JP2009145119A - Deformation sensor system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-precision deformation sensor system which can detect a position at which an external force is received, while reducing the number of electrodes. <P>SOLUTION: The deformation sensor having a pressure-receiving surface 121 for receiving external force is formed with one or more through-holes 123 which pass through in the direction from the pressure-receiving surface 121 to its rear surface 122. The pressure-receiving surface 121 is made of an elastic material which elastically deforms by receiving an external force F and increases its electrical resistivity, in accordance with the increase in the amount of elastic deformation, when elastic deformation of all types including compressive deformation and tensile deformation occurs. A plurality of electrodes 13A to 13X are arranged at the perimeter of the pressure receiving surface 121 of the deformation sensor 12, spaced apart from one another. The amount of change in qn electrical resistance R1 between a pair of electrodes selected from among the electrodes 13A to 13X is measured, and on the basis of the measured amount of change in the electrical resistance R1, the position at which the external force F is received on the pressure-receiving surface 121 is calculated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a deformation sensor system that can be used in, for example, a pressure distribution sensor.

  Conventional pressure distribution sensors are described in, for example, JP-A-6-281516 (Patent Document 1), JP-A-2006-284404 (Patent Document 2) and JP-A-2003-98022 (Patent Document 3). There is something that was done.

  In the pressure distribution sensor described in Patent Literature 1, electrodes on which a large number of detection points are formed in a matrix are arranged on both sides or one side of a pressure-sensitive conductive elastomer sheet. And the position of the pressure received by the pressure-sensitive conductive elastomer sheet by the electrode near the deformation site by utilizing the change in the electrical resistivity of the deformation site of the pressure-sensitive conductive elastomer sheet by receiving the pressure. Is detected.

  Moreover, the pressure distribution sensor described in Patent Document 2 has electrodes formed on each of the first sensor sheet and the second sensor sheet to be stacked. And the position of a pressure is detected by the electrical resistance between the electrodes of each sensor sheet using the fact that the electrical resistivity is lowered by receiving pressure on the sensor sheet. In addition, in the pressure distribution sensor described in Patent Document 3, an electrode is disposed on the back surface side of the pressure receiving surface in substantially the same manner as in Patent Documents 1 and 2.

  That is, in each of the pressure distribution sensors described in Patent Documents 1 to 3, electrodes for detection are arranged on the entire pressure receiving surface. Thus, since the detection location by an electrode is arrange | positioned in the whole pressure receiving surface, if a pressure receiving surface is expanded, the detection location where an electrode will be arrange | positioned will become very huge. As a result, the wiring connected to the electrodes becomes enormous, the mountability is poor, and the stretchability of the sensor itself is impaired.

Therefore, research for solving this problem has been conducted, and the research results have been published in the paper of Non-Patent Document 1. In the pressure distribution sensor described in Non-Patent Document 1, a plurality of electrodes are installed on the outer periphery of the pressure-sensitive rubber sheet, and a technique based on an inverse problem analysis called EIT (Electrical Impedance Tomography) is used. This is to estimate the resistance distribution in the inner region. Here, as the pressure-sensitive rubber sheet, a material whose electrical resistivity decreases in accordance with compression deformation is used.
JP-A-6-281516 JP 2006-284404 A JP 2003-98022 A Akihiko Nagakubo, Yasuo Kuniyoshi, “Tactile sensor based on inverse problem analysis: Principle”, The 24th Annual Conference of the Robotics Society of Japan (September 14-16, 2006)

  Here, in the sensor described in Non-Patent Document 1, when an external force is applied to the pressure receiving surface, the electrical resistivity of the portion receiving the external force is reduced. Therefore, when an external force is applied to the pressure receiving surface, the electrical resistance between the predetermined electrode pair theoretically decreases according to the position and magnitude of the external force. For example, when the entire pressure receiving surface is compressed and deformed, the electrical resistivity is sufficiently low over the entire pressure receiving surface. Therefore, the absolute value of the amount of decrease in electrical resistance between the predetermined electrode pair is sufficiently larger than that in the no-load state. In the no-load state, almost no current flows between the electrode pairs, whereas a current flows between the electrode pairs when the entire pressure receiving surface is compressed and deformed. Therefore, in this case, it is possible to detect that an external force has been received even when a deformation sensor whose electric resistivity decreases when an external force is applied is used.

  On the other hand, when an external force is applied to a part of the pressure receiving surface, the electrical resistivity of only that part becomes low. Also in this case, theoretically, the electrical resistance between the predetermined electrode pair is lower than that in the no-load state. However, since the portion not receiving external force has high electrical resistivity, the amount of decrease in electrical resistance between the predetermined electrode pair is only slight. When there is a portion with high electrical resistivity at any part between the electrode pairs, it becomes difficult for current to flow between the electrode pairs. That is, when an external force is applied to a part of the pressure receiving surface, the voltage between the predetermined electrode pair is almost in a state of almost zero as in the no-load state. As described above, when a current is supplied to the sensor, the detection voltage between the predetermined electrode pair hardly changes, so that it is difficult to detect the position and size of the external force.

  In particular, the amount of change in the electrical resistance between the electrode pair decreases as the position where the external force is applied is further away from the outer peripheral electrode, that is, near the center of the pressure receiving surface. That is, the sensitivity is lower as the position where the external force is received is closer to the center of the pressure receiving surface. This is because there are many portions with high electrical resistivity (portions where current does not easily flow) between the predetermined electrode pairs. Thus, when the position for receiving the external force is only near the center of the pressure receiving surface, the above-described phenomenon becomes significant. In other words, the closer the position to which the external force is received is near the center of the pressure receiving surface, the more difficult it is to detect that the external force has been received.

  This invention is made | formed in view of such a situation, and it aims at providing the deformation | transformation sensor system which can detect the position which received the highly accurate external force, reducing the number of electrodes.

The deformation sensor system of the present invention comprises:
It has a pressure-receiving surface that can receive an external force, and has one or more through-holes penetrating in a direction from the pressure-receiving surface toward the back surface thereof, elastically deforming by receiving the external force on the pressure-receiving surface, and compressive deformation and tension A deformation sensor made of an elastic material whose electrical resistivity increases as the amount of elastic deformation in each elastic deformation increases when all types of elastic deformation including deformation are generated;
A plurality of electrodes spaced apart from each other at the peripheral edge of the pressure receiving surface;
An electrical resistance change amount measuring unit that measures the amount of change in electrical resistance between the electrode pair selected from the electrodes;
An external force position calculation unit that calculates a position received by the external force on the pressure-receiving surface based on the change amount of the electrical resistance measured by the electrical resistance change amount measurement unit;
It is characterized by providing.

  According to the deformation sensor system of the present invention, the electrode is disposed on the peripheral edge of the pressure receiving surface. That is, the number of electrodes can be reduced as compared with the case where the electrodes are arranged on the entire pressure receiving surface as in the pressure distribution sensors described in Patent Documents 1 to 3. In particular, the larger the pressure receiving surface, the more remarkable the effect.

  Here, when the deformation sensor constituting the deformation sensor system of the present invention causes all types of elastic deformation including compression deformation and tensile deformation, the electrical resistivity increases as the amount of elastic deformation in each elastic deformation increases. Will increase. “All kinds of elastic deformation” means not only compression deformation and tensile deformation, but also bending deformation, shear deformation and torsion deformation. That is, no matter how elastically the deformation sensor is deformed, the electrical resistivity of the deformation sensor always increases. Specifically, when the deformation sensor is subjected to tensile deformation, compression deformation, bending deformation, shear deformation, etc. The electrical resistivity of the sensor increases. In addition, when tensile deformation and compression deformation occur simultaneously in the deformation sensor, the electric resistance of the deformation sensor is due to both the effect of the increase in electrical resistivity due to the tensile deformation and the effect due to the increase in electrical resistivity due to the compression deformation. To increase. Note that an increase in the electrical resistivity of the deformation sensor means that the impedance of the deformation sensor increases when viewed as alternating current.

  And in the deformation | transformation sensor system of this invention, when the external force is received in the pressure receiving surface, the position which the external force receives in a pressure receiving surface can be detected with high precision. The reason will be described below. As described above, the deformation sensor according to the present invention is made of an elastic material whose electrical resistivity increases as the amount of elastic deformation increases.

  That is, this elastic material has the smallest electrical resistance between the electrode pair in a state where the pressure receiving surface of the deformation sensor is not subjected to an external force (hereinafter referred to as “no load state”), and the external force is applied to the pressure receiving surface of the deformation sensor. The electrical resistance between the electrode pair in the received state (hereinafter referred to as “load state”) increases. Therefore, the no-load state is a state in which current flows most easily between the electrode pairs, and the load state changes to a state in which current does not easily flow between the electrode pairs. That is, even when the external force received by the pressure receiving surface is very small, a change that makes it difficult for current to flow between the electrode pairs can be reliably detected.

  For example, when an external force is applied over the entire pressure receiving surface of the deformation sensor of the present invention, the electrical resistivity increases over the entire pressure receiving surface. In this case, the current flowing between the electrode pair in the no-load state changes to a state in which it hardly flows with the deformation of the deformation sensor. And the change of this electric current can be grasped | ascertained easily. Therefore, when an external force is applied over the entire pressure receiving surface, this can be reliably detected. However, when an external force is applied over the entire pressure-receiving surface, it can be sufficiently detected even in the case of a conventional deformation sensor having a reduced electrical resistivity.

  On the other hand, when an external force is applied to a part of the pressure receiving surface of the deformation sensor of the present invention, the electrical resistivity of only that part increases, and the electrical resistivity of the other part remains low. In this case, the current flowing between the electrode pair in the no-load state changes to a state in which it hardly flows with the deformation of the deformation sensor. For example, even if the electrical resistivity increases until the part that has received an external force is in an insulating state, there is a plurality of paths between the electrode pairs, so there is always a current between the electrode pairs. It will be in a flowing state. And even if the position where the external force is received is a position far from the electrodes, a current always flows between the electrode pairs. In this way, even if the part receiving the external force is a part of the pressure receiving surface, particularly only at a position far from the electrodes, a current can flow between the electrode pairs. The detection voltage changes. Therefore, it is possible to reliably detect a change in electrical resistance between the electrode pair. That is, it is possible to detect the position and size of the external force.

  Furthermore, the deformation sensor of the present invention has one or more through holes penetrating in a direction from the pressure receiving surface toward the back surface. Here, in the case of a deformation sensor in which no through-hole is formed, the path of the current flowing between the electrode pairs is any path that freely connects the electrode pairs on all surfaces of the deformation sensor. On the other hand, in the case of the deformation sensor of the present invention in which the through hole is formed, the path is a path that freely connects between the electrode pair in the portion where the through hole is not formed. That is, the portion in which the through hole is formed does not serve as a path for current flowing between the electrode pair. Therefore, in the deformation sensor of the present invention, the path of the current flowing between the electrode pair is limited. That is, according to the present invention, the influence of the increase in the electrical resistivity of the portion of the pressure receiving surface that has received an external force is increased with respect to the increase in the electrical resistance between the electrode pairs. Then, regardless of the position where the external force is received on the pressure receiving surface, the amount of increase in electrical resistance is greater than when no through-hole is formed. An increase in the electrical resistance increases means that detection sensitivity is improved.

  Therefore, detection sensitivity can be increased by forming a through hole in the deformation sensor. In particular, the present invention can solve the problem that the detection sensitivity at a position far from the electrode on the pressure receiving surface is reduced by arranging the electrode at the peripheral edge of the pressure receiving surface. Furthermore, according to the present invention, even when the position receiving the external force is a position close to the electrode on the pressure receiving surface, for the reason described above, the detection is performed as compared with the case where a deformation sensor without a through hole is used. Increases sensitivity. As described above, according to the present invention, it is possible to obtain a more accurate pressure distribution while reducing the number of electrodes.

  Further, in the deformation sensor system of the present invention, the back surface of the deformation sensor is formed in an uneven shape, and the deformation sensor system further has a convex portion on the back surface in a state where the external force is not applied to the pressure receiving surface. It is good to provide the base arrange | positioned at the said back surface side of the said deformation sensor so that it may contact | abut and may not contact | abut to the recessed part of the said back surface.

  Here, it is desirable that the thickness from the pressure receiving surface of the deformation sensor of the present invention to the back surface thereof is a thin sheet. In addition, since a conductor such as carbon is mixed, the deformation sensor is relatively hard. As a result, when a pressure external force is applied to the pressure receiving surface, the amount of compressive deformation in the direction from the pressure receiving surface toward the back surface is not so large due to the pressure external force.

  On the other hand, when the back surface of the deformation sensor is formed in an uneven shape as described above, a gap is formed between the recess on the back surface of the deformation sensor and the base. In this case, when a pressing external force is applied to the pressure receiving surface of the deformation sensor corresponding to the concave portion, the deformation sensor is easily bent due to the presence of a gap with the base. And even if it is a case where a deformation sensor carries out bending deformation, the electrical resistivity of the bending deformation part of a deformation sensor increases. That is, even when the external force is the same, the deformation amount of the deformation sensor can be increased by forming the back surface to be uneven. Therefore, the external force position can be detected with high accuracy.

  By the way, when the back surface is formed in a flat shape, when an external force is applied to the pressure receiving surface, the pressure receiving surface is deformed to a peripheral portion of the range where the external force is received. In the deformation sensor system of the present invention, the position of the pressure receiving surface that receives an external force is obtained by utilizing the fact that the electrical resistivity increases due to the deformation of the deformation sensor. However, when the deformed range of the deformation sensor is different from the range subjected to the external force, it is not easy to obtain the position of the pressure receiving surface that has received the external force with high accuracy. Here, when the back surface of the deformation sensor of the present invention is made uneven, since the convex portion on the back surface is in contact with the base, the convex portion on the back surface is less likely to deform than the concave portion on the back surface. By utilizing this, when an external force is applied to the pressure receiving surface, it is possible to suppress the deformation of the surrounding portion in the range where the external force is applied. That is, the deformed range of the deformation sensor can be brought close to a state where the deformed sensor receives the external force. Therefore, it is possible to detect the position receiving the external force with higher accuracy.

  In the deformation sensor system of the present invention, the pressure receiving surface of the deformation sensor may be formed in an uneven shape. The above describes making the back surface of the deformation sensor uneven. Here, the pressure-receiving surface of the deformation sensor, that is, the surface of the deformation sensor is made uneven. Here, the deformation sensor of the present invention forms a through hole. If the through hole is a space and an external force is applied only to the through hole, the deformation sensor is not deformed at all. Therefore, when the external force is received only by the through hole, it cannot be detected that the external force has been received. Therefore, by making the pressure receiving surface (surface) of the deformation sensor uneven, the external force applying member can easily come into contact with the convex portion of the pressure receiving surface. In other words, it is possible to avoid a state in which the external force applying member is located only in the through hole. That is, the position where the external force is received can be detected by deforming at least the convex portion of the pressure receiving surface by the external force.

  In the deformation sensor system of the present invention, the pressure receiving surface and the back surface of the deformation sensor are formed in an uneven shape, and the pressure receiving surface is formed with a recess at a position corresponding to the convex portion of the back surface, and the back surface Is formed with a concave portion at a position corresponding to the convex portion of the pressure receiving surface, and the deformation sensor system is further in contact with the convex portion of the back surface in a state where the external force is not applied to the pressure receiving surface, and It is good to provide the base arrange | positioned at the said back surface side of the said deformation sensor so that it may not contact | abut to the recessed part of the said back surface.

  By forming the back surface of the deformation sensor in a concavo-convex shape, the deformation amount of the deformation sensor can be increased as described above, and the deformed range of the deformation sensor is substantially equal to the range subjected to external force. be able to. Furthermore, by forming the pressure receiving surface of the deformation sensor in an uneven shape, it is possible to avoid the state where the external force applying member is located only in the through hole as described above. Furthermore, according to this invention, the convex part of a pressure receiving surface becomes a position corresponding to the concave part of a back surface. Thereby, when the convex part of a pressure receiving surface receives pressing external force, it will be in the state where the concave part of a back surface deform | transforms. Here, the concave portion on the back surface is a portion that is easily deformed as described above. On the other hand, the convex portion on the back surface is a portion that is difficult to deform. However, by making the pressure receiving surface uneven, the convex portion of the pressure receiving surface is in a state where it is susceptible to external force, so that the concave portion on the back surface is susceptible to external force. Therefore, the convex part of the pressure receiving surface is set at a position corresponding to the concave part on the back surface, so that the concave part on the back surface can easily receive external force. That is, the deformation amount of the deformation sensor can be increased, and as a result, the position where the external force is received can be detected with higher accuracy.

  Moreover, in the deformation sensor system of the present invention described above, the through-hole is composed of a plurality, and the deformation sensor is preferably formed in a lattice shape. Thereby, it becomes easy to calculate the position that the external force receives on the pressure receiving surface based on the change in the electric resistance of the deformation sensor between the electrode pair. That is, it is possible to reduce the arithmetic processing.

  The deformation sensor system of the present invention may further include an insulating elastic body filled in the through hole. That is, when viewed as a whole of the deformation sensor and the insulating elastic body, the shape is such that no through hole is formed. Here, when an external force is applied to the pressure receiving surface due to the influence of the through hole, there is a possibility that the deformation mode of the deformation sensor may vary. Therefore, by filling the through hole with an insulating elastic body, variations in deformation modes of the deformation sensor can be suppressed, and the external force position can be detected with high accuracy. Note that no current flows through the insulating elastic body. Therefore, the insulating elastic body does not affect the detection sensitivity of the external force position received on the pressure receiving surface.

  Here, when the through hole of the deformation sensor is a space, there is a problem that when the external force applying member is positioned in the space of the through hole, the position of the external force cannot be detected because the deformation sensor is not deformed. On the other hand, by filling the through hole of the deformation sensor with an insulating elastic body, the insulating elastic body receives an external force when the external force applying member is located only at the site of the through hole of the deformation sensor. Become. When the insulating sensor itself is deformed as the insulating elastic body is deformed by the external force, the external force position can be calculated based on the deformation of the deformation sensor.

  In addition, the deformation sensor system of the present invention may include a sheet that covers the entire pressure receiving surface of the deformation sensor and an opening on the pressure receiving surface side of the through hole. Thereby, when a through-hole is space, it can suppress that an external force provision member is located only in a through-hole. Therefore, the external force position can be detected reliably. Furthermore, when the pressure receiving surface is formed in a concavo-convex shape, the external force applying member can reliably apply an external force to the convex portion of the pressure receiving surface by covering with a sheet. Thereby, the effect by forming the pressure-receiving surface mentioned above in uneven | corrugated shape can be show | played reliably.

  Next, the present invention will be described in more detail with reference to embodiments.

<First embodiment>
(1) Overall Configuration of Deformation Sensor System The overall configuration of the deformation sensor system of this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is an overall configuration diagram of a deformation sensor system. 2 (a) is a view taken in the direction of arrow A in FIG. 1, FIG. 2 (b) is a sectional view taken along line BB in FIG. 1, and FIG. 2 (c) is a sectional view taken along line CC in FIG. 2D is a view taken along arrow D in FIG. 1, FIG. 2E is a cross-sectional view taken along line EE in FIG. 1, and FIG. 2F is a cross-sectional view taken along line FF in FIG. FIG. 3A is a cross-sectional view taken along line BB in FIG. 1 in a state where the deformation sensor 12 does not receive the pressing external force F (no load state). FIG. 3B is a cross-sectional view taken along the line BB in FIG. 1 in a state where the deformation sensor 12 receives the pressing external force F (load state). FIG. 3C is a diagram corresponding to a cross-sectional view taken along the line BB in FIG. 1 in a state where the deformation sensor in which the through hole 123 is not formed receives a pressing external force F as a comparative example.

  As shown in FIG. 1, the deformation sensor system includes a sensor structure 10, a control unit 20, and a monitor 30. The sensor structure 10 includes a base 11, a deformation sensor 12, 24 electrodes 13A to 13X, a connector 14, and wiring (not shown).

  As shown in FIGS. 1, 2 (a) to 2 (f), and FIGS. 3 (a) and (b), the base 11 has a square flat plate shape and is an elastic foaming material or cushioning material. Etc. That is, when the upper surface of the base 11 is pressed (the front side of the paper in FIG. 1), the pressed portion is deformed into a concave shape. The base 11 is disposed on a flat base, for example.

  In the present embodiment, the deformation sensor 12 uses a resistance increasing type sensor. Specifically, when the deformation sensor 12 generates all types of elastic deformation including compression deformation and tensile deformation, a rubber elastic material whose electrical resistivity increases as the amount of elastic deformation in each elastic deformation increases. Consists of. The material of the rubber elastic material of the deformation sensor 12 will be described in detail in the item “(2) Material description of the deformation sensor 12” described later.

  Here, the shape of the deformation sensor 12 will be described. The outer shape of the deformation sensor 12 is formed in a square flat plate shape, and is arranged so as to overlap the upper surface of the base 11. Here, the upper surface of the deformation sensor 12, that is, a flat spreading surface forms a pressure receiving surface 121 that can receive a pressing external force F toward the back side of the sheet of FIG. 1 (downward in FIG. 3B). Furthermore, a plurality of (49 in the present embodiment) square through-holes 123 are formed in the deformation sensor 12 so as to penetrate in the direction from the pressure receiving surface 121 toward the back surface 122 of the pressure receiving surface 121. These through holes 123 are arranged in a grid pattern so that there are seven rows in the left-right direction in FIG. 1 and seven rows in the up-down direction in FIG. That is, the deformation sensor 12 is formed in a lattice shape. Furthermore, the through-hole 123 is formed so that the width | variety of the deformation | transformation sensor 12 formed in the grid | lattice form may become the same.

  Furthermore, the pressure receiving surface 121 and the back surface 122 of the deformation sensor 12 are both formed in an uneven shape. The convex portion 121a of the pressure receiving surface 121 has a small columnar shape, and is formed at a position jumping one in the vertical and horizontal directions in FIG. The convex portion 121a of the pressure receiving surface 121 is a portion indicated by a solid circle in FIG. Moreover, the convex part 122a of the back surface 122 has comprised the small cylinder shape of the shape substantially the same as the convex part 121a of the pressure receiving surface 121. FIG. The convex portion 122a of the back surface 122 is formed at a position jumping one by one in the vertical and horizontal directions in FIG. The convex part 122a of the back surface 122 is a part shown with a broken-line circle in FIG. The convex portion 122 a of the back surface 122 is disposed so as to contact the upper surface of the base 11 in a state where the external pressure is not applied to the pressure receiving surface 121 of the deformation sensor 12. Further, the concave portion 122 b of the back surface 122 is disposed so as not to contact the upper surface of the base 11 when no external force is applied to the pressure receiving surface 121 of the deformation sensor 12. That is, a gap is formed between the recess 122 b on the back surface 122 and the upper surface of the base 11.

  Furthermore, the convex part 121a of the pressure receiving surface 121 and the convex part 122a of the back surface 122 are formed at mutually different positions in the planar coordinates of FIG. 1 (FIGS. 1, 2B, and 2E). 3 (a) (b)). That is, in the pressure receiving surface 121, the concave portion 121b is formed at a position corresponding to the convex portion 122a on the back surface. On the back surface 122, a recess 122 b is formed at a position corresponding to the protrusion 121 a of the pressure receiving surface 121.

  When the pressure receiving surface 121 of the deformation sensor 12 receives a pressing external force F in the normal direction, the portion of the deformation sensor 12 that has received the pressing external force F is illustrated in FIG. Bending elastically deforms so as to curve toward the lower side of 3 (b). Specifically, as shown in FIG. 3B, when a pressing external force F is received at a position corresponding to the concave portion 122 b of the back surface 122 of the pressure receiving surface 121, the portion of the concave portion 122 b of the back surface 122 becomes the base 11. The deformation sensor 12 is bent and deformed so as to enter the gap. That is, it becomes a state like a doubly supported beam that supports the vicinity of the convex portion 122 a of the back surface 122. Here, for comparison, in the case of the deformation sensor 12 in which the back surface 122 is not formed in a concavo-convex shape as shown in FIG. 3C, the deformation amount is much smaller although it is bent. Thus, by forming the back surface 122 in an uneven shape, the bending deformation amount (deflection amount) of the deformation sensor 12 can be increased. In particular, the deformation sensor 12 in this embodiment is more effective because it is made of a material that is relatively difficult to deform because of its high bending rigidity. Since increasing the deformation amount of the deformation sensor 12 increases the amount of change in the electrical resistivity of the part, the position where the deformation sensor 12 is deformed, that is, the position where the pressing external force F is received is highly accurate. Can be detected.

  Further, as shown in FIG. 3B, when the range of the pressing external force F is F1, the deformation range F2 of the deformation sensor 12 when the back surface 122 is formed in an uneven shape is a range slightly larger than F1. Become. Specifically, the deformation range F2 is a range narrower than the convex portion 122a of the back surface 122 positioned outside the range F1 of the pressing external force F. On the other hand, as shown in FIG. 3C, the deformation range F3 of the deformation sensor 12 when the back surface 122 is not formed in an uneven shape is a wide range centering on the range F1 of the pressing external force F. And the deformation | transformation range F3 of FIG.3 (c) becomes a range wider than the deformation | transformation range F2 of FIG.3 (b). That is, it is possible to suppress the deformation of the peripheral portion of the deformation sensor 12 in the range where the pressing external force F is actually received. In other words, the range of the deformation sensor 12 deformed by the pressing external force F can be brought close to a state where the pressure receiving surface 121 has actually received the pressing external force F.

  Further, the deformation sensor 12 is formed with a through hole 123. If the pressing external force F is applied to the through-hole 123, the deformation sensor 12 may not be deformed by the pressing external force F. However, since the pressure receiving surface 121 of the deformation sensor 12 of the present embodiment is formed in a concavo-convex shape, the convex portion 121a of the pressure receiving surface 121 can receive a pressing external force F. And the deformation | transformation sensor 12 deform | transforms reliably because the convex part 121a of the pressure receiving surface 121 receives the press external force F. As shown in FIG.

  Further, the convex portion 121 a of the pressure receiving surface 121 is at a position corresponding to the concave portion 122 b of the back surface 122. As described above, since the convex portion 121a of the pressure receiving surface 121 can receive the pressing external force F, the pressing external force F acts to bend and deform the portion of the concave portion 122b of the back surface 122. Accordingly, since the pressing external force F can be received at the portion corresponding to the concave portion 122b of the back surface 122, the deformation sensor 12 can be reliably bent and deformed.

Twenty-four electrodes 13A to 13X are attached to the peripheral edge of the deformation sensor 12 formed in this way. Specifically, it is bonded to the peripheral edge portion of the pressure receiving surface 121 of the deformation sensor 12 by vulcanization bonding. And these electrodes 13A-13X are arrange | positioned so that it may extend outside from the connection point (adhesion point) to the peripheral part of this pressure receiving surface 121 (it protrudes). Furthermore, these 24 electrodes 13 </ b> A to 13 </ b> X are arranged apart from each other so that the distance between adjacent electrodes is equal on each side of the peripheral edge of the pressure receiving surface 121.
The connector 14 is a member for electrical connection with the control unit 20 described later. The connector 14 is arranged at the lower left corner of FIG. 1 on the upper surface of the base 11 and outside the peripheral edge of the deformation sensor 12. That is, the connector 14 is disposed at a position separated from the deformation sensor 12. And this connector 14 is electrically connected with each electrode 13A-13X by wiring (not shown).

The control unit 20 includes a power supply circuit 21, a detection unit 22, and an output unit 23. The power supply circuit 21 includes two electrodes (hereinafter referred to as “electrode pairs”) selected from the electrodes 13A to 13X via the connector 14, and an electric resistance change measurement unit 22a of the detection unit 22 described later. The circuit is electrically connected and applies a DC voltage Vin.
When the detection unit 22 applies the DC voltage Vin between the electrode pairs selected from the electrodes 13A to 13X, the detection unit 22 measures the amount of change in the electrical resistance of the deformation sensor 12 between the electrode pairs, Based on the measured change amount of the electrical resistance, the position of the pressure receiving surface 121 of the deformation sensor 12 that receives the pressing external force F is calculated. The output unit 23 outputs to the monitor 30 the position of the pressure receiving surface 121 calculated by the detection unit 22 that has received the pressing external force F. A surface corresponding to the pressure receiving surface 121 of the deformation sensor 12 is displayed on the monitor 30, and the position where the pressing external force F is received is displayed using various colors, or is displayed using the brightness of the color. . Details of the control unit 20 will be described in an item “(3) Detailed description of the control unit 20” described later.

(2) Material Description of Deformation Sensor 12 Next, when the rubber elastic material used for the deformation sensor 12, that is, when all types of elastic deformation including compression deformation and tensile deformation occur, the amount of elastic deformation in each elastic deformation A rubber elastic material having a property that the electrical resistivity increases as the value of A increases will be described in detail with reference to FIG. 4A shows a schematic cross-sectional view of the deformation sensor 12 in a no-load state, and FIG. 4B shows a schematic cross-sectional view of the deformation sensor 12 in a load state. In addition, in FIG.4 (b), the shape of the deformation sensor 12 of a no-load state is shown with a broken line.

  The rubber elastic material of the deformation sensor 12 has an elastomer 124 made of a predetermined rubber and a spherical conductive filler 125 blended in the elastomer 124 in a substantially single particle state with a high filling rate. is there. Here, the elastomer 124 itself made of a predetermined rubber has an insulating property. Further, “substantially single particle state” and “compounding at a high filling rate” have the above-mentioned meanings.

  And in a no-load state, as shown to Fig.4 (a), many of the conductive fillers 125 exist in the primary particle state in the elastomer 124. FIG. Moreover, the filling rate of the conductive filler 125 is high, and it is blended in a state close to closest packing. Thereby, in the no-load state, the deformation sensor 12 is formed with a three-dimensional conductive path Ps by the conductive filler 125. Therefore, in the no-load state, the electrical resistivity of the deformation sensor 12 is small.

  On the other hand, as shown in FIG. 4B, when the external force F (for example, pressing external force) is applied to the pressure receiving surface 121 of the deformation sensor 12 (load state), the deformation sensor 12 is elastically deformed. Here, since the conductive filler 125 is blended in a state close to closest packing, there is almost no space where the conductive filler 125 can move. Therefore, when the deformation sensor 12 is elastically deformed, the conductive fillers 125 repel each other, and the contact state between the conductive fillers 125 changes. As a result, the three-dimensional conductive path Ps formed in the no-load state collapses, and the electrical resistivity of the deformation sensor 12 increases.

  Here, in the deformation sensor 12, as the blending amount of the conductive filler 125 is increased with respect to the elastomer 124, the electrical resistivity of the deformation sensor 12 decreases. Specifically, considering the case where the conductive filler 125 is blended with a predetermined amount of elastomer 124, the electrical resistivity of the deformation sensor 12 exhibits a large value when the blending amount of the conductive filler 125 is small. That is, the electrical resistivity of the deformation sensor 12 in this case is almost equal to the electrical resistivity of the elastomer 124 in a state where the conductive filler 125 is not blended.

  Then, when the blending amount of the conductive filler 125 is increased and the blending amount reaches a predetermined volume fraction, the electrical resistivity of the deformation sensor 12 is rapidly decreased, and an insulator-conductor transition occurs ( First inflection point). The blending amount (volume%) of the conductive filler 125 at the first inflection point is called a critical volume fraction. Further, when the blending amount of the conductive filler 125 is further increased, the change amount of the electric resistivity of the deformation sensor 12 is reduced from the predetermined volume fraction, and the change of the electric resistivity is saturated (second change). pole). The blending amount (volume%) of the conductive filler 125 at the second inflection point is referred to as a saturated volume fraction.

  Such a change in the electrical resistivity of the deformation sensor 12 is called a percolation curve and is considered to be due to the formation of a conductive path Ps (shown in FIG. 4A) by the conductive filler 125 in the elastomer 124. Yes. In order to form a three-dimensional conductive path Ps based on the fact that the conductive filler 125 is blended in a substantially single particle state in a state close to the closest packing, in the elastomer 124 in an unloaded state. The saturated volume fraction of the conductive filler 125 is preferably 35% by volume or more. This is because the saturated volume fraction is as large as 35% by volume or more, so that the conductive filler 125 is stably present in the elastomer 124 in a substantially single particle state, and a state close to closest packing is realized.

  For this reason, the deformation sensor 12 has an electric resistance to the external force F when the filling volume of the conductive filler 125 is 30% by volume or more and 65% by volume or less, which is close to the saturated volume fraction, when the entire volume is 100% by volume. It is possible to induce an increasing behavior of the rate.

  On the other hand, when the conductive filler 125 is aggregated and an aggregate is formed because the conductive filler 125 has a small particle diameter or poor compatibility between the conductive filler 125 and the elastomer 124, The original conductive path Ps is easily formed. In such a case, the critical volume fraction of the elastomer composition is relatively small, about 20% by volume. Similarly, the saturated volume fraction is relatively small. In other words, when the critical volume fraction and the saturated volume fraction are small, the conductive filler 125 is unlikely to exist as primary particles, and secondary particles (aggregates) are easily formed. Therefore, in this case, it is difficult to mix a large amount of the conductive filler 125 in the elastomer 124. That is, it is difficult to mix the conductive filler 125 in a state close to closest packing. Further, when a large amount of the conductive filler 125 having a small particle diameter is blended, the aggregated structure grows three-dimensionally, so that the change in conductivity due to deformation becomes poor.

  Here, a specific example of the rubber elastic material forming the deformation sensor 12 is given below. First, 85 parts by weight of oil exhibition EPDM (“Esprene (registered trademark) 6101” manufactured by Sumitomo Chemical Co., Ltd.), 34 parts by mass of oil exhibition EPDM (“Esplen 601” manufactured by Sumitomo Chemical Co., Ltd.), and EPDM (“Esplen 505 manufactured by Sumitomo Chemical Co., Ltd.) ”) 30 parts by mass, 5 parts by mass of zinc oxide (manufactured by Hakusui Chemical Co., Ltd.), 1 part by mass of stearic acid (“ Lunac (registered trademark) S30 ”manufactured by Kao Corporation), paraffinic process oil (Nihon Sun Oil Co., Ltd.) 20 parts by mass of “Samper (registered trademark) 110”) was masticated with a roll kneader.

  Next, 270 parts by mass of carbon beads (“Nika Beads ICB0520” manufactured by Nippon Carbon Co., Ltd., average particle diameter of about 5 μm, D90 / D10 = 3.2 in the particle size distribution) are added, mixed and dispersed by a roll kneader. It was. Furthermore, as a vulcanization accelerator, 1.5 parts by mass of zinc dimethyldithiocarbamate (“Noxeller (registered trademark) PZ-P” manufactured by Ouchi Shinsei Chemical Co., Ltd.), tetramethylthiuram disulfide (“Sunseller (registered by Sanshin Chemical Co., Ltd.)) (Trademark) TT-G ") 1.5 parts by mass, 0.5 part by mass of 2-mercaptobenzothiazole (" Noxeller MP "manufactured by Ouchi Shinsei Chemical Co., Ltd.) and sulfur (" Sunfax T "manufactured by Tsurumi Chemical Co., Ltd.) −10 ”) and 0.56 parts by mass were added, mixed and dispersed by a roll kneader to prepare an elastomer composition.

  The critical volume fraction in the percolation curve of this elastomer composition was about 43% by volume, and the saturated volume fraction was about 48% by volume. Next, the elastomer composition was formed into a predetermined size (circular shape in this embodiment), and the deformation sensor 12 was formed by press vulcanization at a predetermined temperature. The filling rate of carbon beads in the formed deformation sensor 12 was about 48% by volume when the volume of the deformation sensor 12 was 100% by volume.

  In the above description, the case where the deformation sensor 12 is compressed and deformed by receiving the pressing external force F has been described as an example. However, the deformation sensor 12 is also deformed in the case of tensile deformation, bending deformation, and torsion deformation. It has been found that the electrical resistivity at the site has an increasing property.

(3) Detailed Configuration of Control Unit 20 Next, a detailed configuration of the control unit 20 in the deformation sensor system will be described with reference to FIGS. 1 and 5. FIG. 5 is a diagram for explaining the electrical resistance change amount measurement unit 22 a that constitutes the detection unit 22 of the control unit 20.

  As shown in FIG. 1, the control unit 20 includes a power supply circuit 21, a detection unit 22, and an output unit 23. The power supply circuit 21 includes a pair of electrodes (two electrodes selected from the electrodes 13A to 13X) via the connector 14 and wiring (not shown), and an electric resistance change amount of the detection unit 22 described later. It is a circuit that is electrically connected to the measurement unit 22a and applies a DC voltage Vin.

  The detection unit 22 includes an electrical resistance change amount measurement unit 22a, a coefficient storage unit 22b, and an external force calculation unit 22c. The electrical resistance change amount measurement unit 22a is electrically connected to the power supply circuit 21 and the electrode pair. Here, the electrode pairs in the present embodiment are two electrodes that are positioned facing each other in the vertical direction or the horizontal direction in FIG. 1 among the electrodes 13A to 13X. For example, a pair of electrode 13A and electrode 13R, a pair of electrode S and electrode L, and the like. In this embodiment, there are 12 electrode pairs.

  As shown in FIG. 5, the electrical resistance change measuring unit 22a constitutes a Wheatstone bridge circuit in which the electrical resistance of the sensor body 12 between each pair of electrodes is a first resistance R1. However, both end electrodes of the first resistor R1 are sequentially switched from the first electrode pair to the twelfth electrode pair. That is, the first resistor R1 here is the electrical resistance of the sensor body 12 between the first electrode pair (13A and 13R), the electrical resistance of the sensor body 12 between the second electrode pair (13B and 13P), ..., the electrical resistance of the sensor body 12 between the eleventh electrode pair (13K and 13T) and the electrical resistance of the sensor body 12 between the twelfth electrode pair (13L and 13S) are sequentially switched.

  Here, as described above, the sensor body 12 is made of a rubber elastic material whose electrical resistivity increases as the amount of elastic deformation increases. Therefore, the electrical resistance of each sensor body 12 between the first to twelfth electrode pairs changes according to the amount of elastic deformation (mainly bending elastic deformation) generated by the pressing external force F. In addition, the second resistor R2, the third resistor R3, and the fourth resistor R4 constituting the Wheatstone bridge circuit have constant resistance values. Here, the value obtained by multiplying the first resistor R1 and the fourth resistor R4 is set to be equal to the value obtained by multiplying the second resistor R2 and the third resistor R3.

  In FIG. 5, the applied voltage Vin is a DC voltage applied by the power supply circuit 21. The electrical resistance change amount measuring unit 22a detects the bridge intermediate potential difference Vm. That is, the bridge intermediate potential difference Vm changes with a change in the electrical resistance of the sensor body 12 between each electrode pair. That is, the electrical resistance change amount measuring unit 22a can detect the change amount of the electrical resistance of the sensor body 12 between each electrode pair when a voltage is applied between each electrode pair.

  The coefficient storage unit 22b corresponds to the relationship between the pressing external force F and the amount of change in the electrical resistance R1 between the electrode pair according to the position of the pressure receiving surface 121 of the sensor body 12 and the respective electrode pairs. The coefficient is memorized.

  This coefficient will be described below. For example, the influence degree of the electric resistance R1 of the sensor body 12 between the second electrode pair (13B and 13Q) varies depending on the position where the pressing external force F is received. For example, the amount of change in the electrical resistance R1 between the second electrode pair (13B and 13Q) when the pressing external force F is received on the line connecting the second electrode pair (13B and 13Q) and the pressure receiving surface 121 The amount of change in the electric resistance R1 between the second electrode pair (13B and 13Q) when the pressing external force F is applied to the right end portion of 1 is different. The change amount of the former electric resistance R1 is larger than the change amount of the latter electric resistance R1. In other words, this is because as the position of the pressing external force F is farther from the electrodes constituting the electrode pair, the degree of influence that appears as the amount of change in electrical resistance between the electrode pairs is smaller.

  Thus, even if the pressure receiving surface 121 of the sensor body 12 receives the same pressing external force F, the amount of change in the electric resistance R1 between the respective electrode pairs varies depending on the position. Therefore, by converting this relationship into a coefficient and multiplying the detected change amount of the electric resistance R1 between the electrode pair by the coefficient, the calculated value gives the pressing external force F to any position on the pressure receiving surface 121. Even if it is received, if it receives the same pressing external force F, it is interpolated to have the same value. The coefficient is stored in the coefficient storage unit 22b.

  When the voltage Vin is applied by the power supply circuit 21, the external force calculation unit 22c changes each electric resistance R1 measured by the electric resistance change measuring unit 22a and each coefficient stored in the coefficient storage unit 22b. Based on the coefficient, the magnitude of the pressing external force F at each position of the pressure receiving surface 121 of the sensor body 12 is calculated.

  Here, since the deformation sensor 12 in the present embodiment has a lattice shape in which the through-holes 123 are formed, the part of the deformation sensor 12 that is actually deformed is only the part where the deformation sensor 12 exists. Therefore, the external force calculation unit 22c calculates the distribution of the pressing external force F when it is assumed that the deformation sensor 12 has a planar shape in which the through hole 123 is not formed, based on the calculated pressing external force F at each position.

  Then, the output unit 23 outputs the magnitude of the pressing external force F at each position of the pressure receiving surface 121 calculated by the external force calculating unit 22 c to the monitor 30. At this time, as shown in FIG. 1, the monitor 30 is displayed such that the position where the pressing external force F is larger is, for example, a brighter color. That is, it can be understood that the position displayed brightly on the monitor 30 is the position where the pressure receiving surface 121 receives the pressing external force F. It is also possible to grasp how large the pressure receiving surface 121 has received the pressing external force.

(4) Explanation of Effect by Forming Through Hole 123 Here, the deformation sensor 12 of the present embodiment forms the through hole 123. Thereby, compared with the case where the through-hole 123 is not formed, the variation | change_quantity of the electrical resistance R1 between electrode pairs becomes large. That is, the detection sensitivity is improved. This will be described with reference to FIGS.

  First, in order to explain the above-described effect by forming the through-hole 123 in an easy-to-understand manner, an example in which the number of the through-holes 123 is four as shown in FIG. As a comparative example, the deformation sensor 12 in which the through hole 123 shown in FIG. 6B is not formed is taken as an example.

  Consider a case where the electrical resistance between A and B in FIGS. 6 (a) and 6 (b) is measured. In the case of FIG. 6A of the present invention, the path of the current flowing between A and B is a portion other than the through hole 123. That is, the path of the current flowing between A and B is limited by the presence of the through hole 123. On the other hand, in the case of FIG. 6B as a comparative example, the path of the current flowing between A and B is formed at any position and in any direction within the plane. That is, comparing the deformation sensor 12 of FIG. 6A and FIG. 6B, the deformation sensor 12 of FIG. 6A has fewer paths of current flowing between A and B.

  FIGS. 7A and 7B show this in a schematic circuit diagram. The circuit diagram of FIG. 7A corresponds to FIG. 6A, and the circuit diagram of FIG. 7B corresponds to FIG. FIGS. 7A and 7B show that the resistance values are the same in the state where the pressing external force F is not received, that is, in the initial state.

  As shown in FIGS. 7A and 7B, in either case, the number of parallel resistors is small at positions close to point A or B, and the number of parallel resistors increases as the distance from points A and B increases. It becomes a relationship. Further, in FIG. 7A, the number of parallel resistors is smaller between A and B than in FIG. 7B.

  Here, when a predetermined external position of the pressure receiving surface 121 of the deformation sensor 12 receives the pressing external force F and the electrical resistivity of the predetermined portion increases, how the circuits in FIGS. 7A and 7B change. Explain what to do. In this case, the resistance value of the predetermined one resistor shown in FIGS. 7A and 7B increases. In the circuit of FIG. 7A, since the number of resistors is small, when the resistance value of one resistor increases, the electrical resistance between A and B is greatly affected. On the other hand, in FIG. 7B, since the number of resistors is large, even if the resistance value of one resistor increases, the influence on the electrical resistance between A and B is small. In particular, as the position is farther from the point A and the point B, the difference in the degree of influence on the electrical resistance between A and B becomes larger in FIGS. 7A and 7B. In other words, the deformation sensor 12 of the present embodiment in which the through hole 123 is formed has higher sensitivity on the entire pressure receiving surface 121 than the deformation sensor in which the through hole 123 is not formed. In particular, the closer to the center of the pressure receiving surface 121, the greater the difference in sensitivity of the deformation sensor 12 of the present embodiment.

  The deformation sensor 12 in which the above-described through-hole 123 was formed and the deformation sensor in which the through-hole 123 was not formed were analyzed by a schematic circuit. The circuit diagrams used for this analysis are shown in FIGS. The circuit in FIG. 8A corresponds to FIGS. 6A and 7A, and the circuit in FIG. 8B corresponds to FIGS. 6B and 7B.

  Here, in FIGS. 8A and 8B, the resistors r1 to r20 are set to 1 kΩ as an initial state (no load state). As a first analysis, when only the resistor r7 is changed to 10 kΩ, as a second analysis, when only the resistor r6 is changed to 10 kΩ, as a third analysis, only the resistor r10 is changed to 10 kΩ. Then, when the point H was grounded, the voltages at the points A to I when a predetermined current was supplied to the point A were obtained.

  Table 1 shows the voltages at points A to I in the initial state, Table 2 shows the voltages at points A to I in the first analysis, and Table 3 shows the voltages at points A to I in the second analysis. Table 4 shows the voltages at points A to I in the third analysis.

  According to the first to third analysis results, the voltage difference from the initial value at all the measurement points except the grounded H point is higher in the circuit of FIG. 8A than in FIG. 8B. It can be seen that it is larger than the circuit. That is, it can be said that the detection sensitivity is improved.

<Second embodiment>
Next, the deformation sensor 112 of the second embodiment will be described with reference to FIG. FIG. 9 is a view corresponding to the BB cross-sectional view of FIG. Although the through hole 123 of the deformation sensor 12 of the first embodiment is a space itself, the through hole 123 of the deformation sensor 112 of the second embodiment is not a space, and the insulating elastic body 126 is filled in the through hole 123. Yes. Since other configurations are the same as those of the first embodiment, the same reference numerals are given in the drawings, and description thereof is omitted.

  Thereby, when it sees as a whole with the deformation | transformation sensor 112 and the insulating elastic body 126, it becomes a shape in which the through-hole 123 is not formed. Here, due to the influence of the through-hole 123, when the pressure receiving surface 121 receives the pressing external force F, the deformation mode of the deformation sensor 112 may vary. Therefore, by filling the through hole 123 with the insulating elastic body 126, variation in the deformation mode of the deformation sensor 112 can be suppressed, and the position of the pressing external force F can be detected with high accuracy. Since no current flows through the insulating elastic body 126, the insulating elastic body 126 does not affect the detection sensitivity of the external force position received by the pressure receiving surface 121.

  Further, when the through hole 123 of the deformation sensor 112 is a space, the external force position may not be detected because the deformation sensor 112 is not deformed when the external force applying member is located in the space of the through hole 123. In contrast, when the through-hole 123 of the deformation sensor 112 is filled with the insulating elastic body 126, the external elastic body 126 is positioned only in the portion of the through-hole 123 of the deformation sensor 112. Receives a pressing external force F. Then, when the insulating elastic body 126 is deformed by the pressing external force F and the deformation sensor 112 itself is deformed, the external force position is calculated based on the deformation of the deformation sensor 112. can do.

<Third embodiment>
Next, the deformation sensor 212 of the third embodiment will be described with reference to FIG. FIG. 10A is a plan view of the deformation sensor 212, and FIG. 10B is a cross-sectional view taken along line GG in FIG. In the deformation sensor 12 of the first embodiment, the pressure receiving surface 121 and the back surface 122 are formed in an uneven shape. However, as shown in FIGS. 10A and 10B, the deformation sensor 212 of the third embodiment has a pressure receiving surface 121. Both the back surface 122 and the back surface 122 are formed in a planar shape. Further, the through hole 123 of the deformation sensor 212 is filled with an insulating elastic body 126.

  According to the deformation sensor 212, there are an effect obtained by forming the through hole 123 and an effect obtained by providing the insulating elastic body 126. However, the effect of the unevenness of the pressure receiving surface 121 and the unevenness of the back surface 122 is not achieved.

<Fourth embodiment>
A deformation sensor 312 according to a fourth embodiment will be described with reference to FIG. FIG. 11A is a plan view of the deformation sensor 312 according to the fourth embodiment, FIG. 11B is a cross-sectional view taken along line HH in FIG. 11A, and FIG. It is II sectional drawing of 11 (a).

  As shown in FIGS. 11A to 11C, the deformation sensor 312 of the fourth embodiment has a pressure receiving surface 121 formed in a planar shape with respect to the deformation sensor 12 of the first embodiment, and penetrates. The difference is that the hole 123 is filled with the insulating elastic body 126.

  In this case, the effect of forming the through hole 123, the effect of providing the insulating elastic body 126, and the effect of making the back surface 122 uneven are provided. However, the effect of making the pressure receiving surface 121 uneven is not achieved.

<Fifth embodiment>
A deformation sensor system according to a fifth embodiment will be described with reference to FIG. 12 is a view corresponding to the BB cross-sectional view of FIG. The same components as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. The deformation sensor system of the fifth embodiment is different from the deformation sensor system of the first embodiment in that it further includes a covering sheet 15. Others have the same configuration.

  The covering sheet 15 is a square having the same shape as the outer shape of the deformation sensor 12, is formed thinner than the thickness of the deformation sensor 12, and is formed of an insulating material. The covering sheet 15 covers the entire pressure receiving surface 121 and the opening on the pressure receiving surface 121 side of the through hole 123. That is, the back surface side of the covering sheet 15 is in contact with the convex portion 121 a of the pressure receiving surface 121 and is not in contact with the concave portion 121 b of the pressure receiving surface 121.

  Thereby, when the through-hole 123 is space, it can suppress that an external force provision member is located only in the through-hole 123. FIG. Therefore, the external force position can be detected reliably. Further, when the pressure receiving surface 121 is formed in a concavo-convex shape, the external force applying member can reliably apply an external force to the convex portion 121 a of the pressure receiving surface 121 by covering with the covering sheet 15. Thereby, the effect by forming the pressure-receiving surface 121 in uneven | corrugated shape can be show | played reliably.

It is a whole block diagram of a deformation sensor system. It is an arrow view or sectional drawing of AF of FIG. It is a figure which shows the deformation | transformation aspect of the deformation sensor. It is a cross-sectional schematic diagram of the deformation sensor 12 in an unloaded state and a loaded state. It is a figure explaining the electrical resistance variation | change_quantity measurement part 22a. It is a figure which shows an electric current path | route in the deformation | transformation sensor of the presence or absence of the through-hole 123. FIG. It is a typical circuit diagram of Drawing 6 (a) (b). It is the circuit diagram used for the analysis. It is a figure which shows the deformation sensor 112 of 2nd embodiment. It is a figure which shows the deformation | transformation sensor 212 of 3rd embodiment. It is a figure which shows the deformation | transformation sensor 312 of 4th embodiment. It is a figure which shows the sensor structure 10 among the deformation | transformation sensor systems of 5th embodiment.

Explanation of symbols

10: sensor structure, 20: control unit, 30: monitor 11: base 12, 112, 212, 312: deformation sensor 121: pressure receiving surface, 121a: convex portion of pressure receiving surface, 121b: concave portion of pressure receiving surface 122: back surface 122a: convex portion on the back surface, 122b: concave portion on the back surface 123: through-hole 124: elastomer, 125: conductive filler, 126: insulating elastic bodies 13A to 13X: electrodes, 14: connector, 15: covering sheet Ps: conductive path

Claims (7)

It has a pressure-receiving surface that can receive an external force, and has one or more through-holes penetrating in a direction from the pressure-receiving surface toward the back surface thereof, elastically deforming by receiving the external force on the pressure-receiving surface, and compressive deformation and tension A deformation sensor made of an elastic material whose electrical resistivity increases as the amount of elastic deformation in each elastic deformation increases when all types of elastic deformation including deformation are generated;
A plurality of electrodes spaced apart from each other at the peripheral edge of the pressure receiving surface;
An electrical resistance change amount measuring unit that measures the amount of change in electrical resistance between the electrode pair selected from the electrodes;
An external force position calculation unit that calculates a position received by the external force on the pressure-receiving surface based on the change amount of the electrical resistance measured by the electrical resistance change amount measurement unit;
A deformation sensor system comprising: The back surface of the deformation sensor is formed in an uneven shape,
The deformation sensor system further contacts the convex portion of the back surface and does not contact the concave portion of the back surface on the back surface side of the deformation sensor in a state where the external force is not received by the pressure receiving surface. The deformation | transformation sensor system of Claim 1 provided with the base arrange | positioned.   The deformation sensor system according to claim 1, wherein the pressure receiving surface of the deformation sensor is formed in an uneven shape. The pressure receiving surface and the back surface of the deformation sensor are formed in an uneven shape,
The pressure receiving surface has a recess formed at a position corresponding to the protrusion on the back surface,
The back surface is formed with a concave portion at a position corresponding to the convex portion of the pressure receiving surface,
The deformation sensor system further contacts the convex portion of the back surface and does not contact the concave portion of the back surface on the back surface side of the deformation sensor in a state where the external force is not received by the pressure receiving surface. The deformation | transformation sensor system of Claim 1 provided with the base arrange | positioned. The through hole comprises a plurality of
The deformation sensor system according to any one of claims 1 to 4, wherein the deformation sensor is formed in a lattice shape.   The deformation sensor system according to any one of claims 1 to 5, wherein the deformation sensor system includes an insulating elastic body filled in the through hole.   The deformation sensor system according to any one of claims 1 to 6, further comprising a sheet that covers an entire surface of the pressure receiving surface of the deformation sensor and an opening on the pressure receiving surface side of the through hole.