JP4998811B2 - Torque sensitive display that breaks brittlely. - Google Patents

Description

The present invention detects and displays , as a torque value, the amount of deformation of a holding plate caused by tightening a nut of a mounting bracket such as a U-bolt having a pair of bolt portions , and displays the torque- sensitive display that causes brittle fracture and plastic deformation with the predetermined amount of deformation. About the body.

  Conventionally, in a deformation amount display body for displaying an applied external force value, a sensor for detecting the amount of bending such as pressure or bending applied to the large-scale structure to a small individual member, or the external force value or deformation caused by the sensor. A display device that displays a deformation state by a color change of the display body in proportion to the amount is known.

  In addition, a torque wrench for setting and displaying the tightening torque value of the screw fastening force applied to the management of the applied external force value and managing the tightening is known. A pair used for a tightening operation with a constant torque by a wrench and for checking the torque, and a pair of rebar rods that are assembled in a grid with rebars or mounting brackets having a pair of bolts such as U-bolts. There are known mounting and holding brackets having bolt portions, and the torque wrench is known for confirming the pair of tightening balances and managing the tightening torque when the nuts and bolts to be used are tightened.

  Thus, as a prior art, a first block composed of a fixing portion attached to the surface of the structure to which force is transmitted and an extension extending from the fixing portion, and a fixing attached to the same surface as the structure surface. And a second block consisting of an extension extending from the fixed portion and facing the extension of the first block, and the extension blocks of the first block and the second block are elastically coupled to each other. And a “deformation detector for structure” showing an embodiment of a displacement detecting means provided between the extensions and detecting displacement between the extensions. (For example, see Patent Document 1)

  Further, as another prior art, a deformation amount display body for displaying a deformation amount due to an external force, including a polymer composition composed of a polymer and a dye, wherein the dye is specified in the polymer composition In addition, the dye is an associative fluorescent dye having different fluorescence wavelengths in the excimer state and the monomer state, and the deformation amount indicator is more than a certain amount by an external force. An embodiment used for detecting the deformation or the amount of deformation in an article made of a polymer molded body that can be changed to a hue different from the initial hue when deformed and is deformed by a certain amount or more by an external force. There is a “deformation amount display body and a modification using the same or a method for detecting the deformation amount”. (For example, see Patent Document 2)

  Further, as another prior art, as a prior art related to confirmation of the tightening torque, a bolt 2 having a male screw, a nut 7 having a female screw screwed to the male screw of the bolt 2, and tightening the fastening member 100, A pair of torque washers 4, 5 that are inserted between the head of the bolt 2 or the nut 7 and the member to be fastened 100 and curved in opposite directions so as to flatten when a predetermined tightening torque is reached. There are “screw fasteners and torque washers” showing an embodiment in which (For example, see Patent Document 3)

Japanese Patent No. 2730596 JP 2009-300411 A JP 2006-9823 A

Conventionally, the strain sensitive display that displays the applied external force value is expensive, such as a strain sensor of a corresponding means for each large-scale structure to small individual parts, and when greatly deformed, the color changes according to the deformation. However, it can only be used for large deformations and cannot be used for fine deformations. It is also necessary to know the amount of deformation from each large-scale structure to small parts, and display the deformation and the torque value as seen on the torque wrench from the deformation amount. No one knows the torque value within a predetermined range from the upper limit to the lower limit of the torque value, and it has not been proposed to apply the deformation amount as such.

  In addition, a torque wrench that has been used in the past is that the operator himself sets the tightening torque at the time of work, and performs the tightening work with that torque. Even if the tightening can be confirmed, there is nothing that can confirm the overtorque that is overtightened, and in particular, there is nothing that can be confirmed visually, so even in the operator's own confirmation and inspection of the tightening torque after the work Therefore, it is required to be able to confirm appropriateness and tightening of the excessive torque. In particular, since excessive tightening leads to breakage, a simple means that can be visually confirmed has been required.

  In other words, it is expected that excessive torque tightening will directly lead to the rupture of the bolt. Especially, it has other tightening means and tightening confirmation means that do not use a torque wrench. Even if tightened, over tightening could not be confirmed in the torque inspection at a later date, and therefore there was a need for a simple means for knowing the range of the predetermined appropriate torque from the predetermined torque to the excessive torque.

  Thus, the disclosed “deformation detector for structure” of Patent Document 1 is a strain gauge for fixing the deformation detector 10 to the frame 1 with bolts 11b1 and 11b2, and the flat plates 13a and 13b and the shear plate by external force. 14 is deformed, and the change in resistance value due to expansion and contraction due to the deformation is detected by a bridge circuit (not shown) composed of four strain gauges and an electronic circuit. Knowing the amount of continuous change by the circuit, such advanced detection is expensive. Rather, a simple detection of whether or not there is a change in the predetermined value is required depending on the application, and an inexpensive one is required. What is fixed by 11b1 and 11b2 and cannot be used for such a fixing cannot be used, and what can be easily attached such as sticking has been demanded.

  Thus, the disclosed “deformation amount display body and the deformation using the same or a method for detecting the deformation amount” in “Patent Document 2” discloses “deformation amount display by attaching or sticking the deformation amount display body to the article. Based on the change in the hue of the body, the deformation of the article or the amount of the deformation is detected, and the form and degree of the deformation that occurs in the article are elongation, blurring, bending (bending), tearing, dent, distortion, swelling, etc. In addition, by detecting the degree of change (amount of change) in the hue of the deformation amount display body, how long the article is physically deteriorated or whether the article has reached its lifetime As a means of knowing the specific form of the deformation amount display body and its use, the cap such as a bottle, the shrink film, the open state such as a package, or the breakage state. Therefore, it can detect deformation due to external force exceeding a certain level as a physical degradation group according to the change of the life sensor, and it can be used not only in the field corresponding to minute deformation but also for displaying minute deformation. There wasn't.

  Thus, in the disclosed “Screw Fastener and Torque Washer” of Patent Document 3, a torque washer that is curved so as to be flattened when reaching a predetermined tightening torque is inserted. In a state where the predetermined value is not reached, there is a gap that can be visually observed, and by tightening the nut with a predetermined tightening torque, the torque washer is flattened and the gap disappears. Tightening can be confirmed, but with the means that the torque washer is flattened and there is no gap, it is not possible to confirm over-tightening. Even after the tightening inspection after the work, what can confirm proper and excessive tightening has been required.

  As described above, detection by replacing deformation detection with an electronic circuit, replacement of a large amount of deformation with a color change, display of a breakage state, detection of deterioration due to progress, and other member deformation amount Prior art has been disclosed up to knowing that an external force has been applied, but it is used in response to a specific thing in use, lacks versatility, and strain sensitive to plastic deformation due to brittle fracture of this application There is nothing that solves the problems of many inexpensive and simple applications by detecting and displaying distortion on the display body, and alarms etc. corresponding to predetermined external force by combining with single use and electronic circuit There was nothing to emit and I had been waiting for a long time.

In order to effectively achieve the above-mentioned problems, the present invention provides a first solution means that when a holding plate of a mounting holding bracket having a pair of bolt parts such as a U bolt is fastened and held by a nut, the holding plate is bent. Each of the predetermined length, width, and thickness corresponding to the difference in the desired fracture point of brittle fracture in ceramics, alumina, glass, plastic, etc. so that a predetermined tightening torque can be displayed by the strain a combination of dimensions is formed in a plate shape having a predetermined shape, or the formation, directly, by which is formed by applying and drying a predetermined shape as a coating to a predetermined position of the holding plate,
It is assumed that the tightening torque that is fastened and held by the nut of the mounting and holding bracket having a pair of bolts is detected and displayed by plastic deformation due to brittle fracture of the torque sensitive display body .

In addition, as a second solution, a torque- sensitive display body that brittlely breaks is colored , and a soft contrast display layer having ductility is formed by a thin film colored in a color other than the same color as the torque- sensitive display body in the lower layer. By providing
The torque- sensitive display body is made to show the contrast display layer of the different color as a base through the gap which is a crack in which the torque- sensitive display is brittlely broken, so that it is known that a certain amount of external force has been applied due to brittle fracture.

Further, a third aspect of the invention, by a torque-sensitive display body to brittle fracture, the fracture point of plastic deformation and brittle fracture was juxtaposed to suppose a plurality of torque sensing display body differ,
A plurality of torque- sensitive display bodies correspond to the torque applied thereto, and the torque- sensitive display bodies undergo brittle fracture and plastically deform within a range of upper and lower limits.

In addition, as a fourth solving means, the torque- sensitive display body provided on the holding plate is provided at the bent portion near the center of one side of the holding plate or the left and right side surfaces,
The tightening torque by the nut is detected on the side surface side of the holding plate, and is displayed by plastic deformation due to brittle fracture of the torque sensitive display body .

The present invention is such that an effective effect can be obtained by each of the above-described means, and in particular, a U-bolt that bridges a holding plate between a pair of bolt portions and is fastened and held by a nut of the first solving means, or Oite rebar rebar cage in mounting the holding bracket to hold the bridge the holding plate to the pair of bolt portion in a lattice shape in a cross state assembled in a lattice shape by engaging holding a nut, holds the holding bracket with said mounting When the plate is clamped and held by a nut, the ceramic plate is displayed so that the specified tightening torque can be displayed by carrying out a brittle fracture due to the strain that the holding plate bends at that predetermined tightening torque value and breaking or cracking and plastically deforming. In a brittle material such as alumina, glass, plastic, etc., a plate-like body having a predetermined shape by combining the dimensions of a predetermined length, width and thickness corresponding to the difference in the desired fracture point for brittle fracture Formed, or the formation, directly, by which is formed by applying and drying a predetermined shape as a coating to a predetermined position of the holding plate,
Since the operator can know the tightening torque of the nut by a simple display, the predetermined torque can be known even if a wrench of a general tool is used without using an expensive torque wrench.

In addition, the second solution means that a torque- sensitive display body that brittlely breaks is colored , and a soft contrast display layer having ductility is provided in a lower layer of the thin film that is colored in a color other than the same color as the torque- sensitive display body. By
When a brittle fracture is caused by the tightening torque , a gap that is a brittle fracture crack is generated, and a contrast display layer having a different color is clearly visible through the gap.For example, the torque- sensitive display body is colored white, and the contrast display layer is By coloring in red, the red color of the ground can be seen through the white gap of the torque- sensitive display body, so that it can be easily known that a certain level of external force has been applied due to brittle fracture.

Further, the third solving means, torque sensing display body to brittle fracture, the plurality juxtaposed to Rukoto the torque sensitive display of which the breaking point is different from plastic deformation and brittle fracture,
A plurality of torque sensitive display member by tightening torque applied respectively, since the plastic deformation to brittle fracture in response to the torque, the tightening torque range applied to the plurality of torque sensitive display body due to the difference in the fracture point, which can know whether the applied extent, thus advance if it difference in breaking points respectively set, the countermeasures and its management for tightening torque applied at the same time knowing the tightening torque applied in the range of upper and lower limit it can be, it is later, means to know visually obtained in the tightening torque inspection or tightening of the nut is being performed by the torque of the reference range.

In addition, with this simple configuration, it is possible to obtain a means for visually knowing the appropriate range from a predetermined torque to immediately before the excessive torque, that is, the upper limit value and the lower limit torque range , thereby preventing troubles caused by excessive or insufficient tightening. Can reduce costs.

In addition, the torque- sensitive display body provided on the holding plate of the fourth solving means is provided in the bent portion near the center of one side or the left and right side of the holding plate,
Plastic deformation by brittle fracture of the torque sensitive display body becomes larger than the distortion of the planar side surfaces, i.e. at the strain amount with respect to the distance of the thickness of the torque sensitive display body is a plan side surface, the torque detection display member is a side surface against The amount of strain with respect to the distance of the width is increased, and the applied strain force is partially increased by the distance between the thickness and width, and brittle fracture is likely to occur by minute deformation.

In addition, if a V-shaped notch is provided in the approximate center of the torque- sensitive display body , stress concentration applied to the narrow portion acts, and brittle fracture occurs with slight deformation against the bending strain force. Therefore, a precise torque value can be set, and the management becomes easy.
Therefore, the present invention has a practically significant effect.

It is a perspective view of the torque sensitive display body 1 of 1st Example of this invention. It is a perspective view of the coloring torque sensitive display body 1a of 2nd Example of this invention. It is a front view which shows the brittle fracture state of the coloring torque sensitive display body 1a of 2nd Example of this invention. It is a perspective view of the torque sensitive display body 1b of the Example which formed the notch part 4. FIG. It is a perspective view of the torque sensitive display body 1c of the Example in which the groove part 5 was formed. In the usage example of this invention , it is a perspective view of the principal part used for a steel-frame large-scale structure. It is a front view of the principal part which shows the state used for the crack 9 of the wall surface 8 in the usage example of this invention. FIG. 3 is a perspective view of a main part used for a U bolt 13 in a usage example of the first embodiment of the present invention. It is a usage example of 3rd Example of this invention, and is a perspective view of the principal part used for the attachment holding | maintenance metal fitting 20 hold | maintained in the cross shape. It is front sectional drawing of the principal part which shows the use condition of the torque sensitive display body 1e of 3rd Example of this invention. It is a top view of the principal part which shows the use condition of the torque sensitive display body g of this invention. It is a top view of the principal part which shows the use condition of 4th Example of this invention. It is a front view of the principal part which shows the use condition of 4th Example of this invention.

In a mounting / holding bracket having a pair of bolt parts such as a U-bolt or a crossed state, when the holding plate of the mounting / holding bracket is fastened and held with a nut, the distortion due to the bending of the holding plate with a predetermined tightening torque Is a torque sensitive indicator that displays the presence or absence of deformation and the scale of deformation as fracture or crack, and is a brittle material such as ceramics that undergoes brittle fracture and plastic deformation with its deforming strain force. Depending on the desired breaking point for brittle fracture, a predetermined length, width and thickness are combined to form a plate-shaped body having a predetermined shape, or the formation is applied and dried as a paint into a predetermined shape. Torque sensitive display body formed by
Further, the as coloring torque sensing display body colored torque sensitive display body, a colored torque sensitive display body is provided in a combination of contrasting display layer having a ductility colored with a color other than the similar color,
Also, when a plurality of torque- sensitive display bodies having different fracture points that undergo plastic deformation due to brittle fracture are arranged side by side,
In addition, a torque-sensitive display that displays the presence or absence of deformation of the holding plate and the scale of deformation as a brittle fracture, provided as a torque- sensitive display on the bent portion near the center of one side or the left and right sides of the holding plate. Realization of body provision.

A first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a torque- sensitive display body, and the torque- sensitive display body 1 is a brittle material such as ceramics, alumina, glass, plastic, etc. In accordance with the difference in fracture point of brittle fracture, a predetermined length, width and thickness are combined to form a plate-shaped body having a predetermined shape so as to cause brittle fracture, or the formation can be directly performed at a predetermined position. The paint is applied and dried in a predetermined shape as a paint to obtain a torque sensitive display body, and the torque sensitive display body 1 can display whether or not a specific portion is deformed by plastic deformation due to brittle fracture and the scale of the deformation.

The coating material may be a material other than the above as long as it is a brittle material that has a predetermined shape and is prone to brittle fracture when dried, and when the torque sensitive display 1 is used, Since it is easy to cause brittle fracture due to deformation such as deformation when sticking when using it, before sticking, seal it so that it does not dry with a sheet-like sealing material in an undried soft ductility state, open, Although it is preferable to form it in a use state where brittle fracture occurs when it is stuck and dried, the illustration is omitted.

And Thus, FIG. 2, the second colored torque sensitive display body 1a embodiment, colored torque sensitive display body 1a of the present invention, ductile film on the lower layer is colored the torque sensitive display 1 The colored torque sensitive display 1a and the comparative display layer 2 are colored with a color other than the same color as the colored torque sensitive display 1a.

When the colored torque sensitive display 1a is brittle fractured and plastically deformed, a brittle fracture part 3 is formed as shown in FIG. By coloring with a color other than the same color as the colored torque sensitive display 1a, the color of the lower contrast display layer 2 is conspicuously colored, for example, the colored torque sensitive display 1a is colored white, By coloring the layer 2 red, the red color of the lower layer can be seen from the white gap of the colored torque sensitive display 1a, so that the brittle fracture portion 3 can be easily confirmed.

FIG. 4 shows a notch distortion sensitive display 1b according to another embodiment of the present invention. The notch distortion sensitive display 1b is a substantially V-shaped notch from one side of the torque sensitive display 1. By forming the portion 4 and adjusting the depth of the substantially V-shaped cutout portion 4 (the distance of the width of the torque sensitive display 1), it is possible to change the breaking point where the brittle fracture and plastic deformation occur. Formed.

FIG. 5 shows a V-groove strain sensitive display 1c according to another embodiment of the present invention. The V-groove strain sensitive display 1c has a plane in the vicinity of the center in the longitudinal direction of the torque sensitive display 1. A substantially V-shaped groove portion 5 is formed so as to cross, and by adjusting the depth of the substantially V-shaped groove portion 5 (the distance of the thickness of the torque sensitive display body 1), brittle fracture occurs. The V-groove strain sensitive display 1c is effective when a relatively wide flat surface such as a wall surface described later needs to be provided on the flat surface side. It is also effective when used in a portion where it is necessary to detect a small bending distortion force on the plane side.

  Thus, when each of the above embodiments is used, it is appropriately selected according to the object to be used, and the use example shown in FIG. 6 is used for a large-scale structure such as a steel tower 6 constructed of a steel structure. Thus, the notch strain sensitive display 1b is attached to a predetermined position of the steel frame 7 of the steel tower 6 so as to know the bending state of the steel tower 6 as a whole. Therefore, the notch distortion sensitive display body 1b which is longer than usual is used and the depth of the substantially V-shaped notch 4 is increased to make it easy to catch the deformation. The notch distortion sensitive display bodies 1b and 1b having different V-shaped cutout portions 4 and 4a are arranged in parallel so that the change in the deformation scale of bending can be displayed as the upper limit and the lower limit.

Therefore, the conductive strain sensitive display 1d of another embodiment shown in FIG. 7 detects a change in which a crack 9 of the wall surface 8 such as a viaduct or a tunnel is enlarged. The conductive strain sensitive display 1d is provided across the crack 9 of the wall surface 8 so as to detect a change in the crack 9 due to brittle fracture of the torque sensitive display 1 of the embodiment. Conductive strain sensitive displays 1d, 1d having different depths of substantially V-shaped notches 4, 4a are arranged side by side so that the magnitude of deformation due to external force applied to the crack 9 of the wall surface 8 can be displayed. ing.

And the notch distortion sensitive display body 1b of another Example shown in FIG. 4 used for unmanned monitoring and detecting the change, such as expansion of the crack 9, contains a conductive material such as metal or carbon. 7 formed as the conductive strain sensitive display 1d of the other embodiment shown in FIG. 7 is used as a break sensor and is used together with an electronic circuit 10 for detecting disconnection, and in the drawing, it is arranged in parallel so as to cross the crack 9. A signal is applied to the electronic circuit 10 from both ends of the conductive strain-sensitive display bodies 1d and 1d. When the conductive strain-sensitive display bodies 1d and 1d are brittlely broken, the electronic circuit 10 detects disconnection and transmits. 11, the fact that the crack 9 has changed such as expansion is transmitted.

Note that the transmission of the signal of the transmission device 11 is selected to be wired or wireless according to the installation site, and the electronic circuit 10 that detects disconnection is a commonly known electronic circuit 10 that detects disconnection, Although the shape of the notch distortion sensitive display body 1b of the above-described embodiment is used, the torque sensitive display body of the first embodiment may be simply used regardless of the shape of the other embodiment. use 1, a change such as the crack 9 has expanded as a display of plastic deformation in brittle fracture, it can also be used so as to visually confirm.

Thus, in the usage example of the embodiment shown in FIG. 8 and FIG. 9, the torque sensitive display 1 is indicated by the plastic deformation due to its brittle fracture, and whether or not the specific portion is deformed and the scale of the deformation are displayed. Thus, it is used as the torque-sensitive display bodies 1e and 1f of the embodiment that can replace the index that a predetermined force is applied by the plastic deformation due to the brittle fracture with the tightening torque, thereby knowing the tightening torque.

  Therefore, in the usage target member shown in FIG. 8, two rod-like members 12 and 12 a that are generally provided are used in the usage example in which the rod-like member 12 a that is added in parallel is connected to the rod-like member 12 that is erected in a columnar shape. The U-bolts 13 that are generally available on the market are used for connecting and holding, and the rod-like members 12 and 12 a are held between the U-bolts 13 and the holding plate 14 and are held and fixed with nuts 15 and 15.

  The commercially available U-bolt 13 includes a U-shaped curved portion 16, a pair of linear portions 17 and 17 continuously parallel from both ends thereof, and screw portions 18 and 18 formed on the tip side. In general, it is used together with the holding plate 14 described above. As shown in FIG. 8, the threaded portions 18 and 18 are inserted into holes formed in the holding plate 14 and screwed with the nuts 15 and 15. The rod-shaped members 12 and 12a are used in such a manner that they are held and fixed in a sandwiched manner between the curved portion 16 and the holding plate 14.

Another use target member shown in Figure 9, those commonly used to hold the bar-like member in a cross state, for example, assembling the reinforcing frame rebar cage, such as those used in seismic foundation piers, etc. In the shape of a metal fitting that is sometimes used and held in a cross state, a pair of straight portions 17 and 17 of the U-bolt 13 that are parallel to each other are bent into a substantially U shape, and the substantially U-shaped bottom portion. Bar-shaped support portions 19 and 19 are formed in the corresponding portion, and, like the U-bolt 13 described above, a U-shaped curved portion 16 and a mounting and holding bracket 20 provided with screw portions 18 and 18 are formed.

  8 and 9, in the tightening torque management of the U bolt 13 and the mounting bracket 20, the use example of the U bolt 13 shown in FIG. 8 is to hold the rod-shaped members 12 and 12 a with the holding plate 14. The torque sensitive indicator 1e is attached to the substantially central portion of the surface of the holding plate 14 fastened and held by the nuts 15 and 15, and the mounting example of the mounting holding metal 20 shown in FIG. A plate-shaped reinforcing frame 21 is placed, and a round bar-shaped main bar 22 is mounted on the reinforcing frame 21 in a cross shape so as to be sandwiched between the curved portion 16 and the holding plate 14 provided on the screw portions 18 and 18. Then, the torque sensitive display bodies 1e and 1f are juxtaposed and attached to the substantially central portion of the surface of the holding plate 14 that is fastened and held by the nuts 15 and 15 while supporting the main bar 22, and tightening torque by the fastening and holding thereof. The holding plate 14 corresponding to the amount of distortion force, 4 is curved, the deflection by the torque-sensitive display body 1e, 1f is in brittle fracture by plastic deformation, and displays a predetermined tightening torque.

Further, the torque-sensitive display bodies 1e and 1f of the embodiment shown in FIG. 9 are arranged in parallel by the difference in brittle fracture values to know the upper and lower limits. That is, the torque-sensitive display bodies 1f are first brittlely fractured. It is set as a predetermined torque value, and when the torque sensitive display 1e breaks brittlely, an excessive torque value is set so as to cause a brittle fracture with a larger deflection than the torque sensitive display 1f. The upper and lower limits of the torque value can be known.

  In the use of the torque sensitive display bodies 1e and 1f shown in FIG. 9, a rectangular plate-shaped torque sensitive display body 1e is formed on the surface of the holding plate 14 and the rectangular plate-shaped central portion is constricted along with it. The torque sensitive display 1f is attached, and the torque sensitive display 1f has a narrowing width so as to have substantially the same function as the notch strain sensitive display 1b and the V-groove strain sensitive display 1c. The tightening torque value at which brittle fracture occurs due to the corresponding strain force can be set.

  Then, the management of the tightening torque value by the torque sensitive display bodies 1e and 1f by the bending of the holding plate 14 shown in FIGS. 8 and 9 described above will be described in more detail as a representative example. As shown in FIG. 8, the rod-shaped members 12 and 12a are inserted between the screw portions 18 and 18 of the U-bolt 13 and the holding plate 14 is inserted and screwed with nuts 15 and 15 to bend the bent portion 16. The rod-shaped members 12, 12a are held and fixed by the holding plate 14 and the nuts 15, 15.

  As shown in FIG. 10, when the nuts 15 and 15 are tightened to a predetermined torque value, the holding plate 14 is bent by the fastening force from a flat state, and a part of the torque sensitive display body 1e is bent by the bending. As shown in the drawing, it is possible to know that the brittle fracture part 3 is formed by forming the brittle fracture part 3 (in the drawing, approximately the center part of the torque sensitive display 1e), and that a predetermined tightening torque has been reached by plastic deformation.

  The value that reaches the brittle fracture is set according to the material of the design specifications required for the holding plate 14 to be used and the thickness, length, etc. of the dimensions. Set by specification.

Further, the torque-sensitive display bodies 1g and 1g of FIG. 11 showing an example of use of another embodiment are respectively provided on one of the side surfaces so that brittle fracture occurs corresponding to the strength of the strain force due to the fastening force. Two types of cutouts 4 and 4a each having a substantially V shape and different depths are formed and adhered to the plane of the holding plate 14 for use, which is the strength of the fastening force of a predetermined torque value, The notch 4 having a deep notch is first brittlely fractured, and the notch 4a having a shallow notch that is set to be brittle fractured at an excessive tightening torque value is then brittlely fractured. With the torque, the notch 4 is first brittlely fractured, the illustrated brittle fracture 3 appears, and it can be known that it has been fastened with a predetermined tightening torque value. If there is excessive fastening, the notch 4a becomes brittle. You can know by destroying.

  The torque-sensitive display bodies 1g and 1g having different notch depths in the above-described use example set the notch 4 having a deep notch to a predetermined torque value and the notch 4a having a shallow notch to an excessive torque value. Thus, it can be displayed that the bolt has been tightened within a certain range, and since the brittle fracture is a plastic deformation, it can be confirmed even in a tightening inspection after work.

  That is, when the nuts 5 and 5 shown in FIG. 10 are tightened to the predetermined torque value, the holding plate 14 is bent by the distortion force, so that the notch 4 described above is brittlely broken and reaches the predetermined torque. It can be known that this can be tightened with a predetermined torque without using a generally used torque wrench but with a normal tool wrench.

  Further, since the V-shaped notch causes stress concentration in the V-shaped narrow portion, when a strain force occurs, the V-shaped notch always breaks brittlely from the V-shaped narrow portion. By concentrating the stress in the narrow portion, ductility is reduced, and thus the brittle fracture can be caused accurately by the strain force of the fastening, and the predetermined torque can be known.

  12 and FIG. 13 shows an example of use by sticking to the side surface of the holding plate 14, and the torque sensitive display bodies 1g and 1g having different depths of the notches 4 and 4a, respectively. Affixed to both side surfaces, and the holding plate 14 is bent by the above-described tightening distortion force, a distortion force is applied to open the notches 4 and 4a from the width side of the torque sensitive display bodies 1g and 1g. The brittle fracture occurs, and the brittle fracture portion 3 shown in FIG. 13 is formed. By applying the strain force so as to open, the brittle fracture is likely to occur even with a small strain force, and a precise torque value can be set accordingly.

  In other words, in the embodiment provided on the side surface side, brittle fracture occurs more sensitively reflecting the bending strain force than in the embodiment provided on the plane side, and this is because the stress concentration applied to the V-shaped narrow portion is reduced on the plane side. On the side surface side, the stress concentration applied to the V-shaped narrow portion acts greatly, and the deflection corresponding to the curvature of the holding plate 14 is compared with the torque sensitive display bodies 1g, 1g on the plane side. In the case of the side of the side in the thickness direction, it is a distortion in the width direction, so the bending width is large with respect to the bending, and the strain force is large by the difference in thickness. If the strain force is so small that it cannot be handled on the flat surface side, it can be handled on the side surface side. Also, precise torque value It can be set also.

  In addition to the U-bolt 13 and the mounting / holding metal fitting 20, the pair of straight portions 17 and 17 and the screw portions 18 and 18 are provided on the distal end side, and the screw portions 18 and 18 are fastened with nuts 15 and 15. The holding plate 14 is held and fixed by a pair of screw members such as bolts, and is not particularly shown as long as it is used at a position where the holding plate 14 is bent and generates a strain force.

Moreover, each used examples, while rice each identify one embodiment shown, without being bound by this each use case, to change the respective embodiments with each other, also in combination of the respective embodiments using However, the illustration is omitted.

Each of the torque or strain sensitive display bodies for brittle fracture of the present invention is used as confirmation and inspection management of the mounting holding metal fittings having a pair of bolt parts used for rebar rods assembled with U bolts or rebars , the flexural deformation amount of the display of a large structure to be built like in steel structure or concrete, or used as a display of the amount of deformation of the deformation amount of the display or small separately members of large structures such as changes in cracks in the wall, such as a tunnel it can.

1 torque sensitive display body 1a colored torque sensitive display body 1b notch strain sensitive display body 1c V Mizoibitsu sensitive display body 1d conductive strain sensitive display body 1e, 1f, 1g torque sensitive display 2 contrasting display layer 3 brittle fracture unit 4 notch Part 5 Groove part 6 Steel tower 8 Wall surface 9 Crack 10 Electronic circuit 13 U bolt 14 Holding plate 15 Nut 18 Screw part 20 Mounting bracket.

Claims (4)

U-bolts that hold a holding plate between a pair of bolt parts and fasten and hold with nuts, or rebars of reinforcing steel rods in a lattice shape, and a holding plate that bridges a pair of bolts and fastens and holds with nuts to assemble in a lattice shape Oite the mounting holding bracket for holding the cross state Te, when the retaining plate of the mounting holding bracket is fastened retained with a nut, fracture or brittle fracture by the strain retention plate is bent at the predetermined tightening torque value A predetermined length, width, and width corresponding to the desired fracture point of brittle fracture in a brittle material such as ceramics, alumina, glass, and plastic so that a predetermined tightening torque can be displayed by cracking and plastic deformation Forming a plate-shaped body having a predetermined shape by combining the respective dimensions of the thickness, or forming the coating directly on a predetermined position of the holding plate by applying and drying in a predetermined shape as a paint. Torque-sensitive display body to brittle fracture and butterflies.   2. The brittle fracture according to claim 1, wherein a torque-sensitive display body that is brittlely broken is colored and a soft contrast display layer having ductility is provided in a lower layer of the thin film that is colored in a color other than the same color as the torque-sensitive display body. Torque sensitive indicator.   The torque-sensitive display for brittle fracture according to claim 1 or 2, wherein the torque-sensitive display body for brittle fracture is arranged in parallel with a plurality of torque-sensitive display bodies having different fracture points that undergo brittle fracture and plastic deformation. body.   The torque-sensitive display body for brittle fracture according to claim 1 or 2, wherein the torque-sensitive display body provided on the holding plate is provided at a bent portion near the center of one side or the left and right side of the holding plate. .

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