JP6585512B2 - Displacement detector and displacement detection method - Google Patents

Description

  The present invention relates to a displacement detector and a displacement detection method, for example, a displacement detector suitable for measuring displacement generated in a metal frame, a pressure vessel, a concrete structure, a reinforced concrete structure, and the like. Regarding the method. Note that “displacement” may be referred to as “strain” or “distortion” or may be described together. The terms “distortion” and “distortion” include distortion as a phenomenon and distortion as a physical quantity, and when the distortion is clearly indicated, it is described as “distortion”.

  Conventionally, there is a displacement detection device described in Patent Document 1 as a displacement detection device for measuring mechanical strain and displacement of a building or structure, and a structure described in Patent Document 2 as a device for evaluating fatigue damage of a structure. There is a device for evaluating fatigue damage of objects. Generally, such a building or structure is constructed so that its main stress is supported by a structure made of steel.

  Mild steel (SS400, etc.) is mainly used for construction, and its tensile strength is 426 Pa, with a safety factor of 3 (140 MPa) for a long-term static load, and a safety factor of 5 (85 MPa) for a single swing repeated load. Designed. Moreover, the yield point (proof stress) of mild steel is 245 MPa.

  Since the Young's modulus of mild steel is about 200 GPa, the amount of elastic deformation strain at each stress is 0.07%, 0.04%, and 0.12%. If it can be detected, it is effective in evaluating the degree of damage to the structure. However, since the amount of distortion is very small, an advanced and complicated measuring device as described below is necessary for detection.

  The displacement detection device described in Patent Document 1 is attached to a structural member such as a building or a structure, and a lever mechanism that scales distortion and displacement generated in the structural member, and a displacement that is enlarged or reduced by the lever mechanism. It consists of a displacement detector that detects the quantity.

  The fatigue damage evaluation apparatus described in Patent Document 2 includes a deformation amount detection unit that detects a deformation amount of the evaluation target structure, and a fatigue damage rate of the evaluation target structure according to the deformation amount detected by the deformation amount detection unit. Fatigue damage rate detection means for detecting, and fatigue damage rate integration means for integrating the fatigue damage rates detected by the fatigue damage rate detection means.

JP 2000-065508 A JP 2002-014014 A

  The displacement detector of the displacement detection device described in Patent Document 1 is necessary, and since switches such as microswitches are used as the displacement detector, wiring to a power source and various sensors is necessary, such as detection work. Is troublesome.

  Since the deformation amount detection means of the fatigue damage evaluation apparatus described in Patent Document 2 only requires a mechanical structure, it does not require a power source or wiring, but is composed of a first fixed plate, a second fixed plate, a movable rod, and a rotating shaft. Therefore, the structure is complicated.

  The present invention has been made in consideration of such problems, and is an advanced, complicated and inexpensive apparatus that does not require an expensive power source or electrical wiring and that is free from displacement generated in an inspected object such as a structure. Another object of the present invention is to provide a displacement detector and a displacement detection method that can be confirmed visually.

  Another object of the present invention is to provide a displacement detector and a displacement detection method capable of easily detecting the occurrence of displacement due to a load exceeding the allowable stress on the object to be inspected and the direction of the generated displacement. .

[1] A displacement detector according to the first aspect of the present invention includes a ceramic thin disc, an annular frame portion having an outer diameter equal to or greater than an outer diameter of the ceramic thin disc, and the annular frame. A disk-shaped thin substrate having an outer diameter equal to or greater than the outer diameter of the portion, the disk-shaped thin substrate, the annular frame portion and the ceramic thin disk are coaxial, and It is characterized by being laminated and integrated in the thickness direction in this order.

  There are ceramics and glass materials that can break in the elastic deformation range above the specified strain without plastic deformation, but in the case of glass materials, microcracks develop due to the influence of moisture in the atmosphere and the strength deteriorates. Therefore, in order to detect the displacement of the object to be inspected over a long period of time, a ceramic material having excellent durability is desirable. The ceramic used here is preferably destroyed with a displacement (amount of strain) equal to or greater than a displacement (amount of strain) corresponding to the allowable stress of the inspection object.

[2] In the first aspect of the present invention, it is preferable that the annular frame portion and the disk-shaped thin substrate are integrally formed. The ratio (σ / E) of the strength (σ: MPa) and Young's modulus (E: GPa) of the thin ceramic disk is preferably 0.04% or more. More preferably, it is 0.1% or more, Most preferably, it is 0.3% or more.

  Furthermore, when the structure or building that is the object to be inspected is used under a certain temperature condition, there is no need to consider the thermal expansion coefficient of the structure or building, but the building or structure installed outdoors. Then, a temperature change accompanying a change in temperature occurs during the measurement period. In such a case, in order to reduce the influence of temperature change, the difference in thermal expansion coefficient with the building or structure constituting the object to be inspected is ± 2 ppm / K or less, more preferably ± 1 ppm / K or less. It is desirable to be. By selecting such a ceramic material, it becomes possible to detect displacement over a long period of time in a building or structure installed outdoors without being affected by temperature changes. For example, if the object to be inspected is steel or reinforced concrete, if the material of the ceramic thin disk is selected from zirconia, forsterite, etc. that have the same thermal expansion coefficient, the displacement is hardly affected by temperature changes. Detection is possible.

[3] In the first aspect of the present invention, it is preferable that a through hole is formed in at least one of the annular frame portion and the disk-shaped thin substrate. In the displacement detector, if the internal pressure is high if there is a difference between the pressure in the closed space (internal pressure) and the external atmospheric pressure (external pressure) consisting of a ceramic thin disk, annular frame, and disk-shaped thin substrate When the thin ceramic disk is deformed into a convex shape and the internal pressure is low, the ceramic is deformed into a concave shape and the detection level of the displacement may fluctuate. For this reason, it is preferable to provide a through hole in the displacement detector so that the internal pressure and the external pressure are equal. When the through-hole is provided so as to penetrate from the outside to the side of the annular frame part or the disk-shaped thin substrate with a hole diameter that does not affect the strength of the annular frame part or the disk-shaped thin substrate. Good.

[4] In the first aspect of the present invention, it is preferable that one or more stress concentration portions are provided in the ceramic thin disc. As a result, when a load is applied to the object to be inspected, for example, a predetermined displacement (distortion) occurs in the object to be inspected, a predetermined displacement also occurs in the thin ceramic disk, and the stress concentration portion is selectively destroyed. Will do. Further, by confirming whether or not the stress concentration portion is broken, it is possible to confirm whether or not a predetermined displacement has occurred in the object to be inspected. Furthermore, since this confirmation only needs to confirm whether the ceramic thin-walled disk has cracks, it can be easily performed with the naked eye. Therefore, by using the displacement detector according to the first aspect of the present invention, an expensive and complicated power source and electrical wiring are not required, and even after the distortion generated in the object to be inspected over a long period of time, Detection and confirmation can be easily performed at low cost by visual observation (including visual observation using binoculars or the like) and the presence or absence of a simple electric signal.

[5] In the first aspect of the present invention, the thickness of the stress concentration portion provided in the ceramic thin disc may be smaller than the thickness of a portion of the ceramic thin disc different from the stress concentration portion. preferable. Thereby, a stress concentration part can be easily formed in a ceramic thin disk.

[6] In this case, it is preferable that the thickness of the stress concentration portion is 0.01 mm or more and 0.5 mm or less.

[7] Moreover, it is preferable that the said stress concentration part has one main-body part and several branch parts branched from the said main-body part.

[8] In this case, the main body portion is formed at the center of the ceramic thin disc, and the plurality of branch portions are formed radially from the main body portion toward the outer periphery of the ceramic thin disc. May be.

[9] Alternatively, the main body is formed in a frame shape on the outer peripheral side of the ceramic thin disc, and the plurality of branch portions are radially directed from the main body toward the center of the ceramic thin disc. It may be formed.

[10] A plurality of the stress concentration portions may be arranged radially.

[11] In the first aspect of the present invention, a colored substance is imparted and fixed to the surface of the thin disk-like substrate, and the color of the outer surface of the thin ceramic disk is different from the color of the colored substance. preferable. For example, painting or adhesion can be preferably used for applying and fixing the coloring substance to the surface of the thin disk-like substrate.

  In this case, when a load is applied to the object to be inspected, for example, when a predetermined distortion occurs in the object to be inspected, a crack is generated in the ceramic thin disk, and a part of the thin object is dropped out. The colored substance on the back surface (the surface of the disk-shaped thin substrate) can be directly observed through the gap. Thereby, it can be easily known by visual observation (including visual observation using binoculars or the like) that a load exceeding the allowable stress is applied to the inspection object. Moreover, by confirming the formation direction of the gap, it is possible to easily detect the direction of displacement (distortion) that has occurred in the object to be inspected.

[12] In the first aspect of the present invention, there is provided a sealed space defined by the disc-shaped thin substrate, the annular frame portion, and the ceramic thin disc, and a coloring substance sealed in the sealed space. However, it is preferable that the color of the outer surface of the thin ceramic disk is different from the color of the coloring substance.

  In this case, when a load is applied to the object to be inspected and, for example, a predetermined distortion occurs in the object to be inspected, a crack is generated in the ceramic thin disk, and the colored substance oozes out from the crack. Therefore, by confirming whether or not the coloring material oozes out from the ceramic thin disk, it is visually confirmed that the object to be inspected is subjected to a load exceeding the allowable stress (including visual observation using binoculars etc.) You can easily know at In addition, by confirming the direction of the crack formed by the color substance oozing out, the direction of displacement (distortion) generated in the object to be inspected can be easily detected.

[13] In this case, it is preferable that a fixing film of the colored substance is formed on the outer surface of the ceramic thin disk. Because the colored material that exudes from cracks in the ceramic thin disk is stabilized and fixed by the fixing film, the object to be inspected is subjected to a load exceeding the allowable stress, and the generated displacement (distortion) The direction can be displayed stably over a long period of time.

[14] Furthermore, it is preferable that an index indicating an orientation is displayed on the surface of the fixing film. In this case, when fixing the displacement detector to the object to be inspected, the direction of the generated crack can be confirmed at a glance by aligning the index with the direction.

[15] It is preferable that a transparent protective layer is provided on the outer surface of the fixing film. Thereby, the colored substance fixed by the fixing film can be stabilized for a longer period of time.

[16] The colored substance may be a paint film formed by painting, a sheet-like or tape-like fixable film, a liquid, a powder, a slurry in which a powder is dispersed in a liquid, or vaporized at room temperature to be colored. It may be a solid or liquid that generates smoke. When the colored material is liquid or slurry, or solid or liquid that vaporizes at room temperature and generates colored smoke, the side of the annular frame of the displacement detector or a through-hole for injecting the colored material into the thin disk substrate in advance A hole is provided, and the colored substance can be sealed using the through hole after the assembly of the displacement detector is completed. The through hole has a hole diameter that does not affect the strength of the annular frame portion or the disk-shaped thin substrate, and the sealed through hole can be sealed with a stopper or an adhesive after the completion of the encapsulation.

[17] The colored substance may be a fluorescent material that emits fluorescence with light from an external light source.

[18] The colored substance may be a luminous pigment that emits light by light from an external light source. In the case of a phosphorescent pigment, the phosphorescent pigment that has oozed out to the surface through the crack gap is excited by external light and emits light for a while even after extinguishing the external light. It becomes possible to recognize.

[19] In the first aspect of the present invention, it is preferable that an inner diameter of the annular frame portion is 3 mm or more and 200 mm or less.

[20] In the first aspect of the present invention, the annular frame portion preferably has a width of 1 mm to 20 mm, and the annular frame portion has a height (thickness) of 0.1 mm to 2 mm. The annular frame may be integrally formed of the same material as the disk-shaped thin substrate.

[21] In the first aspect of the present invention, the thickness of the thin ceramic disk is preferably 0.1 mm to 0.5 mm, and the thickness of the thin disk substrate is preferably 0.05 mm to 2 mm. .

[22] In the first aspect of the present invention, the disk-shaped thin substrate and the annular frame portion are preferably made of metal, and the ceramic thin-walled disc is preferably made of zirconia.

[23] In the first aspect of the present invention, the annular frame portion and the disk-shaped thin substrate may be steel or stainless steel.

[24] In the first aspect of the present invention, the annular frame portion and the disk-shaped thin substrate are made of aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, nickel steel, nickel, or a combination thereof. It may be.

[25] In the first aspect of the present invention, a hole (through hole) penetrating from the outside to the inside of the displacement detector may be formed in at least one of the annular frame portion and the disk-shaped thin substrate. The diameter of the through hole needs to be a size that does not affect the strength of the annular frame portion and the disk-shaped thin substrate, and is preferably 2 mm or less.

[26] In the first aspect of the present invention, there is an index indicating an orientation on the surface of the annular frame portion, the surface of the disk-shaped thin substrate, or each surface of the annular frame portion and the disk-shaped thin substrate. It is preferably displayed.

[27] A displacement detection method according to a second aspect of the present invention includes a ceramic thin disk, an annular frame having an outer diameter equal to or greater than an outer diameter of the ceramic thin disk, and the circle A disk-shaped thin substrate having an outer diameter equal to or greater than the outer diameter of the annular frame portion, the disk-shaped thin substrate, the annular frame portion and the ceramic thin disk are coaxial, And using the displacement detector laminated and integrated in the thickness direction in this order, the disk-shaped thin substrate of the displacement detector is fixed to the inspection object, and the displacement generated in the inspection object The direction of displacement generated in the object to be inspected is detected based on the direction of cracks generated by the deformation of the thin ceramic disk of the displacement detector.

[28] In the second aspect of the present invention, the displacement detector has a colored substance applied and fixed to the surface of the thin disk-shaped substrate, and the displacement is generated in the ceramic thin disk by the displacement generated in the inspection object. The crack is generated and a part is dropped off, and the colored substance on the back surface (the surface of the disk-shaped thin substrate) can be directly observed through the gap formed by the part dropping. The direction of the crack may be detected. For example, painting or adhesion can be preferably used for applying and fixing the coloring substance to the surface of the thin disk-like substrate.

[29] In the second aspect of the present invention, the displacement detector includes a colored substance sealed in a sealed space defined by the disc-shaped thin substrate, the annular frame portion, and the ceramic thin disc, The occurrence of the crack and the direction of the crack may be detected based on the colored material that has oozed out of the thin ceramic disk due to the displacement generated in the inspection object.

[30] In this case, in the displacement detector, a fixing film of the coloring substance is formed on the outer surface of the ceramic thin disk, and stains from the ceramic thin disk due to the displacement generated in the inspection object. The colored substance that has come out may be fixed to the fixing film.

[31] Furthermore, the displacement detector may have a transparent protective layer on the surface of the fixing film, and may protect the colored substance fixed to the fixing film over a long period of time.

[32] Further, the coloring substance may be a fluorescent material that emits fluorescence with light from an external light source.

[33] Alternatively, the coloring substance may be a phosphorescent pigment that self-emits by storing light with an external light source.

[34] In the second aspect of the present invention, the annular frame portion may have an inner diameter of not less than 3 mm and not more than 200 mm.

  According to the displacement detector and the displacement detection method of the present invention, an expensive and complicated power source and electrical wiring are not required, and distortion generated in the structure can be reduced by using an inexpensive device or visual inspection (using binoculars or the like). Can be confirmed. Furthermore, when an unexpected load occurs in a building or structure that is used for a long period of time, it is possible to easily detect the occurrence of a displacement (amount of strain) that exceeds the allowable stress. .

It is a top view which shows the displacement detector (1st displacement detector) which concerns on 1st Embodiment fixed to the to-be-inspected object from the upper surface. It is a longitudinal cross-sectional view on the II-II line in FIG. It is explanatory drawing which shows the effect | action of a 1st displacement detector. It is a longitudinal cross-sectional view which shows the displacement detector (2nd displacement detector) which concerns on 2nd Embodiment fixed to the to-be-inspected target object. It is explanatory drawing which shows the effect | action of a 2nd displacement detector. It is a longitudinal cross-sectional view which shows the displacement detector (3rd displacement detector) based on 3rd Embodiment fixed to the to-be-inspected target object. It is explanatory drawing which shows the effect | action of a 3rd displacement detector. It is a longitudinal cross-sectional view which shows the displacement detector (4th displacement detector) based on 4th Embodiment fixed to the to-be-inspected target object. It is explanatory drawing which shows the effect | action of a 4th displacement detector. It is a top view which shows the displacement detector (5th displacement detector) which concerns on 5th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a top view which shows the displacement detector (6th displacement detector) which concerns on 6th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a longitudinal cross-sectional view on the XII-XII line | wire in FIG. It is a top view which shows the displacement detector (7th displacement detector) based on 7th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a longitudinal cross-sectional view on the XIV-XIV line | wire in FIG. It is explanatory drawing which shows the effect | action of a 7th displacement detector. It is a top view which shows the displacement detector (8th displacement detector) based on 8th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a top view which shows the displacement detector (9th displacement detector) based on 9th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a top view which shows the displacement detector (10th displacement detector) based on 10th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a top view which shows the displacement detector (11th displacement detector) based on 11th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a top view which shows the displacement detector (12th displacement detector) based on 12th Embodiment fixed to the to-be-inspected object from the upper surface. It is a top view which shows the displacement detector (13th displacement detector) based on 13th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a top view which shows the displacement detector (14th displacement detector) based on 14th Embodiment fixed to the to-be-inspected object seeing from an upper surface. It is a longitudinal cross-sectional view on the XXIII-XXIII line in FIG. It is explanatory drawing which shows the effect | action of a 14th displacement detector.

  Embodiments of a displacement detector and a displacement detection method according to the present invention will be described below with reference to FIGS. In addition, in this specification, "-" which shows a numerical range is used as the meaning containing the numerical value described before and behind that as a lower limit and an upper limit.

  First, as shown in FIGS. 1 and 2, the displacement detector according to the first embodiment (hereinafter referred to as the first displacement detector 10A) is an object for detecting displacement (inspected object 12). Attached to. 1 and 2 show an example in which the first displacement detector 10A is attached to the upper surface of the object 12 to be inspected. However, although not shown, the first displacement detector 10A may be attached to the lower surface or side surface of the object 12 to be examined. Good. Examples of the inspection object 12 include a metal frame, a pressure vessel, a concrete structure, a reinforced concrete structure, and the like. Further, the first displacement detector 10A is attached to the inspection object 12 by using, for example, bolting or an adhesive. The same applies to the second displacement detector 10B to the fourteenth displacement detector 10N described below.

  As shown in FIGS. 1 and 2, the first displacement detector 10 </ b> A includes an annular frame (annular frame portion 14) and a thin ceramic disk plate (thick ceramic) having a thickness tb. A thin disk 16) and a disk-shaped thin substrate 18 having an outer diameter Dc larger than the outer diameter Db of the annular frame portion 14. The disk-shaped thin substrate 18, the annular frame portion 14, and the ceramic thin disk 16 are coaxially stacked and integrated in the thickness direction in this order. In particular, the annular frame portion 14 and the disk-shaped thin substrate 18 are integrally formed to constitute one substrate structure 20.

  The inner diameter db of the annular frame portion 14 is preferably 3 mm or more. This is because the visibility decreases when the inner diameter db of the annular frame portion 14 is less than 3 mm. The inner diameter db of the annular frame portion 14 is preferably 200 mm or less. This is because if the inner diameter db of the annular frame 14 exceeds 200 mm, the difficulty of manufacture increases. The width Wb of the annular frame portion 14 is preferably 1 mm or more in order to secure an adhesion area with the ceramic thin disc 16 and 20 mm or less so that the sensitivity of displacement detection does not decrease. When the outer diameter Db of the annular frame portion 14 is larger than the outer diameter of the ceramic thin disc 16, the outer peripheral surface of the ceramic thin disc 16 is placed on the annular frame portion 14 so as to be coaxial with the annular frame portion 14. A step that can be inserted, preferably a step in which the outer peripheral surface is fitted may be provided. The outer diameter Db of the annular frame portion 14 may be the same as the outer diameter of the disk-shaped thin substrate 18, but the outer diameter of the disk-shaped thin substrate 18 is larger than the outer diameter of the annular frame portion 14, In addition, when the annular frame portion 14 and the disk-shaped thin substrate 18 are separately formed and stacked, the disk-shaped thin substrate so that the annular frame portion 14 and the disk-shaped thin substrate 18 are coaxial. 18 may be provided with a step where the outer peripheral surface of the annular frame portion 14 enters, preferably a step with which the outer peripheral surface is fitted.

  The height ha (thickness) of the annular frame portion 14 is 0.1 mm or more and 2 mm or less, the thickness tb of the ceramic thin disc 16 is 0.1 mm or more and 0.5 mm or less, and the thickness of the disc-like thin substrate 18. tc is preferably 0.05 mm or more and 2 mm or less.

  The material of the disk-shaped thin substrate 18 and the annular frame portion 14 includes metal, and the difference in thermal expansion coefficient from the object to be inspected 12 is ± 2 ppm / K or less, more preferably ± 1 ppm / K or less. It is desirable to use a material. For example, if the material of the inspection object 12 is concrete or steel, the material of the disk-shaped thin substrate 18 and the annular frame portion 14 is, for example, steel or stainless steel, and the material of the inspection object 12 is an aluminum alloy. For example, it is preferable that the material of the disk-shaped thin substrate 18 and the annular frame portion 14 is, for example, an aluminum alloy.

  The thin ceramic disk 16 is preferably made of a material that is elastically deformed without plastic deformation. In this case, there are ceramics and glass materials that can be destroyed by elastic deformation above a predetermined strain without plastic deformation, but in the case of glass materials, minute cracks develop due to the influence of moisture in the atmosphere. Since strength deterioration may occur, a ceramic material excellent in strength stability and durability is desirable in order to detect the amount of strain more accurately. The ceramic used here is preferably broken with a strain amount equal to or greater than the strain amount corresponding to the allowable stress of the inspection object 12. That is, it is preferable that the ratio (σ / E) of the strength (σ: MPa) and the Young's modulus (E: GPa) of the thin ceramic disk 16 is 0.04% or more. More preferably, it is 0.1% or more, Most preferably, it is 0.3% or more.

  As the substrate structure 20, it is preferable to use a structure in which the annular frame portion 14 and the disk-shaped thin substrate 18 are integrated with the same metal material. Although it may be configured as a separate body, peeling and destruction are likely to occur at the joint portion. Such an inconvenience hardly occurs if the structure is integrated. The material of the annular frame portion 14 and the disk-shaped thin substrate 18 may be aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, nickel steel, nickel, or a combination thereof.

  Further, as the ceramic constituting the ceramic thin disc 16, the difference in thermal expansion coefficient between the annular frame portion 14 and the disc-like thin substrate 18 or the substrate structure 20 is ± 2 ppm / K or less, more preferably ± It is desirable to use a material that is 1 ppm / K or less. For example, if the material of the annular frame portion 14 and the disk-shaped thin substrate 18 or the substrate structure 20 is steel or stainless steel, it is preferable to use zirconia, for example. Thereby, it can avoid that the ceramic thin disc 16 peels from the annular frame part 14, the disc-shaped thin substrate 18, and the substrate structure 20. For example, an adhesive or the like can be used for joining the annular frame portion 14 and the ceramic thin disc 16 or joining the annular frame portion 14 and the disc-like thin substrate 18.

  Here, a displacement detection method using the first displacement detector 10A will be described with reference to FIG.

  As shown in FIGS. 1 and 2, the first displacement detector 10 </ b> A is attached to the inspection object 12 using, for example, bolting, an adhesive, or the like (not shown).

  Thereafter, when a load is applied to the inspection object 12 and, for example, a predetermined displacement (distortion) occurs in the inspection object 12, a predetermined displacement (distortion) is also applied to the ceramic thin disc 16 of the first displacement detector 10A. The ceramic thin disk 16 is deformed by the generated displacement, and stress is generated in the ceramic thin disk 16 to generate the crack 22.

  Even if the load applied to the object 12 to be inspected thereafter is reduced and the elastic deformation strain generated in the object 12 to be inspected is reduced, the object to be inspected is detected from the crack 22 generated in the ceramic thin disc 16. It can be easily known that a load exceeding the allowable stress is applied to the object 12. Further, the direction of displacement (strain) generated in the inspection object 12 can be easily detected from the shape of the crack 22 generated in the ceramic thin disk 16.

  Next, a displacement detector (hereinafter referred to as a second displacement detector 10B) according to a second embodiment will be described with reference to FIGS.

  As shown in FIG. 4, the second displacement detector 10 </ b> B has substantially the same configuration as the first displacement detector 10 </ b> A described above, but the coloring material 26 is formed on the surfaces of the annular frame 14 and the disk-shaped thin substrate 18. It is different in that is given. The color of the outer surface of the thin ceramic disk 16 and the color of the coloring material 26 are different. The coloring substance 26 may be a paint or a sheet tape coated with a coloring substance that is fixed by drying. Specifically, the coloring material 26 includes, for example, a fluorescent material for illumination, a high-luminance phosphorescent pigment, a sulfide-based phosphorescent pigment, a paint pigment, a non-volatile ink, a volatile ink, and the like, a heat-resistant ink, a dye ink, and a pigment. Ink can be mentioned. Further, it differs from the first displacement detector 10A in that a through hole 15 is formed in the annular frame portion 14. The through hole 15 penetrates from the outside of the side surface of the annular frame portion 14 toward the inside, and has an effect of eliminating the pressure difference between the inside and the outside of the second displacement detector 10B. This is effective when measuring outdoors with large changes in temperature and pressure. The hole diameter of the through-hole 15 needs to be a size that does not affect the strength of the annular frame portion 14 and is preferably 2 mm or less. 4 and 5 show an example in which the through hole 15 is provided in the annular frame portion 14, it may be provided in the disk-shaped thin substrate 18. Also in this case, it is preferable to provide the through hole 15 from the outside to the inside of the disk-shaped thin substrate 18. Of course, the through holes 15 may be provided in the annular frame portion 14 and the disk-shaped thin substrate 18.

  In the second displacement detector 10B, as shown in FIG. 5, when a load is applied to the inspection object 12, for example, a predetermined distortion occurs in the inspection object 12, a ceramic thin disk 16 is provided. A crack 22 is generated in this case, and a part of it is dropped. In particular, in the second displacement detector 10B, the colored substance 26 on the back surface (the surface of the disk-shaped thin substrate 18) can be directly observed through the gap formed by the partial dropout. Accordingly, by confirming whether or not the colored substance 26 can be observed from the gap formed in the ceramic thin disk 16, it is visually confirmed that the load to be inspected 12 exceeds the allowable stress (using binoculars or the like). (Including all visual observations). In addition, if a fluorescent paint is used for the colored material 26, the shape of the crack 22 can be easily grasped by confirming the observed shape, and the direction of the displacement (distortion) generated in the inspection object 12 Can be easily detected.

  Next, a displacement detector (hereinafter referred to as a third displacement detector 10C) according to a third embodiment will be described with reference to FIGS.

  As shown in FIG. 6, the third displacement detector 10 </ b> C has substantially the same configuration as the first displacement detector 10 </ b> A described above, and the annular frame portion 14 and the disk-shaped thin substrate 18 are integrally made of the same material. The substrate structure 20 is formed by forming a structure, but the sealed space 24 divided by the disk-shaped thin substrate 18, the annular frame portion 14 (substrate structure 20), and the ceramic thin disk 16 is colored. The difference is that the substance 26 is encapsulated. The color of the outer surface of the thin ceramic disk 16 and the color of the coloring material 26 are different. The colored substance 26 may be a liquid, powder, slurry in which the powder is dispersed in liquid, or a solid or liquid that vaporizes at room temperature and generates colored smoke (including white), or light from an external light source. Or a phosphorescent pigment that self-emits by storing light from an external light source. Specifically, the coloring material 26 includes, for example, a fluorescent material for illumination, a high-luminance phosphorescent pigment, a sulfide-based phosphorescent pigment, a paint pigment, a non-volatile ink, a volatile ink, and the like, a heat-resistant ink, a dye ink, and a pigment. Ink can be mentioned.

  For the assembly of the third displacement detector 10C, it is preferable to use, for example, a thermosetting adhesive having high adhesive strength. In this case, when the third displacement detector 10C is assembled, the annular frame portion 14 or the disk-shaped thin substrate is used in advance to enclose the liquid or the colored substance 26 that is vaporized at room temperature because high temperature heat treatment is required. It is preferable that a through hole is formed in 18 and the liquid and the colored substance 26 are sealed using the through hole after the assembly / heat treatment of the third displacement detector 10C.

  In the third displacement detector 10C, as shown in FIG. 7, when a load is applied to the inspection object 12, for example, a predetermined distortion occurs in the inspection object 12, a ceramic thin disk 16 is provided. In particular, in the third displacement detector 10 </ b> C, the colored substance 26 oozes out from the crack 22. Therefore, by confirming whether or not the coloring material 26 oozes out from the thin ceramic disk 16, it is visually confirmed that a load exceeding the allowable stress is applied to the inspection object 12 (visual observation using binoculars or the like). Easily). Moreover, by confirming the shape formed by the coloring material 26 oozing out (the oozing shape), the shape of the crack 22 can be easily grasped, and the displacement (distortion) generated in the object 12 to be inspected. ) Direction can be easily detected.

  Next, a displacement detector according to a fourth embodiment (hereinafter referred to as a fourth displacement detector 10D) will be described with reference to FIGS.

  The fourth displacement detector 10D has substantially the same configuration as the third displacement detector 10C described above, but fixes the coloring substance 26 on the outer surface of the ceramic thin disc 16 as shown in FIG. The difference is that a fixing film 28 is formed, and a transparent protective layer 30 is formed on the outer surface of the fixing film 28.

  In this case, as shown in FIG. 9, the coloring material 26 oozing out from the crack 22 generated in the ceramic thin disk 16 is stabilized and fixed by the fixing film 28, so that an allowable stress is applied to the inspection object 12. It is possible to display stably that a load exceeding the load is applied and the direction of the displacement (distortion) generated over a long period of time. In addition, since the protective layer 30 is formed on the outer surface of the fixing film 28, the coloring material 26 fixed by the fixing film 28 can be stabilized for a longer period of time. Examples of the material of the fixing film 28 include a thin paper so that the coloring material 26 is infiltrated and penetrates to the front side, and examples of the material of the protective layer 30 include a pet film, an acrylic resin film, a polypropylene film, and a vinyl film. And vinyl chloride film.

  Next, a displacement detector according to a fifth embodiment (hereinafter referred to as a fifth displacement detector 10E) will be described with reference to FIG.

  The fifth displacement detector 10E has substantially the same configuration as the above-described fourth displacement detector 10D, but on the portion of the outer surface of the fixing film 28 (see FIG. 8) that overlaps the annular frame portion 14, An index 32 indicating the azimuth is displayed. The indicators 32 display azimuth angles corresponding to 16 azimuths.

  Therefore, when the fifth displacement detector 10E is fixed to the inspection target object 12, the direction of the generated crack 22 can be confirmed at a glance by aligning the index 32 with the orientation.

  Next, a displacement detector according to a sixth embodiment (hereinafter referred to as a sixth displacement detector 10F) will be described with reference to FIGS.

  The sixth displacement detector 10F has substantially the same configuration as the above-described fifth displacement detector 10E, but, as shown in FIG. 11, one stress concentration portion 34 is provided on the ceramic thin disc 16. Is different. The stress concentration part 34 has, for example, a circular shape.

  As shown in FIG. 12, the stress concentration part 34 is formed by thinning a part of the surface of the ceramic thin disk 16 (for example, the surface facing the disk-shaped thin substrate 18) to form a recess. be able to. That is, the thickness td of the stress concentration portion 34 provided on the ceramic thin disc 16 is thinner than the thickness tb of a portion of the ceramic thin disc 16 that is different from the stress concentration portion 34. The thickness td of the stress concentration part 34 is preferably 0.01 mm or more and 0.5 mm or less.

  In this case, the crack 22 can be generated in the stress concentration portion 34 with a preset displacement (denoted as a predetermined displacement) by appropriately adjusting the size, thickness td, and the like of the stress concentration portion 34 viewed from the plane. .

  That is, when a load is applied to the inspection object 12 and, for example, a predetermined displacement (distortion) occurs in the inspection object 12, a predetermined displacement also occurs in the ceramic thin disk 16 and the stress concentration portion 34 is selected. Will be destroyed. Thereby, it is possible to confirm whether or not a predetermined displacement has occurred in the inspection target object 12 by confirming whether or not the stress concentration portion 34 is broken.

  Next, a displacement detector according to a seventh embodiment (hereinafter referred to as a seventh displacement detector 10G) will be described with reference to FIGS.

  As shown in FIGS. 13 and 14, the seventh displacement detector 10G has substantially the same configuration as the above-described sixth displacement detector 10F, but the shape of the stress concentration portion 34 is different.

  That is, the stress concentration portion 34 includes a rectangular main body portion 34a formed at the central portion, and four strip-shaped branch portions branched in four directions from the main body portion 34a toward the outer periphery of the ceramic thin disc 16. 34b.

  In this case, for example, as shown in FIG. 15, a preset displacement (denoted as a predetermined displacement) is appropriately adjusted by adjusting the size and thickness of the main body portion 34a as viewed from the plane and the width and thickness of the branch portion 34b. The crack 22 can be generated in the stress concentration portion 34. If the stress concentration portion 34 is not provided, the crack 22 may occur in an arbitrary direction or the crack 22 may not occur even if a predetermined displacement occurs. However, the stress concentration portion 34 having a plurality of branch portions 34b is not provided. By providing, it becomes easy to produce the crack 22 along the branch part 34b corresponding to the predetermined displacement which arose in the to-be-inspected object 12. FIG.

  That is, when a load is applied to the inspection object 12 and, for example, a predetermined displacement (distortion) occurs in the inspection object 12, a predetermined displacement also occurs in the ceramic thin disk 16 and the stress concentration portion 34 is selected. Will be destroyed. Thereby, it is possible to confirm whether or not a predetermined displacement has occurred in the inspection target object 12 by confirming whether or not the stress concentration portion 34 is broken.

  In addition, on the outer surface of the fixing film 28, on the portion overlapping the annular frame portion 14, an index 32 indicating the orientation is displayed corresponding to the four branch portions 34 b constituting the stress concentration portion 34. That is, the characters “North”, “South”, “East”, and “West” are displayed.

  Therefore, when the seventh displacement detector 10G is fixed to the inspection object 12, the direction of the generated crack 22 can be confirmed at a glance by aligning the index 32 with the orientation.

  In the seventh displacement detector 10G described above, the main body portion 34a of the stress concentration portion 34 has a rectangular shape, but in addition to the displacement detector (eighth displacement detector 10H) according to the eighth embodiment in FIG. As shown, the main body portion 34a of the stress concentration portion 34 may be circular. Of course, various other shapes are possible. For example, a hexagonal shape or an octagonal shape.

  Next, a displacement detector according to a ninth embodiment (hereinafter referred to as a ninth displacement detector 10I) will be described with reference to FIG.

  The ninth displacement detector 10I has substantially the same configuration as the seventh displacement detector 10G described above, but differs in the following points.

  That is, in the ninth displacement detector 10I, the main body portion 34a of the stress concentration portion 34 has an octagonal shape, and eight strip-shaped branch portions branched in eight directions from the main body portion 34a toward the outer periphery of the ceramic thin disc 16. 34b. In addition, on the outer surface of the fixing film 28, on the portion overlapping the annular frame portion 14, an index 32 indicating the orientation is displayed corresponding to the eight branch portions 34 b constituting the stress concentration portion 34. That is, the characters “north”, “northeast”, “east”, “southeast”, “south”, “southwest”, “west”, and “northwest” are displayed.

  In this case, since the branching part 34b corresponding to eight directions is provided as the stress concentration part 34, the direction of the displacement (distortion) generated in the inspection target 12 can be detected more accurately. .

  Next, a displacement detector according to a tenth embodiment (hereinafter referred to as a tenth displacement detector 10J) will be described with reference to FIG.

  The tenth displacement detector 10J has substantially the same configuration as the above-described sixth displacement detector 10F (see FIG. 11), but the shape of the stress concentration portion 34 is different.

  That is, as shown in FIG. 18, the stress concentration portion 34 has one main body portion 34 a formed at the center portion, and twelve pieces radially radiating from the main body portion 34 a toward the outer periphery of the ceramic thin disc 16. Branch part 34b. Unlike the branch portion 34b of the eighth displacement detector 10H (see FIG. 16), the branch portion 34b has a curved shape or an arc shape.

  In this case, when a load is applied to the inspection object 12 and, for example, a predetermined displacement (distortion) occurs in the inspection object 12, a predetermined displacement also occurs in the ceramic thin disc 16, and the stress concentration portion 34 is generated. It will be destroyed selectively. That is, the crack 22 can be generated along the branch portion 34b corresponding to the predetermined displacement generated in the inspection target object 12. Thereby, it is possible to confirm whether or not a predetermined displacement has occurred in the inspection target object 12 by confirming whether or not the stress concentration portion 34 is broken.

  Further, in the outer surface of the fixing film 28 (see FIG. 8), the portion overlapping the annular frame portion 14 corresponds to the twelve branch portions 34b constituting the stress concentration portion 34, and the time (short hand position). An index 32 indicating the azimuth using is displayed. That is, characters “1” to “12” are displayed.

  Therefore, when fixing the tenth displacement detector 10J to the inspection object 12, the direction of the crack 22 that has occurred can be confirmed at a glance by aligning the index 32 with the orientation.

  Next, a displacement detector according to an eleventh embodiment (hereinafter referred to as an eleventh displacement detector 10K) will be described with reference to FIG.

  The eleventh displacement detector 10K has substantially the same configuration as the tenth displacement detector 10J described above, but the shape of the stress concentration portion 34 is different.

  That is, as shown in FIG. 19, the stress concentration portion 34 has one main body portion 34 a formed in the center portion, and 16 pieces radially radiating from the main body portion 34 a toward the outer periphery of the ceramic thin disc 16. Branch part 34b.

  In addition, on the portion of the outer surface of the fixing film 28 (see FIG. 8) that overlaps with the annular frame portion 14, the index 32 indicating the orientation corresponds to the 16 branch portions 34 b that constitute the stress concentration portion 34. Is displayed. That is, “north”, “north-northeast”, “north-east”, “east-northeast”, “east”, “east-southeast”, “southeast”, “south-southeast”, “south”, “south-southwest”, “southwest”, “west-southwest” ”,“ West ”,“ West NW ”,“ NW ”, and“ NW ”are displayed.

  Therefore, also in this case, when the eleventh displacement detector 10K is fixed to the inspection object 12, the direction of the crack 22 that has occurred can be confirmed at a glance by aligning the index 32 with the orientation. Since the branch portions 34b corresponding to the 16 orientations are provided as the stress concentration portion 34, the direction of displacement (distortion) generated in the inspection object 12 can be detected more accurately.

  Next, a displacement detector according to a twelfth embodiment (hereinafter referred to as a twelfth displacement detector 10L) will be described with reference to FIG.

  The twelfth displacement detector 10L has substantially the same configuration as the eleventh displacement detector 10K described above, but the shape of the stress concentration portion 34 is different, and the index 32 indicating the orientation is the disk-shaped thin substrate 18. It differs in that it is displayed on the outer periphery.

  That is, as shown in FIG. 20, the stress concentration portion 34 has one main body portion 34 a formed in the central portion, and 32 pieces branched radially from the main body portion 34 a toward the outer periphery of the ceramic thin disc 16. Branch part 34b. Unlike the case of the eleventh displacement detector 10 </ b> K, the shape of each branch portion 34 b is formed sharply toward the outer periphery of the ceramic thin disc 16.

  On the outer peripheral portion exposed from the annular frame portion 14 on the outer surface of the disk-shaped thin substrate 18, an index 32 indicating the orientation is displayed as in the eleventh displacement detector 10 </ b> K.

  Therefore, also in this case, when fixing the twelfth displacement detector 10L to the inspection object 12, the direction of the generated crack 22 can be confirmed at a glance by aligning the index 32 with the orientation. Since the branch portions 34b corresponding to the 32 orientations are provided as the stress concentration portion 34, the direction of displacement (distortion) generated in the inspection object 12 can be detected more accurately. Of course, in addition to the display of the index 32 on the disk-shaped thin substrate 18, the index 32 may be displayed on a portion of the outer surface of the fixing film 28 that overlaps the annular frame portion 14.

  Next, a displacement detector according to a thirteenth embodiment (hereinafter referred to as a thirteenth displacement detector 10M) will be described with reference to FIG.

  The thirteenth displacement detector 10M has substantially the same configuration as the tenth displacement detector 10J described above, but differs in that a plurality of stress concentration portions 34 are formed radially. In the example of FIG. 21, twelve stress concentration portions 34 are formed near the outer periphery of the ceramic thin disc 16. The shape of each stress concentration portion 34 is, for example, an elliptical shape with the major axis aligned with the azimuth so that the crack 22 is likely to occur along the azimuth.

  Accordingly, also in this case, when fixing the thirteenth displacement detector 10M to the inspection object 12, the direction of the generated crack 22 can be confirmed at a glance by aligning the index 32 with the orientation. Further, since the twelve stress concentration portions 34 are provided corresponding to the azimuth using the time (short hand position), it is possible to accurately detect the direction of the displacement (distortion) generated in the inspection object 12. It becomes possible.

  Next, a displacement detector according to a fourteenth embodiment (hereinafter referred to as a fourteenth displacement detector 10N) will be described with reference to FIGS.

  As shown in FIGS. 22 and 23, the fourteenth displacement detector 10N has substantially the same configuration as the first displacement detector 10A described above, but one stress concentrating portion 34 is provided in the ceramic thin disc 16. It differs in that it is provided. Further, in the fourteenth displacement detector 10N, the outer diameter of the annular frame portion 14 is set larger than the outer diameter of the ceramic thin disc 16. Therefore, the step where the outer peripheral surface of the ceramic thin disc 16 enters the annular frame portion 14, preferably the outer peripheral surface is fitted, so that the ceramic thin disc 16 and the annular frame portion 14 can be positioned coaxially. A step 14a is provided.

  The stress concentration portion 34 includes a main body portion 34a formed in a frame shape on the outer peripheral side of the ceramic thin disc 16 and a plurality of branches radially formed from the main body portion 34a toward the center of the ceramic thin disc 16. Part 34b. FIG. 22 shows an example in which 32 branch portions 34b are formed. Each branch part 34 b is formed in a sharp shape toward the center of the ceramic thin disk 16.

  Also in this case, for example, as shown in FIG. 24, by appropriately adjusting the size and thickness of the main body portion 34a as viewed from the plane, and the width and thickness of each branch portion 34b, a predetermined displacement (predetermined displacement and The crack 22 can be generated in the stress concentration portion 34.

  That is, when a load is applied to the inspection object 12 and, for example, a predetermined displacement (distortion) occurs in the inspection object 12, a predetermined displacement also occurs in the ceramic thin disk 16 and the stress concentration portion 34 is selected. Will be destroyed. That is, the crack 22 can be generated along the branch portion 34b corresponding to the predetermined displacement generated in the inspection target object 12. Thereby, it is possible to confirm whether or not a predetermined displacement has occurred in the inspection target object 12 by confirming whether or not the stress concentration portion 34 is broken.

  The predetermined displacement (strain) described above is a strain within a range in which it is determined whether or not the inspection object 12 has deformed beyond the allowable stress, and for example, 0.1% or 0.2% is selected. In this case, the object 12 to be inspected includes, for example, a pressure vessel, a metal frame (a frame of heavy machinery, a frame of a press machine, a frame of a device that applies hydrostatic pressure), a utility pole, a steel tower, a concrete structure, a reinforced concrete structure. Things are included. However, if the inspection object 12 has a yield point that clearly appears in the stress strain diagram, the amount of strain can be selected within a range before and after the yield point is sandwiched. In the case of the inspection object 12 in which the yield point does not appear clearly, the strain amount can be selected in a range before and after the strain amount when the stress corresponding to 0.2% proof stress is generated.

  One reason for selecting the strain within the elastic deformation range of the inspection object 12 below the yield point as the predetermined strain is as follows. That is, normally, even if a distortion in the range of elastic deformation occurs in the building or structure, it returns to its original state, so it is difficult to determine whether the distortion occurred, that is, whether a load was applied. Therefore, for example, by periodically checking the destruction of the ceramic thin disc 16 in the first displacement detector 10A or the like, and repeating the operation of replacing the new first displacement detector 10A or the like if it has been destroyed, It is possible to know how many times the distortion of about 0.1% has occurred, which can be used for analysis of aging of the inspection object 12. Of course, by shortening the inspection cycle, it is possible to more accurately know the number of times that distortion of about 0.1% has occurred.

  As the ceramics constituting the thin disc 16 made of ceramic, it is preferable to contain zirconia. Further, by providing the stress concentration portion 34, the ceramic thin disk 16 can be broken with a strain within a range in which the test object 12 is elastically deformed, for example, 0.1% or 0.2%. Moreover, since zirconia has a thermal expansion coefficient substantially the same as that of carbon steel (mild steel material) or reinforced concrete, it can compensate for the temperature change. This leads to the ability to detect distortion without being affected by temperature changes, and is advantageous for improving detection accuracy.

  Next, the manufacturing method of the ceramic thin disc 16 and the substrate structure 20 of the first displacement detector 10A to the 14th displacement detector 10N described above will be briefly described below. When the first displacement detector 10A to the fourteenth displacement detector 10N are collectively referred to, they are simply referred to as a displacement detector.

  First, the manufacturing method of the ceramic thin disk 16 is not particularly limited, and may be any method such as a doctor blade method, an extrusion method, a gel casting method, a powder pressing method, and an imprinting method. Particularly, for a complicated shape in which the stress concentration portion 34 is formed, the gel casting method is particularly preferably used. In a preferred embodiment, a slurry containing a ceramic powder, a dispersion medium and a gelling agent is cast, the slurry is gelled to obtain a molded body, and the molded body is sintered to obtain a ceramic product. A thin disk 16 can be obtained (see JP 2001-335371 A).

As a material for the ceramic thin disc 16, a raw material in which ₃ mole% of yttria (Y ₂ O ₃ ) auxiliary agent is added to the zirconia powder is used. As the auxiliary agent, yttria is preferable, but calcia (CaO), magnesia (MgO) and the like can also be exemplified.

  The gel casting method includes the following methods.

(1) Along with inorganic powder, a prepolymer such as polyvinyl alcohol, epoxy resin, phenol resin or the like, which becomes a gelling agent, is dispersed in a dispersion medium together with a dispersant to prepare a slurry. The slurry is solidified by crosslinking and gelation.

(2) The slurry is solidified by chemically bonding an organic dispersion medium having a reactive functional group and a gelling agent. This method is the method described in Japanese Patent Application Laid-Open No. 2001-335371 of the present applicant.

  On the other hand, the substrate structure 20 having the annular frame portion 14 and the disk-like thin substrate 18 can be manufactured by a generally known method such as press molding or machining of metal or the like.

  It should be noted that the displacement detector and the displacement detection method according to the present invention are not limited to the above-described embodiments, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10A-10N ... 1st displacement detector-14th displacement detector 12 ... Test object 14 ... Ring-shaped frame part 15 ... Through-hole 16 ... Ceramic thin disk 18 ... Disk-shaped thin board | substrate 20 ... Board | substrate structure DESCRIPTION OF SYMBOLS 22 ... Crack 24 ... Sealed space 26 ... Colored substance 28 ... Fixing film 30 ... Protective layer 32 ... Index 34 ... Stress concentration part 34a ... Main-body part 34b ... Branch part

Claims (34)

Ceramic thin disk,
An annular frame having an outer diameter equal to or greater than the outer diameter of the ceramic thin disk,
A disk-shaped thin substrate having an outer diameter equal to or greater than the outer diameter of the annular frame portion;
The displacement detector, wherein the disk-shaped thin substrate, the annular frame portion, and the ceramic thin disk are coaxially stacked and integrated in the thickness direction in this order. The displacement detector according to claim 1.
The displacement detector, wherein the annular frame portion and the disk-shaped thin substrate are integrally formed. The displacement detector according to claim 1 or 2,
A displacement detector, wherein a through hole is formed in at least one of the annular frame portion and the disk-shaped thin substrate. The displacement detector according to any one of claims 1 to 3,
A displacement detector, wherein the ceramic thin-walled disc is provided with one or more stress concentration portions. The displacement detector according to claim 4.
The thickness of the said stress concentration part provided in the said ceramic thin disc is thinner than the thickness of the site | part different from the said stress concentration part among the said ceramic thin discs, The displacement detector characterized by the above-mentioned. The displacement detector according to claim 4 or 5,
A displacement detector, wherein the stress concentration portion has a thickness of 0.01 mm to 0.5 mm. The displacement detector according to any one of claims 3 to 6,
The stress concentration part includes a main body part and a plurality of branch parts branched from the main body part. The displacement detector according to claim 7, wherein
The main body is formed in the center of the ceramic thin disc,
The displacement detector, wherein the plurality of branch portions are formed radially from the main body portion toward an outer periphery of the thin ceramic disk. The displacement detector according to claim 7, wherein
The main body is formed in a frame shape on the outer peripheral side of the ceramic thin disc,
The displacement detector is characterized in that the plurality of branch portions are radially formed from the main body portion toward the center of the thin ceramic disk. The displacement detector according to any one of claims 4 to 6,
A displacement detector, wherein a plurality of the stress concentration portions are arranged radially. The displacement detector according to any one of claims 1 to 10,
A coloring substance is imparted and fixed on the surface of the thin disk-shaped substrate,
A displacement detector characterized in that the color of the outer surface of the thin ceramic disk is different from the color of the colored substance. The displacement detector according to any one of claims 1 to 10,
A sealed space defined by the disk-shaped thin substrate, the annular frame, and the ceramic thin disk;
A colored substance enclosed in the sealed space,
A displacement detector characterized in that the color of the outer surface of the thin ceramic disk is different from the color of the colored substance. The displacement detector of claim 12,
A displacement detector, wherein a fixing film of the colored substance is formed on an outer surface of the ceramic thin disk. The displacement detector according to claim 13.
A displacement detector characterized in that an index indicating an orientation is displayed on the surface of the fixing film. The displacement detector according to claim 13 or 14,
A displacement detector comprising a transparent protective layer on an outer surface of the fixing film. The displacement detector according to any one of claims 11 to 15,
The colored substance is a paint film formed by painting, a sheet-like or tape-like fixable film, liquid, powder, slurry in which powder is dispersed in liquid, or vaporized at room temperature to generate colored smoke Displacement detector characterized by being solid or liquid. The displacement detector according to any one of claims 11 to 16,
The displacement detector according to claim 1, wherein the colored substance is a fluorescent substance that develops fluorescence with light from an external light source. The displacement detector according to any one of claims 11 to 16,
The displacement detector according to claim 1, wherein the coloring substance is a phosphorescent pigment that emits light by light from an external light source. The displacement detector according to any one of claims 1 to 18,
An inner diameter of the annular frame part is 3 mm or more and 200 mm or less. The displacement detector according to any one of claims 1 to 19,
A displacement detector, wherein the annular frame portion has a width of 1 mm to 20 mm, and the annular frame portion has a height (thickness) of 0.1 mm to 2 mm. The displacement detector according to any one of claims 1 to 20,
A displacement detector, wherein the ceramic thin disk has a thickness of 0.1 mm to 0.5 mm, and the disk-shaped thin substrate has a thickness of 0.05 mm to 2 mm. The displacement detector according to any one of claims 1 to 21,
The material of the disk-shaped thin substrate and the annular frame is a metal,
A displacement detector characterized in that the ceramic thin disk is made of zirconia. The displacement detector according to any one of claims 1 to 22,
The displacement detector according to claim 1, wherein the annular frame portion and the disc-shaped thin substrate are made of steel or stainless steel. The displacement detector according to any one of claims 1 to 23,
A material for the annular frame and the thin disk substrate is aluminum, aluminum alloy, copper, copper alloy, titanium, titanium alloy, nickel steel, nickel, or a combination thereof. . The displacement detector according to any one of claims 1 to 24,
A displacement detector, wherein a hole penetrating from the outside to the inside of the displacement detector is formed in at least one of the annular frame portion and the disk-shaped thin substrate. The displacement detector according to any one of claims 1 to 25,
Displacement characterized in that an index indicating an orientation is displayed on the surface of the annular frame, the surface of the disk-shaped thin substrate, or each surface of the annular frame and the disk-shaped thin substrate. Detector. A ceramic thin disc, an annular frame having an outer diameter equal to or greater than the outer diameter of the ceramic thin disc, and an outer diameter equal to or greater than the outer diameter of the annular frame Displacement detector comprising: a disk-shaped thin substrate; and the disk-shaped thin substrate, the annular frame portion, and the ceramic thin disk are coaxially stacked and integrated in the thickness direction in this order. Use
Fixing the disk-shaped thin substrate of the displacement detector to an object to be inspected;
The direction of the displacement generated in the inspection object is detected based on the direction of the crack generated by the deformation of the ceramic thin disk of the displacement detector due to the displacement generated in the inspection object. A displacement detection method characterized by the above. The displacement detection method according to claim 27,
The displacement detector is provided with a colored substance on the surface of the thin disk-shaped substrate, and is fixed.
Detecting the occurrence of the crack and the direction of the crack by directly observing the colored substance from the gap generated by the occurrence of a crack in the ceramic thin disk due to the displacement generated in the inspection object. The displacement detection method characterized by this. The displacement detection method according to claim 27,
In the displacement detector, a colored substance is enclosed in a sealed space defined by the disk-shaped thin substrate, the annular frame portion, and the ceramic thin disk,
A displacement detection method comprising: detecting the occurrence of cracks and the direction of the cracks based on the colored material that has oozed out of the thin ceramic disk due to the displacement generated in the inspection object. The displacement detection method according to claim 29, wherein:
In the displacement detector, a fixing film of the coloring substance is formed on an outer surface of the ceramic thin disk,
A displacement detection method comprising fixing the colored material that has exuded from the thin ceramic disk due to the displacement generated in the inspection object to the fixing film. The displacement detection method according to claim 30, wherein
The displacement detector has a transparent protective layer on the surface of the fixing film,
A displacement detection method comprising protecting the colored substance fixed on the fixing film for a long period of time. The displacement detection method according to any one of claims 27 to 31,
The displacement detection method, wherein the coloring substance is a fluorescent substance that develops fluorescence with light from an external light source. The displacement detection method according to any one of claims 27 to 31,
The displacement detection method according to claim 1, wherein the coloring substance is a phosphorescent pigment that self-emits by storing light with an external light source. The displacement detection method according to any one of claims 27 to 33,
A displacement detection method, wherein an inner diameter of the annular frame portion is 3 mm or more and 200 mm or less.

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