JPH058501Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a structure of a light receiving portion of a measuring device using an optical fiber, such as a surface temperature measuring device.

[Conventional technology]

In a measurement device using an optical fiber, a light receiving section is placed in the environment of the object to be measured. Therefore,
In environments where there is a lot of splashing water, water vapor, dust, etc., such as in steel manufacturing processes, the light receiving side of the optical fiber gets dirty, and the energy of the received light is attenuated, making accurate measurements impossible. Therefore, the light receiving section is usually provided with an air purge mechanism to prevent dirt on the light receiving side.

The light receiving structure with a conventional air purge mechanism is
For example, Utility Model Application Publication No. 52-29182, Utility Model Application Publication No. 53
-As described in Publication No. 74273, the tip of an outer tube with an optical fiber inside is extended in front of the optical fiber receiving end, air is supplied into the outer tube, and this air is ejected from the opening at the tip. It is common to have a structure.

[Problem that the invention attempts to solve]

By the way, in conventional optical fiber measurement devices, the diameter of the focusing fiber is relatively large and the tip of the outer cylinder of the light receiving section is extended long in front of the receiving end of the optical fiber. Therefore, a large amount of air is required to prevent dust from entering the outer cylinder and to secure the air jetting pressure necessary to purge dust and the like within the measurement field of view. Even if a large amount of air were supplied into the outer cylinder, it was insufficient from a structural standpoint to clean the receiving end face of the optical fiber or the protective glass surface.

In view of the above points, it is an object of the present invention to provide a structure for a light receiving part of an optical fiber measuring device, which can effectively prevent the intrusion of dust and the like and clean the light receiving surface with a small amount of air.

[Means for solving problems]

The structure of the light receiving part of the optical fiber measuring device of this invention is as follows:
In a light receiving section of a measuring device, which includes an outer cylinder having an opening at the tip, an optical fiber provided in the outer cylinder, and a mechanism for supplying air into the outer cylinder and causing it to be ejected from the opening at the tip,
An outer cylinder tip member 7 having an opening 8 of a size corresponding to the field of view of the central optical fiber 1 is removable from the outer cylinder body with a screw, and an optical A recess into which the protective glass 6 fitted with the fiber protection part 5 is fitted is formed;
A feature is that a plurality of grooves 10 are radially provided on the side and bottom surfaces 9 of the recess to allow air to pass from the inner surface of the outer cylinder toward the central opening 8.

[Example and operation]

The present invention will be explained in detail below based on the illustrated embodiments.

FIG. 1 is a longitudinal sectional view showing the structure of a light receiving section in an embodiment of the present invention, and FIG. 2 is an enlarged perspective view (partially cut away) of the outer cylinder tip member of FIG. 1.

In FIG. 1, reference numeral 1 denotes an optical fiber, and the optical fiber of the device of this embodiment is a single wire with a diameter of 0.4 mm.
2 is a tube for protecting the optical fiber and supplying air, 3 is the outer tube body, 5 is the optical fiber protection tube, 6 is the protective glass at the receiving end of the fiber, 7 is the outer tube tip member, 8 is the opening, and S is the object to be measured. It is a warm material.

Purge air is supplied from air supply tube 2 to air supply port 4
It passes through a groove 10 (described later) between the front surface of the protective glass 6 at the receiving end of the optical fiber and the outer cylinder tip member 7, and is ejected to the outside from the central opening 8.

The outer cylinder tip member 7 can be attached to and detached from the outer cylinder main body 3 using screws (not shown), and has a shape that corresponds to the field of view of the optical fiber in the center, as shown in FIG. It has an opening 8, and a recess into which the protective glass 6 is fitted is formed on the inner surface, and grooves 10 are radially formed on the bottom surface 9 of the recess for allowing air to pass from the inner surface of the outer cylinder toward the central opening 8. A plurality of them (four in this embodiment) are provided.

In the process of blowing out the purge air from the central opening 8 through the groove 10, the 6 surfaces of the protective glass are cleaned and the intrusion of dust is prevented, and the material to be temperature measured in the range corresponding to the field of view of the optical fiber is cleaned. Dust and the like on the S surface and its vicinity are purged.

[Effect of idea]

Since the light receiving section of the optical fiber measuring device of the present invention has the above structure, it is possible to effectively prevent dust from entering the outer cylinder and clean the light receiving surface with a small amount of purge air. In addition, it is easy to remove the outer tube tip member and carefully clean the inner surface and light receiving surface of the tip member if necessary, which has great practical effects.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of the light receiving portion in one embodiment of the present invention, and FIG. 2 is an enlarged perspective view (partially cut away) of the outer tube tip member of FIG. 1. 1: optical fiber, 3: outer tube body, 6: protective glass, 7: outer tube tip member, 8: opening, 9:
...Bottom surface of recess, 10...groove, 11...screw hole.

Claims (1)

[Claims for Utility Model Registration] An optical fiber measuring device comprising an outer tube having an opening at its tip, an optical fiber provided inside the outer tube, and a mechanism for supplying air into the outer tube and ejecting it from the tip opening. In the light receiving section, an outer cylinder tip member 7 having an opening 8 of a size corresponding to the field of view of the optical fiber 1 in the center is removable from the outer cylinder body with a screw, and an inner surface of the outer cylinder tip member 7 is provided. A recess into which the protective glass 6 fitted with the optical fiber protector 5 is fitted is formed on the side;
A structure of a light receiving section of an optical fiber measuring device, characterized in that a plurality of grooves 10 for passing air from the inner surface of the outer cylinder toward the central opening 8 are provided radially on the side and bottom surfaces 9 of the recess.