JP2016219724A - Force sensor and force detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil device which is easy to manufacture, and to provide a force sensor and a force detection device using the same.SOLUTION: A coil device 50 includes: a core 4 which is made of a magnetic body and formed in an annular shape surrounding a hollow part 40; a path structure 51 having a bundle of a plurality of conductors 53 electrically insulated from each other; and a connection structure 52 electrically connected to both ends of the path structure 51. The path structure 51 is applied to the core 4 through the hollow part 40. The connection structure 52 has a pair of terminals 551, 552 and is constituted such that between the pair of terminals 551, 552, the plurality of conductors 53 are electrically connected in series and a coil 5 is formed by the plurality of conductors 53.SELECTED DRAWING: Figure 1

Description

  The present invention generally relates to a coil device, and a force sensor and a force detection device using the coil device. More specifically, the present invention relates to a coil device having a configuration in which a lead wire is wound around a core, and a force sensor and a force detection device using the coil device. .

  2. Description of the Related Art Conventionally, a magnetostrictive load sensor that detects a load applied to a magnetic body based on a change in magnetic permeability accompanying a distortion of the magnetic body magnetized by a current flowing through a coil is known. Yes. A magnetostrictive load sensor described in Patent Document 1 includes a load receiving portion of a ferromagnetic body that receives an external load, a coil that is wound around the load receiving portion, and a ferromagnetic body that houses the load receiving portion and the coil. And at least the case. Further, the coil is housed in a bobbin made of resin disposed around the load receiving portion.

  The load receiving portion has a rod shape, and an axially symmetric region including the central axis in the height direction is penetrated to form a cylindrical hollow portion. The load receiving portion receives a load applied in the axial direction of the rod-shaped member by inserting a rod-shaped member such as a wire or cable in close contact with the hollow portion.

  When a load is applied to the load receiving portion, the magnetic permeability of the load receiving portion changes due to the inverse magnetostrictive effect, and the impedance of the circuit including the coil inductance changes. This magnetostrictive load sensor detects (detects) a load caused by the movement of a rod-shaped member inserted into the hollow portion of the load receiving portion by measuring a voltage change at both ends of the coil accompanying this impedance change.

JP 2004-226196 A

  In the magnetostrictive load sensor (force sensor) as described above, a coil device composed of a magnetic body and a coil is required. In manufacturing the coil device, an operation of forming a coil by winding a conductive wire around the magnetic body is necessary. . However, depending on the size and shape of the magnetic material, there is a problem that the work of winding the conductive wire around the magnetic material is not easy and the coil device is not easily manufactured.

  This invention is made | formed in view of the said reason, and it aims at providing the coil apparatus which is easy to manufacture, and the force sensor and force detection apparatus using the same.

  A coil device according to a first aspect of the present invention includes a magnetic core and an annular core that surrounds a hollow portion, and a bundle of a plurality of conductive wires that are electrically insulated from each other. An electrical circuit structure hung on the core, and a connection structure electrically connected to both ends of the electrical circuit structure, the connection structure having a pair of terminals, and between the pair of terminals A coil is formed by the plurality of conducting wires by electrically connecting the plurality of conducting wires in series.

  The coil device according to a second aspect is characterized in that, in the first aspect, the electric circuit structure is a cable in which the plurality of conductive wires are covered with a covering member having electrical insulation.

  In the coil device according to a third aspect, in the first aspect, the electric circuit structure is a flexible substrate in which the plurality of conductive wires are formed on at least one surface of a base film having electrical insulation and flexibility. It is characterized by that.

  The coil device according to a fourth aspect is characterized in that, in the first aspect, the electric circuit structure has a structure in which the plurality of conductive wires are formed on a surface of a molded body having electrical insulation.

  The coil device according to the fifth aspect is characterized in that, in the second or third aspect, the coil device further includes a binding member for binding the electric circuit structure between the core and the connection structure.

  In the coil device according to any one of the first to fifth aspects, the core has a mounting portion having a smaller cross-sectional area than other portions in a portion of the hollow portion in the circumferential direction, The electric circuit structure is hung on the attachment portion.

  A force sensor according to a seventh aspect includes the coil device according to any one of the first to sixth aspects, and a magnetic path through which a magnetic flux generated by a current flowing between the pair of terminals passes through the core. The core is formed along a circumferential direction, and the core includes a load receiving portion that receives a load on one surface intersecting a surface on which the magnetic path is formed.

  A force sensor according to an eighth mode is formed of a first plate and a second plate arranged so as to sandwich the core from both sides in the intersecting direction and a material having a lower elastic modulus than the core in the seventh mode. And an elastic body for positioning between the first plate and the second plate.

  The force sensor according to a ninth aspect is the eighth aspect, wherein the first plate, the second plate, the elastic body, and the coil device constitute a detection block, and the detection block penetrates in the intersecting direction. The coil device is disposed around the through hole, and the detection block has an opening that opens the through hole to the outside in a direction along a plane perpendicular to the intersecting direction. It is characterized by.

  A force detection device according to a tenth aspect includes the force sensor according to any one of seventh to ninth aspects, and a detection circuit that detects a load based on a change in magnetic characteristics of the coil device.

  In the present invention, a coil is formed by a bundle of a plurality of conducting wires passing through the hollow portion of the core. Therefore, when manufacturing a coil device, the hollow portion of the core is wound as if a single long conducting wire is wound around the core. It is not necessary to pass the lead wire through the core many times, and it is only necessary to pass the electric circuit structure once through the hollow portion of the core. As a result, there exists an advantage that manufacture of a coil apparatus becomes easy.

1A is a perspective view of a coil device according to Embodiment 1. FIG. 1B is a cross-sectional view taken along the line XX of FIG. 1A. 2A and 2B are perspective views illustrating the method for manufacturing the coil device according to the first embodiment. It is a perspective view of the coil apparatus which concerns on the modification 1 of Embodiment 1. FIG. 4A is a perspective view of a coil device according to Embodiment 2. FIG. 4B is a cross-sectional view taken along the line XX in FIG. 4A. 6 is a perspective view of a coil device according to a first modification of the second embodiment. FIG. It is a perspective view of the coil apparatus which concerns on the modification 2 of Embodiment 2. FIG. It is a perspective view of the coil apparatus which concerns on Embodiment 3. FIG. FIG. 8A is a perspective view showing only the electric circuit structure and the connection structure of the coil device according to the third embodiment. FIG. 8B is a plan view illustrating the connection structure of the coil device according to the third embodiment. FIG. 9A is a perspective view showing only an electric circuit structure and a connection structure of a coil device according to Modification 1 of Embodiment 3. FIG. 9B is a plan view illustrating the connection structure of the coil device according to the first modification of the third embodiment. 10A is a schematic diagram illustrating a force sensor and a force detection device according to Application Example 1. FIG. FIG. 10B is a plan view of the force sensor according to the first application example. FIG. 10C is a cross-sectional view of the force sensor according to the first application example. 10 is a schematic diagram of a detection circuit in a force detection device according to application example 1. FIG. FIG. 12A is a diagram illustrating a magnetic flux distribution of an open magnetic path in a core having a hollow portion. FIG. 12B is a diagram illustrating a magnetic flux distribution of an open magnetic path in a core that does not have a hollow portion. In the force sensor which concerns on the application example 1, it is sectional drawing which shows the structure using structures other than a board | substrate. 14A is a cross-sectional view of a force sensor according to Application Example 2. FIG. 14B is a plan view of the force sensor according to the application example 2. FIG. FIG. 15A is a plan view illustrating an example of a substrate in the force sensor according to the application example 2. FIG. FIG. 15B is a plan view illustrating another example of the substrate in the force sensor according to the application example 2. 16A is a schematic diagram illustrating an example in which each detection unit is individually connected to a detection circuit in the force detection device according to Application Example 2. FIG. FIG. 16B is a schematic diagram illustrating an example in which each detection unit is individually connected to a detection circuit in the force detection device according to application example 2. 10 is a schematic diagram illustrating an example in which each detection unit is connected in series to a detection circuit in the force detection device according to Application Example 2. FIG. 10 is a schematic diagram illustrating a usage example of a force sensor according to Application Example 2. FIG. FIG. 19A is a plan view illustrating an example of an arrangement of detection units in the force sensor according to the application example 2. FIG. FIG. 19B is a plan view illustrating an example of the arrangement of the detection units in the force sensor according to Application Example 2. FIG. 20A is a plan view illustrating an example in which a detection unit is arranged on a square substrate in the force sensor according to Application Example 2. FIG. 20B is a plan view illustrating an example in which the detection unit is arranged on a semi-annular substrate in plan view in the force sensor according to Application Example 2. FIG. FIG. 20C is a plan view illustrating an example in which the detection unit is arranged on an annular substrate in plan view in the force sensor according to the application example 2. In the force sensor according to the application example 2, it is a cross-sectional view showing an example in which an insulator is arranged. In the force sensor which concerns on the application example 2, it is a top view which shows an example which formed the coil in the board | substrate. In the force sensor which concerns on the application example 2, it is sectional drawing which shows an example which provided the recessed part instead of the positioning hole. In the force sensor which concerns on the application example 2, it is sectional drawing which shows an example which has arrange | positioned the rigid body. FIG. 25A is a cross-sectional view illustrating a configuration using a structure other than a substrate in the force sensor according to Application Example 2. FIG. 25B is a plan view illustrating a configuration using a structure other than a substrate in the force sensor according to the application example 2. FIG. 26A is a cross-sectional view illustrating another configuration using a structure other than a substrate in the force sensor according to Application Example 2. FIG. 26B is a plan view showing another configuration using a structure other than the substrate in the force sensor according to the application example 2. FIG. 27A is a plan view of a force sensor according to application example 3. FIG. 27B is a cross-sectional view taken along the line XX in FIG. 27A. FIG. 28A and FIG. 28B are schematic diagrams illustrating usage examples of the force sensor according to the application example 3, respectively. FIG. 29A and FIG. 29B are plan views of a configuration including a force sensor blocking member according to Application Example 3, respectively. FIG. 30A and FIG. 30B are side views of a configuration in which a restricting portion is provided on an elastic body in the force sensor according to Application Example 3, respectively. FIG. 31A and FIG. 31B are side views showing a configuration in which the first plate and the second plate are each provided with a restricting portion in the force sensor according to Application Example 3. 32A is a plan view of a force sensor according to Modification 1 of Application Example 3. FIG. 32B is a cross-sectional view taken along the line XX of FIG. 32A. 33A and 33B are schematic diagrams illustrating usage examples of the force sensor according to Modification 1 of Application Example 3, respectively. FIG. 34A and FIG. 34B are plan views of a configuration including a force sensor closing member according to Modification 1 of Application Example 3, respectively. FIG. 35A is a plan view of a configuration in which the force sensor according to the application example 3 includes another closing member. FIG. 35B is a plan view of a configuration including another blocking member in the force sensor according to Modification 1 of Application Example 3; FIG. 36A and FIG. 36B are plan views of configurations in which the connecting portion is a wire in the force sensor according to Application Example 4, respectively. FIG. 37A is a side view of a configuration in which, in the force sensor according to the application example 4, the elastic body includes a restriction portion. FIG. 37B is a side view of a configuration in which the first plate and the second plate are provided with a restriction portion in the force sensor according to the fourth application example. FIG. 38A is a plan view of a configuration in which the connecting portion is a hinge in the force sensor according to the fourth application example. FIG. 38B is a side view of a configuration in which the connecting portion is a hinge in the force sensor according to the fourth application example. 39A and 39B are plan views of a force sensor according to Modification 1 of Application Example 4, respectively. 40A and 40B are plan views of a force sensor according to Modification 2 of Application Example 4, respectively. FIG. 41A is a plan view of a configuration including a blocking member in a force sensor according to Modification 1 of Application Example 4. FIG. FIG. 41B is a plan view of a configuration including a closing member in a force sensor according to Modification 2 of Application Example 4.

  Below, the coil apparatus which concerns on embodiment of this invention, and the force sensor and force detection apparatus using the same are demonstrated. First, the coil device will be described in the first to third embodiments, and further, a force sensor and a force detection device using the coil device will be described with reference to application modes (application examples 1 to 4). A force sensor and a force detection device here are a force sensor and a force detection device which detect the load added to a magnetic body using the inverse magnetostriction effect of the magnetic body of a coil device.

(Embodiment 1)
(1.1) Outline As shown in FIGS. 1A and 1B, the coil device 50 according to the present embodiment includes a core 4 formed in an annular shape surrounding a hollow portion 40 with a magnetic material and a bundle of a plurality of conducting wires 53. The electric circuit structure 51 which has, and the connection structure 52 electrically connected to the both ends of the electric circuit structure 51 are provided. The multiple conducting wires 53 are electrically insulated from each other. The electric circuit structure 51 is hung on the core 4 through the hollow portion 40. The connection structure 52 has a pair of terminals 551 and 552, and a plurality of conductors 53 are electrically connected in series between the pair of terminals 551 and 552, and the coil 5 is formed by the plurality of conductors 53. Is configured to do.

  Here, the relationship between the electric circuit structure 51 and the core 4 suffices if the electric circuit structure 51 is hung on the core 4 through the hollow portion 40, and the electric circuit structure 51 may be in contact with or in contact with the core 4. It does not have to be. The state where the electric circuit structure 51 is hung on the core 4 through the hollow portion 40 means a state where the electric circuit structure 51 is attached to the core 4 so as to surround a part of the core 4 through the hollow portion 40. In other words, the electric circuit structure 51 is not wound around the core 4 several times, but is part of the core 4 to such an extent that the coil 5 composed of the plurality of conductive wires 53 and the core 4 are magnetically coupled. It is provided so as to be entangled loosely. In addition, the “terminal” in the present embodiment does not necessarily have an entity as a part for connecting an electric wire, for example, a lead of an electronic part or a part of a conductor included in a printed board. Good.

  That is, in the coil device 50 of the present embodiment, the coil 5 is not formed by winding a single long conducting wire around the core 4 but by a bundle of a plurality of conducting wires 53 that pass through the hollow portion 40 of the core 4. A coil 5 is formed. Therefore, when manufacturing the coil device 50, it is not necessary to pass the conductor wire through the hollow portion 40 of the core 4 many times as in the case of winding a single long conductor wire around the core 4. It is only necessary to pass the bundle of electric wires 53 (electric circuit structure 51) once. As a result, there exists an advantage that manufacture of the coil apparatus 50 becomes easy.

  The coil device 50 configured as described above is not limited to a force sensor (and a force detection device) to be described later, and various uses as a cored coil such as a CT (Current Transformer) sensor used for measuring current, for example. It is applicable to.

(1.2) Specific Configuration Hereinafter, the coil device 50 of the present embodiment will be described in detail. However, the configuration described below is only an example of the present invention, and the present invention is not limited to the following embodiment, and the technical idea according to the present invention is not deviated from this embodiment. Various changes can be made in accordance with the design or the like as long as they are not. Moreover, in the following description, although the penetration direction (thickness direction of the core 4) of the hollow part 40 in the core 4 will be described as the vertical direction, this direction is not intended to limit the use form of the coil device 50.

  As shown in FIG. 1A, the coil device 50 according to the present embodiment includes a core 4, an electric circuit structure 51, and a connection structure 52.

  The core 4 is made of a magnetic material such as Ni (nickel) -Zn (zinc) ferrite. In the coil device 50 of the present embodiment, the core 4 is formed in a disk shape with the vertical direction as the thickness direction, and the circular hollow portion 40 penetrating in the thickness direction (vertical direction) is formed. In other words, the core 4 is a toroidal core that is formed in an annular shape in plan view and has a hollow portion 40. In addition, since the coil apparatus 50 of this embodiment is applied to the force sensor which detects the load added to a magnetic body using the inverse magnetostriction effect of a magnetic body, when the core 4 is applied with a load on the core 4, the reverse magnetostriction It is formed of a magnetic material that has an effect. The inverse magnetostriction effect is an effect in which the magnetized core 4 is distorted when a load is applied, and the permeability of the core 4 changes due to the distortion.

  The core 4 has a mounting part 41 having a smaller cross-sectional area than other parts in a part of the circumferential direction of the hollow part 40, and the electric circuit structure 51 is hung on the mounting part 41. That is, the electric circuit structure 51 is attached to the attachment portion 41 provided in a part of the core 4 in the circumferential direction. The mounting portion 41 has a smaller cross-sectional area (area of a cross section perpendicular to the circumferential direction of the hollow portion 40), that is, is thinner than other portions of the core 4 (portions other than the mounting portion 41). Here, the attachment portion 41 is formed to be thinner than other portions of the core 4 in both the thickness direction (vertical direction) of the core 4 and the radial direction of the core 4. For this reason, in the coil device 50 of the present embodiment, the electric circuit structure 51 is disposed within the width of the core 4 in the vertical direction so that the electric circuit structure 51 does not protrude from both surfaces (upper surface and lower surface) in the thickness direction of the core 4. Can fit. Furthermore, the electric circuit structure 51 can be accommodated within the width of the core 4 in the radial direction of the core 4 so that the electric circuit structure 51 does not protrude into the hollow portion 40 from the core 4. Note that whether or not the mounting portion 41 is designed with the above dimensions is arbitrary.

  As shown in FIG. 1B, the electric circuit structure 51 is a cable in which a plurality of conductive wires 53 are covered with a covering member 513 having electrical insulation. Here, as an example, the cable (electric circuit structure 51) is a flat coaxial cable in which a plurality of thin coaxial cables are covered with a jacket (skin). The thin coaxial cable here has a structure in which a central conductor (core wire) made of an extremely fine stranded wire is covered with a dielectric and a shield. In this flat coaxial cable, each of the plurality of central conductors corresponds to the conductive wire 53, and the dielectric and the jacket correspond to the covering member 513. Here, the electric circuit structure 51 is a multi-core (six-core) cable having six conductors 53. When distinguishing these six conducting wires 53, they are distinguished as conducting wires 531 to 536.

  In the example of FIG. 1B, the electric circuit structure 51 is formed in a strip shape that is long in the longitudinal direction of the plurality of conducting wires 53. At least at both ends in the longitudinal direction of the electric circuit structure 51, a plurality of (here, six) conductors 531 to 536 are arranged in a line along the width direction (short direction) of the electric circuit structure 51. A plurality of thin coaxial cables are integrated. As a result, a bundle of a plurality of conducting wires 53 is formed in the electric circuit structure 51. The dimension of the electric circuit structure 51 in the short direction is smaller than the dimension of the mounting portion 41 (the dimension in the circumferential direction of the hollow portion 40). Both ends in the longitudinal direction of the electric circuit structure 51 configured as described above are electrically connected to the connection structure 52.

  In addition, in the electric circuit structure 51, the several conducting wire 53 should just be bundled, and a several thin coaxial cable (plural conducting wire 53) is scattered except the both ends of the longitudinal direction of the electric circuit structure 51. It may be provided so that it may be integrated. In the present embodiment, a plurality of thin coaxial cables are provided apart from both ends in the longitudinal direction of the electric circuit structure 51.

  The electric circuit structure 51 has a portion protruding from the hollow portion 40 along the radial direction of the core 4 with the central portion in the longitudinal direction passing through the core 4 so as to be located in the hollow portion 40 of the core 4. 4 is bent outward. Here, the part located in the hollow portion 40 in the electric circuit structure 51 is defined as the insertion part 510, and the parts on both sides of the insertion part 510 in the longitudinal direction of the electric circuit structure 51 are the first extraction part 511 and the second extraction part 512. And The first lead portion 511 and the second lead portion 512 are extended in the same direction from both end edges of the insertion portion 510 and face each other in the vertical direction (the thickness direction of the core 4). Thereby, the electric circuit structure 51 is attached to the core 4 so as to surround the attachment portion 41 with the insertion portion 510, the first extraction portion 511, and the second extraction portion 512.

  In the following description, in the facing direction (vertical direction) of the first drawer portion 511 and the second drawer portion 512, the first drawer portion 511 side is viewed downward and the second drawer portion 512 side is viewed upward from the core 4. To do.

  In this embodiment, the connection structure 52 is a connector device that is electrically connected to both ends (in the longitudinal direction) of the electric circuit structure 51. The connection structure (connector device) 52 includes a first connector 521 and a second connector 522 that are mechanically coupled and electrically connected to each other. The first connector 521 and the second connector 522 are detachable. The first connector 521 is electrically connected to the end of the first lead portion 511 opposite to the insertion portion 510. The second connector 522 is electrically connected to the end of the second lead portion 512 opposite to the insertion portion 510. Therefore, in a state where the first connector 521 and the second connector 522 are connected to each other, both ends of the electric circuit structure 51 are mechanically coupled and electrically connected via the connection structure 52. Become.

  Each of the first connector 521 and the second connector 522 has a plurality of terminals, and the plurality of conductors 53 of the electric circuit structure 51 are electrically connected to each of the plurality of terminals one by one. Here, the number of terminals (the number of contacts) of each of the first connector 521 and the second connector 522 is set to be at least one more than the number (here, six) of the conductive wires 53 of the electric circuit structure 51. In the present embodiment, the number of terminals of each of the first connector 521 and the second connector 522 is “7”. Each of the plurality of terminals is assigned a terminal number. When the first connector 521 and the second connector 522 are connected to each other, the terminals having the same terminal number are connected via the connection conductors 541 to 547. It will be electrically connected. Here, each of the connection conductors 541 to 547 includes a contact for electrically connecting terminals between the first connector 521 and the second connector 522. Hereinafter, of the connection conductors 541 to 547, the connection conductor 54n connected to the terminal having the terminal number “n” (n is a natural number) is referred to as a connection conductor 54n having the terminal number “n”.

  The electric circuit structure 51 is electrically connected to the connection structure 52 so that the terminal numbers of the terminals to which the conductive wires 53 are connected are shifted one by one between the first connector 521 and the second connector 522. . In the example of FIG. 1B, in the first connector 521, the conducting wire 531 is connected to the “No. 1” connecting conductor 541, and similarly, the conducting wires 532 to 536 are connected to the “No. 2” to “No. 6” connecting conductors 542 to 546. Are connected in a one-to-one correspondence. On the other hand, in the second connector 522, the lead wire 531 is connected to the “second” connection conductor 542, and similarly, the lead wires 532 to 536 are one-to-one on the “third” to “seventh” connection conductors 543 to 547. Connected to correspond to.

  Thus, in a state where the first connector 521 and the second connector 522 are connected, between the “first” terminal 552 in the second connector 522 and the “seventh” terminal 551 in the first connector 521. The plurality of conductive wires 53 are electrically connected in series. That is, the connection structure 52 has a pair of terminals 551 and 552, and is configured to electrically connect a plurality of conductive wires 53 between the pair of terminals 551 and 552.

  Specifically, one end of the conducting wire 531 is electrically connected to one (first) terminal 552 of the pair of terminals 551 and 552 via the connecting conductor 541, and the other end of the conducting wire 531 is connected to the other end of the conducting wire 531. One end of the conducting wire 532 is electrically connected through the connection conductor 542. One end of a conducting wire 533 is electrically connected to the other end of the conducting wire 532 via a connecting conductor 543, and one end of the conducting wire 534 is electrically connected to the other end of the conducting wire 533 via a connecting conductor 544. . One end of a conducting wire 535 is electrically connected to the other end of the conducting wire 534 via a connecting conductor 545, and one end of a conducting wire 536 is electrically connected to the other end of the conducting wire 535 via a connecting conductor 546. . The other (second) terminal 551 of the pair of terminals 551 and 552 is electrically connected to the other end of the conducting wire 536 through a connection conductor 547.

  Thus, the plurality of conducting wires 531 to 536 connected in series between the pair of terminals 551 and 552 are equivalent to one conducting wire (winding) wound around the mounting portion 41 of the core 4. . Therefore, according to the configuration of the present embodiment, the plurality of conductive wires 53 form the coil 5 attached to the attachment portion 41. Thereby, the coil apparatus 50 of this embodiment comprises the toroidal coil with which the coil 5 was attached to the annular | circular shaped core (toroidal core) 4. FIG. Here, since the number of the conductive wires 53 is the number of turns of the coil 5, in the present embodiment in which the six conductive wires 53 are provided, the number of turns of the coil 5 is “6”.

  In the coil device 50 configured as described above, since the pair of terminals 551 and 552 correspond to both ends of the coil 5, the coil 5 can be electrically connected to an external circuit using the pair of terminals 551 and 552. is there. For example, by connecting a pair of connecting wires to the pair of terminals 551 and 552, an electrical connection between the external circuit and the coil 5 can be realized via the pair of connecting wires.

(1.3) Manufacturing Method Next, a manufacturing method of the coil device 50 configured as described above will be described with reference to FIGS. 2A and 2B.

  First, as shown in FIG. 2A, an electric circuit structure 51 in which connection structures 52 (first connector 521 and second connector 522) are connected to both ends and a core 4 are prepared. In FIG. 2A, the connection between the first connector 521 and the second connector 522 is released. In this state, by passing the second connector 522 through the hollow portion 40 from below the core 4, the electric circuit structure 51 passes through the hollow portion 40 of the core 4. At this time, the positional relationship between the electric circuit structure 51 and the core 4 is determined so that the electric circuit structure 51 is hung on the mounting portion 41 of the core 4.

  Thereafter, as shown in FIG. 2B, the first connector 521 and the second connector 522 are connected to each other. Thereby, both ends of the electric circuit structure 51 are mechanically coupled and electrically connected, and the coil 5 is formed by the plurality of conductive wires 53.

(1.4) Effects In the coil device 50 of the present embodiment described above, a single long conducting wire is not wound around the core 4 to form the coil 5, but a plurality of wires that pass through the hollow portion 40 of the core 4. The coil 5 is formed of a bundle of conductive wires 53 (electric circuit structure 51). Therefore, when manufacturing the coil device 50, it is not necessary to pass the conductor wire through the hollow portion 40 of the core 4 many times as in the case of winding a single long conductor wire around the core 4. It is only necessary to pass the bundle of electric wires 53 (electric circuit structure 51) once. As a result, there exists an advantage that manufacture of the coil apparatus 50 becomes easy.

  That is, by applying the configuration of the present embodiment, a toroidal coil that is difficult to manufacture even when an automatic winding machine is used can be easily manufactured manually. In particular, in the case of a relatively small coil device 50, it is difficult to pass the lead wire through the hollow portion 40 of the core 4 many times, so it is useful to apply the configuration of the present embodiment.

  Furthermore, since the coil device 50 is configured such that the coil 5 is attached to the core 4 having the hollow portion 40, the magnetic path along the circumferential direction of the hollow portion 40 is provided in the core 4 when the coil 5 is energized. (Magnetic circuit) is formed. This magnetic path is a closed magnetic path. Therefore, in this coil device 50, since the leakage of the magnetic flux from the core 4 to the outside hardly occurs, it is not necessary to provide a ferromagnetic case to prevent the leakage of the magnetic flux.

  In addition, when the electric circuit structure (the plurality of conducting wires 53) is attached so as to be loosely entangled with the core 4 as in the present embodiment, the coil device 50 is compared with the case where one long conducting wire is wound around the core 4. The design accuracy of the characteristics (inductance, etc.) may be lowered. However, if the application uses a change (relative value) of the characteristic instead of the absolute value of the characteristic of the coil device 50 as in a force sensor described later, the design accuracy of the characteristic of the coil device 50 may be relatively low. The coil device 50 of this embodiment is sufficiently applicable.

  Further, as in the present embodiment, the electric circuit structure 51 is preferably a cable in which a plurality of conductive wires 53 are covered with a covering member 513 having electrical insulation. According to this configuration, since the electric circuit structure 51 can be realized by a general-purpose cable, the manufacturing of the coil device 50 is further facilitated. In addition, the number of turns of the coil 5 can be changed depending on the number of cores (number of cores) of the cable, that is, the number of conductive wires, and coils with various numbers of turns can be realized by using cables having different numbers of cores.

  Further, as in the present embodiment, the core 4 has a mounting portion 41 having a smaller cross-sectional area than other portions in a part of the circumferential direction of the hollow portion 40, and the electric circuit structure 51 is attached to the mounting portion 41. Preferably it is hung. According to this configuration, the electric circuit structure 51 can be contained within the width in the thickness direction of the core 4 so that the electric circuit structure 51 does not protrude from both surfaces (upper surface and lower surface) of the core 4 in the thickness direction. Furthermore, the electric circuit structure 51 can be accommodated within the width of the core 4 in the radial direction of the core 4 so that the electric circuit structure 51 does not protrude into the hollow portion 40 from the core 4.

(1.5) Modified Example FIG. 3 shows a first modified example of the first embodiment. In the first modification, the coil device 50 further includes a binding member 56 that binds the electric circuit structure 51 between the core 4 and the connection structure 52. In the example of FIG. 3, the binding member 56 is a band-shaped adhesive tape, and the first drawing portion 511 and the second drawing portion 512 of the electric circuit structure 51 are bundled outside the hollow portion 40. The binding member 56 includes a first drawing portion 511 and a second drawing portion 512 so that the distance between the first drawing portion 511 and the second drawing portion 512 in at least the vertical direction is smaller than the thickness dimension of the core 4. You just have to bundle.

  According to the first modification, the electric circuit structure 51 including the plurality of conductive wires 53 forms a loop that surrounds a part of the core 4 (attachment portion 41) in the vicinity of the core 4. The degree of magnetic coupling between the coil 5 made of the conductive wire 53 and the core 4 is improved. Here, it is preferable that the binding member 56 has the first lead portion 511 and the second lead portion 512 in close contact with each other, thereby further improving the degree of magnetic coupling between the coil 5 and the core 4. Further, the position of the binding member 56 may be between the core 4 and the connection structure 52, but is preferably closer to the core 4. The binding member 56 only needs to be configured to bundle the electric circuit structure 51 between the core 4 and the connection structure 52, and is not limited to the adhesive tape, and may be, for example, a binding band or a clip. Further, the bundling member 56 may be an adhesive or the like that adheres the first drawing portion 511 and the second drawing portion 512.

  Other modifications of the first embodiment are listed below.

  The electric circuit structure 51 may be a cable in which a plurality of conductive wires 53 are covered with a covering member 513 having electrical insulation, and is not limited to a flat coaxial cable, but may be, for example, a general-purpose flat cable or a round cable. May be. Further, the number of cores of the cable, that is, the number of the conductive wires 53 is not limited to 6, and may be 5 or less or 7 or more.

  Moreover, the coil apparatus 50 should just be the structure by which the electric circuit structure 51 was hung on the core 4 which has the hollow part 40, and is not restricted to the toroidal coil which employ | adopted the annular core (toroidal core) 4, For example, rectangular shape Various cores 4 such as a triangular shape and a polygonal shape can be employed.

  Further, the plurality of conductive wires 53 are not limited to a single-layer structure that is wound around the core 4, and may have a multilayer structure. Specifically, a flat cable in which a plurality of conductive wires 53 are provided in a plurality of layers in the thickness direction of the electric circuit structure 51 as well as in the width direction of the electric circuit structure 51, or the electric circuit structure 51 is used as the core 4. On the other hand, a multi-layer structure is realized by multiple times. Even when the electric circuit structure 51 is hung around the core 4 a plurality of times, the coil device 50 can be easily manufactured as compared with the case where one long conducting wire is wound around the core 4 to form the coil 5 having the same number of turns. Become.

  In the first embodiment, the electric circuit structure 51 is bent with a predetermined radius of curvature in the hollow portion 40 of the core 4. However, the configuration is not limited to this, and the insertion portion 510, the first extraction portion 511, and the second It may be bent at a substantially right angle at a boundary portion with each of the drawing portions 512. In this case, a gap (gap) between the electric circuit structure 51 and the core 4 can be reduced, and the degree of magnetic coupling between the coil 5 formed of the plurality of conductive wires 53 and the core 4 is improved.

  The connection structure 52 is a connector device including the first connector 521 and the second connector 522 in the present embodiment, but is not limited to this configuration, and may be, for example, a terminal block or a printed board. Examples in which the connection structure 52 is formed of a printed circuit board will be described in Embodiments 2 and 3. Furthermore, both ends of the electric circuit structure 51 may be directly connected to each other by aerial wiring using a lead wire or solder. In this case, the lead wire or solder corresponds to the connection structure 52.

(Embodiment 2)
As shown in FIGS. 4A and 4B, the coil device 50 according to the present embodiment is different from the coil device 50 according to the first embodiment in that the electric circuit structure 51 is a flexible substrate. The flexible substrate has a structure in which a plurality of conductive wires 53 are formed on at least one surface of a base film 514 having electrical insulation and flexibility. In the present embodiment, the connection structure 52 is a printed board. Hereinafter, the same configurations as those of the first embodiment are denoted by common reference numerals, and description thereof is omitted as appropriate.

  The flexible substrate here includes a flexible printed circuit (FPC) and a flexible flat cable (FPC). That is, the flexible substrate has a configuration in which a plurality of conductive wires 53 made of metal foil (for example, copper foil) is formed on at least one surface of the base film 514, and may be a substrate having flexibility as a whole. In the example of FIGS. 4A and 4B, the plurality of conductive wires 53 are formed only on one surface of the base film 514.

  The printed circuit board as the connection structure 52 is a rigid board such as a glass epoxy board. This connection structure (printed circuit board) 52 has a plurality of terminals on each surface in the thickness direction, and each of the plurality of terminals is electrically connected with a plurality of conductive wires 53 of the electric circuit structure 51. Connected. Here, the terminal is composed of a connection pad (metal foil) formed on each surface in the thickness direction of the printed board. Here, the connection conductors 541 to 547 that electrically connect the terminals between both surfaces in the thickness direction of the printed circuit board are formed of through-hole conductors.

  Also in the present embodiment, as in the first embodiment, a plurality of conductive wires 53 are electrically connected in series between the “No. 1” connection conductor 541 and the “No. 7” connection conductor 547. . That is, the connection structure 52 has a pair of terminals 551 and 552, and is configured to electrically connect a plurality of conductive wires 53 between the pair of terminals 551 and 552. In this embodiment, the connection pad connected to the “No. 7” connection conductor 547 constitutes the terminal 551, and the connection pad connected to the “No. 1” connection conductor 541 constitutes the terminal 552.

  According to the configuration of the present embodiment described above, since the electric circuit structure 51 can be realized by a flexible substrate, the coil device 50 can be easily manufactured. And compared with the case where the electric circuit structure 51 consists of a cable, the electric circuit structure 51 can be reduced in thickness, and the coil apparatus 50 can be further reduced in size (thinner).

  Further, since the connection structure 52 is a printed circuit board, the connection structure 52 can be simplified and thinned as compared with the case where the connection structure 52 is a connector device. That is, since the connection form between the electric circuit structure 51 and the connection structure 52 can be realized by solder bonding or the like, the dimensions in the vertical direction can be kept relatively small with a simple configuration.

(2.1) Modified Example FIG. 5 illustrates a first modified example of the second embodiment. In the first modification, both ends of the electric circuit structure 51 are connected to one surface (upper surface) in the thickness direction of the connection structure 52. In the first modification, the electric circuit structure is formed on one surface in the thickness direction of the connection structure 52 and in the direction in which the core 4 and the connection structure 52 are aligned (the extension direction of the first extraction portion 511 and the second extraction portion 512). The both ends of the body 51 are spaced apart.

  FIG. 6 shows a second modification of the second embodiment. In the second modification, as in the first modification, both ends of the electric circuit structure 51 are connected to one surface (upper surface) in the thickness direction of the connection structure 52. In the second modification, a direction that is on one surface in the thickness direction of the connection structure 52 and is orthogonal to the direction in which the core 4 and the connection structure 52 are arranged (extension direction of the first extraction portion 511 and the second extraction portion 512). , The both ends of the electric circuit structure 51 are spaced apart.

  In the first and second modifications, the terminal is composed of a connection pad (metal foil) formed on one surface in the thickness direction of the printed board. A connection conductor that electrically connects terminals on one surface in the thickness direction of the printed board is made of a metal foil (for example, copper foil) formed on one surface in the thickness direction of the printed board. That is, the connection structure 52 is composed of a single-sided printed board. The connection structure 52 having such a configuration will be described in detail in the third embodiment.

  Other configurations and functions are the same as those of the first embodiment. Further, the configuration (including the modification) described in the second embodiment can be applied in appropriate combination with the configuration (including the modification) described in the first embodiment.

(Embodiment 3)
The coil device 50 according to the present embodiment is different from the coil device 50 according to the second embodiment in that the electric circuit structure 51 has a molded body 515 as shown in FIGS. 7, 8 </ b> A, and 8 </ b> B. The electric circuit structure 51 has a structure in which a plurality of conductive wires 53 are formed on the surface of a molded body 515 having electrical insulation. Hereinafter, the same configurations as those of the second embodiment are denoted by common reference numerals, and the description thereof is omitted as appropriate.

  The electric circuit structure 51 in the present embodiment is a molded circuit component (MID: Molded Interconnect Devices) in which a plurality of conductive wires 53 are three-dimensionally formed of metal foil (for example, copper foil) on the surface of a molded body 515 made of resin or ceramics. ). Here, in the molded body 515, the insertion portion 510 and each of the first extraction portion 511 and the second extraction portion 512 are substantially orthogonal, and the first extraction portion 511 and the second extraction portion 512 are parallel to each other. It is formed as follows. Thus, the molded body 515 forms a space between the molded body 515 and the connection structure 52 in a state where the molded body 515 is mounted on one surface of the printed board as the connection structure 52. In this space, a part of the core 4 (attachment portion 41) is located.

  As shown in FIG. 8A, the plurality of conductive wires 53 (here, the four conductive wires 531 to 534) are end surfaces orthogonal to the circumferential direction of the hollow portion 40 in the molded body 515, that is, the width direction of the electric circuit structure 51. It is formed on one end face of.

  In addition, the connection structure 52 of the present embodiment is a single-sided printed board in which connection pads (metal foils) 571 to 578 as terminals are formed on one surface in the thickness direction. A plurality of conductive wires 53 are connected to the plurality of connection pads 571 to 578 by soldering or the like at both ends of the electric circuit structure 51. In the present embodiment, the connection conductors 541 to 543 are made of a metal foil (for example, a copper foil) formed on one surface in the thickness direction of the printed board. The connection conductors 541 to 543 electrically connect the connection pads 571 to 574 connected to one end of the electric circuit structure 51 and the connection pads 575 to 578 connected to the other end of the electric circuit structure 51. Connecting.

  Here, the connection pad 574 electrically connected to the conductive wire 534 constitutes the terminal 551, and the connection pad 575 electrically connected to the conductive wire 531 constitutes the terminal 552. The connection conductors 541 to 543 have a one-to-one connection between the connection pads 571 to 573 and the connection pads 576 to 578 so that the plurality of conductive wires 53 are electrically connected in series between the pair of terminals 551 and 552. Connect electrically. That is, the connection pads 571 to 574 connected to one end of the electric circuit structure 51 and the connection pads 575 to 578 connected to the other end of the electric circuit structure 51 are shifted one by one, and the connection conductor 541 is shifted. Connected at ˜543.

  According to the configuration of the present embodiment described above, since the electric circuit structure 51 can be realized by the molded circuit component, the coil device 50 can be easily manufactured. In addition, as compared with the case where the electric circuit structure 51 is made of a cable, it is possible to reduce the interval between the plurality of conductive wires 53 and increase the number of the conductive wires 53.

(3.1) Modified Example FIGS. 9A and 9B illustrate a modified example of the third embodiment. In this modification, a plurality of conductive wires 53 (here, five conductive wires 531 to 535) are formed on the outer peripheral surface of the molded body 515. That is, the multiple conducting wires 53 are arranged so as to be aligned along the circumferential direction of the hollow portion 40.

  In the connection structure 52, the connection conductors 541 to 544 include connection pads 571 to 575 connected to one end of the electric circuit structure 51 and connection pads 576 to 580 connected to the other end of the electric circuit structure 51. And electrically connect. Here, the connection pad 575 electrically connected to the conductive wire 535 constitutes the terminal 551, and the connection pad 576 electrically connected to the conductive wire 531 constitutes the terminal 552. The connection conductors 541 to 544 have a one-to-one connection between the connection pads 571 to 574 and the connection pads 577 to 580 so that the plurality of conductive wires 53 are electrically connected in series between the pair of terminals 551 and 552. Connect electrically. In other words, the connection pads 571 to 575 connected to one end portion of the electric circuit structure 51 and the connection pads 576 to 580 connected to the other end portion of the electric circuit structure 51 are shifted one by one and the connection conductor 541. Connected at ~ 544.

  Other configurations and functions are the same as those of the second embodiment. Further, the configuration (including the modification) described in the third embodiment can be applied in appropriate combination with the configuration (including the modification) described in the first embodiment.

(Application form)
Hereinafter, with reference to FIGS. 10 to 42, the force sensor 2 and the force detection device 1 using the coil device 50 described in each of the above embodiments will be described. The force sensor 2 and the force detection device 1 here detect a load applied to the magnetic body (core 4) by using the inverse magnetostriction effect of the magnetic body (core 4) of the coil device 50.

  The force sensor 2 shown in the following application example includes the coil device 50 described in each of the above embodiments as the detection unit 20. In the force sensor 2, a magnetic path M <b> 1 (see FIG. 10B) through which a magnetic flux generated by a current flowing between the pair of terminals 551 and 552 passes is formed in the core 4 along the circumferential direction of the hollow portion 40. The core 4 has a load receiving portion 42 (see FIG. 10B) that receives a load on one surface in the intersecting direction (vertical direction) intersecting the surface on which the magnetic path M1 is formed. That is, in this force sensor 2, since the “crossing direction” that intersects the surface on which the magnetic path M1 is formed becomes the load detection direction, the “crossing direction” is also referred to as “detection direction” below.

  Further, the force sensor 2 shown in the following application example includes a first plate 21 (see FIG. 10C) and a second plate 22 (see FIG. 10C) that are arranged so as to sandwich the core 4 from both sides in the detection direction (crossing direction). And an elastic body 23 (see FIG. 10C). The elastic body 23 is formed of a material having a lower elastic modulus than the core 4 and positions between the first plate 21 and the second plate 22. However, in the force sensor 2 using the coil device 50 described in the above embodiments, the first plate, the second plate, and the elastic body 23 are not essential components and can be omitted as appropriate.

  Moreover, the force detection apparatus 1 (refer FIG. 10A) shown to the following application examples is provided with the force sensor 2 and the detection circuit 3 (refer FIG. 10A). The detection circuit 3 detects a load based on a change in the magnetic characteristics (inductance or conductance) of the coil 5.

(Application example 1)
The force detection device 1 of the application example 1 includes a force sensor 2 and a detection circuit 3 as illustrated in FIG. 10A. Further, as shown in FIGS. 10A to 10C, the force sensor 2 of Application Example 1 includes a detection unit 20, a first plate 21, a second plate 22, an elastic body 23, a substrate (structure) 24, and the like. It has. In FIG. 10B, illustration of the second plate 22 and the elastic body 23 is omitted.

  As shown in FIG. 10A, the detection unit 20 includes a core 4 made of a magnetic material and a coil 5 that is magnetically coupled to the core 4. That is, the detection unit 20 is configured by the coil device 50 described in the above embodiments.

  A magnetic flux generated when the coil 5 is energized passes through the core 4 as shown in FIG. 10B. For this reason, a magnetic path (magnetic circuit) M <b> 1 along the circumferential direction of the hollow portion 40 is formed in the core 4. This magnetic path M1 is a closed magnetic path. Therefore, in the force sensor 2 of this application example, since the leakage of the magnetic flux from the core 4 to the outside hardly occurs, it is not necessary to provide a ferromagnetic case in order to prevent the leakage of the magnetic flux.

  The first plate 21 and the second plate 22 are both plate-like members formed of, for example, a metal material. As shown in FIG. 10B, the first plate 21 is formed in a circular shape in plan view. Further, the second plate 22 is formed in a circular shape in a plan view like the first plate 21. As shown in FIG. 10C, the first plate 21 is disposed on the lower side of the core 4 so as to be in contact with the lower surface of the core 4. Moreover, the 2nd plate 22 is arrange | positioned at the upper side of the core 4 in the form which contact | connects the upper surface of the core 4, as shown to FIG. 10C. That is, the first plate 21 and the second plate 22 are arranged so as to sandwich the core 4 from both sides in the vertical direction (detection direction).

  In addition, the shape of the 1st plate 21 and the 2nd plate 22 is not limited to circular shape by planar view, For example, rectangular shape and annular | circular shape may be sufficient by planar view. Moreover, the 1st plate 21 and the 2nd plate 22 should just have the intensity | strength which can endure the assumed load. Furthermore, the first plate 21 and the second plate 22 may not be formed of a metal material, and may be formed of a resin material such as CFRP (Carbon-Fiber-Reinforced Plastic).

  The elastic body 23 is an adhesive mainly composed of an epoxy resin or a silicone resin, for example. The elastic body 23 bonds the first plate 21 and the second plate 22 to each other by adhering to the outer peripheral edge of the upper surface of the first plate 21 and the outer peripheral edge of the lower surface of the second plate 22. The elastic body 23 is not limited to the adhesive, and may be formed of a material having a lower elastic modulus than the material forming the core 4. Moreover, the elastic body 23 should just be the structure which positions between both the 1st plate 21 and the 2nd plate 22. FIG.

  As shown in FIG. 10C, the substrate 24 is accommodated in a space surrounded by the first plate 21, the second plate 22, and the elastic body 23. The substrate 24 is fixed by the outer peripheral edge thereof being in contact with the elastic body 23. Further, the substrate 24 is formed in an annular shape in a plan view as shown in FIG. 10C, and its central portion has a circular positioning in a plan view having a diameter slightly larger than the diameter of the core 4. It is a hole 240. The core 4 is positioned at a predetermined position by fitting the core 4 into the positioning hole 240. In other words, the substrate (structure) 24 is a member that is disposed between the first plate 21 and the second plate 22 and positions the detection unit 20 at a predetermined position. The substrate (structure) 24 has a positioning hole 240 penetrating in the vertical direction (detection direction). The core 4 is disposed inside the positioning hole 240. The shape of the positioning hole 240 is not limited to a circular shape in a plan view, and may be a rectangular shape in a plan view, for example. That is, the positioning hole 240 may have a shape into which the core 4 is fitted.

  As shown in FIG. 11, the detection circuit 3 includes an oscillation circuit 30, a period measurement circuit 31, a square circuit 32, a temperature compensation circuit 33, and a signal processing circuit 34. The oscillation circuit 30 is configured to maintain the oscillation of the resonance circuit 35 including the coil 5. The oscillation circuit 30 is configured to output an oscillation signal that oscillates at a frequency corresponding to the resonance frequency of the resonance circuit 35. The period measurement circuit 31 is configured to measure the period of the oscillation signal output from the oscillation circuit 30 and output a signal corresponding to the measured period. The square circuit 32 is configured to calculate and output the square value of the signal output from the period measurement circuit 31. The temperature compensation circuit 33 is configured to suppress temperature fluctuation of the signal output from the squaring circuit 32 by temperature compensation processing. The signal processing circuit 34 is configured to detect a change in load applied to the core 4 based on a signal output from the temperature compensation circuit 33.

  As shown in FIG. 11, the equivalent circuit of the resonance circuit 35 is composed of a series circuit of an inductor L1 and a resistor R1 and a parallel circuit of a capacitor C1. Here, the inductance of the inductor L1 is equivalent to the inductance of the coil 5. Further, the resistance value of the resistor R1 is equivalent to the resistance value of the winding resistance of the coil 5. Further, the capacitance value of the capacitor C1 is equivalent to the capacitance value of the parasitic capacitance of the coil 5. The resonance circuit 35 may be configured by electrically connecting a capacitor in parallel with the coil 5.

  In the force sensor 2 of this application example, the detection circuit 3 is configured by mounting electronic components on the substrate 24. In other words, a circuit (detection circuit 3) is formed on the substrate (structure) 24. That is, in the force detection device 1 of this application example, the detection circuit 3 is provided integrally with the force sensor 2. Note that the detection circuit 3 does not need to be provided on the substrate 24 and may be provided separately from the substrate 24. Further, the detection circuit 3 may be provided on a substrate outside the force sensor 2, for example. That is, in the force detection device 1 of this application example, the detection circuit 3 may be provided separately from the force sensor 2.

  Hereinafter, operations of the force sensor 2 and the force detection device 1 of the application example will be described. First, by supplying a current from an external power source to the coil 5, the core 4 is magnetized and the magnetic path M1 is formed. Here, the oscillation circuit 30 of the detection circuit 3 supplies a current to the coil 5.

  Next, when an upward load is applied to the lower surface of the first plate 21 (see the upward arrow shown in FIG. 10C), the first plate 21 is pushed up due to the elastic body 23 being bent, and the first plate 21 passes through the first plate 21. A load is applied to the core 4. Then, due to the inverse magnetostrictive effect, the magnetic permeability of the core 4 changes according to the magnitude of the load, so that the inductance of the coil 5 changes. Similarly, when a downward load (see the downward arrow shown in FIG. 10C) is applied to the upper surface of the second plate 22, the second plate 22 is pushed down by the elastic body 23 being bent, and the second plate 22 passes through the second plate 22. A load is applied to the core 4. At this time, in the core 4, the load is received by the load receiving portion 42 (see FIG. 10B) composed of one surface (here, the upper surface) in the detection direction intersecting the surface on which the magnetic path M <b> 1 is formed. Also in this case, the inductance of the coil 5 changes according to the magnitude of the load. That is, in the force sensor 2 of this application example, the core 4 (detection unit 20) is configured to receive a load applied from the first plate 21 and the second plate 22 in a direction along the vertical direction (detection direction). .

  When the inductance of the coil 5 changes, the resonance frequency of the resonance circuit 35 including the coil 5 changes. For this reason, the oscillation circuit 30 outputs an oscillation signal having a frequency corresponding to the resonance frequency of the resonance circuit 35, and the period measurement circuit 31 outputs a signal corresponding to the period of the oscillation signal. Here, the period of the oscillation signal is represented by the square root of the product of the inductance of the inductor L1 and the capacitance value of the capacitor C1 in the equivalent circuit. And since the square circuit 32 calculates and outputs the square value of the output signal of the period measurement circuit 31, the output signal of the square circuit 32 changes linearly with respect to the change of the inductance of the coil 5. The output signal of the square circuit 32 is corrected for temperature fluctuations by the temperature compensation circuit 33. The signal processing circuit 34 calculates the inductance of the coil 5 based on the output signal of the temperature compensation circuit 33, and calculates the load applied to the core 4 from the amount of change in the inductance of the coil 5. That is, the detection circuit 3 detects the load applied to the core 4 based on the change in the inductance of the coil 5.

  As described above, in the force sensor 2 of this application example, the detection unit 20 is sandwiched between the first plate 21 and the second plate 22, and the elastic body 23 positions between the first plate 21 and the second plate 22. It has a configuration. For this reason, in the force sensor 2 of this application example, it is not necessary to provide a strain-generating portion on the first plate 21 and the second plate 22, so the dimensions in the thickness direction of the first plate 21 and the second plate 22 are determined. Can be small. Therefore, the force sensor 2 of this application example can be thinned by reducing the dimension of the first plate 21 and the second plate 22 in the thickness direction. Further, the force sensor 2 of this application example includes an elastic body 23. For this reason, the force sensor 2 of this application example can improve the load detection accuracy because the load is easily transmitted to the core 4 when a load is applied to the first plate 21 or the second plate 22.

  Further, in the force sensor 2 of this application example, the coil 5 is provided so that the magnetic path M1 formed when the coil 5 is energized is a closed magnetic path. However, as shown in FIG. You may be comprised by winding along the outer periphery of the core 4. FIG. In this configuration, the magnetic flux generated when the coil 5 is energized forms a magnetic path M <b> 2 that passes not only inside the core 4 but also outside the core 4. That is, in this configuration, the magnetic path M2 is an open magnetic path. This configuration has an advantage that the core 4 is easy to manufacture because it is not necessary to process the core 4 by providing the attachment portion 41 or the like. In addition, this configuration has an advantage that the coil 5 can be easily manufactured because the coil 5 can be manufactured simply by winding a conducting wire around the outer periphery of the core 4. That is, in this configuration, the core 4 and the coil 5 can be easily designed, so that the force sensor 2 can be easily reduced in size and thickness. When the coil 5 is configured by winding a conducting wire along the outer periphery of the core 4, the core 4 may not have the hollow portion 40 as illustrated in FIG. 12B.

  Further, in the force sensor 2 of this application example, the core 4 is positioned by using the substrate 24. However, as shown in FIG. 13, for example, the core 4 is positioned by a structure 27 other than the substrate 24. Also good. In this configuration, the first plate 21 is provided with a circular through-hole 210 in the center in a plan view. Similarly, in this configuration, the second plate 22 is provided with a circular through-hole 220 in the center in a plan view. These through holes 210 and 220 are used, for example, to pass the shaft portion of the bolt through the hollow portion 40 of the core 4 when detecting the tightening axial force of the bolt. Further, these through holes 210 and 220 pass the tendon 102A (see FIG. 18) of the anchor 100 through the hollow portion 40 of the core 4 when detecting the tensile force of the anchor 100 (see FIG. 18). Used for. Of course, the shape of the through-holes 210 and 220 is not limited to a circular shape in plan view, and may be any shape as long as it allows the shaft portion of the bolt and the tendon 102A to pass therethrough.

  The structural body 27 is formed in a sheet shape from, for example, a metal material or a resin material, and is housed in a space surrounded by the first plate 21 and the second plate 22 and the elastic body 23. The structure 27 is fixed by filling the elastic body 23 in a part of the space. The structure 27 is formed in an annular shape in a plan view like the substrate 24, and a central portion thereof is an annular positioning hole 270 in the plan view. The core 4 is positioned at a predetermined position by fitting the core 4 into the positioning hole 270. The shape of the positioning hole 270 is not limited to a circular shape in a plan view, and may be a rectangular shape in a plan view, for example. That is, the positioning hole 270 only needs to have a shape into which the core 4 is fitted.

  In this configuration, the force sensor 2 does not include the substrate 24. That is, the detection circuit 3 is disposed outside the force sensor 2. Therefore, in this configuration, since it is not necessary to design a circuit such as the detection circuit 3 in the structure 27, the dimension in the thickness direction of the structure 27 can be reduced as compared with the substrate 24. Therefore, the force sensor 2 can be reduced in thickness.

  In addition, in the force sensor 2 of this application example, it is arbitrary whether the board | substrate 24 and the structure 27 are provided. That is, the force sensor 2 of this application example does not have to be provided with the substrate 24 and the structure 27 as long as the core 4 is positioned by the first plate 21 and the second plate 22 and the elastic body 23. However, if the configuration includes the substrate 24 and the structure 27, there is no need to provide a structure for positioning the core 4 by processing the first plate 21 and the second plate 22, and the first plate 21 and the second plate. There is an advantage that the thickness dimension of 22 can be reduced.

  Further, in the force detection device 1 of this application example, the detection circuit 3 does not include the square circuit 32 and the temperature compensation circuit 33, and the signal processing circuit 34 changes the load based on the signal output from the period measurement circuit 31. The structure which detects this may be sufficient. Further, the configuration of the detection circuit 3 shown in FIG. 11 is an example, and the detection circuit 3 may be another configuration as long as it detects a load based on a change in magnetic characteristics (inductance or conductance) of the coil 5. May be.

(Application example 2)
The force sensor 2 and the force detection device 1 of the application example 2 are used, for example, in a ground anchor method. Here, the ground anchor method will be briefly described. For example, when a slope is formed by excavation or embankment of a natural ground, a ground anchor method is generally used to stabilize a structure provided on the slope. In order to detect and monitor the tensile force of the anchor used in this ground anchor method, it is conceivable to use the force sensor 2 and the force detection device 1 of Application Example 1.

  Here, when using the force sensor 2 of the application example 1 for a large member such as an anchor, it is necessary to use the core 4 having a large diameter according to the large member. However, it is difficult to increase the diameter of the core 4 without increasing the thickness of the core 4 in the thickness direction. In the force sensor 2 of Application Example 1, the core 4 can be prevented from being enlarged in the thickness direction. Absent. Therefore, when detecting the load of a large member, the force sensor 2 preferably includes a plurality of detection units 20.

  Hereinafter, the force sensor 2 and the force detection device 1 of the application example including the plurality of detection units 20 will be described with reference to the drawings. In the force sensor 2 and the force detection device 1 of the application example, the description of the components common to the application example 1 is omitted as appropriate.

  As shown in FIGS. 14A and 14B, the force sensor 2 of this application example includes a plurality (here, 12) of detection units 20, a first plate 21, a second plate 22, an elastic body 23, And a substrate (structure) 24. Moreover, the some detection part 20 is arrange | positioned along the plane orthogonal to an up-down direction (detection direction). In FIG. 14B, the second plate 22 and the elastic body 23 are not shown. Further, “orthogonal” is an expression including “substantially orthogonal” as well as complete “orthogonal”.

  The first plate 21 is formed in a square shape in plan view as shown in FIG. 14B. Further, the second plate 22 is formed in a square shape in plan view like the first plate 21. As shown in FIG. 14A, the first plate 21 is disposed below the plurality of cores 4 in contact with the lower surfaces of the plurality (two in the drawing) of the cores 4. Further, as shown in FIG. 14A, the second plate 22 is disposed on the upper side of the plurality of cores 4 so as to be in contact with the upper surfaces of the plurality (two in the drawing) of the cores 4. That is, the first plate 21 and the second plate 22 are arranged so as to sandwich the plurality of cores 4 from both sides in the vertical direction (detection direction).

  As shown in FIGS. 14A and 14B, the first plate 21 is provided with a circular through hole 210 in a plan view that penetrates the central portion in the vertical direction (detection direction). Further, as shown in FIG. 14A, the second plate 22 is provided with a circular through hole 220 in a plan view that penetrates the central portion in the vertical direction (detection direction). Of course, the shape of the through-holes 210 and 220 is not limited to a circular shape in plan view, and may be any shape as long as it allows the shaft portion of the bolt and the tendon 102A to pass therethrough.

  In the force sensor 2 of this application example, the through hole 210 is provided in the central portion of the first plate 21 and the through hole 220 is provided in the central portion of the second plate 22, but the positions where the through holes 210 and 220 are provided. It is not intended to limit. That is, the through-hole 210 may be provided so as to penetrate the first plate 21 in the vertical direction (detection direction), and the position thereof is not limited to the central portion. Similarly, the through hole 220 may be provided so as to penetrate the second plate 22 in the vertical direction (detection direction), and the position thereof is not limited to the central portion.

  As shown in FIG. 14A, the elastic body 23 is bonded to the outer peripheral edge of the upper surface of the first plate 21 and the outer peripheral edge of the lower surface of the second plate 22, thereby connecting the first plate 21 and the second plate 22 to each other. Join. Further, as shown in FIG. 14A, the elastic body 23 is adhered to the periphery of the through hole 210 on the upper surface of the first plate 21 and the periphery of the through hole 220 on the lower surface of the second plate 22. 21 and the second plate 22 are coupled together. That is, the elastic body 23 may be configured to position between the first plate 21 and the second plate 22.

  As shown in FIG. 14A, the substrate 24 is accommodated in a space surrounded by the first plate 21, the second plate 22, and the elastic body 23. The board | substrate 24 is formed in square shape by planar view, as shown to FIG. 14B. In addition, a circular through hole 241 is provided in a central portion of the substrate 24 in a plan view having a diameter (for example, a diameter of 140 mm) slightly larger than the diameter of the through holes 210 and 220. Similar to the through holes 210 and 220, the through hole 241 may have any shape that allows the shaft portion of the bolt and the tendon 102A to pass therethrough. The substrate 24 is fixed so that the outer peripheral edge thereof and the inner peripheral edge of the through hole 241 are in contact with the elastic body 23.

  Further, as shown in FIGS. 14B and 15A, the substrate 24 is provided with a plurality of (in the figure, 12) positioning holes 240 around the through hole 241. Each positioning hole 240 is formed in a circular shape in plan view, and is provided at equal intervals along the circumferential direction of the through hole 241. Note that the shape of the positioning hole 240 is not limited to a circular shape in a plan view, and may be a rectangular shape in a plan view as shown in FIG. 15B, for example. That is, the positioning hole 240 may have a shape into which the core 4 is fitted.

  In the force sensor 2 of this application example, as shown in FIG. 14B, each positioning hole 240 is line-symmetric with respect to a reference line B1 passing through the center of the through hole 241 in a plane orthogonal to the vertical direction (detection direction). It is arranged to become. Each positioning hole 240 is arranged to be point-symmetric with respect to the reference point B2 with the center of the through hole 241 as the reference point B2 on a plane orthogonal to the vertical direction (detection direction). Therefore, by arranging the core 4 in each positioning hole 240, each detection unit 20 is also arranged so as to be line-symmetric with respect to the reference line B1, and is arranged so as to be point-symmetric with respect to the reference point B2. Is done. In other words, the plurality of detection units 20 are arranged around the through holes 210 and 220.

  In the force detection device 1 of this application example, each detection unit 20 is electrically connected to the detection circuit 3 individually as shown in FIG. 16A. That is, both ends of each coil 5 are individually electrically connected to the detection circuit 3. The detection circuit 3 can detect the load applied to all the cores 4 (that is, the load applied to the force sensor 2) by calculating based on the total value of the output signal levels of the detection units 20.

  The detection circuit 3 can also calculate a load applied to each detection unit 20 based on the level of the output signal of each detection unit 20. In this configuration, the detection circuit 3 can detect the distribution of the load applied to the first plate 21 or the second plate 22 by comparing the load applied to each detection unit 20. That is, in this configuration, it is possible to detect whether a load is uniformly applied to the first plate 21 or the second plate 22.

  In this configuration, as shown in FIG. 16B, the detection circuit 3 can detect a load even when there is a detection unit 20 that does not include the coil 5. Therefore, in this configuration, the number of detection units 20 can be reduced according to the detection target, and the manufacturing cost can be reduced.

  Moreover, the structure which connected each detection part 20 to the detection circuit 3 in series electrically may be sufficient as the force detection apparatus 1 of this application example, as shown in FIG. That is, both ends of the series circuit of each coil 5 are electrically connected to the detection circuit 3. In this configuration, even if the level of the output signal of one detection unit 20 is very small, the detection circuit 3 calculates the load based on the total value of the levels of the output signals of all the detection units 20. There is an advantage that accuracy is improved. In addition, this configuration has an advantage that mutual interference hardly occurs between the adjacent coils 5.

  Hereinafter, an embodiment for detecting the tensile force of the anchor 100 used in the ground anchor method by using the force sensor 2 and the force detection device 1 of this application example will be described with reference to FIG. In FIG. 18, the detection circuit 3 is not shown. The anchor 100 is used to transmit the tensile force from the structure A1 to the ground. The anchor 100 includes an anchor body having a function of transmitting a tensile force to the ground, an anchor head 101 for coupling the anchor 100 to the structure A1, and a tension portion that transmits the tensile force from the anchor head 101 to the anchor body. 102.

  The anchor head 101 includes a nut 101A that is a fixing tool, and an anchor plate 101B that is a pressure bearing plate disposed on the structure A1. The anchor plate 101B is provided with a hole 101C through which the tendon 102A can pass. The tension portion 102 includes a rod-shaped tendon 102A made of, for example, a PC (Prestressed Concrete) steel strand. An anchor body is mechanically connected to the first end in the longitudinal direction of the tendon 102A. Further, the second end in the longitudinal direction of the tendon 102A is tightened with the nut 101A while being passed through the hole 101C of the anchor plate 101B and the through holes 210, 220, and 241 of the force sensor 2 of this application example. .

  The force sensor 2 of this application example is arranged in such a manner as to be sandwiched between the nut 101A and the anchor plate 101B. Therefore, the force detection device 1 of this application example can detect the tensile force of the anchor 100 when the detection circuit 3 detects a load in which the nut 101A pushes down one surface of the force sensor 2.

  As described above, the force sensor 2 and the force detection device 1 of this application example are configured to detect a load using a plurality of detection units 20 instead of a single detection unit 20. Therefore, the force sensor 2 and the force detection device 1 of this application example can reduce the diameter of the core 4 of each detection unit 20 as compared with the case where only one detection unit 20 is provided. The dimension in the thickness direction of 4 can also be reduced. Therefore, even when the force sensor 2 and the force detection device 1 of the application example are used for a large member such as the anchor 100, the thickness can be reduced.

  In the force sensor 2 of this application example, the cores 4 (that is, the cores 4 included in each of the plurality of detection units 20) have the same dimension in the thickness direction (see 'T1' in FIG. 14A). Yes. For this reason, the force sensor 2 of this application example has the advantage that the surfaces perpendicular to the thickness direction of the cores 4 are aligned with each other, and therefore, it is easy to apply a load evenly to the cores 4 and that an uneven load is not easily generated. “Equal” is an expression including “same” or “substantially identical”. Therefore, it is an error within an allowable range that the dimension in the thickness direction of each core 4 is slightly different from each other due to a manufacturing error. Note that whether or not the cores 4 have the same thickness in the thickness direction is arbitrary.

  Further, in the force sensor 2 of this application example, as shown in FIG. 14B, the detection units 20 are arranged so as to be symmetrical with respect to the reference line B1, and are symmetrical with respect to the reference point B2. Is arranged. For this reason, in the force sensor 2 of this application example, the respective cores 4 are evenly arranged on a plane perpendicular to the vertical direction (detection direction) (for example, a plane parallel to the lower surface of the first plate 21 and the upper surface of the second plate 22). Be placed. Therefore, the force sensor 2 of this application example has an advantage that a load is easily applied evenly to each core 4 and an uneven load is hardly generated.

  In the force sensor 2 of this application example, each detection unit 20 may be arranged along a diagonal line of the substrate 24 as illustrated in FIG. 19A, for example. Even in this configuration, the detection units 20 are arranged symmetrically with respect to the reference line B1 and are arranged symmetrically with respect to the reference point B2. Each detection unit 20 may be arranged so as to be not symmetrical with respect to the reference point B2 although it is symmetrical with respect to the reference line B1. Further, each detection unit 20 may be arranged so as to be point-symmetric with respect to the reference point B2, although it is not line-symmetric with respect to the reference line B1.

  In addition, each detection part 20 may be selectively arrange | positioned in any of the some positioning hole 240, for example, as shown to FIG. 19B. In other words, the plurality of detection units 20 may be arranged in a one-to-one correspondence with two or more detection positions selected from a plurality of detection positions (here, the positioning holes 240). Moreover, each detection part 20 may be arrange | positioned asymmetrically with respect to any of the reference line B1 and the reference point B2, similarly as shown to FIG. 19B. 19A and 19B, the second plate 22 and the elastic body 23 are not shown.

  Further, in the force sensor 2 of this application example, the first plate 21 is provided with the through hole 210, the second plate 22 is provided with the through hole 220, and the substrate 24 is provided with the through hole 241, but the through holes 210, 220, and 241 are provided. Whether or not is provided is arbitrary. That is, the force sensor 2 of this application example has a configuration in which a plurality (nine in the drawing) of detection units 20 are arranged on a square substrate 24 in a plan view without the through-hole 241 as shown in FIG. 20A, for example. It may be. In this configuration, the first plate 21 and the second plate 22 also do not have the through holes 210 and 220, respectively.

  The force sensor 2 of the application example includes the first plate 21 and the second plate 22 and the substrate 24 that are square in a plan view, but the first plate 21, the second plate 22, and the substrate 24 are It is not intended to limit the shape. That is, the force sensor 2 of this application example may include a first plate 21 and a second plate 22 and a substrate 24 that are semicircular in a plan view, as shown in FIG. 20B, for example. In addition, as shown in FIG. 20C, the force sensor 2 of this application example may include an annular first plate 21 and second plate 22 and a substrate 24 in plan view. 20A to 20C, the second plate 22 and the elastic body 23 are not shown.

  Further, as shown in FIG. 21, the force sensor 2 of this application example is disposed between the outer shell including at least one of the first plate 21 and the second plate 22 and the substrate 24, and The structure provided with the insulator 25 which electrically insulates between may be sufficient. In the example shown in FIG. 21, the outer shell is the first plate 21. The insulator 25 is an adhesive made of a material having elasticity and insulation, for example. In this configuration, the insulation between the first plate 21 (or the second plate 22) and the substrate 24 on which a circuit such as the detection circuit 3 is designed can be improved. This is particularly effective when the first plate 21 (or the second plate 22) is formed of a metal material. Therefore, in this configuration, it is not necessary to provide a spacer in order to secure an insulating distance between the first plate 21 (or the second plate 22) and the substrate 24, and a bolt for fixing the spacer is not necessary. Therefore, the enlargement of the force sensor 2 can be avoided.

  The insulator 25 may be an insulating sheet formed of an insulating material or a coating agent formed of an insulating material and applied to one surface of the substrate 24. Moreover, the structure which provided the insulator 25 in both between the 1st plate 21 and the board | substrate 24 and between the 2nd plate 22 and the board | substrate 24 may be sufficient. That is, both the first plate 21 and the second plate 22 may be outlines. Note that whether or not the insulator 25 is provided is arbitrary. For example, if the force sensor 2 of this application example does not include the substrate 24 on which a circuit such as the detection circuit 3 is designed, the insulator 25 need not be provided.

  Further, as shown in FIG. 22, the force sensor 2 of this application example may have a configuration in which the coil 5 is provided by patterning a conductor along the circumferential direction of the positioning hole 240 of the substrate 24. The coil 5 is configured by patterning a conductor on either the upper surface or the lower surface of the substrate 24. If the substrate 24 is a multilayer substrate, the coil 5 is configured by patterning a conductor on any layer of the substrate 24. In this configuration, since the coil 5 is provided on the substrate 24, it is not necessary to wind a conducting wire around the core 4. For this reason, the core 4 does not need to have a thickness dimension required in order to wind a conducting wire. That is, this configuration can reduce the thickness of the core 4. In addition, in this structure, since it is not necessary to wind a conducting wire around the core 4, the core 4 which does not have the hollow part 40 is used, but the core 4 which has the hollow part 40 may be used.

  Note that the force sensor 2 of this application example has a configuration in which the positioning hole 240 is provided in the substrate 24, but may have a configuration in which a recess 242 is provided instead of the positioning hole 240 as shown in FIG. As shown in FIG. 23, the recess 242 is formed in a shape recessed downward from the upper surface of the substrate 24. In addition, the shape of the recessed part 242 should just be a shape in which the core 4 fits in, and the opening may be circular shape in planar view, and another shape may be sufficient as it. Even in this configuration, the core 4 can be positioned at a predetermined position by disposing the core 4 inside the recess 242. Note that the force sensor 2 of Application Example 1 may also have a configuration in which the concave portion 242 is provided in the substrate 24 instead of the positioning hole 240.

  Further, as shown in FIG. 24, the force sensor 2 of this application example may have a configuration in which the elastic body 23 is provided so as to sandwich the rigid body 26 from both sides in the vertical direction (detection direction). The rigid body 26 is made of a material having higher rigidity than the elastic body 23 such as a metal material. In this configuration, the strength of the elastic body 23 with respect to the load can be improved as compared with the case where the rigid body 26 is not provided. The thickness of the rigid body 26 is preferably adjustable according to the thickness of the core 4. The configuration shown in FIG. 24 is a configuration in which a rigid body 26 is provided on the outer elastic body 23, but a configuration in which the rigid body 26 is also provided on the inner elastic body 23 may be used.

  Furthermore, the force sensor 2 of this application example may have a configuration in which the core 4 is positioned by a structure 27 other than the substrate 24 as in the force sensor 2 of Application Example 1 (see FIGS. 25A and 25B). In addition, in FIG. 25B, illustration of the 2nd plate 22 and the elastic body 23 is abbreviate | omitted. The structure 27 is accommodated in a space surrounded by the first plate 21, the second plate 22, and the elastic body 23. The structure 27 is fixed by filling the elastic body 23 in a part of the space.

  Similar to the substrate 24, the structure 27 is formed in a square shape in plan view. As shown in FIG. 25B, a circular through hole 271 in a plan view having a diameter dimension (for example, a diameter of 140 mm) slightly larger than the diameter dimension of the through holes 210 and 220 is provided in the central portion of the structure 27. It has been. Similar to the through holes 210 and 220, the through hole 271 may have a shape that allows the shaft portion of the bolt and the tendon 102A to pass therethrough. In addition, as shown in FIG. 25B, the structure 27 is provided with a plurality of (12 in the drawing) positioning holes 270 around the through-hole 271. Each positioning hole 270 is formed in a circular shape in plan view, and is provided at equal intervals along the circumferential direction of the through hole 271. The shape of the positioning hole 270 is not limited to a circular shape in a plan view, and may be a rectangular shape in a plan view, for example. That is, the positioning hole 270 only needs to have a shape into which the core 4 is fitted.

  In this configuration, similarly to the force sensor 2 of the application example 1, since it is not necessary to design a circuit such as the detection circuit 3 in the structure 27, the dimension in the thickness direction of the structure 27 is smaller than that of the substrate 24. Since it can be made small, the force sensor 2 can be made thin.

  Further, the force sensor 2 of this application example may have a structure in which the structure 27 is formed integrally with the first plate 21 (or the second plate 22) as shown in FIGS. 26A and 26B. In FIG. 26B, the second plate 22 and the elastic body 23 are not shown. The structure 27 is formed integrally with the first plate 21 (or the second plate 22) by a processing technique such as welding. Even with this configuration, the force sensor 2 can be thinned.

  In the force sensor 2 of this application example, whether or not the substrate 24 and the structure 27 are provided is arbitrary as in the force sensor 2 of Application Example 1. That is, the force sensor 2 of this application example does not have to be provided with the substrate 24 and the structure 27 as long as the core 4 is positioned by the first plate 21 and the second plate 22 and the elastic body 23. However, if the configuration includes the substrate 24 and the structure 27, there is no need to provide a structure for positioning the core 4 by processing the first plate 21 and the second plate 22, and the first plate 21 and the second plate. There is an advantage that the thickness dimension of 22 can be reduced.

(Application example 3)
Hereinafter, the force sensor 2 according to Application Example 3 will be described in detail. However, in the following, description of components common to the force sensor 2 of Application Example 2 will be omitted as appropriate.

  As shown in FIGS. 27A and 27B, the force sensor 2 of Application Example 3 is formed in a U shape as a whole in plan view. The force sensor 2 of this application example includes a detection block 6. The detection block 6 includes a first plate 21, a second plate 22, an elastic body 23, and a plurality of (here, nine) detection units 20. In the force sensor 2 of this application example, the detection block 6 further includes a substrate (structure) 24, but whether or not the substrate 24 is included is arbitrary.

  The detection block 6 has a circular through-hole 200 in the center in a plan view. The through hole 200 is provided so as to penetrate the first plate 21, the second plate 22, and the substrate 24 in the vertical direction (detection direction). The through hole 200 is a hole that connects the through hole 210 of the first plate 21 and the through hole 220 of the second plate 22 in the vertical direction. In other words, the through hole 210 and the through hole 220 correspond to the through hole 200. The through hole 200 is used for inserting the shaft portion of the bolt or the tendon 102A (see FIG. 28A) of the anchor 100 in the same manner as the force sensor 2 of the application example 2. Of course, the shape of the through hole 200 is not limited to a circular shape in plan view, and may be any shape as long as the shaft portion of the bolt or the tendon 102A can be inserted.

  The plurality of detection units 20 are arranged around the through hole 200. For this reason, for example, in a state where the shaft portion of the bolt is passed through the through hole 200, the nut easily faces each detection unit 20. Accordingly, when the bolt is tightened, the load by which the nut pushes down one surface of the force sensor 2 is easily transmitted to each detection unit 20.

  The detection block 6 further has an opening 201. The opening 201 is provided so as to open the through hole 200 to the outside in a direction along a plane orthogonal to the vertical direction (detection direction) (that is, a direction along the axial direction of the bolt or the radial direction of the tendon 102A). Yes. The opening 201 only needs to have a width dimension (a dimension in the left-right direction in FIG. 27A) that allows the shaft portion of the bolt and the tendon 102A to pass through in the radial direction.

  The force sensor 2 and the force detection device 1 of this application example can be used when detecting the tensile force of the anchor 100 as shown in FIGS. 28A and 28B, for example. In FIG. 28A, illustration of the detection circuit 3 and the anchor plate 101B is omitted.

  Here, consider a case where the force sensor 2 of this application example is attached to the anchor 100 in a state where the anchor 100 has already been constructed. In this case, in the force sensor 2 in which the detection block 6 does not have the opening 201 (that is, the through hole 200 is closed in a direction along the radial direction of the tendon 102A), the anchor 100 is not removed from the structure A1. The tendon 102A cannot be inserted into the through hole 200. That is, in the force sensor 2 in which the detection block 6 does not have an opening, the force sensor 2 cannot be attached to the anchor 100 unless the anchor 100 is removed from the structure A1.

  On the other hand, in the force sensor 2 of this application example, since the detection block 6 has the opening 201, as shown in FIG. 28B, the tendon 102A is passed through the opening 201 from the direction along the radial direction. It can be inserted into the hole 200. For this reason, in the force sensor 2 of this application example, the tendon 102A is inserted into the through-hole 200 from the opening 201 by loosening the tightening of the nut 101A and inserting the force sensor 2 into the gap between the nut 101A and the structure A1. can do.

  That is, since the force sensor 2 of this application example can be attached to the anchor 100 without removing the anchor 100 from the structure A1, workability can be improved. Of course, even when attached to the bolt, the force sensor 2 of this application example can be attached to the bolt without removing the bolt, as in the case of attaching to the anchor 100.

  By the way, the force sensor 2 of this application example may further include a closing member 7 that closes the opening 201 as shown in FIGS. 29A and 29B. The blocking member 7 is formed in a rectangular shape in plan view. Similar to the detection block 6, the closing member 7 includes a first plate 21, a second plate 22, an elastic body 23, a substrate 24, and a plurality of (here, four) detection units 20. Note that whether or not the closing member 7 includes the substrate 24 is arbitrary.

  That is, in this configuration, the closing member 7 is also the detection block 60. In other words, the force sensor 2 of this application example may include a plurality of detection blocks 6 and 60. In addition, at least one of the plurality of detection blocks 6, 60 (here, the detection block 60) may also serve as the closing member 7.

  The detection block 6 and the closing member 7 are restricted in relative movement in the vertical direction (detection direction) by the restriction portion 8. The restricting portion 8 includes a convex portion 81 and a concave portion 82. The recesses 82 are respectively provided at both ends (left and right ends in FIG. 29A) across the opening 201 of the detection block 6. The convex portions 81 are provided at both ends in the longitudinal direction of the closing member 7 (left and right direction in FIG. 29A).

  By fitting these convex portions 81 into the corresponding concave portions 82, the closing member 7 closes the opening 201 of the detection block 6. For this reason, in the force sensor 2 of this application example, the shaft portion of the bolt inserted into the through hole 200 and the tendon 102 </ b> A are difficult to come out through the opening 201.

  Further, the restricting portion 8 restricts relative movement of the detection block 6 and the closing member 7 in the vertical direction (detection direction). For this reason, in the force sensor 2 of this application example, even if the detection block 6 and the closing member 7 receive a load, the vertical displacement is unlikely to occur.

  Further, in the force sensor 2 of this application example, the detection block 60 also serves as the closing member 7. For this reason, in the force sensor 2 of this application example, in addition to the function of detecting the load, the detection block 60 can have a function of closing the opening 201.

  Here, for example, as shown in FIG. 30A and FIG. 30B, the restricting portion 8 is configured by providing the convex portion 81 on the elastic body 23 of the closing member 7 and the concave portion 82 on the elastic body 23 of the detection block 6. Also good. Further, for example, as shown in FIG. 31A and FIG. 31B, the restricting portion 8 includes a convex portion 81 in each of the first plate 21 and the second plate 22 of the closing member 7 and a concave portion 82 in the first plate 21 of the detection block 6. And it may be configured by being provided on each of the second plates 22. Further, the restricting portion 8 may be configured by providing the convex portion 81 in the detection block 6 and the concave portion 82 in the closing member 7.

(Modification 1)
The force sensor 2 of the modification 1 of the application example 3 is different from the force sensor 2 of the application example 3 in that it is formed in a Y shape in plan view as a whole as shown in FIGS. 32A and 32B. In the force sensor 2 of this modification, the detection block 6 includes seven detection units 20.

  In the force sensor 2 of this modification, the through hole 200 is formed in a triangular shape in plan view. Further, in the force sensor 2 of the present modification, the width dimension (the dimension in the left-right direction in FIG. 32A) increases from the through hole 200 toward the opening 201. For this reason, in the force sensor 2 of this modification, it is possible to insert into the through hole 200 the shaft part of various bolts and tendons 102A having different diameters.

  The force sensor 2 and the force detection device 1 of this modification can be used when detecting the tensile force of the anchor 100 as shown in FIGS. 33A and 33B, for example. In FIG. 33A, the detection circuit 3 and the anchor plate 101B are not shown.

  In the force sensor 2 of the present modification, the detection block 6 has an opening 201 as in the force sensor 2 of Application Example 3. For this reason, the force sensor 2 of this modification can produce the same effect as the force sensor 2 of the application example 3.

  Further, the force sensor 2 of the present modification may further include a closing member 7 (detection block 60), similarly to the force sensor 2 of Application Example 3 (see FIGS. 34A and 34B). The closing member 7 is different from the closing member 7 in the force sensor 2 of the application example 3 in that it includes five detection units 20, but the other configurations are the same.

  By the way, in the force sensor 2 of the application example 3, the closing member 7 is the detection block 60, but may have other configurations. For example, as illustrated in FIG. 35A, the closing member 7 may have a function of closing only the opening 201 of the detection block 6 without having a function of detecting a load. In this case, it is preferable that the closing member 7 is formed of a resin material such as a metal material or CFRP, and has a structure having rigidity equivalent to that of the core 4. Similarly, in the force sensor 2 of the first modification, the closing member 7 may have a configuration having only a function of closing the opening 201 of the detection block 6 as shown in FIG. 35B, for example.

  Further, in the force sensor 2 of the application example 3 and the modification example 1, the detection block 6 includes a plurality of detection units 20, but may include only one detection unit 20. Similarly, when the blocking member 7 has the same configuration as the detection block 6, it may include only one detection unit 20.

  Further, in the force detection device 1 of the application example 3 and the modification example 1, the detection circuit 3 individually processes the output signal of the detection unit 20 included in the detection block 6 and the output signal of the detection unit 20 included in the blocking member 7. Alternatively, they may be processed integrally.

(Application example 4)
Hereinafter, the force sensor 2 of the application example 4 will be described. However, in the following, description of components common to the force sensor 2 of Application Example 3 is omitted as appropriate. As shown in FIGS. 36A and 36B, the force sensor 2 of this application example is formed in a square shape as a whole in plan view. The force sensor 2 of this application example includes two detection blocks 61 and 62.

  The detection blocks 61 and 62 are both formed in a rectangular shape in plan view. As with the detection block 6, each of the detection blocks 61 and 62 includes the first plate 21, the second plate 22, the elastic body 23, the substrate 24, and a plurality of (here, five) detection units 20. ing. Whether or not the detection blocks 61 and 62 include the substrate 24 is arbitrary.

  Each of the detection blocks 61 and 62 has a semicircular through hole 200 and an opening 201 in plan view. As shown in FIG. 36B, the through-hole 200 constitutes a circular closed region in plan view by abutting the openings 201 of the detection blocks 61 and 62 with each other. That is, the detection block 61 also serves as the blocking member 7 when viewed from the detection block 62. Similarly, the detection block 62 also serves as the blocking member 7 when viewed from the detection block 61. In the following description, it is assumed that the detection block 62 also serves as the closing member 7.

  The relative movement of the detection block 61 and the detection block 62 (the closing member 7) in the vertical direction (detection direction) is restricted by the restriction unit 8. The restricting portion 8 is provided at the concave portion 82 provided at the first corner of the detection block 61 (upper right corner in FIG. 36A) and at the first corner of the detection block 62 (upper left corner in FIG. 36A). And a convex portion 81. Further, the restricting portion 8 includes a convex portion 81 provided at the second corner (the lower right corner in FIG. 36A) of the detection block 61 and a second corner (the lower left corner in FIG. 36A) of the detection block 62. ) Provided in the concave portion 82.

  For example, as shown in FIG. 37A, the restricting portion 8 may be configured by providing a convex portion 81 and a concave portion 82 in the elastic body 23. Further, as shown in FIG. 37B, for example, the restricting portion 8 is provided with a convex portion 81 in each of the first plate 21 and the second plate 22 and a concave portion 82 in each of the first plate 21 and the second plate 22. It may be configured.

  The detection block 61 and the detection block 62 (the closing member 7) are connected to each other by the connecting portion 9. The connecting portion 9 is composed of a wire 91. Of the both ends of the wire 91, the first end is mechanically connected to one end in the longitudinal direction of the detection block 61 (lower end in FIG. 36B), and the second end is one end in the longitudinal direction of the detection block 62 (lower end in FIG. 36B). ) Mechanically connected.

  In the force sensor 2 of this application example, the detection blocks 61 and 62 each have an opening 201 as in the force sensor 2 of the application example 3. For this reason, in the force sensor 2 of this application example, the effect similar to the force sensor 2 of the application example 3 can be show | played.

  Moreover, in the force sensor 2 of this application example, since the detection block 61 and the detection block 62 (closing member 7) are connected to each other by the wire 91 (connecting portion 9), these members are not separated. . That is, in the force sensor 2 of this application example, since the detection block 61 and the detection block 62 can be handled integrally, one of them is not lost at the construction site, and the workability can be improved. it can.

  By the way, the connection part 9 is not limited to the wire 91, The other structure may be sufficient. For example, as shown in FIGS. 38A and 38B, the connecting portion 9 may be a hinge 92. The hinge 92 includes a first arm portion 921, a second arm portion 922, a pin 923, and a pair of retaining rings 924.

  The first arm portion 921 is provided to protrude outward (downward in FIG. 38A) from the first plate 21 of the detection block 61. The second arm portion 922 is provided to protrude outward (downward in FIG. 38A) from the second plate 22 of the detection block 62. The first arm portion 921 and the second arm portion 922 overlap each other in the vertical direction (detection direction).

  Each of the first arm portion 921 and the second arm portion 922 has a circular hole in plan view. In these holes, round bar-like pins 923 elongated in the vertical direction (detection direction) are inserted. The pin 923 is prevented from coming off by a pair of retaining rings 924.

  In this configuration, the detection block 61 and the detection block 62 (closing member 7) are connected to each other by the hinge 92. The detection blocks 61 and 62 can rotate about the pin 923 as an axis. That is, in this configuration, by rotating the detection blocks 61 and 62, the state in which the through holes 200 of the detection blocks 61 and 62 are opened to the outside and the state in which the through holes 200 are closed are alternatively selected. Can be switched.

  In this configuration, the hinge 92 also functions as the restricting portion 8. That is, since the first plate 21 and the second plate 22 are sandwiched between the pair of retaining rings 924 in the vertical direction (detection direction), the relative movement in the vertical direction is restricted by the pair of retaining rings 924 of the hinge 92. Has been.

  In the configuration shown in FIGS. 38A and 38B, the restricting portion 8 includes a pair of projecting pieces 83 and 84 and a fastener 85 instead of the convex portion 81 and the concave portion 82. The projecting piece 83 is provided to project outward (upward in FIG. 38A) from the first corner of the detection block 61. The projecting piece 84 is provided so as to project outward (upward in FIG. 38A) from the first corner of the detection block 62. The fastener 85 is made of a wire, for example. As shown in FIG. 38A, the projecting pieces 83 and 84 are fixed by a fastener 85 in a state where the detection blocks 61 and 62 are abutted with each other.

  That is, in this configuration, the restricting portion 8 has a function of holding the detection block 61 and the detection block 62 (the closing member 7) in a state where the through hole 200 is closed. For this reason, in this configuration, the force sensor 2 is unlikely to be detached from the bolt or the anchor 100.

  By the way, although the force sensor 2 of this application example is provided with the connection part 9, it is arbitrary whether the connection part 9 is provided. That is, in the force sensor 2 of this application example, the detection blocks 61 and 62 may be mechanically separated.

  In the force sensor 2 of this application example, the detection blocks 61 and 62 each include a plurality of detection units 20, but may include only one detection unit 20.

  Further, in the force detection device 1 of this application example, the detection circuit 3 may individually process the output signal of the detection unit 20 included in the detection block 61 and the output signal of the detection unit 20 included in the detection block 62. However, they may be processed integrally. Further, an electrical connection between the detection block 61 and the detection block 62 may be ensured by an electric wire passing through the connecting portion 9.

(Modification 1)
As shown in FIGS. 39A and 39B, the force sensor 2 of the first modification of the application example 4 is configured by three detection blocks 61 to 63 and the application example 4 in that the connecting portion 9 is not provided. The force sensor 2 is different. In the force sensor 2 of this modification, the detection blocks 61 and 63 each include three detection units 20, and the detection block 62 includes two detection units 20.

  As with the detection block 6, the detection blocks 61 to 63 each include the first plate 21, the second plate 22, the elastic body 23, the substrate 24, and a plurality of detection units 20. Note that whether or not the detection blocks 61 to 63 include the substrate 24 is arbitrary.

  Each of the detection blocks 61 to 63 has a fan-shaped through hole 200 and an opening 201 in plan view. As shown in FIG. 39B, the through-hole 200 constitutes a circular closed region in plan view by abutting each opening 201 of the detection blocks 61 to 63 with each other. That is, when viewed from any one of the plurality of detection blocks 61 to 63, the other detection blocks also serve as the blocking member 7.

  Each of the detection blocks 61 to 63 includes a convex portion 81 and a concave portion 82. As shown in FIG. 39A, the convex portion 81 of the detection block 61 and the concave portion 82 of the detection block 63 constitute a restricting portion 8. Similarly, the convex portion 81 of the detection block 63 and the concave portion 82 of the detection block 62, and the convex portion 81 of the detection block 62 and the concave portion 82 of the detection block 61 constitute the restricting portion 8.

  In the force sensor 2 of this modification, the detection blocks 61 to 63 each have an opening 201 as in the force sensor 2 of Application Example 3. For this reason, in the force sensor 2 of this modification, the effect similar to the force sensor 2 of the application example 3 can be show | played.

  Here, the force sensor 2 of the present modification does not include the connecting portion 9, but may include the connecting portion 9. For example, the force sensor 2 of this modification may have a configuration in which the detection block 61 and the detection block 62, and the detection block 62 and the detection block 63 are connected to each other by wires 91. Further, the connecting portion 9 may be a hinge 92 instead of the wire 91.

  Moreover, in the force sensor 2 of this modification, although the detection blocks 61-63 are each provided with the some detection part 20, you may provide only the one detection part 20. FIG.

  Further, in the force detection device 1 of the present modification, the detection circuit 3 may individually process the output signals of the detection units 20 included in each of the detection blocks 61 to 63 or may integrally process them. .

(Modification 2)
As shown in FIGS. 40A and 40B, the force sensor 2 of the second modification of the application example 4 is configured by four detection blocks 61 to 64 and is not provided with the connecting portion 9. The force sensor 2 is different. In the force sensor 2 of this modification, the detection blocks 61 to 64 each include two detection units 20.

  As with the detection block 6, the detection blocks 61 to 64 each include the first plate 21, the second plate 22, the elastic body 23, the substrate 24, and a plurality of detection units 20. Note that whether or not the detection blocks 61 to 64 include the substrate 24 is arbitrary.

  Each of the detection blocks 61 to 64 has a fan-shaped through hole 200 and an opening 201 in plan view. As shown in FIG. 40B, the through-hole 200 constitutes a circular closed region in plan view by abutting each opening 201 of the detection blocks 61 to 64 with each other. That is, when viewed from any one of the plurality of detection blocks 61 to 64, the other detection blocks also serve as the blocking member 7.

  Each of the detection blocks 61 to 64 includes a convex portion 81 and a concave portion 82. As shown in FIG. 40A, the convex portion 81 of the detection block 61 and the concave portion 82 of the detection block 64 constitute a restricting portion 8. Similarly, the convex portion 81 of the detection block 64 and the concave portion 82 of the detection block 63, the convex portion 81 of the detection block 63 and the concave portion 82 of the detection block 62, and the convex portion 81 of the detection block 62 and the concave portion 82 of the detection block 61 Respectively constitute the restricting portion 8.

  In the force sensor 2 of this modification, the detection blocks 61 to 64 each have an opening 201 as in the force sensor 2 of Application Example 3. For this reason, in the force sensor 2 of this modification, the effect similar to the force sensor 2 of the application example 3 can be show | played.

  Here, the force sensor 2 of the present modification does not include the connecting portion 9, but may include the connecting portion 9. For example, the force sensor 2 of the present modification may have a configuration in which the detection block 61 and the detection block 62, the detection block 62 and the detection block 63, and the detection block 63 and the detection block 64 are connected to each other by wires 91. Good. Further, the connecting portion 9 may be a hinge 92 instead of the wire 91.

  Moreover, in the force sensor 2 of this modification, although the detection blocks 61-64 are each provided with the some detection part 20, you may be provided with only one detection part 20. FIG.

  Furthermore, in the force detection device 1 of the present modification, the detection circuit 3 may individually process the output signals of the detection units 20 included in each of the detection blocks 61 to 64, or may process them integrally. .

  By the way, in the force sensor 2 of Modification 1 of Application Example 4, at least one detection block among the plurality of detection blocks 61 to 63 may be replaced with the blocking member 7. The closing member 7 does not have a function of detecting a load, but has only a function of closing the opening 201 of the detection block 6. For example, as shown in FIG. 41A, the detection block 62 among the three detection blocks 61 to 63 may be replaced with the closing member 7.

  Similarly, in the force sensor 2 of Modification 2 of Application Example 4, at least one detection block among the plurality of detection blocks 61 to 64 may be replaced with the closing member 7. For example, as shown in FIG. 41B, the detection block 63 among the four detection blocks 61 to 64 may be replaced with the closing member 7.

  In addition, the force sensor 2 of the application example 3 and the modification example 1 and the application example 4 and the modification examples 1 and 2 is, for example, between the detection block 6 and the closing member 7 or between the plurality of detection blocks 61 to 64. You may attach to the volt | bolt and the anchor 100 in the state which opened the clearance gap.

DESCRIPTION OF SYMBOLS 1 Force detection apparatus 2 Force sensor 20 Detection part 200,210,220 Through-hole 201 Opening 21 1st plate 22 2nd plate 23 Elastic body 3 Detection circuit 4 Core 40 Hollow part 41 Mounting part 42 Load receiving part 5 Coil 50 Coil apparatus 51 Electrical path structure 513 Cover member 514 Base film 515 Molded body 52 Connection structure 53,531-536 Conductor 551,552 Terminal 56 Binding member 6,61-64 Detection block M1 Magnetic path (closed magnetic path)
M2 magnetic path (open magnetic path)

The present invention relates generally to a force sensor and a force sensing device, and more particularly, to a force sensor and a force sensing device using coils equipment configuration conductor is wound on the core.

The present invention has been made in view of the above circumstances, and an object thereof is produced to provide a force sensor and a force sensing device with a simple coil equipment.

A force sensor according to a first aspect of the present invention includes a magnetic core and an annular core that surrounds a hollow portion and a bundle of a plurality of conductive wires that are electrically insulated from each other. An electrical circuit structure hung on the core, and a connection structure electrically connected to both ends of the electrical circuit structure, the connection structure having a pair of terminals, and between the pair of terminals A coil device configured to form a coil with the plurality of conductive wires by electrically connecting the plurality of conductive wires in series, and the core includes a gap between the pair of terminals. A magnetic path through which a magnetic flux generated by a flowing current passes is formed along the circumferential direction of the hollow portion, and the core is a load receiving portion that receives a load on one surface intersecting the surface on which the magnetic path is formed. And sandwich the core from both sides in the crossing direction. A first plate and a second plate disposed on the core, and an elastic body formed of a material having a lower elastic modulus than the core and positioning between the first plate and the second plate, The body is adhered to the outer peripheral edge of the first plate and the outer peripheral edge of the second plate, so that the body is sandwiched from both sides in the intersecting direction by the first plate and the second plate. It is provided between one plate and the second plate .

The force sensor according to a second aspect is characterized in that, in the first aspect, the electric circuit structure is a cable in which the plurality of conductive wires are covered with a covering member having electrical insulation.

A force sensor according to a third aspect is the flexible circuit board according to the first aspect, wherein the plurality of conductors are formed on at least one surface of a base film having electrical insulation and flexibility. It is characterized by that.

A force sensor according to a fourth aspect is characterized in that, in the first aspect, the electric circuit structure has a structure in which the plurality of conductive wires are formed on a surface of a molded body having electrical insulation.

The force sensor according to a fifth aspect is characterized in that, in the second or third aspect, a binding member for bundling the electric circuit structure is provided between the core and the connection structure.

The force sensor according to a sixth aspect is any one of the first to fifth aspects, wherein the core has a mounting portion having a smaller cross-sectional area than other portions in a part of the circumferential direction of the hollow portion. The electric circuit structure is hung on the attachment portion.

The force sensor according to a seventh aspect is any one of the first to sixth aspects, wherein the first plate, the second plate, the elastic body, and the coil device constitute a detection block, and the detection block includes: The coil device has a through hole penetrating in the intersecting direction, the coil device is disposed around the through hole, and the detection block opens the through hole to the outside in a direction along a plane perpendicular to the intersecting direction. It is characterized by having an opening.

The force detection device according to an eighth aspect includes the force sensor according to any one of the first to seventh aspects, and a detection circuit that detects a load based on a change in magnetic characteristics of the coil device.

Claims (10)

In a magnetic body, a core formed in an annular shape surrounding the hollow portion;
An electric circuit structure having a bundle of a plurality of conductive wires electrically insulated from each other and hung on the core through the hollow portion;
A connection structure electrically connected to both ends of the electric circuit structure,
The connection structure has a pair of terminals, and is configured to form a coil with the plurality of conductors by electrically connecting the plurality of conductors in series between the pair of terminals. A coil device characterized by that.   2. The coil device according to claim 1, wherein the electric circuit structure is a cable in which the plurality of conductive wires are covered with a covering member having electrical insulation.   2. The coil device according to claim 1, wherein the electric circuit structure is a flexible substrate in which the plurality of conductive wires are formed on at least one surface of a base film having electrical insulation and flexibility.   The coil device according to claim 1, wherein the electric circuit structure has a structure in which the plurality of conductive wires are formed on a surface of a molded body having electrical insulation.   4. The coil device according to claim 2, further comprising a binding member that binds the electric circuit structure between the core and the connection structure. 5. The core has a mounting portion having a smaller cross-sectional area than the other part in a part of the circumferential direction of the hollow portion,
The coil device according to claim 1, wherein the electric circuit structure is hung on the attachment portion. A coil device according to any one of claims 1 to 6, comprising:
In the core, a magnetic path through which a magnetic flux generated by a current flowing between the pair of terminals passes is formed along a circumferential direction of the hollow portion,
The core has a load receiving portion for receiving a load on one surface in an intersecting direction intersecting a surface on which the magnetic path is formed. A first plate and a second plate arranged so as to sandwich the core from both sides in the intersecting direction;
The force sensor according to claim 7, further comprising: an elastic body that is formed of a material having a lower elastic modulus than the core and positions between the first plate and the second plate. The first plate, the second plate, the elastic body, and the coil device constitute a detection block,
The detection block has a through hole penetrating in the intersecting direction,
The coil device is disposed around the through hole,
9. The force sensor according to claim 8, wherein the detection block has an opening that opens the through hole to the outside in a direction along a plane orthogonal to the intersecting direction. A force detection device comprising: the force sensor according to any one of claims 7 to 9; and a detection circuit that detects a load based on a change in magnetic characteristics of the coil device.

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