JPH0587563A - Method and sensor for detecting strain expansion - Google Patents

Abstract

PURPOSE:To provide a small-sized inexpensive strain sensor developing high accuracy. CONSTITUTION:One elastic substrate 1 is continuously subjected to groove carving processing 4 to parallelly form a first fulcrum A1, a second fulcrum A2 and a first lever 5 and forms a fulcrum, an acting point and a lever in the same way in a continuous state and the displacement quantity of the final end of the lever is detected while strain is expanded by utilizing the principle of the lever. Since a strain expanding mechanism can be constituted only by subjecting one elastic substrate 1 to groove carving processing, a strain sensor can be minimized in the max. magnification and can be inexpensively produced only by groove carving processing. Since there is no assembling part in an expansion mechanism, there is no axiety of an assembling error and followability is well and high accuracy is achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a strain magnification detection sensor for continuously magnifying and detecting micro strains in all fields such as crustal movements, dams, buildings and rocks.

[0002]

2. Description of the Related Art Conventional strain sensors include a. A mechanism for sealing oil silicon in a stainless pipe and detecting a volume change of the oil silicon; b. A detection mechanism is known in which a silicon chamber divided into three parts in a 120 ° direction is formed in a stainless pipe, and oil silicon is sealed in each chamber to detect a three-component strain.

[0003]

However, the above-mentioned known examples have the following drawbacks.

A. Oil silicon is easily affected by temperature changes, and neither a nor b is stable in accuracy.

B. In order to detect the volume change of oil silicon, the amount of oil silicon sealed in the pipe must be increased to some extent. Therefore, the overall shape,
The weight increases, which is inconvenient for handling and installation.

C. Both the known examples a and b are expensive.

The first object of the present invention is to reduce the size and weight of the strain detection sensor, the second object is to achieve high accuracy, and the third object is to be unaffected by temperature. , The fourth purpose is to be able to manufacture inexpensively,
The fifth purpose is to enable detection of continuous distortion.

[0008]

The constitution of the present invention is as follows.

1. A strain magnifying detection method in which the strain is continuously magnified by applying the lever principle, and the sensor detects the magnified displacement of the final end.

2. a. One elastic substrate, b. A first fulcrum and a first action point that are machined side by side by continuously grooving the substrate; c. The first line is aligned with the straight line connecting the first fulcrum and the first action point.
First formed by continuous carving with the fulcrum as the base point
A lever, d. A second fulcrum formed by continuous groove engraving side by side with the first lever on the tip side of the first lever and a second action point where the tip of the first lever is continuous; e. A strain magnifying mechanism formed by continuous grooving in a similar pattern, and f. A strain detection sensor provided with a displacement detection sensor provided to detect the amount of displacement of the end of the final lever.

[0011]

When the strain acts on the first action point, the first lever is displaced about the first fulcrum in the direction in which the strain acts (the direction perpendicular to the plane of the substrate), and this displacement amount is the first lever. Is enlarged at the tip end side, that is, at the second action point, and this enlargement continues successively to reach the final detection end. The displacement amount of the detection end can be taken out as an electrical output by a displacement sensor, for example.

[0012]

EXAMPLE An example is shown in FIGS.

Reference numeral 1 is a substrate made of one elastic material (for example, stainless steel), 2 is a strain acting portion, 3 is a fixing portion of the substrate 1, 4
Is a grooving portion, and by grooving processing, a first fulcrum A ₁ , a first action point B ₁ and a first lever 5 continuous with the strain action portion 2, a second fulcrum A ₂ , a second action point B ₂ , The second lever 6, the third fulcrum A ₃ , the third action point B ₃ , and the third lever 7 are formed in parallel arrangement.

Reference numeral 8 is a detection end attached to the tip of the third lever 7, and reference numeral 9 is a displacement detection sensor. The displacement amount of the detection end 8 is detected as a change amount of the voltage, and the strain amount is measured.

Numeral 10 is a support column 10 for reinforcement in a groove carved to form a first fulcrum A ₁ and a first action point B _1.
It is a reinforcing plate in which a and 10b are fitted.

FIG. 3 and FIG. 4 show three parts in a waterproof cylindrical case 11.
In the embodiment in which the strain detection sensor is incorporated in the step, the position of the strain acting portion 2 (first action point B ₁ ) is 120 as shown in FIGS. 5 (A), 5 (B) and 5 (C). There is a shift by °, and it is devised so that the strain from the 360 ° direction that acts can be detected.

FIG. 6 shows a structure in which the case inner substrate 1a is integrally formed in the waterproof case 11 as an integral structure with the waterproof case 11, and each fulcrum, action point and lever are formed on the case inner substrate 1a in the pattern shown in FIG. In this way, there is no assembly error and high accuracy can be expected. A multi-component detector can be constructed by stacking the in-case substrates 1a in several stages.

[0018]

[Experimental example] In Fig. 7, a borehole with a diameter of 12 cm and a depth of 1 m was drilled in the experimental trench, and the sensor shown in Figs. Shows a part of. As is clear from FIG. 7, the diurnal variation of crustal strain due to the earth tide and ocean tide is clearly shown, and this record also shows that the sensitivity of 10 ⁻⁷ is sufficient.

[0019]

The strain detecting method and strain sensor according to the present invention have the following effects because they have the above-described configurations and operations.

A. By forming each fulcrum and the point of action in parallel, maximum patterning is possible with a minimum area.
As a result, it is possible to reduce the size and weight of the sensor.

B. By arranging each fulcrum, action point and lever side by side, the deformation part (R strut) of the fulcrum and action point that makes a pair is deformed in parallel during action and the error is absorbed by the spring effect, so that the expansion continues smoothly. And practically 36
It is possible to double the size.

C. By selecting a substrate that is not affected by temperature, the effect of temperature can be completely ignored. Therefore, there is a high degree of freedom in installation in dams, buildings, etc., which are easily affected by temperature.

D. Since the sensor can be configured simply by grooving the substrate, the manufacturing is simple and the cost is low.

E. Since it is processed into a single board, there is no concern about assembly error, and there is no back crush for displacement transmission, so high followability and high accuracy can be achieved.

[Brief description of drawings]

FIG. 1 is a perspective view of a strain sensor according to the present invention.

FIG. 2 is a plan view of a strain sensor.

FIG. 3 is an external view showing an example of a case of a strain sensor.

FIG. 4 is a sectional view of the strain sensor shown in FIG.

FIG. 5A is a cross-sectional view taken along the line AA ′.

FIG. 5B is a sectional view taken along line BB ′.

FIG. 5C is a sectional view taken along the line CC ′.

FIG. 6 is a cross-sectional view showing an embodiment in which a case and a sensor are integrally formed.

FIG. 7 is an explanatory diagram of experimental data.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate 2 Working part 3 Fixed part 4 Groove part 5 1st lever 6 2nd lever 7 3rd lever 8 Detection part 9 Displacement detection sensor 10 Reinforcement plate 11 Cylindrical case A ₁ 1st fulcrum A ₂ 2nd fulcrum A ₃ Third fulcrum B ₁ First action point B ₂ Second action point B ₃ Third action point

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideo Sugaya Techno Sugatani Co., Ltd. 2-2-40 Nishishinagawa, Shinagawa-ku, Tokyo

Claims (6)

[Claims] 1. A strain magnifying detection method in which strain is continuously magnified by applying the principle of leverage and a sensor detects the amount of displacement of the magnified final end. 2. a. One elastic substrate, b. A first fulcrum and a first action point that are machined side by side by continuously grooving the substrate; c. The first line is aligned with the straight line connecting the first fulcrum and the first action point.
First formed by continuous carving with the fulcrum as the base point
A lever, d. A second fulcrum formed by continuous groove engraving side by side with the first lever on the tip side of the first lever and a second action point where the tip of the first lever is continuous; e. A strain magnifying mechanism formed by continuous grooving in a similar pattern, and f. And a displacement detection sensor provided to detect the amount of displacement of the tip of the final lever. 3. The strain enlargement according to claim 2, wherein the first fulcrum, the first action point and the first lever are formed on one substrate and the following fulcrum, action point and lever are formed side by side. Detection sensor. 4. The strain according to claim 2, wherein the elastic plate surface integrally formed with the case is grooved to form a fulcrum, a point of action, and a lever continuously in the case. Enlargement detection sensor. 5. The strain magnifying detection sensor according to claim 2, wherein the strain magnifying sensors are installed in multiple stages in the case, and the first action points of the strain magnifying detection sensors are shifted by equal angles. 6. The strain enlargement detection sensor according to claim 2, wherein a reinforcing plate is attached to the first action point.