JP3527558B2 - Maximum deformation detection sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure material, a film material, etc. in various structures such as ground structures such as buildings, bridges and membrane structures, or non-ground structures such as aircraft and ships. A technology for non-destructively detecting changes in strength caused by the load of external forces such as earthquakes on members over time to make a predictive diagnosis of the possibility of structural damage. The present invention relates to a maximum deformation amount detection sensor used to detect a maximum deformation amount corresponding to a load.

[0002]

2. Description of the Related Art As a maximum deformation amount detecting sensor, there are sensors proposed in Japanese Patent Application No. 5-138977 and Japanese Patent Application No. 5-297609. These have a structure in which a plurality of conductive elements having an appropriate electric resistance value, such as carbon fiber, are connected in parallel between a pair of terminals while slightly changing the degree of slack of each, The conductive member is attached and used so that tension is applied to each of the conductive elements in accordance with the deformation of the component to be detected. Then, when tension is applied, the conductive elements having different degrees of slack are sequentially broken in the order of increasing slack, and the result is detected as a change in electric resistance between the terminals. In other words, the electrical resistance value between both terminals indicates which conductive element has been broken, and it is possible to know the maximum value in the deformation that has occurred in the component member, depending on which conductive element is broken. ing.

These maximum deformation amount detection sensors can be used universally for various types of structures, can be expected to have considerably high detection accuracy, and have many advantages such as a simple structure. have. However, as its basis, it gives the conductive element a slightly different slack,
Since the maximum deformation amount is detected by using this difference in the degree of slack to generate sequential self-breaking in accordance with the deformation amount of the component to be detected, the stability of detection accuracy is improved. Has the disadvantage that it cannot always hold enough. That is, in these maximum deformation amount detection sensors, the setting of the degree of slack in each conductive element is an important factor in stabilizing the detection accuracy, and the variation in the tensile strength of each conductive element affects the detection accuracy. It is easy, but it is relatively difficult to set a slightly different degree of slack in each conductive element, and therefore sequential breakage of each conductive element according to the amount of deformation in the constituent member to be detected does not necessarily occur reliably. In some cases, it is unexpectedly difficult to maintain the uniformity of the tensile strength of each conductive element, and the stability of detection accuracy cannot be sufficiently maintained.

[0004]

SUMMARY OF THE INVENTION The present invention has been made against such a background by the present invention. In the present invention, the electric resistance having a plurality of conductive elements as described above is correlated with the deformation amount of the object to be detected. It is an object of the present invention to make it possible to more stably obtain high detection accuracy with respect to a maximum deformation amount detection sensor that performs a fixed change to detect the maximum deformation amount.

[0005]

To this end, according to the present invention, a plurality of conductive elements each having a predetermined electric resistance value are arranged side by side, and the conductive elements are sequentially cut. A conductor formed so as to form a circuit that changes the resistance value in a correlated manner, and a cutting means capable of cutting the conductive element of the conductor. A maximum deformation amount detection sensor is formed with a structure that is relatively movable with respect to the structure, and the maximum deformation amount detection sensor is formed relative to the constituent member of the structure to be detected according to the deformation of the constituent member. It is attached so as to cause movement, and by sequentially cutting the conductive element of the conductor by the cutting means according to the movement amount of this relative movement, it is possible to detect the maximum deformation amount in the component member to be detected. There is.

One of the preferred embodiments of such a maximum deformation amount detection sensor (hereinafter referred to as the first embodiment) is, as schematically shown in FIG. 1, a plurality of linear bodies such as carbon fibers. The conductive elements 1, 1, ... Are arranged side by side and connected between a pair of terminals 2, 2, and each conductive element is folded back at an intermediate portion to provide a bent portion 3, and the bent portion is laterally bent. The conductor 4 is formed in a structure in which the conductors 4 are arranged in a line, and when the relative movement with the conductor as indicated by the arrow X is performed, the blade portion 5 moves relative to each conductive element at the bent portions arranged in a horizontal line as described above. An example is a structure in which the cutting means 6 is formed by sequentially pressing the conductive elements in contact with each other according to the amount.

In another one of the other preferred embodiments (second embodiment below), the conductor 10 is, for example, printed or attached with a suitable conductive material, as schematically shown in FIG. , The linear conductive elements 12, 12, ... Are formed side by side at a predetermined interval on the sheet-shaped substrate 11, and the conductive elements 12, 12, are formed on the terminals 13, 13 formed on the substrate 11 in the same manner. The structure is such that both ends of ... are connected. Then, the cutting means 14 is moved relative to this conductor as indicated by an arrow Y, or the conductor 10 is cut.
4 is moved relative to 4 so that each conductive element is cut sequentially from the end with the substrate or on the substrate.

The detection accuracy of the above-described maximum deformation amount detection sensor according to the present invention is mainly determined by the accuracy of arrangement of the conductive elements and the accuracy of the cutting means. It is easy to give the necessary arrangement to the conductive elements with high accuracy, and there is no particular difficulty in configuring the cutting means in terms of accuracy.

For example, in the case of the first aspect, since the arrangement of the conductive elements only needs to arrange the bent portions of the conductive elements in a horizontal line, it is easy to give high precision to it. In particular, in the case of this configuration, since the conductive element is folded back, even if a lateral straight line of the bent portion and an error occur, the influence can be halved and higher accuracy can be maintained. Further, the length of each conductive element may be uniform, and it is preferable that the length is uniform. Therefore, by uniformly setting the length of each conductive element, the processing can be further facilitated. You can Further, the cutting means only needs to be provided with, for example, a structure in which the blade portions are arranged in a stepwise manner, and the processing thereof is not particularly difficult in terms of accuracy.

Further, in the case of the second aspect, the arrangement of the conductive elements may be simply arranged side by side at a predetermined interval, and high precision processing can be easily performed by utilizing, for example, a technique of printed wiring. be able to. Further, the cutting means may be of a structure like a general cutter, which is generally sufficient, and there is no difficult element in terms of accuracy.

In addition to the above accuracy factors, the relative movement accuracy between the conductor and the cutting means also affects the detection accuracy of the maximum deformation amount detecting sensor according to the present invention, but the relative movement between the conductor and the cutting means is given. The structure only needs to movably support the moving element with a suitable support structure, and this is not a difficult element in terms of accuracy.

As described above, in the maximum deformation amount detection sensor according to the present invention, since the stability of the detection accuracy is given by the element which is easily processed with high accuracy, the high detection accuracy is stable. It is possible to obtain it.

In the above-described maximum deformation amount detection sensor, particularly in the maximum deformation amount detection sensor of the first aspect, the bending portions of the conductive elements of the plurality of conductors are moved in the direction of relative movement with the cutting means. It is possible to provide a structure in which they are provided in a state of being lined up with each other at a predetermined interval. According to this structure, a larger number of conductive elements can be accommodated in a compact structure, and thus even a large amount of deformation can be detected, and the detection range can be widened despite the compact structure.

Further, in the maximum deformation amount detection sensor of the first aspect, by using carbon fiber for the conductive element, it is possible to perform detection with higher accuracy. That is, in the maximum deformation amount detection sensor of the first aspect, as described above, the blade of the cutting means is pressed against the bent portion to cut the conductive element. ", Which causes disconnection. Therefore, by using the carbon fiber which has a high tensile strength and is difficult to stretch but is relatively weak against cutting due to breakage, this breaking breakage can be caused sensitively and detection accuracy can be improved.

Further, in the maximum deformation amount detection sensor of the first aspect, if a dummy resistance is added to each conductive element, the linearity of resistance change at the terminal is improved,
Output processing becomes easy.

Further, in the maximum deformation amount detection sensor of the first aspect and the second aspect, particularly the maximum deformation amount detection sensor of the second aspect, the conductive element is formed by using a material having an appropriate resistance value. In addition to this, it is also possible to form a conductive element having a necessary resistance as a whole by forming a portion to be cut with a good conductor such as copper or aluminum and connecting a resistance element to this.

Furthermore, regarding the maximum deformation amount detection sensor of each of the first and second aspects, a conductive element for initial setting is provided, and by cutting this with the cutting means, the initial position between the cutting means and the conductor is set. Being able to set the relationship is convenient for making accurate initial settings when actually using it.

Further, in the maximum deformation amount detecting sensor of each of the first and second aspects, a conductive element which is not cut by the cutting means is provided for inspection, and the conductive element for inspection is used for disconnection of the output circuit. By making it possible to inspect the presence or absence, the reliability can be further enhanced.

[0019]

EXAMPLES Examples of the present invention will be described below. The first embodiment is an example corresponding to the first aspect described above, and FIGS. 2 and 3 show a maximum deformation amount detection sensor 20 according to the present embodiment. As shown in the figure, the maximum deformation amount detection sensor 20 of this embodiment is
Accommodates a conductor 22, a cutting means 23, a slider 24, and a pair of output pins 25, 25 inside a flat transparent plastic case 21. These are also covered by a transparent plastic cover. The structure is covered with 26.

The conductor 22 is basically based on the principle structure described above with reference to FIG. 1, and is a conductive element 27 using a carbon fiber bundle having an electric resistance of about 200 μΩ / cm,
27 are connected side by side at a predetermined interval as shown in FIG. 3 between a pair of terminals 28, 28 (only one of which is shown in FIG. 3), and folded back at the middle portion. The bent portions 29 (FIG. 2) are provided such that they are aligned in a horizontal line, and in order to maintain such an arrangement state of the conductive elements 27, the holding sheets 30 are provided on both sides of the bent portions 29. Hold it. The holding sheet 30 is formed by sandwiching two transparent insulating sheets from both sides of the conductive element 27 with the interposition of an adhesive, so that the conductive element 27 has two sheets. It is in a state of being wrapped in an adhesive between the insulating sheets. Lead wires not shown in the figure extend from the terminals 28, 28 and are connected to the output pins 25, 25.

The cutting means 23 is formed by using a thin plastic plate, and an engaging receiving portion 31 which engages with a slider 24 described later is provided at a front end portion of the cutting means 23. A guide groove 32 is formed in a comb shape toward the side (FIG. 3), and a blade portion is provided at the back end of the guide groove 32. Each guide groove 32 has a conductive element 27.
The intervals are set to correspond to the above array intervals, and the lengths from the tip end side are made different in order. More specifically, the upper end is the shortest as seen in FIG.
2nd from top, 2nd from bottom, 3rd from top, 3 from bottom
The length is gradually increased in the order of th.

The cutting means 23 has a structure in which the conductive elements 27 are inserted into the guide grooves 32 one by one so that the conductive material 2 is formed.
When the slider is moved as shown by an arrow Z in FIG. 3 via a slider 24, which will be described later, the blade portion at the back end of the guide groove 32 has the above guide groove length in accordance with the amount of movement. The conductive elements 27 are pressed in order and cut in order. As described above, the cutting means 23 is moved in this example, but the conductor 22 can be moved by slightly changing the structure.

The slider 24 is made of aluminum and has a rear end portion which engages with the engagement receiving portion 31 of the cutting means 23.
3 and the brake portion 34, an opening portion 35 in the middle portion, and a connection portion 36 at the tip end portion are formed in a flat plate shape. The slider 24 can move while slidingly contacting the inside of the side wall of the case 21 with an appropriate frictional resistance provided by the brake portion 34.
In addition, the locking projection 37 provided at the tip of the case 21 enters the opening 35, and the opening 3 is moved during the movement.
The rear end surface of the plate 5 contacts the locking projection 37 so that it can be prevented from falling out of the case 21.

The other elements will be briefly described. A brake member 38 is incorporated in the brake portion 34, and the case 21 is urged by an urging means (not shown).
Brake force is generated by pressing against the inner wall of the. Further, the slider 24 can be locked by a lock pin 39 when it is not used. Further, the conductor 22 is locked to the case 21 by a locking pin 41 together with the spacer 40 interposed between the holding sheets 30 and 30.

The maximum deformation amount detection sensor 20 described above is used as schematically shown in FIG. That is, case 21
One end is fixed near one end of the constituent member P of the structure to be detected through the fixing portion 42 formed in
A wire W or the like having an appropriate length is connected to the connecting portion 36 of the slider 24, and the end of the wire W is fixed near the other end of the component P. The tension of the wire W depends on the component P.
Parallel to the main direction of deformation that is expected to occur.
When the component P is deformed in this state, the wire W is correspondingly tensioned, and as a result, the slider 24 moves, and the conductive element 27 is moved as described above according to the amount of movement.
Cut off in sequence. Then, in response to this, the resistance value of the conductor 22 gradually increases, and by measuring the resistance value periodically or at a necessary time, it is possible to know the degree of the maximum deformation amount of the deformation that has occurred in the past.

FIG. 5 shows another example of a conductor that can be used in the maximum deformation amount detecting sensor of the first embodiment. This conductor is electrically conductive to each conductive element 27, 27, .... The same carbon fiber bundle as the sex element 27 bypasses the dummy resistor 43.
Connected as. The equivalent circuit in this case is as shown in FIG. 6, and the portion marked with X is to be cut. When the dummy resistor is used in this way, the linearity of the resistance change in the output is improved, and the output processing is facilitated.

FIG. 7 shows an example in which a plurality of, in this example, three conductors 44a, 44b, and 44c are used in combination, and can be used in the maximum deformation amount detection sensor of the first embodiment as well. it can. In this composite structure, the cutting means 2
3, first, the conductive elements 27 of the conductor 44a are sequentially cut, then the conductive elements 27 of the conductor 44b are sequentially cut, and finally the conductive elements 27 of the conductor 44c are sequentially cut. . As a result, the moving width of the cutting means 23, that is, the range of the maximum detectable deformation amount can be increased.

FIG. 8 shows an example of a conductor formed by interposing an insulating spacer 45 between each conductive element 27, and FIG. 9 corresponds to the holding sheet 30 described above. In the example in which the holding groove 46 is provided in the object and the conductive element 27 is housed in the holding groove 46, these are also the first
It can be used for the maximum deformation amount detection sensor of the embodiment.

FIG. 10 shows still another example of a conductor that can be used in the maximum deformation amount detection sensor of the first embodiment. This conductor is a linear conductive element (not shown).
Is entirely covered with a flexible holding sheet 47, and a cutting means 49 having a blade portion 48 continuously inclined at a predetermined angle is used for cutting.

12 to 14 show a maximum deformation amount detection sensor 50 according to the second embodiment, which corresponds to the second mode. As shown in the figure, the maximum deformation amount detection sensor 50 of the present embodiment is a case 5 formed in a horizontally long cylindrical shape.
1 has a structure in which a conductor 52, a cutting means 53, and a slider 54 are incorporated. The maximum deformation amount detection sensor 50 according to the second embodiment is also used in the same manner as the maximum deformation amount detection sensor 20.

As shown in FIG. 15, the conductor 52 is formed by the method of a flexible printed circuit board. Specifically, the copper wire patterns 56 for conductive elements are horizontally arranged at a predetermined interval on the plastic film substrate 55, and the copper wire patterns 57 and 58 for terminals are connected to the respective ends of the copper wire pattern 56. Each of them is formed by printing, and a chip resistor 59 is connected to each copper wire pattern 56. The equivalent circuit of the conductor 52 is as shown in FIG. 16, but it is also possible to form it as the equivalent circuit shown in FIG.

The cutting means 53 is knife-shaped, and is held by screws at the rear end of the slider 54 formed in the shape of an elongated rod.

A slider 54 holding a cutting means 53
Is slidably guided by a slide guide portion (not shown in the drawing) formed on the case 51 so that it can be moved to the right in FIG. 12, and the cutting means 53 is moved according to this movement. The copper patterns 56, 56, ... Of the conductor 51 are cut together with the substrate 55.

[0034]

As described above, the maximum deformation amount detection sensor according to the present invention has a structure in which each conductive element in the conductor is cut by the relative movement of the cutting means with respect to the conductor, and both are highly accurate. Since the stability of the detection accuracy can be provided by the element that is easily processed, the high detection accuracy can be stably exhibited.

[Brief description of drawings]

FIG. 1 is a principle diagram of an embodiment of a maximum deformation amount detection sensor according to the present invention.

FIG. 2 is an exploded view of the maximum deformation amount detection sensor according to the first embodiment of the present invention.

FIG. 3 is a plan view of the maximum deformation amount detection sensor of FIG. 2 excluding a cover.

FIG. 4 is a schematic diagram of a usage state of the maximum deformation amount detection sensor of FIG.

FIG. 5 is a perspective view of a conductor according to another example.

FIG. 6 is an equivalent circuit diagram of the conductor of FIG.

FIG. 7 is a perspective view showing a state in which a plurality of conductors are used in combination.

FIG. 8 is a developed plan view of a conductor having a structure in which an insulating spacer is interposed between the conductive elements.

FIG. 9 is a partial perspective view of a conductor having a structure forming a holding groove for a conductive element.

FIG. 10 is a perspective view schematically showing a conductor having a structure in which the conductive element is entirely covered with a flexible holding sheet and a cutting means for cutting the conductor.

FIG. 11 is a principle view of another form of the maximum deformation amount detection sensor according to the present invention.

FIG. 12 is a side view showing the internal structure of the maximum deformation amount detection sensor according to the second embodiment of the present invention.

FIG. 13 is a plan view seen from the direction of the arrow DA in FIG.

FIG. 14 is a cross-sectional view that simplifies the state viewed from the arrow DB direction in FIG. 12;

15 is a perspective view of a conductor of the maximum deformation amount detection sensor of FIG.

16 is an equivalent circuit diagram of the conductor of FIG.

FIG. 17 is an equivalent circuit diagram of another conductor.

[Explanation of symbols]

1, 12, 27, 56 Conductive element 4, 10, 22, 52 conductor 3, 29 fold 6, 14, 23, 53 Cutting means 20, 50 Maximum deformation amount detection sensor 55 substrate P component

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Yoshiike 2480 Mitakedo, Maruko-cho, Oka-gun, Nagano Nagano Keiki Seisakusho Co., Ltd. Maruko factory (72) Inventor Masato Ichikawa 2480, Mitakedo, Maruko-cho, Ogo-gun, Nagano Nagano Co., Ltd. Keiki Mfg. Co., Ltd.Maruko Plant (72) Inventor Hirokazu Nakasone 2480 Mitakedo Maruko-cho, Ogata-gun, Nagano Nagano Keiki Co., Ltd. Maruko Plant (72) Inventor Ikuya Toda 3-22-1 Higashiyama, Meguro-ku, Tokyo (56) References JP-A-7-128156 (JP, A) JP-A-6-331581 (JP, A) JP-A-4-109102 (JP, A) (58) Fields investigated (58) Int.Cl. ⁷ , DB name) G01L 1/00 G01L 1/20 G01N 27/00 G01B 5/30

Claims (3)

(57) [Claims] 1. A maximum deformation amount detection sensor for detecting the maximum deformation amount of deformation of a structural member of a structure, wherein a plurality of conductive elements each having a predetermined electric resistance value are arranged side by side. It is formed so as to form a circuit that gives a relative change in resistance value in accordance with the sequential cutting of the conductive element, so that it does not deform due to the deformation of the structure.
And a cutting means for abutting the conductive element of the conductor to cut the abutting conductive element. The conductor and the cutting means are movable relative to one another. And is attached so as to cause relative movement between the electric conductor and the cutting means in response to a deformation of the constituent member to be detected in the structure according to a deformation amount of the constituent member. The maximum deformation amount detection sensor is characterized in that the conductive element of the conductor is sequentially cut by the cutting means. 2. The conductor has a structure in which each conductive element formed of a linear body is folded back at an intermediate portion to provide a bent portion, and the bent portions of each conductive element are arranged in a horizontal line. Further, the cutting means has a structure in which the blade portion sequentially cuts the conductive elements by pressing the conductive elements at the bent portions arranged in a line in the horizontal direction in accordance with the relative movement amount when the cutting means moves relative to the conductor. The maximum deformation amount detection sensor according to claim 1. 3. The conductor has a structure in which linear conductive elements are formed side by side on a sheet-shaped substrate at predetermined intervals, and the conductive elements are formed in accordance with relative movement of the cutting means with respect to the conductor. The maximum deformation amount detection sensor according to claim 1, wherein the maximum deformation amount detection sensor has a structure in which the ends are sequentially cut.