showing a tube inner surface inspection apparatus showing an embodiment of the present invention. FIG. 3 shows the external appearance, and the illumination inspection device 2 inserted into the tube 1 includes an observation endoscope 3 with a built-in image guide 11 and a light guide cable 4 for illumination, both of which are fixed inside the tube 1. It consists of a scope fixing member 5 that is inserted into the scope. Further, the rear end of the light guide cable 4 is connected to a light source device 6. Also, as shown in FIG. 4, a scope fixing member 5 inserted into the tube 1 is provided.
is formed in the shape of a short circular column slightly smaller than the inner diameter of the tube 1 so as to be able to move back and forth in the axial direction within the tube 1. At approximately the center of the scope fixing member 5, a first
A through hole 5a is formed, and the endoscope 3 is inserted into this through hole 5a.
The distal end of the insertion section can be inserted through it. Further, a set screw 7 is screwed into the side surface of the scope fixing member 5, so that the endoscope 3 can be fixed to the scope fixing member 5 by pressing the outer skin 8 of the insertion portion. At the tip of the endoscope 3, there is a prism 9 that bends the light from the observation section on the inner surface of the tube 1 at right angles, and an objective lens system 10 for imaging the object.
An image guide 11 for transmitting an observation image is further provided so that its front end surface is located at the position where the objective lens system 10 forms an image. Through this image guide 11, the optical image formed on the front end surface is transmitted to the rear end surface on the near side, and is enlarged through an eyepiece 13 housed in the eyepiece section 12 to enable observation optical system. is formed. Further, the scope fixing member 5 has a second through hole 5b adjacent to the through hole through which the endoscope 3 is inserted, as shown in FIG. 4, through which the flexible light guide cable 4 can be inserted. The light guide cable 4, which is formed parallel to the first through hole 5a and inserted through the through hole 5b, can be fixed from the side surface of the scope fixing member 5 with a set screw 14. A base for fixing a light guide fiber extends from the distal end surface of the light guide cable 4 to form a mirror member 15. The mirror member 15 is a semi-cylindrical member whose inner surface is finished with a mirror surface,
This mirror surface is formed to face the observation section on the inner surface of the tube.

The light guide cable 4 is integrated with the endoscope 3 using a tape 16 or the like, as shown in FIG. 3, so that it can be easily inserted into the tube 1.

Next, the operation of the present invention based on the above configuration will be described. a first through hole 5a of the scope fixing member 5;
The distal end sides of the endoscope 3 and the light guide cable 4 are respectively inserted into the second through-hole 5b with set screws 7,
Fix at 14. At this time, the endoscope 3 and the light guide cable 4 are adjusted and fixed so that the observation range of the endoscope 3 and the illumination range of the light guide cable 4 provided with the mirror member 15 at the tip thereof are substantially the same. Then, the light source device 6 connected to the rear end side of the light guide cable 4 is turned on and inserted into the tube 1. Then, of the illumination light from the distal end surface of the light guide cable 4, the illumination light emitted in the direction opposite to the observation section on the inner surface of the tube 1 is reflected by the mirror member 15 attached to the distal end and goes toward the observation section. That is, the illumination light from the light guide cable 4 consists of the illumination light that goes directly to the observation section and the illumination light that is reflected by the mirror member 15 and goes to the observation section, and as shown in FIG. The light will be illuminated from direction B, which is inclined at an angle of . Therefore, if there is even a slight unevenness on the inner surface of the tube 1, a shadow is formed on the side opposite to the illumination direction B, and bright and dark areas corresponding to the unevenness are observed, resulting in sharp contrast. Furthermore, looking at the light intensity distribution on the inner surface of the tube ₁ at this time, as shown in FIG. Since the light intensity distribution C ₂ due to the illumination light that illuminates the area shifts by an amount corresponding to the distance from which it is reflected by the mirror member 15, the light intensity distribution of the entire observation range by the endoscope 3 is obtained by adding the above two light intensity distributions. The result is a gentle curve C.

As described above, by providing the mirror member 15 which is a reflective member at the tip of the light guide cable 4, the illumination light is irradiated from an oblique direction with respect to the observation direction by the endoscope 3, and the inner surface of the tube 1 is not uneven or uneven. If there is a damaged area, a shadow is created depending on the protrusion or crack, which increases the contrast of that area and makes it easier to identify the uneven state. In addition, as shown in FIG. 4, a curve C of the light amount distribution in the observation field
becomes gentler. In other words, compared to the conventional example, rather than only a specific narrow area becoming brighter, almost uniform illumination light can be obtained over the entire observation field, making it easier to observe and take photographs, and making it easier for the examiner to see. You will feel less tired.

Furthermore, since the endoscope 3 is fixed approximately at the center of the scope fixing member 5, the entire inner peripheral surface of the tube 1 can be observed by rotating the scope fixing member 5. Furthermore, the two through holes formed in the scope fixing member 5 can be formed adjacently and in parallel, so that they can be easily formed. This saves processing time and reduces costs. Furthermore, since the outer diameter of the scope fixing member 5 can be made smaller, it can also be used when observing small diameter tubes.

FIG. 7 is a diagram showing another embodiment of the present invention. Incidentally, the same parts as in the above embodiment are given the same reference numerals, and the explanation of the structure of the same parts will be omitted. In this embodiment, the distal end surface 16 of the light guide cable 4 is inclined at α° in the direction of the central axis of the tube 1.

With the above configuration, illumination light from the light source device 6 passes through the light guide cable 4 and is emitted from the inclined tip surface 16. At this time, since it is tilted by α° in the direction of the central axis of the tube 1, the entire emitted illumination light is tilted toward the inner surface of the tube 1.

According to this embodiment, the amount of light directed toward the observation section on the inner surface of the tube 1 is increased, and the distribution of light amount is made more uniform.

FIG. 8 is a diagram showing still another embodiment of the present invention. In this embodiment, instead of the mirror member 15 in the previous embodiment, a semi-cylindrical single optical transmission element 19 is used as a reflecting member, with a core glass 17 at the center and a clad glass 18 having a smaller refractive index than the core glass surrounding the core glass 17. It uses

With the above configuration, the illumination light emitted from the distal end surface of the light guide cable 4 is directly transmitted to the tube 1.
Illumination light directed toward the observation section on the inner surface and the core glass 17
Pass through the core glass 17 and clad glass 18
The illumination light is reflected at the interface with the tube 1 and passes through the core glass 17 toward the observation section on the inner surface of the tube 1.

According to this embodiment, since there is no need to use a mirror member, there is no need to finish the inner surface of the tube to a mirror surface, and the manufacturing process is not labor-intensive.

In each of the above embodiments, by changing the mounting angle of the reflective member provided at the tip of the light guide cable 4, it is possible to widen the uniform portion of the light intensity distribution, overlap the peak portions, or adjust the angle of the tube to be observed. Depending on the size, the observation range of the endoscope 3 can be made to correspond to a portion where the amount of illumination light from the light guide cable 4 is uniform.

In addition, by remotely controlling the reflecting member using a wire or the like at hand to change the angle of the reflecting member, even if the inner diameter of the tube changes midway, it can be observed by following changes in the inner diameter of the tube. It is possible to make the range correspond to a portion where the amount of illumination light is uniform.

Moreover, the reflective member may be integrally molded with the fiber fixing member.

Effects In this invention, since the semi-cylindrical reflective member that illuminates the observation area from an oblique direction is disposed at the tip of the illumination means such as a light guide cable, if there are unevenness or damaged areas on the inner surface of the tube, the convexity Shadows with high contrast occur depending on the part and crack. Therefore, it becomes easy to observe the unevenness. In addition, the semi-cylindrical reflection member makes the illumination light uniform within the viewing field of view, making it easy to observe, easy to take pictures, and easy on the eyes. In addition, the structure becomes simpler and the cost becomes lower.

[Brief explanation of the drawing]

Fig. 1 is an overall view of a conventional example, Fig. 2 is an enlarged sectional view of the conventional example, Fig. 3 is an external view of an embodiment of the present invention, and Fig. 4 is an enlarged sectional view of an embodiment of the invention. , FIG. 5 is a view of FIG. 4 viewed from the direction D, FIG. 6 is an explanatory diagram showing how it is illuminated by illumination light, and FIG.
The figure is a partially enlarged sectional view showing another embodiment of the invention, and FIG. 8 is a partially enlarged sectional view showing still another embodiment of the invention. 1: Tube, 2: Inspection device, 3: Endoscope, 4: Light guide cable, 5: Scope fixing member, 1
5: Mirror member, 19: Single light transmission element.

Claims (1)

[Scope of Claims] 1. An illumination means consisting of an endoscope having a side-view observation optical system facing the inner surface of the tube and a light guide cable is attached to a scope fixing member movable within a tubular member, and the illumination means consists of a light guide cable. An inspection device for the inner surface of a tube, characterized in that a semi-cylindrical reflecting member is provided at its tip to direct illumination light in an observation direction. 2. Inspection of the inner surface of a tube according to claim 1, wherein the semi-cylindrical reflecting member is a single semi-cylindrical optical transmission element made of a core glass and a clad glass whose refractive index is lower than that of the core glass. Device.