JPH0446173Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Purpose of the invention] (Field of industrial application) This invention is intended for measuring the vertical inclination of general measuring instruments, industrial machinery, building structures, etc. This invention relates to improvements in tilt sensors used to measure tilt.

(Prior art) Bubble level is widely used as an inclination sensor used in architecture, construction equipment, and general industrial machinery, and various detection methods that apply its principle include electromagnetic detection and photoelectric detection. The method used has been adopted. The general structure of this bubble tube type level is that two types of fluids, namely a first fluid and a second fluid, are sealed in a container, as shown in Figure 2a. A mixed liquid 1 of alcohol and ether as a first fluid is placed in a glass container 11 whose upper inner wall surface forms an arc shape with a radius R.
It is constructed by enclosing 3.

When the glass container 11 is tilted by .theta. as shown in FIG. 2b, the bubbles 12 inside the container move by .delta.. At this time, since there is a relationship of δ=R×θ, the inclination angle θ to be measured can be detected by reading δ with the naked eye.

(Problem to be solved by the invention) The bubble level described above works correctly according to the above logic when the temperature inside and outside the container is stable, but when the ambient temperature of the container changes, it actually Due to the non-uniform temperature distribution inside the container, a mechanical imbalance occurs and the bubbles become agitated, making reading difficult. This is because, as mentioned above, when the ambient temperature of the container changes, the temperature inside the container tends to become uneven, and a temperature gradient occurs, which causes the bubbles to lose their smooth movement and stay in an oscillating state forever. It is presumed that this is due to instability. As a result, the detected value was unstable for a considerable period of time, causing detection errors and making rapid measurement difficult. On the other hand, in order to increase the detection sensitivity, the radius of curvature of the inner surface of the container is increased, increasing the fluidity of the sealed liquid and improving the response to changes in the container's inclination. When used attached to a mechanical device, there were problems such as the time required to detect the degree of inclination. Inclination sensors that use electrical reading methods incorporate a temperature compensation circuit into the electrical circuit to reduce errors in measured values, but this has no effect on the mechanical disturbances caused by heat. Nakatsuta.

[Configuration of the invention] (Means for solving the problem, action) In order to solve the above-mentioned drawbacks, this invention provides an inclinometer that can perform measurement operations quickly and with high accuracy without being affected by changes in the ambient temperature of the inclinometer.The surface of the container that constitutes the sensor is covered with a thin plate of good thermal conductivity, or is plated with good thermal conductivity metal, or the container itself is made of good thermal conductivity, thereby making the temperature distribution in the container and its interior uniform and preventing temperature gradients.

(Example) An example of this invention will be described below with reference to the drawings.

The tilt sensor in FIG. 1 adopts an electromagnetic detection method, and as shown in the figure, a curved surface having a radius of curvature R is formed on the upper part of the inner wall surface of a tubular container 1 made of glass. Air bubbles 2, which are a second fluid, are sealed inside the tubular container 1, and the space other than the air bubbles 2 is filled with a magnetic fluid 3, which is a first fluid. A thin copper plate 4, which is a good thermal conductor, is provided on the outer peripheral wall surface of the tubular container 1 made of glass. This thin copper plate 4
is a glass tubular container 1 with a thickness of 0.2 mm.
This layer forms a layer that improves heat conduction by being wrapped in a single layer.As shown in the drawing, this layer has a divided structure using two thin copper plates 4. This suppresses the generation of eddy currents due to the electromagnetic action of the magnetic fluid 3. It is for. A differential transformer coil 5 is wound around a glass tubular container 1 and a copper thin plate 4 provided on its outer peripheral wall surface to constitute a tilt sensor for detection.

When the tilt sensor configured as described above is used outdoors and the ambient temperature of the tilt sensor changes due to the influence of the environment such as direct rays of the sun or wind, the sensor is installed on the outer peripheral wall of the glass tubular container 1. The thin copper plate 4, which is a good thermal conductor, quickly adapts to the ambient temperature and conducts the heat to the glass tubular container 1, making the container equal to the ambient temperature and also making the temperature inside the container uniform. As a result, no temperature gradient occurs inside the container, so the bubbles move smoothly, and the oscillating state ends in a short period of time, so that the bubbles become stable.

In addition, in the present invention, as shown in FIG. 3, a copper thin plate 4, which is a good heat conductor, is provided on the outer peripheral wall of the glass tubular container 1, and a copper thin plate 4, such as that seen in a molded semiconductor heat sink, is used. By providing the fins 4' made of the same material, it is possible to quickly adapt the glass tubular container 1 to the ambient temperature. As a result, even if a temperature gradient occurs inside the container, the oscillating state of the bubbles becomes stable in a short time.

[Effects of the invention] As explained above, the inclination sensor of this invention allows for good heat conduction even when the ambient temperature of the container changes due to the thermal conductor covered with the container or the container itself made of a thermally good conductor. Since the thermal response speed is improved, it is possible to quickly equalize the temperature distribution of the fluid inside the container, so it is possible to quickly equalize the temperature distribution of the fluid inside the container. The detected value does not become unstable for a considerable period of time due to oscillation.

Therefore, it has a practical effect of ensuring the stability of the sensor even against thermodynamic disturbances that could not be resolved by conventional means of providing a temperature compensation circuit in an electric circuit.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing an embodiment of the inclination sensor according to this invention, and FIG. 2 is a schematic cross-sectional view illustrating the structure and operating principle of a bubble level. FIG. 3 is a schematic sectional view showing another embodiment of the present invention. 1... Glass tubular container, 2... Air bubbles, 3...
...Magnetic fluid, 4... Copper thin plate, 4'... Fin, 5
...Differential transformer coil.

Claims (1)

[Claims for Utility Model Registration] 1. A container whose upper inner surface has an arcuate cross-section is partially filled with a first fluid so that a second fluid can be enclosed therein, and a second fluid is enclosed in the part. A tilt sensor comprising: a container whose upper inner surface has an arcuate cross section; the surface of the container is covered with a thermally conductive material; or the container itself is made of a thermally conductive material. 2. The inclination sensor according to claim 1 of the registered utility model, wherein a heat dissipation fin is provided around a heat conductor covering the container or a heat conductor constituting the container.