JPS6344191B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solution concentration detection device that detects the concentration of a solution by measuring the amount of light reflected from the solution. The present invention relates to a solution concentration detection device that allows accurate measurement values to be obtained.

Conventionally, as shown in FIG. 1, a conventional solution concentration detection device of this type has a device 3 built into the back side of a cap 2 of a battery 1 to measure the solution concentration of battery fluid 4. What I was detecting was hot.

The measurement principle of this solution concentration detection device 3 is as shown in FIG. A detection light guide 5 is immersed in a battery liquid 4 of a predetermined concentration, and light from a light emitting element 7 disposed at one end of the detection light guide 5 is guided into the detection light guide 5 and its inspection surface 6 is immersed. Based on the relationship between the refractive index of the detection light guide 5 itself and the refractive index depending on the concentration of the battery liquid 4, it is separated into transmitted light and reflected light at the inspection surface 6, and only the reflected light is further used for detection. The light is guided to a light receiving element 8 such as a photoelectric conversion element disposed at the other end of the light guide 5, and the concentration of the solution is detected based on the amount of light received by the light receiving element 8.

The reason why the light from the light emitting element 7 is separated into transmitted light and reflected light on the inspection surface 6 is because the incident angle of the incident light is different at each curved point on the inspection surface 6. , due to the difference in refractive index between the detection light guide 5 and the solution concentration, for example, as shown by ray A and ray B in Fig. 2, the portion of the transmitted light and the portion of the reflected light differ depending on the size of the incident angle. By being separated into parts. Therefore, as the refractive index of the solution changes as the solution concentration changes, the critical angle of reflection also changes gradually, which changes the amount of reflected light guided to the light receiving element 8, which is converted into voltage. If the solution concentration is below the standard value, check the battery fluid 4.
It becomes possible to replenish or replace as appropriate.

However, in such a conventional solution concentration detection device, since the inspection surface 6 of the detection light guide 5 is constantly immersed in the solution, the solute in the solution is deposited on the inspection surface 6 over time. Even the precipitated light that should originally be transmitted collides with the precipitate and is detected as reflected light, making it difficult to obtain an accurate amount of reflected light and accurately grasp the solution concentration.

The present invention has been made based on the above-mentioned conventional viewpoint, and provides a solution in which a measured value of solution concentration can be obtained accurately by providing a correction means for detecting dirt attached to a detection light guide. The object of the present invention is to provide a concentration detection device.

That is, a feature of the present invention is that a correction light guide having a correction inspection surface at its lower end that is substantially perpendicular to the axial direction is immersed in a solution near the detection light guide, and a correction light guide is provided at the upper end of the correction light guide. A light-emitting element for correction and a light-receiving element for correction are provided in close proximity, and dirt on the surface of the light guide for detection is measured based on the amount of light received by the light-receiving element for correction,
It is possible to correct the measured value of the amount of reflected light from the detection light guide.

The present invention will be described in detail below based on embodiments shown in the accompanying drawings.

FIG. 3 shows an embodiment of the solution concentration detection device according to the present invention, and this solution concentration detection device is immersed in a solution 4 having a predetermined concentration and has a partially curved shape, as in the conventional case. A linear detection light guide 5 having an inspection surface 6, a detection light emitting element 7 disposed at one end of the detection light guide 5, and a detection light emitting element 7 disposed at the other end of the detection light guide 5. It has a detection light receiving element 8, but unlike the conventional one, a correction test is provided near the detection light guide 5, which is immersed in the same solution 4 as the detection light guide 5, and is substantially orthogonal to the axial direction at the lower end. A linear correction light guide 9 having a surface 10 and a correction light emitting element 1 disposed close to the upper end of the correction light guide 9.
1 and a correction light receiving element 12.

The correction light guide 9 is made of the same fibrous glass material as the detection light guide 5 and is constructed in a straight line, and its lower end surface can transmit all the light incident orthogonally from the correction light emitting element 11. It is formed as a flat correction inspection surface 10 like this. Note that this correction light guide 9 has a correction inspection surface 10 that is similar to the detection light guide 5.
It is desirable that the test surface 6 is immersed so that the height is approximately the same as that of the inspection surface 6.

The correction light emitting element 11 is of the same type as the detection light emitting element 7, and is, for example, a light emitting diode, a very small lamp, etc. arranged at the upper end of the correction light guide 9 so as to face downward. The correction light emitting element 11 can also be used as the detection light emitting element 7 by arranging the correction light guide 9 close to the detection light guide 5.

On the other hand, the correction light-receiving element 12 is also of the same type as the detection light-receiving element 8, and for example, a photoelectric conversion element such as a photodiode or a phototransistor is arranged with its light-receiving surface facing the correction light guide 9. be done.

Therefore, the light from the correction light emitting element 11 is guided along the axial direction of the correction light guide 9 and enters the correction inspection surface 10 perpendicularly, but the inspection surface 10 is free from dirt. When the light is not detected, the light passes through the solution 4 as it is, as shown by the symbol C in FIG.
However, if the solute in the solution precipitates and adheres to the correction inspection surface 10 of the correction light guide 9, the light collides with the deposit and is reflected, as shown by the symbol D in FIG. Then, the reflected light travels backward again along the axial direction of the correction light guide 9 and reaches the correction light receiving element 12 . This reflected light increases or decreases depending on the amount of precipitates attached to the correction inspection surface 10 of the correction light guide 9,
When the amount of precipitates is large, the amount of reflected light increases accordingly, and the amount of light received by the correction light receiving element 12 also increases, which can be detected as an increase in the measurement voltage. And the correction inspection surface 1 of this correction light guide 9
Since precipitates adhere to the detection light guide 5 at approximately the same rate as the inspection surface 6 of the detection light guide 5, by measuring the dirt on the correction inspection surface 10 of the correction light guide 9, the detection The degree of contamination of the light guide 5 can be known. Therefore, the concentration measurement value at the detection light-receiving element 8 can be corrected by the correction amount set in advance according to the measurement value at the correction light-receiving element 12, and an accurate solution concentration value can be obtained. Furthermore, when the measured voltage value of the correction light-receiving element 12 exceeds a permissible value, the detection light guide 5 can be taken out of the solution 4 and precipitates attached to the surface can be cleaned off.

In the above embodiment, the correction inspection surface 10 of the correction light guide 9 is formed into a substantially flat shape. Even in this case, the light from the correction light emitting element 11 enters the inspection surface 10 of the correction light guide 9 substantially orthogonally.

FIG. 4 shows another embodiment of the present invention, in which the detection light guide and the correction light guide in the previous embodiment are integrally formed. That is, in this embodiment, a linear correction light guide part 14 is made to protrude from one side of a substantially U-shaped detection light guide part 13, and the lower end surface of this correction light guide part 14 is oriented in the axial direction. The correction inspection plane 10 is substantially perpendicular to the plane. Further, in this embodiment, a single light emitting element 15 is used as a detection light source and a correction light source, and a correction light receiving element 12 is provided near this light emitting element 15.
However, a detection light receiving element 8 is provided at the other end of the detection light guide section 13, respectively. Therefore, the light emitting element 15
The light passes through the inspection surface 6 of the detection light guide section 13 and the correction inspection surface 1 of the correction light guide section 14.
0 at the same time, and is separated into transmitted light indicated by symbol A and reflected light indicated by symbol B on the inspection surface 6 of the detection light guide section 13, and this reflected light is reflected by the detection light receiving element 8. light is received. On the other hand, the light incident on the correction inspection surface 10
If the solute in solution 4 is not precipitated in , the light travels straight as a transmitted light as shown by the symbol C,
In addition, if precipitates are present, the light travels backward as reflected light as shown by the symbol D according to the amount of the precipitates, is received by the correction light receiving element 12, and is reflected on the correction inspection surface 10. It is possible to detect the degree of contamination of the detection inspection surface 6 to which precipitates adhere to approximately the same extent as . Since the solution concentration detection device according to this embodiment has a concentration detection portion and a correction portion integrally formed,
In addition to being easy to handle, the present invention has the advantage that a single light-emitting element can be used for both detection and correction purposes.

In addition, in each of the above embodiments, the detection light guide 5
Although it is formed in a substantially U-shape, it is not necessarily limited to this, and the design may be changed as appropriate as long as it has at least a curved inspection surface 6.

As explained above, according to the solution concentration detection device according to the present invention, since a correction means is provided that can detect dirt attached to the detection light guide and correct the measured value of the solution concentration, accurate solution concentration values can be obtained. This makes it possible to accurately know when to replace or replenish the solution.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory diagram of a battery showing a case where the solution concentration detecting device is used for a battery, Fig. 2 is an explanatory diagram of the measurement principle showing an example of a conventional solution concentration detecting device, and Fig. 3 is an explanatory diagram of a battery according to the present invention. FIG. 4 is an explanatory diagram of the measurement principle showing one embodiment of the concentration detection device. FIG. 4 is an explanatory diagram of the measurement principle showing another embodiment of the present invention. 5... Light guide for detection, 6... Inspection surface, 7... Light emitting element for detection, 8... Light receiving element for detection, 9... Light guide for correction, 10... Inspection surface for correction, 11... Correction 12... Light receiving element for correction.

Claims (1)

[Claims] 1. A linear detection light guide that is immersed in a solution of a predetermined concentration and has a curved inspection surface in part, a light emitting element disposed at one end of this detection light guide, and the above detection light guide. and a light receiving element disposed at the other end, the light from the light emitting element is separated into transmitted light and reflected light at the curved part of the detection light guide, and the reflected light is guided to the light receiving element. In a solution concentration detection device that detects solution concentration based on the amount of light received, a correction inspection surface is provided near the detection light guide, which is immersed in the same solution as above, and whose lower end is substantially orthogonal to the axial direction. A solution concentration detection device is provided with a linear correction light guide, and is capable of detecting the degree of contamination of the test surface based on the reflectance of light on the correction test surface.