JPS5831339Y2 - Specific gravity detector for storage batteries - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a specific gravity detector that measures the specific gravity of an electrolyte in a storage battery.

In general, the specific gravity of the electrolyte in a storage battery has a close relationship with the battery condition, and in lead batteries in particular, the remaining capacity can be determined by measuring the specific gravity.

Therefore, various devices have been devised to easily measure specific gravity.

One method is to take note of the fact that the refractive index of the electrolyte changes with changes in the electrolyte concentration, that is, the specific gravity, and use a light emitting part and a light receiving part together to extract changes in the amount of light as an electrical signal.
At present, it has not yet been put into practical use because the change in refractive index is extremely small.

It is thought that the method of detecting changes in the refractive index has an advantage over the method of detecting the buoyancy of the float in that it is completely unaffected by changes in the electrolyte level, fluctuations, etc.

Another advantage is that the specific gravity can be displayed extremely easily by remote control using photoelectric conversion.

The purpose of the present invention is to obtain a hydrometer that has a simple structure and that can easily detect the specific gravity of an electrolytic solution as a change in refractive index.

The gist of the present invention to achieve the above object is as follows.

That is, a light-receiving portion is provided at one end in the axial direction of a cylinder or a prism having parallel surfaces formed of a transparent and uniform substance having a refractive index greater than that of the electrolytic solution, and the light-receiving portion is provided at one end in the axial direction of the cylinder formed of a transparent and uniform substance having a refractive index greater than that of the electrolytic solution. Alternatively, a light emitting element that emits light at a certain solid angle in a direction that is non-parallel to the axis of the prism is provided, and when the refractive index of the electrolyte changes, the light is emitted from the light emitting part, reflected on the side of the cylinder or prism, and received. This is a specific gravity detector that detects changes in the amount of light reaching the area.

Next, a specific gravity detector for a lead-acid battery will be specifically explained using an example shown in the drawings.

FIG. 1 is a diagram explaining the principle of the present invention, and shows a case where light is incident from a substance I having a refractive index n1 to a substance II having a refractive index n2 (nl>n2).

In the case of a ray A, according to the law of reflection and refraction of light, part of it is reflected as A' at a reflection angle equal to the angle of incidence i, and part of it is refracted at a refraction angle γ as A// according to the following formula: .

That is, n, sin i = n 2 sin γ...
(1) When light enters an object with a large refractive index and a small one, the angle of refraction is always greater than the angle of incidence, so if the angle of incidence is gradually increased, the angle of refraction will sometimes reach 90°.

This is the case of ray B, and equation (2) holds true. That is, n1
sinθ=n2Sin90°=n 2−...−(2
) This is a phenomenon called total internal reflection, where θ is called the critical angle, and all light rays with an incident angle greater than θ are reflected.

Incidentally, the refractive index of sulfuric acid at 20° C. is as shown in the following table for each concentration.

Acrylic resin is one of the transparent substances whose refractive index is higher than that of sulfuric acid, and its refractive index is 1.4032 for methyl ester.

If we calculate the intermediate critical angle between the acrylic resin, water and 50%□sulfuric acid from equation l'(2), we find that the angle at the water point is 71.8°,
In 50% sulfuric acid, it becomes 83°8°'.

□ □ ・ ・1 - Figure '2 shows the state of the light beam when the specific gravity detector, which is the second embodiment of the present invention, is placed in dilute sulfuric acid.
・1 1.1 □.

Ru.

・・・ ・ ・ 1゜1 is made of acrylic resin f, = Pl' is a pillar or prismatic pillar, and one end is CdS
Attach a light-receiving element 2'' such as an element or a phototransistor, and attach a lambgo to one end.

The light rays of lamp 3 are within the range of the dashed dot line, and have a shading device (the center of the light is the center of the light, and the optical axis □5. □.

□The optical axis is tilted at 90 degrees with respect to the axis of the lower cylinder or prism, and the light rays emitted from the three lamps are 2. Light receiving element 2
The amount directly incident on □ is suppressed as much as possible.

□ ′□Figure 2 (Touch 7, U・′
If the light rays 6 emitted from the amplifier 3: b and □ are considered as the critical point for one total reflection, all the light rays emitted within the range □ of α+β+δ−90° in the figure enter the light-receiving element 2.

A ray incident on the interface □ at an angle of incidence greater than the critical angle is 1. As shown by the broken line in the figure, the ray of light in the optical axis direction of the 7Si, which travels by manipulating reflection and refraction, gradually attenuates as a part of the □ is refracted at the interface.

Since the ray 5'1 opposes 7 times at the interface, the reflectance can be expressed as K(〈
1), then when the light-receiving element -1-□2 is reached, the lamp 3゛1 emits from: h'# = the strength at the time 1 and 7
As a result, the number of dormitories will be reduced, and the light receiving element 2 will not actually detect it.

Figure 3 shows the situation of Batani's ray placed in concentrated sulfuric acid 11□ζ
Indicates J.

When the sulfuric acid concentration increases and the refractive index increases, the critical angle also increases according to equation (2).

If the light ray 7 is considered to be the critical point for total internal reflection, all the light rays that come out within the range of α10β+δ90° in Fig. 3' are rays α'〈α□ that are incident on the light-receiving element 2, so compared to the light sulfuric acid, In concentrated sulfuric acid, the amount of light incident on the light receiving element 2 is small.

Furthermore, as in dilute sulfuric acid, light rays with an incident angle greater than the critical angle are attenuated.

Above, as described in the example, the length of the prism is 40 m/
m, β=45°, δ==40°, light receiving element 2D,
: When we conducted an experiment using a CdS element by passing a small constant current and increasing the sulfuric acid concentration, we found that the voltage generated in CdS was 0.5 to 0.5 in the case of water. Specific gravity 1.4, 1.3□ with sulfuric acid
V was obtained, and the voltage value also changed in accordance with the change in specific gravity.

Although the embodiment has been described using six light elements and a general small lamp, it is also possible to use a light emitting diode: L'.

□・The present invention can obtain the following effects with the structure described above.

That is, compared to the conventional specific gravity: measurement element, the fluctuation of the electrolyte,
Specific gravity can be measured extremely easily without being affected by changes in liquid level.

□・

[Brief explanation of the drawing]

Fig. 1 shows the principle of the present invention, and Fig. 2' shows an embodiment of the invention, and also shows the state of the light beam when immersed in a dilute electrolyte. Same: Shows the case of being immersed in a thick electrolyte. ・ □1... Acrylic resin cylinder or/prismatic column, 2 =... Light receiving element, 3... lamp,
4... Light shield.

Claims (1)

[Scope of utility model registration request] A light-receiving element is provided at one end in the axial direction of a cylinder or a prism with parallel surfaces formed of a transparent and uniform substance having a refractive index larger than that of the electrolyte of the storage battery, and a light-receiving element is provided at one end in the opposite direction. in a direction that is non-parallel to the axis of the cylinder or prism,
A specific gravity detector for storage batteries equipped with a light emitting element that emits light at a certain solid angle.