JP2015206783A - Bending amount measuring device - Google Patents

Abstract

A bending amount measuring apparatus having a simple configuration is provided.
The bending amount measuring apparatus 1 includes first and third sheets made of the same material, the first and second sheet-like elastic bodies 21 and 22 being dielectrics, and sandwiching these dielectrics in a sandwich shape. The sensor unit 2 is formed by forming the first capacitor C1 and the second capacitor C2 using the electrode-like conductive elastic bodies 23 to 25 as electrodes, and the sensor unit 2 is the first sheet-like conductive elastic body. When bending to 23, the value of the alternating current flowing through the second capacitor C3 increases, and the alternating current flows through the terminal of the second sheet-like conductive elastic body 24, and the bending amount measurement voltage Vo from the electric circuit section 3 is increased. Is output.
[Selection] Figure 1

Description

  The present invention relates to a bending amount measuring apparatus that measures a bending amount of an object that is bent and deformed in a human or animal body or machine.

  2. Description of the Related Art Conventionally, several bending amount measuring apparatuses that measure a bending amount (degree of bending) of an object to be bent and deformed are known. Among them, as a comparatively simple structure, for example, in Patent Document 1, two piezoelectric films are attached in accordance with the amount of bending by closely attaching a sensor unit obtained by bonding two piezoelectric films to the surface of an object. A bending amount measuring apparatus for measuring a bending amount by measuring an electromotive force generated during the period is disclosed.

JP 2006-38710 A

  The bending amount measuring device is an industrial-use device that measures the amount of bending by setting it to a joint part of a medical or exercise device or robot that measures the amount of bending of a part of a human or animal body such as an elbow or knee. Since it can be used for various devices such as devices, it is desirable that it be as simple as possible.

  However, even the bending amount measuring device disclosed in Patent Document 1 having a relatively simple configuration requires a special piezoelectric film that is flexible and has piezoelectricity and exhibits desired characteristics.

  This invention is made | formed in view of the reason which concerns, The objective is to provide the bending amount measuring apparatus which is a more simple structure.

  In order to achieve the above object, the bending amount measuring apparatus according to claim 1 includes first to third sheet-like elastic bodies as dielectrics, and first to third sandwiching these dielectrics in a sandwich shape. Using the sheet-like conductive elastic body as an electrode, the first capacitor, the second sheet-like conductive elastic body, and the third between the first sheet-like conductive elastic body and the second sheet-like conductive elastic body. An AC voltage is applied to the first capacitor by applying an AC voltage to the sensor portion formed by forming a second capacitor between the sheet-like conductive elastic bodies and a terminal of the first sheet-like conductive elastic body. A first AC output circuit for flowing, a second AC output circuit for applying an AC voltage to a terminal of the third capacitor by applying an AC voltage to the terminal of the third sheet-like conductive elastic body, and a second sheet-like conductive elasticity Current measurement that measures alternating current flowing through body terminals and converts it into bending measurement voltage And when the sensor part is bent and deformed toward the first sheet-like conductive elastic body, the third sheet-like conductive elastic body side of the second sheet-like elastic body is When the second sheet-like elastic body is greatly extended and the thickness of the second sheet-like elastic body is reduced in accordance with the extension, the capacitance value of the second capacitor is increased, and the value of the alternating current flowing through the second capacitor is increased. An alternating current flows through the terminal of the elastic elastic body, and a current obtained by combining the alternating current and the alternating current flowing through the first capacitor flows as an alternating current through the second capacitor.

  The bending amount measuring apparatus according to claim 2 is the bending amount measuring apparatus according to claim 1, wherein both the first and second sheet-like elastic bodies are not provided with a gap or a depression. It is characterized by that.

  The bending amount measuring apparatus according to claim 3 is the bending amount measuring apparatus according to claim 1, wherein both or one of the first and second sheet-like elastic bodies is provided with a large number of gaps or depressions. It is characterized by being.

  The bending amount measuring apparatus according to claim 4 is the bending amount measuring apparatus according to any one of claims 1 to 3, wherein the first and second sheet-like elastic bodies are made of the same material. Features.

  The bending amount measuring apparatus according to claim 5 is the bending amount measuring apparatus according to claim 4, wherein the first and second sheet-like elastic bodies have the same thickness.

  The bending amount measuring device according to claim 6 is the bending amount measuring device according to any one of claims 1 to 5, wherein the bending amount is obtained by adding angles of both end portions of the sensor unit. It is characterized by doing.

  According to the present invention, a bending amount measuring apparatus having a simpler configuration can be provided.

It is a schematic diagram which shows the bending amount measuring apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the usage example of a bending amount measuring apparatus same as the above. It is a perspective view which isolate | separates and shows typically the component of the sensor part of a bending amount measuring apparatus same as the above. It is a perspective view which shows the modification of the sensor part of a bending amount measuring apparatus same as the above, and isolate | separates the component and shows typically. It is a perspective view which shows another modification of the sensor part of a bending amount measuring apparatus same as the above, and shows the components separated. It is a perspective view which isolate | separates the component and shows typically the other modification of the sensor part of a bending amount measuring apparatus same as the above. It is a graph which shows the characteristic curve by the experiment of the bending amount measurement voltage with respect to the bending amount in a bending amount measuring apparatus same as the above. It is a side view which shows typically the experimental structure of FIG. It is a graph which shows the characteristic curve by the simulation of the distortion with respect to the bending amount in a bending amount measuring apparatus same as the above. It is a perspective view which shows typically another modification of the sensor part of a bending amount measuring apparatus same as the above. It is a schematic diagram which shows the case where many bending parts generate | occur | produce in the sensor part of the bending amount measuring apparatus same as the above. It is a schematic diagram which expands and shows the bending part of the sensor part of a bending amount measuring apparatus same as the above. It is a graph which shows the characteristic curve by the experiment of the bending amount measurement voltage with respect to the bending amount in a bending amount measuring apparatus same as the above. It is a schematic diagram which shows the mode of wrinkles in the experiment of FIG.

  Hereinafter, modes for carrying out the present invention will be described. As shown in FIG. 1, the bending amount measuring apparatus 1 according to the embodiment of the present invention includes a sensor unit 2 and an electric circuit unit 3. For example, as shown in FIG. 2, the bending amount measuring device 1 includes a sensor unit 2 incorporated in a supporter 4 and applied to an elbow or the like, and from an electric circuit unit 3 through electric wirings 51 to 53 in a cable 5. A signal is sent to the sensor unit 2 or from the sensor unit 2 to the electric circuit unit 3.

  The sensor unit 2 includes a first sheet-like elastic body 23 having a first sheet-like elastic body 21 and a second sheet-like elastic body 22 as dielectrics and sandwiching the dielectric bodies 21 and 22 in a sandwich shape. The second sheet-like conductive elastic body 24 and the third sheet-like conductive elastic body 25 are used as an electrode between the first sheet-like conductive elastic body 23 and the second sheet-like conductive elastic body 24. A second capacitor C2 is formed between the first capacitor C1, the second sheet-like conductive elastic body 24, and the third sheet-like conductive elastic body 25 (see FIG. 3). That is, the sensor unit 2 is formed by stacking five layers of sheet-like elastic bodies 23, 21, 24, 22, 25 in this order. For adhesion between the layers, for example, a thin adhesive can be used. The first and second sheet-like elastic bodies 21 and 22 are made of insulating silicon rubber, and the first to third sheet-like conductive elastic bodies 23, 24, and 25 are made of conductive silicon rubber. Can be used.

  When the sensor unit 2 is bent and deformed toward the first sheet-like conductive elastic body 23, the third sheet-like conductive elastic body 25 greatly extends. At this time, the third sheet-like elastic elastic body 25 side of the second sheet-like elastic body 22 extends greatly, and the thickness of the second sheet-like elastic body 22 decreases according to the extension. Then, since the electrode area of the second capacitor C2 is greatly enlarged and the distance between the electrodes is shortened, the capacitance value thereof becomes very large. On the other hand, since the change in the electrode area and the inter-electrode distance due to the shape change of the first sheet-like conductive elastic body 23 and the first sheet-like elastic body 21 is small, the capacitance value of the first capacitor C1 is changed. It is very small compared to the change of the second capacitor C2.

  Further, when the sensor unit 2 is bent and deformed toward the third sheet-like conductive elastic body 25, similarly, the capacitance value of the first capacitor C1 becomes very large. On the other hand, the change of the capacitance value of the second capacitor C2 is very small compared to the change of the first capacitor C1.

  The terminals 23 a of the first sheet-like conductive elastic body 23, the terminals 24 a of the second sheet-like conductive elastic body 24, and the terminals 25 a of the third sheet-like conductive elastic body 25 are electrical wirings constituting the cable 5. 51, 52, 53 are connected, and these electric wirings 51, 52, 53 are connected to the electric circuit section 3. Normally, the terminals 23a, 24a, and 25a are formed at end portions of the first to third sheet-like conductive elastic bodies 23, 24, and 25, respectively.

Electrical circuit section 3 includes a first AC output circuit 31 supplies the alternating currents I ₁ to the first capacitor C1 by applying an AC voltages V ₁ to the terminal 23a of the first sheet-like conductive elastic body 23, the a second AC output circuit 32 to the terminal 25a of the third sheet-like conductive elastic body 25 by applying an AC voltage V ₂ to the second capacitor C2 supplies the alternating current I _2, the second sheet-like conductive elastic It has a current measuring circuit 33 for converting an AC current I ₃ flowing through the terminals 24a of the body 24 to the voltage (bending amount measuring voltage Vo) measurement, the. The bending amount measurement voltage Vo is a voltage corresponding to the bending amount. The bending amount measurement voltage Vo may be an alternating current or a direct current converted voltage. In the present embodiment, the AC voltage V ₁ applied to the terminal 23 a of the first sheet-like conductive elastic body 23 and the AC voltage V ₂ applied to the terminal 25 a of the third sheet-like conductive elastic body 25 are: The ground potential is set as a reference potential, and the terminal 24a of the second sheet-like conductive elastic body 24 is set to be held at the same potential as the ground potential.

The first AC output circuit 31 and the second AC output circuit 32 are configured such that when the sensor unit 2 is not bent and deformed, the AC current I ₁ and the AC current I ₂ have the same amplitude with a phase difference of 180 degrees. either or both of the AC voltages V ₁ and the AC voltage V ₂ is adjusted. For example, the AC voltage V ₁ and the AC voltage V ₂ have a frequency of about 10 KHz and an amplitude of about 5V. Therefore, when the sensor unit 2 is not bent and deformed, the alternating current I ₁ flowing through the first capacitor C ₁ flows as the alternating current I ₂ through the second capacitor, so that the second sheet-like conductive elastic body 24 The alternating current I ₃ does not flow through the terminal 24a, that is, the current measuring circuit 33.

When the sensor unit 2 is bent and deformed in the first sheet-like conductive elastic body 23 side, since the capacitance value of the second capacitor C2 is very large, the value of the AC current I ₂ flowing in the second capacitor C2 is very Become bigger. On the other hand, the change in the capacitance of the first capacitor C1 is small, the change in value of the AC current I ₁ flowing in the first capacitor C1 is small. Therefore, the alternating current I ₃ flows through the terminal 24a of the second sheet-like conductive elastic body 24, and the current obtained by combining the alternating current I ₃ and the alternating current I ₁ flowing through the first capacitor C1 is the second current. the capacitor C2 flows as AC current _{I 2.}

When the sensor unit 2 is bent and deformed in the third sheet-like conductive elastic body 25 side, since the capacitance value of the first capacitor C1 becomes very large, the value of the AC current I ₁ flowing in the first capacitor C1 is very Become bigger. On the other hand, the change of the capacitance value of the second capacitor C2 is small, the change in value of the AC current I ₂ flowing in the second capacitor C2 is small. Therefore, a second alternating current terminal 24a of the sheet-like conductive elastic body 24 current I ₃ is, the sensor unit 2 to flow in the opposite direction as when bending deformation in the first sheet-like conductive elastic body 23 side, the current AC current I ₂ flowing through the AC current I ₃ to the second capacitor C2 is touched if flows in the first capacitor C1 as an alternating current I _1.

  The sensor unit 2 and the electric circuit unit 3 constitute a bending amount measuring device 1. The sensor unit 2 may be a dielectric body in which the first and second sheet-like elastic bodies 21 and 22 are elastically deformed, and the first to third sheet-like conductive elastic bodies 23, 24 and 25 are elastically deformed. As long as it is conductive, no special material is used. The electric circuit unit 3 is configured by a simple circuit. Therefore, the bending amount measuring apparatus 1 has a simpler configuration than the conventional one.

  As shown in FIG. 3, the first and second sheet-like elastic bodies 21 and 22 are preferably provided with no gaps or depressions in the following points. If the first sheet-like elastic body 21 and the second sheet-like elastic body 22 are not provided with a gap or a depression, the sensor unit 2 is bent and deformed toward the first sheet-like conductive elastic body 23. In this case, the change in the thickness of the second sheet-like elastic body 22 is increased, and the change in the capacitance value of the second capacitor C2 is increased, so that the sensor unit 2 moves toward the third sheet-like conductive elastic body 25. In the case of bending deformation, the change in the thickness of the first sheet-like elastic body 21 increases, and the change in the capacitance value of the first capacitor C1 increases. As a result, the sensitivity (bending amount measurement voltage Vo with respect to the bending amount) is increased. (The slope of the characteristic curve) increases.

  On the other hand, as shown in FIG. 4, the first and second sheet-like elastic bodies 21 and 22 may be provided with a large number of voids 21 a and 22 a or depressions. As an advantage in this case, they are easily bent and deformed. Note that the orientations of the large number of voids 21 a and 22 a or the depressions are not necessarily the same in the first sheet-like elastic body 21 and the second sheet-like elastic body 22. For example, as shown in FIG. 5, the orientations of a large number of voids 21 a or depressions of the first sheet-like elastic body 21 and the orientations of the numerous voids 22 a or depressions of the second sheet-like elastic body 22 may be orthogonal to each other. Is possible. Moreover, as shown in FIG. 6, it is also possible to make many voids 21a, 22a or depressions of the first and second sheet-like elastic bodies 21 and 22 have an oblique orientation such as a diagonal direction. Moreover, it is also possible that only one of the first and second sheet-like elastic bodies 21 and 22 is provided with a large number of voids 21a and 22a or depressions.

  Moreover, it is preferable that the 1st sheet-like elastic body 21 and the 2nd sheet-like elastic body 22 are the same materials. As a result, the first sheet-like elastic body 21 and the second sheet-like elastic body 22 are almost the same or very close to the characteristic curve of the bending amount measurement voltage Vo with respect to the bending amount, so that the entire sensor unit 2 is bent. The characteristic curve of the bending amount measurement voltage Vo with respect to the amount becomes stable. For this advantage, it is more preferable that the first sheet-like elastic body 21 and the second sheet-like elastic body 22 have the same thickness.

  In addition, depending on the object to which the bending amount measuring apparatus 1 is applied, the sensor unit 2 may be bent and deformed only on the first sheet-like conductive elastic body 23 side, but the sensor unit 2 is in the first sheet-like shape. In the case of bending deformation to both the conductive elastic body 23 side and the third sheet-like conductive elastic body 25 side, the first sheet-like elastic body 21 and the second sheet-like elastic body 22 are If the same material, the same thickness, and no gaps or depressions are provided, or both are provided with a large number of gaps 21a, 22a or depressions, the amount of bending relative to the bending amount regardless of which one is bent Almost the same characteristic curve of the measurement voltage Vo can be used.

  Next, experiments and simulations conducted by the present inventors will be described. FIG. 7 shows a characteristic curve obtained by experiment of the bending amount measurement voltage Vo with respect to the bending amount. As shown in FIG. 8, the bending amount is an angle θ of bending deformation when the sensor unit 2 is bent toward the first sheet-like conductive elastic body 23, and actually the both ends of the sensor unit 2 with respect to the horizontal axis. The angles of the parts were added together, that is, doubled. In the initial state before bending deformation, the sensor unit 2 is arranged linearly along the horizontal axis. In addition, the length of the sensor unit 2 in the bending deformation direction (the length between both fixing positions to the experimental device 6) is 50 mm, the length perpendicular to the bending deformation direction (the width direction) is 70 mm, The first sheet-like elastic body 21 and the second sheet-like elastic body 22 are both provided with no gap or depression and have a thickness of 2 mm. The first sheet-like conductive elastic body 23 and the second sheet The thickness of each of the sheet-like conductive elastic body 24 and the third sheet-like conductive elastic body 25 was 0.7 mm. FIG. 9 shows the result of a simulation in which the total sum of strains in the thickness direction of the first sheet-like elastic body 21 and the second sheet-like elastic body 22 is nonlinearly analyzed under the same conditions. The vertical axis represents the total sum of distortion in the thickness direction of each element of the nonlinear analysis.

  As shown in FIG. 7, it can be seen that the bending amount measurement voltage Vo is output according to the bending amount. It can also be seen that the bending amount measurement voltage Vo with respect to the bending amount changes linearly (in a straight line). Further, as shown in FIG. 9, distortion occurs in the thickness direction of the first sheet-like elastic body 21 and the second sheet-like elastic body 22, and the sum total thereof is linear (linearly) with respect to the bending amount. You can see that it is changing.

  Although not shown, in the experiment conducted by the inventor of the present application, the longer the width phrase of the sensor unit 2 is, the higher the sensitivity is, and the thicknesses of the first and second sheet-like elastic bodies 21 and 22 are increased. It was confirmed that the thinner the film, the higher the sensitivity. In the sensor unit 2 in which the first and second sheet-like elastic bodies 21 and 22 are provided with a large number of gaps 21a and 22a, the first and second sheet-like elastic bodies 21 and 22 are provided with gaps or depressions. It was confirmed that the sensitivity was lower than that of the sensor unit 2 that was not provided.

  The bending amount measuring apparatus 1 described above can be applied to a medical or exercise device that measures the bending amount of a part of a human or animal body such as an elbow or a knee as shown in FIG. Further, the present invention can also be applied to industrial equipment that is set in a joint portion such as a robot and measures a bending amount.

  The bending amount measuring device according to the embodiment of the present invention has been described above, but the present invention is not limited to the one described in the embodiment, and various designs within the scope of matters described in the claims. It can be changed. For example, the sensor unit 2 is not limited to the flat shape shown in FIG. 3 or the like in the initial state before bending deformation, but depending on the object to which the bending amount measuring device 1 is applied, the cross section is almost half as shown in FIG. An arc shape or the like is also possible.

  As described in the above-described experiment, it will be described below that the bending amount should be the sum of the angles of both ends of the sensor unit 2. With this definition, when the sensor unit 2 is bent and deformed, even if a large number of wrinkles (bent portions) are generated as shown in FIG. Characteristics can be obtained.

First, the calculation formula will be described with reference to FIG. The sensor unit 2 forms an angle φa at an end A and an angle φb at an end B with respect to a reference axis (for example, a horizontal axis) S. The bent portions C, D, F, and H are bent and deformed toward the first sheet-like conductive elastic body 23 at angles of φc, φd, φf, and φh, respectively, and the bent portions E and G have φe and φg, respectively. It is bent and deformed to the third sheet-like conductive elastic body 25 side at an angle. The relational expression of these angles is as follows.
φa + φb = φc + φd−φe + φf−φg + φh

In the bent portion that is bent and deformed toward the first sheet-like conductive elastic body 23 at the angle φ, the capacitance value of the second capacitor C2 is as follows using the parameters shown in FIG. Note that the thickness of the second sheet-like conductive elastic body 24 is calculated as 0.
C2 = K (R + t) φ / (1-t / R)
Here, R is a bending radius, t is the thickness of the first sheet-like elastic body 21 and the second sheet-like elastic body 22 in a state where they are not bent, and K is a constant. The numerator in this equation is due to a change in length and the denominator is due to a change in thickness. On the other hand, the capacitance value of the first capacitor C1 is as follows.
C1 = K (R−t) φ / (1 + t / R)
Accordingly, the difference between the capacitance value of the second capacitor C2 and the capacitance value of the first capacitor C1 is as follows.
C2-C1 = 4Ktφ
As a result, the difference between the capacitance value of the second capacitor C2 and the capacitance value of the first capacitor C1 at the bent portion does not depend on the bending radius R. The same applies to the bent portion bent and deformed toward the third sheet-like conductive elastic body 25 at an angle of φ.

Therefore, in the bent portions C, D, F, and H, the capacitance value of the second capacitor C2 is larger than the capacitance value of the first capacitor C1 by 4Ktφc, 4Ktφd, 4Ktφf, and 4Ktφh, respectively, and in the bent portions E and G, The capacitance value of the second capacitor C2 is smaller than the capacitance value of the first capacitor C1 by 4Ktφe and 4Ktφg, respectively. When these are added together, the difference between the capacitance value of the second capacitor C2 and the capacitance value of the first capacitor C1 is as follows.
C2-C1 = 4Kt (φc + φd + φf + φh-φe-φg)
That is, it is as follows.
C2-C1 = 4Kt (φa + φb)

  As described above, if the bending amount is defined as the sum of the angles φa and φb at both ends of the sensor unit 2, even if a large number of wrinkles (bending portions) occur, the capacitance of the second capacitor C2 with respect to the bending amount The difference between the value and the capacitance value of the first capacitor C1 is stabilized, and as a result, a stable characteristic of the bending amount measurement voltage Vo with respect to the bending amount can be obtained.

  An experiment confirming this will be described below. The same experimental apparatus 6 (shown in FIG. 8) as in the above-described experiment was used. In the initial state before bending deformation, the sensor unit 2 is arranged linearly along the horizontal axis. The length of the sensor 2 in the bending direction (the length between both fixing positions to the experimental device 6) is 200 mm, the length perpendicular to the bending direction (the width direction) is 30 mm, and the first sheet-like elasticity Both the body 21 and the second sheet-like elastic body 22 are not provided with voids or depressions, have a thickness of 0.5 mm, the first sheet-like conductive elastic body 23, and the second sheet-like conductivity. The thicknesses of the elastic body 24 and the third sheet-like conductive elastic body 25 were all 0.7 mm.

  The circles in FIG. 13 indicate that the angle φa of the end portion A is equal to the angle φb of the end portion B without generating wrinkles, and these are added to obtain the bending amount. It is the measured data. The range indicated by a in FIG. 13 was obtained by adding the angle φa of the end A and the angle φb of the end B as shown in FIGS. 14A to 14C using the same experimental apparatus as described above. This is the range of the bending amount measurement voltage Vo obtained by generating and measuring wrinkles so that the bending amount becomes zero. In the range indicated by b in FIG. 13, the same experimental apparatus as described above was used to generate wrinkles by setting both the angle φa of the end A and the angle φb of the end B to 30 degrees as shown in FIG. The bending amount measurement voltage Vo obtained by measurement. In each experiment shown by (a)-(d) of FIG. 14, the bending method was changed little by little and it measured 5 times.

  The range indicated by a and the range indicated by b in FIG. 13 are both located in the vicinity of the straight line obtained from ●. Thus, it can be seen that stable characteristics of the bending amount measurement voltage Vo with respect to the bending amount can be obtained even when a large number of wrinkles (bent portions) are generated.

DESCRIPTION OF SYMBOLS 1 Bending amount measuring apparatus 2 Sensor part 21 1st sheet-like elastic body 22 2nd sheet-like elastic body 21a, 22a The space | gap of 1st and 2nd sheet-like elastic body 23 1st sheet-like electroconductive elastic body 23a Terminal of first sheet-like conductive elastic body 24 Second sheet-like conductive elastic body 24a Terminal of second sheet-like conductive elastic body 25 Third sheet-like conductive elastic body 25a Third sheet-like conductive body Terminal of elastic elastic body 3 Electric circuit section 31 First AC output circuit 32 Second AC output circuit 33 Current measurement circuit 4 Supporter 5 Cable 51-53 Electrical wiring C1 First capacitor C2 Second capacitor I ₁ First AC current I ₂ second alternating current I ₃ flowing through the capacitor the second sheet-like conductive elastic body alternating current V ₁ flows through the terminal first exchange to the AC output circuit outputs a flowing to the capacitor Voltage V ₂ AC voltage Vo bending amount measurement voltage second AC output circuit outputs

Claims (6)

First and second sheet-like elastic bodies are used as dielectrics, and first to third sheet-like conductive elastic bodies sandwiching these dielectric bodies in sandwich form are used as electrodes. And a second sheet-like conductive elastic body, and a second capacitor is formed between the second sheet-like conductive elastic body and the second sheet-like conductive elastic body. A sensor unit;
A first AC output circuit that applies an AC voltage to the terminal of the first sheet-like conductive elastic body and causes an AC current to flow through the first capacitor, and an AC voltage is applied to the terminal of the third sheet-like conductive elastic body And a second AC output circuit for passing an AC current through the second capacitor, and a current measuring circuit for measuring the AC current flowing through the terminal of the second sheet-like conductive elastic body and converting it into a bending amount measurement voltage. A circuit portion, and
When the sensor portion is bent and deformed toward the first sheet-like elastic body, the third sheet-like elastic body side of the second sheet-like elastic body extends greatly and the thickness of the second sheet-like elastic body is increased. By reducing the thickness in accordance with the extension, the capacitance value of the second capacitor is increased and the value of the alternating current flowing therethrough is increased, and an alternating current flows through the terminal of the second sheet-like conductive elastic body. A bending amount measuring apparatus, wherein a current obtained by combining an alternating current and an alternating current flowing through a first capacitor flows as an alternating current through a second capacitor. The bending amount measuring apparatus according to claim 1,
Both the first and second sheet-like elastic bodies are not provided with voids or depressions. The bending amount measuring apparatus according to claim 1,
A bending amount measuring apparatus, wherein both or one of the first and second sheet-like elastic bodies is provided with a large number of voids or depressions. In the bending amount measuring apparatus according to any one of claims 1 to 3,
The bending amount measuring device, wherein the first and second sheet-like elastic bodies are made of the same material. In the bending amount measuring apparatus according to claim 4,
The bending amount measuring apparatus according to claim 1, wherein the first and second sheet-like elastic bodies have the same thickness. In the bending amount measuring apparatus according to any one of claims 1 to 5,
The bending amount measuring apparatus is characterized in that the bending amount is obtained by adding angles of both end portions of the sensor unit.

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