JPS61169713A - Inclinometer - Google Patents

Abstract

PURPOSE:To achieve a reduction in the cost with a simplified construction, by using an optical fiber concurrently for an angle of inclination measuring section and a casing suspending member. CONSTITUTION:When a casing 1 suspended with an optical fiber 2 is inserted into a casing pipe B in the ground A to be measured, the casing 1 slides through the casing pipe B parallel therewith with a roller 3 and a suppressing roller 4. Then, at a specified measuring point, a rod body 11 is inclined tilted corresponding to the angle of inclination of the casing pipe B and the component of force from a weight 10 working with the tilting thereof is allowed to act on a curved part 2a of an optical fiber through a projection 13 of the rod body 11 to change the curvature radius of the part 2a. Thus, if a fixed quantity of light is made incident into the optical fiber 2 from a light transmitter C beforehand, the quantity of light received of a light receiver D varies corresponding to changes in the curvature radius of the curved part 2a and the angle of inclination is calculated depending on the quantity of light received.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a nine inclinometer using optical fibers.

(Prior art) 7 (Problems that the invention attempts to solve)
7 Conventionally, inclinometers used to measure the inclination angle of the ground, the framework of a structure, or a mountain retaining wall measure the displacement of a companion weight caused by the angle it makes with the vertical direction, or the displacement of a component force fully differential transformer or The friend is configured to measure with a pressure gauge, but
The problem is that the structure is complex, the cost is high, and it is affected by surrounding conditions such as temperature and electromagnetic force.

(Elaborate means for solving the problem) The present invention proposes a tilted wire using an optical fiber, taking advantage of the fact that the amount of light transmitted through the original fiber changes in response to changes in the radius of curvature of the optical fiber. , which attempts to solve the above-mentioned problems, is a casing inserted into the ground or structure to be measured.
- The lower end St is suspended by the original fiber and faces into the casing of the same optical fiber Z - It is curved in a self-closing curve shape, and a rod with a weight at the lower end is swingably suspended in the casing. , relates to an inclinometer characterized in that it is brought into contact with the curved lower end portion of the original fiber.

(Function) Since the inclinometer according to the present invention is configured as described above, when the casing suspended by the original fiber is inserted and slid into the n9 casing pipe inserted into the ground or structure to be measured, Corresponding to the inclination angle of the casing pipe, a rod suspended from the casing circle and having a weight at its lower end tilts, and presses the lower end curved portion of the optical fiber facing the casing circle, thereby changing the radius of curvature of the same portion. change.

As mentioned above, the amount of light that passes through the optical fiber changes in response to changes in the radius of curvature at the curved portion of the optical fiber. By measuring the slope of the ground, it is possible to measure the inclination angle of the structure.

(Effects of the Invention) As mentioned above, the present invention simplifies the structure by using the optical fiber as both the inclination angle measurement unit and the casing suspension member. Can be reduced.

Furthermore, since the inclinometer according to the present invention is configured to perform measurements using light, it is not affected by temperature or electromagnetic force, and can be used even when the casing/tube is underwater, and there is no need for waterproofing. There is no. Furthermore, it can be used over a wide range of temperatures from -40C to +2000C, and since the original fiber diameter is less than 1cm, it is possible to use Accuracy can be expected, and since the material of the original fiber is silicon, it is highly durable and has a long service life.

(Example) The present invention will be described below with reference to the illustrated embodiments.

(1) is a casing, and the ground to be measured (A) is a casing pipe that has been inserted into the structure in advance) so that it slides and hangs inside the casing pipe (a casing pipe that is evenly arranged). A roller (3) is disposed on one side of the casing (I+) to move the inner wall surface of the casing pipe m. .A restraining roller (4) is provided on the other side of the casing (11) so that it is always parallel to the casing nozzle (Bl).Shoes 151+61 are provided on both sides to prevent horizontal deflection. It is set up.

The original fiber (2) is covered with a cord (7) that penetrates the earthen wall of the casing (1), and the lower end of the optical fiber (12) facing into the casing (1) has a self-closing curved portion (2α
) is composed. In the figure (8) is a rubber gasket, (9
) is an original fiber guide with a slit in the horizontal plate, into which the original fiber is loosely inserted.

Inside the casing (11, a rod α0 having a weight frame at the lower end is swingably suspended via a support shaft a3,
The protrusion α placed at υ is connected to the curved part of the fiber (
2α).

Note that if the angle between the long axis of the rod Ql)fl casing (1) and the vertical direction is α, then the rod is inclined at an angle close to α.

In the figure, α4 is a guide for the rod αυ, and a slit is provided in the horizontal plate, and the rod ([11] is loosely inserted into the slit.

The illustrated embodiment is constructed as described above. [It slides in parallel with the casing pipe (T) by the rollers (3) and the holding rollers (4).

Then, at a required measurement point, the rod (one of which is the casing) is tilted corresponding to the inclination angle of the Rib m, and the component force from the weight α acting due to this inclination is expressed as the component force of the rod (11). The optical fiber acts on this curved portion (2a) through the projection Qlt, thereby changing the radius of curvature of this portion (2α).

Therefore, if a constant amount of light is incident on the optical fiber (2) from the original transmitter (q), the amount of light received by the receiver 0 will change from the curved portion (
2α), and the inclination angle is calculated based on the amount of received light.

According to the above-mentioned embodiment, since it is configured to perform measurements using light, it is not affected by temperature or electromagnetic force, and can be used even when the casing pipe (Bl) is underwater. No need for waterproofing.The exchange temperature is -40C to +2
It can be used over a wide range of 00 C, and the original fiber (
2) Since the diameter is 1111 or less, the weight aα and the rod a
High accuracy can be expected by changing the fulcrum of υ. Furthermore, the material of the original fiber (2) is silicon,
It is highly durable and has a long service life.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

Figure wc1 is a longitudinal sectional front view showing one embodiment of the inclinometer according to the present invention, l! FIG. 2 is a longitudinal sectional side view, FIG. 3 is a lateral plan view, FIG. 4 is a slope view, and FIG. 5 is a longitudinal sectional view showing the state of use. +A)...ground to be measured, (g)...casing no save, (1)...casing, (2;...optical fiber Z, (2α)...curved part of optical fiber,
Q(1...weight, (11)...rod, a
z...Spindle of the rod, (13...protrusion. Agent: Patent attorney, Shige Okamoto, 2 people outside the kiln. 10th, 22nd, 31st, Fig.

Claims (1)

[Claims] A casing that slides inside a casing pipe inserted into the ground or structure to be measured is suspended by an optical fiber, and the lower end of the optical fiber facing into the casing is curved into a self-closing curve. An inclinometer characterized in that a rod having a weight at its lower end is swingably suspended and is brought into contact with a curved lower end of the optical fiber.