JP2604914Y2 - Optical fiber level gauge - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber liquid level gauge, and more particularly, to a liquid level detecting surface of an optical fiber which is provided with a member exhibiting a capillary phenomenon and has a large surface tension such as water. The present invention relates to an optical fiber liquid level gauge that removes liquid that is likely to adhere and remains to facilitate detection of the liquid level.

[0002]

2. Description of the Related Art A conventional example will be described with reference to FIG. FIG.
FIG. 3 is a cross-sectional view illustrating a configuration of a liquid level detecting unit of the optical fiber liquid level gauge. In this optical fiber level gauge, an optical fiber 1 is passed through a small-diameter pipe 2, further placed in a detection unit holder 3 and adhered and fixed to each other. The end of the optical fiber 1 is referred to as a liquid level detector 7. A semi-cylindrical drainage sleeve 4 is joined to the outside of the detection unit holder 3.

[0003] The optical fiber level gauge is attached to an upper part of a liquid tank, for example, from a lid of the liquid tank so as to hang down into the liquid tank. When the liquid level in the liquid tank rises and the liquid level detector 7 is immersed in the liquid,
The light that reaches the liquid level detection unit 7 via the optical fiber 1 passes straight through the liquid. On the other hand, when the liquid level in the liquid tank is lowered and the liquid level detecting section 7 is exposed from the liquid level and exists in the air, the light reaching the liquid level detecting section 7 via the optical fiber 1. Is reflected here and goes backwards through the optical fiber 1. Therefore, it is determined whether or not the liquid level has reached the liquid level detection unit 7 based on whether the light that has reached the liquid level detection unit 7 via the optical fiber 1 is reflected or transmitted here. be able to.

Here, in the above-mentioned optical fiber liquid level gauge, when the liquid level falls and the liquid level detecting section 7 is exposed to the air, the liquid remaining on the liquid level detecting section 7 is only gravity. By 4
It was removed down the surface of the liquid level detecting portion 7 polished to 5 ° and further flowing down the liquid draining sleeve 4.

[0005]

The optical fiber liquid level meter as described above has a problem that the liquid level in the liquid tank is lowered and the liquid level detector 7
When the liquid is exposed to the air, the liquid adhering to the liquid level detection unit 7 is removed only by gravity, so that the liquid having a large surface tension, such as water, aggregates in the liquid level detection unit 7 in a polka dot shape. May remain. When the water droplets aggregated in a polka dot form adhere to the tip of the optical fiber 1 in the liquid level detecting section 7, the liquid drops are immersed in the liquid even though the liquid level detecting section 7 is exposed to the air. May be mistakenly determined to be

This invention provides an optical fiber level gauge that does not malfunction as described above.

[0007]

An optical fiber level gauge is provided which is provided with a liquid cutout block 5 having a suction groove 6 exhibiting a capillary phenomenon in the vicinity of a liquid level detecting section 7 of the optical fiber 1.

[0008]

An embodiment of the present invention will be described with reference to FIG. FIG. 1 is a view for explaining the optical fiber level gauge according to the present invention. The optical fiber level gauge according to the present invention also passes the optical fiber 1 through the small-diameter pipe 2 and further enters the detection unit holder 3 and adheres to each other. The optical fiber 1 is fixed and polished at an angle of 45 ° with respect to the longitudinal direction of the optical fiber 1, and the end of the optical fiber 1 is used as the liquid level detecting unit 7. The semi-cylindrical liquid draining sleeve 4 is joined to the outside of the detection unit holder 3 in the same manner as in the conventional example.

Here, referring to FIG. 1B, reference numeral 5 denotes a liquid drain block provided by the present invention. With regard to the shape and structure of the liquid drain block 5, it has a semi-cylindrical outer shape obtained by cutting a cylinder in the longitudinal direction. The tip of the semi-cylindrical liquid drain block 5 is cut at 45 ° in the longitudinal direction. Reference numeral 6 denotes a suction groove formed on the surface of the liquid drain block 5, and its width is extremely narrow enough to exhibit a capillary phenomenon. A large number of the suction grooves 6 are formed in parallel with each other over a cut surface cut at 45 ° and a curved surface continuous with the cut surface.

The liquid drain block 5 is arranged such that a part of the uppermost end of the cut surface cut at 45 ° is located near the liquid level detecting portion 7 of the optical fiber 1 and the suction groove 6 forming surface is formed as described above. 4
5 ゜ Join the lower half of the polished surface and the inner surface of the semi-cylindrical drainage sleeve 4. Here, when the liquid level in the liquid tank is lowered and the liquid level detecting section 7 is exposed to the air, the liquid having a large surface tension such as water adhering in the vicinity of the liquid level detecting section 7 is large. The portion falls at a stretch along the flat surface of the liquid drain block 5 and is removed, but the portion tends to aggregate and remain in the form of a polka dot near the liquid level detection unit 7. However, in the liquid drain block 5, as described above, a large number of suction grooves 6 are formed continuously and in parallel with each other over a cut surface cut at 45 ° and a curved surface continuous with the cut surface. Suction groove 6
When the upper end of the liquid hangs down from the vicinity of the liquid level detection unit 7, even if the liquid tries to aggregate and remain in the shape of a polka dot near the liquid level detection unit 7, it is sucked by the suction groove 6 by the capillary phenomenon, and eventually , Cannot aggregate and remain.

[0011]

As described above, according to the present invention, the surface tension which tends to remain in the form of a polka dot in the liquid level detector 7 at the tip of the optical fiber 1 of the optical fiber liquid level gauge and in the vicinity thereof. Of the liquid having a large volume to the suction groove 6 exhibiting the capillary phenomenon
By providing the out-of-liquid block 5 having the above in the vicinity of the tip of the optical fiber 1, it can be positively removed. Therefore, the optical fiber liquid level gauge of the present invention does not malfunction to judge that the liquid level detecting section 7 is immersed in the liquid even though the liquid level detecting section 7 is exposed to the air.

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams illustrating an embodiment, in which FIG. 1A is a cross-section passing through a central axis of an optical fiber liquid level meter, and FIG.

FIG. 2 illustrates a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Small diameter pipe 3 Detector holder 4 Liquid out sleeve 5 Liquid out block 6 Suction groove 7 Liquid level detector

Claims (1)

(57) [Scope of request for utility model registration] 1. An optical fiber level gauge, comprising: a liquid cutout block having a suction groove exhibiting a capillary phenomenon near a liquid level detecting portion of an optical fiber.