JPS60252215A - Inclinometer of photoelectric bubble tube type - Google Patents

Abstract

PURPOSE:To measure inclinations of two orthogonal components simultaneously with a high sensitivity in a small-sized constitution by putting a bubble in a glass cylinder and irradiating a parallel luminous flux to the bubble and detecting a shadow due to the bubble by a photoelectric element. CONSTITUTION:A parallel transparent glass 4 is provided in one end of a glass cylinder 2, and a concave disc 3 is provided in the other end, and an alcohol is filled up in the cylinder 2, and a bubble 5 is put in the cylinder 2. The parallel luminous flux is made incident on the cylinder 2 from a light source 9 through a convex lens 8 to irradiate the bubble 5. Then, the illuminance is lower than a half of the illuminance of the external because the bubble 5 has the function of a convex lens, and the shadow is vivid because the light is to totally reflected on the side face of the bubble in the outside edge part of the bubble 5. The light emitted from the cylinder 2 is received by a photoelectric element 10 to detect the image of the bubble 5, and the inclination is measured in accordance with positions in X-axis and Y-axis directions. Consequently, the inclination is detected with a high sensitivity because the parallel luminous flux is irradiated to the bubble to form a vivid bubble image.

Description

[Detailed Description of the Invention] Conventional electric inclinometers mainly use a pendulum and detect the rotation angle or displacement of the pendulum caused by the inclination of the main body using a potentiometer or a differential lance. Inclinometers are not only large but also expensive, making it difficult to increase sensitivity or strengthen seismic resistance.

In addition, the bubble tube type inclinometer converts the position of the bubble into an electrical signal by changing the internal liquid to an electrolytic liquid and installing a special electrode in the liquid, which prevents bubble movement and increases sensitivity and improves linearity. It was difficult to maintain, and had the disadvantage of particularly poor hot water temperature characteristics.

The photoelectric bubble tube type inclinometer of the present invention completely eliminates the above-mentioned drawbacks, maintains the characteristics of the conventional bubble tube, and is a small, inexpensive, highly sensitive, revolutionary inclinometer that can simultaneously obtain two orthogonal two-component inclinometers. This is what we provide.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a sectional view showing the optical structure of the photoelectric bubble tube type inclinometer according to the present invention, which is composed of a bubble tube main body 1, an illumination optical system 8.9, and a photoelectric detection element 10. The vial body 1 has a glass cylinder 2 whose upper and lower ends are cut parallel to each other, with a small hole 7 made by hot melting using a burner etc. on the side surface, and the -1- surface is polished into a concave spherical surface 3' with a specified curvature. A circular concave plate 3 with a parallel plane transparent glass 4 attached to the lower surface and a transparent liquid 6 such as alcohol or ether sealed through a small hole 7 on the side with a small bubble 5 left behind. It is a bubble tube.

If you want the sensitivity of 1' Aiki and 12 to be 12 mm, the radius of curvature of the four spheres should be 6000 mm, and 1.94 m.
If m and J2, then 60077! /' Nizuwaba J2i.

At the bottom of the circular bubble tube, a convex lens 8 with an effective diameter of approximately equal to [7℃] is placed coaxially with the bubble tube, and if a light emitting source 9 such as a light emitting diode or an incandescent bulb is placed at its focal position 1. The passed light flux illuminates the bubble tube as a parallel light flux. The light that irradiates the outside of the bubble from the diameter 2r becomes a parallel beam of light that does not pass through the 10th section (a), but the light that irradiates the bubble part diverges due to the concave lens action of the bubble.

At this time, if the radius of the bubble is r, the virtual image focus f is f = −□ = −□ = 2r n-11,5-1 However, I] is the refractive index of the liquid and is generally n:], 5.

The diameter d of the light beam (when irradiating the bubble) is d' - 0,66 f@-r 3r Therefore, the illuminance S' outside the bubble is s' = (0,66)22044. The illuminance is less than half of that outside, 2r and d.
In the area where the diameter of the bubble differs, the light is totally reflected on the sides of the bubble, so the shadow of the bubble becomes extremely clear.

Therefore, the photoheavy element 1 is divided into four parts, facing the upper surface of the concave disk 3.
If 0 is set, a clear bubble image with the aforementioned 44% contrast difference can be obtained as shown in FIG.

The output of the 4-split photoelectric element is obtained by extracting the output difference between the outputs of (a + b) and (c + d) using a differential intensifier, and then the output difference in the left and right direction is obtained, and the output difference between (a + c) and (b + d) is obtained. If taken out, an inclination output in the front and back direction will be obtained, and these two outputs will be output and displayed alternately by a switching circuit, making it possible to detect the inclination angle of two orthogonal components.

As explained above, in the photoelectric bubble tube type inclinometer of the present invention, the bubble tube body as a whole constitutes a parallel optical element and is irradiated by the illumination system as a parallel light beam, so that a clear bubble image can be created on the surface of the photoelectric element. As a result, a high-resolution signal with a low noise ratio can be obtained from the photoelectric output.

In addition, since alcohol or ether, which has been proven in the past, is used as the internal liquid of the bubble tube and no electrodes are placed in the liquid, not only can linear output be obtained, but hysteresis can be completely eliminated by increasing the polishing roughness of the concave spherical surface. Can be removed.

Furthermore, by selecting the radius of curvature of the concave spherical surface, an inclinometer with arbitrary sensitivity can be made without changing the size, and by selecting the viscosity of the liquid, appropriate damping can be obtained even for dynamic purposes.

Furthermore, as mentioned above, the photoelectric bubble tube type inclinometer of the present invention has many features such as being ultra-compact, inexpensive, and having excellent seismic resistance and temperature characteristics, regardless of its sensitivity.

[Brief explanation of the drawing]

FIG. 1 is an optical cross-sectional view of the photoelectric bubble tube type inclinometer of the present invention, and FIG. 2 is a schematic diagram showing a four-part photoelectric element and a bubble image. Explanation of symbols 1...Bubble tube body, 2...Glass cylinder, 3...Concave disk, 3'...Concave spherical surface, 4...Parallel plane transparent glass, 5...Bubble, 6... ...Transparent liquid, 7...Small pore, 8
...Convex lens, 9...Light source, 10...4-segment photoelectric element, F...Patent applicant Sanro Sugawara

Claims (1)

[Claims] A glass cylinder whose upper and lower ends are cut in parallel t7 has a 3' inner surface on the upper surface, a concave glass 4L polished to a curvature of 4, and a parallel flat transparent glass ↓ on the lower surface. A convex lens + is placed at the concentric lower part of the adhesive tube, and a light source of a light emitting diode or an incandescent bulb is placed at a focal position 1" below the convex lens,
Hikariichi's bubble tube features a 4-split photoelectric conversion element coaxially mounted on the top surface of the bubble tube in contact with a concave spherical glass plate, and the bubble position can be photoelectrically detected in the X and Y directions to measure the inclination angle. Type tilt gauge.