Load detector

Abstract

The purpose of the present disclosure is to inhibit a decrease in the detection performance of a load sensor. A load detector (1) comprises a moving body (2), a support body (3), and a load sensor (4). The moving body (2) has a prescribed thickness. The support body (3) has a recess part (30) that accommodates the moving body (2) in a manner movable in a direction (D2) perpendicular to the thickness direction (D1) of the moving body (2). The load sensor (4) is interposed between an outer surface (2A) of the moving body (2) and an inner surface (3A) of the recess part (30), and detects a load that is applied to the moving body (2) in the perpendicular direction (D2). The load sensor (4) includes: a first structural part (4A) held on the moving body (2) side; and a second structural part (4B) held on the support body (3) side.

Description

Load detector

[0001] The present disclosure generally relates to a load detector, and more particularly to a load detector including a load sensor that detects a load in a direction perpendicular to a thickness direction of a moving object.

[0002] Patent Document 1 discloses a load detector installed on the claw of a robot hand. This load detector includes a movable body having a predetermined thickness and a support having a recess that accommodates the movable body so that the movable body can move in a direction perpendicular to the thickness direction. The load detector also includes a first load sensor interposed between the outer surface of the movable body and the inner surface of the recess. The first load sensor detects a load generated as the movable body moves. The first load sensor is installed on the movable body by being fixed to the outer surface of the movable body with an adhesive or the like. Patent Document 1 also describes that the first load sensor may be installed on the inner surface of the recess.

[0003] WO 2024 / 089940

[0004] In the load detector of Patent Document 1, the first load sensor (load sensor) is provided on either the movable body or the support body. Therefore, in the load detector of Patent Document 1, the contact surface between the movable body (movable part) and the support body (fixed part) tends to be large, which tends to increase frictional resistance. As a result, the detection performance of the load detected by the load sensor may be reduced due to the influence of frictional resistance.

[0005] The present disclosure has been made in view of the above circumstances, and aims to provide a load detector that can suppress a decrease in the detection performance of a load sensor.

[0006] A load detector according to one aspect of the present disclosure includes a moving body, a support, and a load sensor. The moving body has a predetermined thickness. The support has a recess that accommodates the moving body so that the moving body can move in a direction perpendicular to the thickness direction of the moving body. The load sensor is interposed between the outer surface of the moving body and the inner surface of the recess, and detects a load acting on the moving body in the perpendicular direction. The load sensor is composed of a first component held by the moving body and a second component held by the support.

[0007] FIG. 1 is a schematic cross-sectional view of a load detector according to an embodiment. FIG. 2 is an external perspective view of the load detector as viewed from above. FIG. 3 is an external perspective view of the load detector as viewed from below. FIG. 4 is an exploded perspective view of the load detector as viewed from above. FIG. 5 is an exploded perspective view of a main part of the load detector as viewed from above. FIG. 6 is an oblique view of a moving body of the load detector and its peripheral configuration as viewed from above. FIG. 7 is an oblique view of a moving body of the load detector and its peripheral configuration as viewed from below. FIG. 8 is an oblique view of a holding substrate of the load detector and its peripheral configuration as viewed from above. FIG. 9 is an oblique view of a support body of the load detector and its peripheral configuration as viewed from above. FIG. 10 is an exploded perspective view of a support body of the load detector and its peripheral configuration as viewed from below. FIG. 11 is an exploded perspective view of a support body of the load detector and its peripheral configuration as viewed from above. FIG. 12 is a top view of the load detector as viewed from above. FIG. 13 is a cross-sectional view of the load detector taken along line II of FIG. 12. Fig. 14 is a cross-sectional view of the load detector taken along line II-II of Fig. 12. Fig. 15 is a perspective view of the support body and its peripheral configuration in the load detector according to Modification 1, as viewed from above.

[0008] (Summary) Load detectors according to embodiments and modifications will be described below with reference to the drawings. Note that the following embodiments and modifications are merely examples of various embodiments of the present disclosure. Furthermore, the following embodiments and modifications can be modified in various ways depending on the design, etc., as long as the object of the present disclosure can be achieved. Furthermore, the configurations of the modifications can be combined as appropriate. Furthermore, the drawings described in this disclosure are schematic diagrams, and the ratios of the sizes and thicknesses of the components in the drawings do not necessarily reflect the actual dimensional ratios.

[0009] As shown in FIG. 1 , a load detector 1 according to one embodiment includes a movable body 2, a support body 3, and a load sensor 4. The movable body 2 has a predetermined thickness. The support body 3 has a recess 30 that accommodates the movable body 2 so that the movable body 2 can move in a direction D2 perpendicular to a thickness direction D1 of the movable body 2. The load sensor 4 is interposed between an outer surface 2A of the movable body 2 and an inner surface 3A of the recess 30, and detects a load acting on the movable body 2 in the perpendicular direction D2. The load sensor 4 is composed of a first component 4A held on the movable body 2 side and a second component 4B held on the support body 3 side. In other words, the load sensor 4 is composed of the first component 4A held directly or indirectly by the movable body 2, and the second component 4B held directly or indirectly by the support body 3.

[0010] According to the configuration of this load detector 1, the first component 4A and the second component 4B that make up the load sensor 4 are separately held on the movable body 2 side, which is the movable part, and on the support body 3 side, which is the fixed part. Therefore, compared to a configuration in which the load sensor 4 (as a whole) is held on either the movable body 2 side or the support body 3 side, it is easier to realize a configuration that reduces frictional resistance caused by contact with the support body 3 when the movable body 2 moves in response to an external force along the direction D2 perpendicular to the thickness direction D1. As a result, the load detector 1 has the advantage of being able to suppress a decrease in the detection performance of the load sensor 4.

[0011] In the following, as an example, it is assumed that the load detector 1 is applied to a robot hand used in a facility such as a factory. The robot hand includes, for example, multiple claws (e.g., a pair of claws) for gripping an object (measurement object M1 shown in FIG. 1 ). A load detector 1 may be disposed on each of the multiple claws. The fixture H1 of the robot hand shown in FIGS. 2 and 3 is a portion for fixing the load detector 1 and may correspond to one of the multiple claws. When an object is gripped and lifted by the multiple claws, the load is detected by the load sensor 4. Although only one load detector 1 is illustrated in FIG. 1 , the robot hand may be used, for example, to clamp an object (measurement object M1) between multiple claws on which multiple load detectors 1 are disposed.

[0012] In the following description, as an example, "the first component 4A held on the movable body 2 side" is assumed to be a case in which the first component 4A is held directly by the movable body 2. However, "the first component 4A held on the movable body 2 side" may also be a case in which the first component 4A is held indirectly by the movable body 2. For example, the substrate 6 described below is held on the movable body 2 and moves integrally with the movable body 2, and even when the first component 4A is held on the substrate 6, it can be said that the first component 4A is held on the movable body 2 side. In short, the first component 4A may be held on the movable body 2, which is a movable part, or on a part that is held on the movable body 2 and moves integrally with the movable body 2.

[0013] Meanwhile, in the following, as an example, "second component 4B held on the support 3 side" assumes a case in which the second component 4B is indirectly held on the support 3. That is, it assumes a case in which a holding substrate 5, which will be described later, is held on the support 3, and the second component 4B is held on this holding substrate 5. However, the second component 4B may also be held directly on the support 3. In short, the second component 4B may be held on the support 3, which is a fixed portion, or on a fixed portion that is held on the support 3 and integrated with the support 3.

[0014] In addition to the load sensor 4, the load detector 1 also includes a load sensor 8 that detects a load in the thickness direction D1 of the moving body 2. Hereinafter, for convenience of explanation, the load sensor 4 may be referred to as the first load sensor 4, and the load sensor 8 may be referred to as the second load sensor 8. However, the second load sensor 8 is not an essential component for the load detector 1, and may be omitted as appropriate.

[0015] For convenience, the following description will be given by defining three axes (X-axis, Y-axis, and Z-axis) of a three-dimensional Cartesian coordinate system for the load detector 1 as shown in FIGS. 1 and 2. That is, the thickness direction D1 of the movable body 2 is defined as the Z-axis direction. The longitudinal direction of the movable body 2, which is perpendicular to the Z-axis direction, is defined as the X-axis direction. The width direction of the movable body 2, which is perpendicular to both the X-axis direction and the Z-axis direction, is defined as the Y-axis direction. In this disclosure, the "direction D2 perpendicular to the thickness direction D1 of the movable body 2" is a direction parallel to the X-Y plane. For convenience, in FIG. 1, the direction D2 is illustrated as a direction parallel to the Y-axis direction.

[0016] For ease of explanation, the Z-axis direction is defined as the up-down direction, and the side where the measurement object M1 (see FIG. 1) is located relative to the moving body 2 (positive direction of the Z-axis) is defined as "up," and the opposite side is defined as "down." The X-axis direction is defined as the front-to-rear direction, and the side where the flexible printed wiring board C2 (see FIG. 2) is located relative to the moving body 2 (positive direction of the X-axis) is defined as "front," and the opposite side is defined as "rear." The Y-axis direction is defined as the left-to-right direction, and the positive direction of the Y-axis is defined as "right," and the opposite side is defined as "left." However, the definitions of axes and directions in this disclosure merely indicate the relative positional relationship in the load detector 1 and do not limit the orientation of the load detector 1 during use, etc.

[0017] (Embodiment) (1) Configuration The configuration of a load detector 1 according to an embodiment will be described in detail below with reference to Figures 1 to 14. Note that Figure 1 is a schematic cross-sectional view of the load detector 1 cut along the YZ plane, and some components of the load detector 1 are not shown in Figure 1.

[0018] 1 and 4, the load detector 1 includes a movable body 2, a support body 3, and one or more (eight in this example) first load sensors 4 (load sensors). Also, as shown in Fig. 4, the load detector 1 further includes a holding substrate 5, a substrate 6, a cover 7, a second load sensor 8, a presser plate 9, an anti-slip member A1, and a back plate P1. Also, as shown in Fig. 4, the load detector 1 further includes an upper plate Q1, two knock pins F1, two hexagon socket head bolts G1, two flexible printed wiring boards C1 and C2, a connector E1, a first lead wire W1 (see Figs. 6 and 7), and a second lead wire W2 (see Fig. 8).

[0019] 3, the load detector 1 is fixed to a fixture H1 of the robot hand via two hexagon socket head bolts G1. The load detector 1 detects the load of an object (measurement object M1) placed on its upper surface with a first load sensor 4 and a second load sensor 8.

[0020] The movable body 2 has a predetermined thickness. As shown in Fig. 4, the movable body 2 has a rectangular plate shape that is long in the front-to-rear direction in a plan view. The movable body 2 is housed in a recess 30 of the support body 3 so as to be movable in a direction D2 perpendicular to the thickness direction D1 of the movable body 2 (i.e., a direction parallel to the X-Y plane). The movable body 2 and the support body 3 are in contact with each other directly or via another member in the thickness direction D1 of the movable body 2.

[0021] The movable body 2 is made of a hard material that is resistant to deformation so that it does not expand in a direction parallel to the YZ plane due to the load when the measurement object M1 is sandwiched between multiple (for example, a pair of) load detectors 1. The movable body 2 is made of a highly rigid material such as acrylic. It is preferable that the movable body 2 has a small specific gravity (weight).

[0022] Specifically, as shown in Figures 4 and 7, the movable body 2 has a main body 20 and one or more (here, nine) contact members 21. The main body 20 is a rectangular plate-like member that is long in the front-rear direction. The main body 20 has two holes 201 (see Figure 4) that penetrate through the thickness direction. Two knock pins F1 are press-fitted into the two holes 201 and two insertion holes 60 (see Figure 5) of the substrate 6, which will be described later, to integrally assemble the substrate 6 and the movable body 2.

[0023] 4, the main body 20 has a restricting protrusion 200 that protrudes in a plate shape on the top surface 2D of the main body 20. The restricting protrusion 200 forms a step on the outer periphery of the top surface 2D of the main body 20.

[0024] As shown in Fig. 7, the main body 20 has nine recesses 202 on its underside 2C, into which nine contact members 21 are respectively accommodated. When the movable body 2 is accommodated in the recess 30 of the support body 3, each contact member 21 comes into contact with the bottom surface 3B of the recess 30 (see Fig. 13). The movable body 2 is supported by the support body 3 via one or more (here, nine) contact members 21 so as to be movable within the recess 30. That is, in this embodiment, the movable body 2 has multiple contact surfaces with the support body 3. Each contact member 21 is, for example, a spherical member made of hard resin. Therefore, each of the multiple contact surfaces is a curved surface.

[0025] By providing the spherical contact members 21 in this manner, the movable body 2 has a structure in which the weight of the object M1 makes it easy for the movable body 2 to slide against the bottom surface 3B of the support body 3 when the object M1 is sandwiched between the pair of load detectors 1. Note that a lubricant or the like may be applied to the surface of each contact member 21 and the bottom surface 3B of the recess 30 to further enhance lubricity.

[0026] Furthermore, the movable body 2 is in contact with the bottom surface 3B of the support body 3 at the spherical contact member 21, and the lower surface 2C of the main body 20 is slightly spaced from the bottom surface 3B of the support body 3 (see FIGS. 13 and 14 ), so the contact area between the movable body 2 and the support body 3 is smaller than the projected area of ​​the movable body 2. Therefore, the contact resistance due to contact between the movable body 2 and the support body 3 in the thickness direction D1 of the movable body 2 can be reduced.

[0027] Furthermore, in the above configuration, since a plurality of contact members 21 are provided, the movable body 2 has a plurality of contact surfaces with the support body 3. Therefore, compared to, for example, a single contact surface, it is possible to reduce contact resistance while realizing stable movement (sliding) of the movable body 2 with respect to the support body 3. In particular, since each of the plurality of contact surfaces of the movable body 2 with the support body 3 is a curved surface, it is possible to further reduce contact resistance compared to, for example, a case in which each of the plurality of contact surfaces is a flat surface.

[0028] The cover 7 covers the movable body 2 so as to prevent the movable body 2 accommodated in the recess 30 of the support body 3 from slipping out of the recess 30. The cover 7 is made of, for example, metal. The cover 7 has a rectangular frame shape. The cover 7 has a rectangular positioning hole 7A (see FIGS. 4 and 5 ) at its center. The cover 7 also has multiple (six in the illustrated example) hooks 7B protruding downward from its front, rear, left, and right outer edges. Each hook 7B has a hole 7C penetrating through in the thickness direction. Each of the multiple (six in the illustrated example) protrusions 3F provided on the front, rear, left, and right outer surfaces of the support body 3 fits into the hole 7C of the corresponding hook 7B, thereby fixing the cover 7 to the support body 3 so as to cover the movable body 2 accommodated in the recess 30 of the support body 3 from above.

[0029] When the cover 7 covers the movable body 2, the restricting protrusion 200 of the main body 20 of the movable body 2 is inserted into the positioning hole 7A and protrudes above the upper surface of the cover 7. The surface surrounding the restricting protrusion 200 on the upper surface 2D of the main body 20 abuts against the lower surface of the cover 7, thereby restricting the movable body 2 from slipping out of the recess 30. Furthermore, when viewed from the top-bottom direction, the opening area of ​​the positioning hole 7A is slightly larger than the area of ​​the restricting protrusion 200, so that the movable body 2 within the recess 30 can move back and forth and left and right, but further movement is restricted when the outer peripheral surface of the restricting protrusion 200 abuts against the edge of the positioning hole 7A.

[0030] As shown in Figures 4 to 7 and 12, the substrate 6 is a rectangular plate that is long in the front-to-rear direction. The substrate 6 is a printed wiring board on which a predetermined conductor pattern is formed. The substrate 6 has two insertion holes 60 (see Figure 5) into which two knock pins F1 are press-fitted.

[0031] The substrate 6 and the movable body 2 are assembled together by press-fitting two knock pins F1 into two insertion holes 60 of the substrate 6 and two holes 201 of the movable body 2. The substrate 6 moves integrally with the movable body 2. A connector E1 to which a flexible printed wiring board C2 is connected is mounted near the front edge of the rear surface (lower surface) of the substrate 6 (see FIG. 7). The flexible printed wiring board C2 flexes, thereby easing the stress received from the substrate 6, which moves integrally with the movable body 2. The substrate 6 also holds a second load sensor 8.

[0032] The second load sensor 8 is, for example, a capacitance sensor. As shown in FIGS. 4 to 6 , the second load sensor 8 is disposed on the upper side of the substrate 6 and detects the load acting on the moving body 2 in the thickness direction D1 (here, the vertical direction). The second load sensor 8 has one or more (here, for example, 45) detection areas. The second load sensor 8 is composed of a first component 8A and a second component 8B.

[0033] Specifically, the first component 8A has 15 conductive wires 81 (see FIGS. 4 to 6 ) as linear first electrodes. Each wire 81 is used as one pole (e.g., an anode) of a capacitor. Each wire 81 is, for example, a single copper wire. However, each wire 81 may also be a twisted wire formed by twisting together multiple core wires. In this embodiment, the first component 8A has 15 first electrodes (wires 81) and a dielectric layer 82 provided on the surface of each first electrode. Each wire 81 is covered with an electrically insulating dielectric layer 82 and is arranged to run along the left-right direction on the upper surface of the substrate 6. The dielectric layer 82 is made of, for example, a resin material, a ceramic material, or a metal oxide material. The 15 wires 81 are arranged parallel to each other in the front-rear direction on the upper surface of the substrate 6 at a predetermined interval. A plurality of halved through-holes 6A (see FIG. 6 ) are provided at both left-right edges of the substrate 6. Both ends of each wire 81 are wound and soldered so as to be hooked onto the halved through-holes 6A at both edges of the substrate 6. As a result, each wire 81 is fixed to the substrate 6 and is also electrically connected to the conductor pattern formed on the substrate 6.

[0034] The second component 8B has three conductive elastic bodies 83 (see FIGS. 4 to 6 ) as sheet-like second electrodes in contact with or adjacent to the dielectric layer 82. Note that in FIG. 5 , the three conductive elastic bodies 83 are illustrated as perspective views to clearly show the positions of the 15 wires 81 located behind the three conductive elastic bodies 83 and the insertion holes 60 in the substrate 6. Each conductive elastic body 83 is used as the other pole (e.g., a cathode) of a capacitor. The three conductive elastic bodies 83 are elongated rectangular sheets. The three conductive elastic bodies 83 are arranged on the upper side of the substrate 6 with their longitudinal directions aligned in the front-to-rear direction, covering the 15 wires 81 from above. The three conductive elastic bodies 83 are arranged parallel to each other and spaced a predetermined distance apart in the left-to-right direction. As a result, when viewed from the top-to-bottom direction, each conductive elastic body 83 is arranged perpendicular to the 15 wires 81. Both ends of each conductive elastic body 83 that straddles the 15 wires 81 are fixed to the upper surface of the substrate 6 and are electrically connected to the conductive pattern of the substrate 6 .

[0035] Each conductive elastic body 83 is made of a resin material with conductive filler dispersed therein, or a rubber material with conductive filler dispersed therein.

[0036] The resin material used for the conductive elastic body 83 is at least one resin material selected from the group consisting of, for example, styrene-based resin, silicone-based resin (polydimethylpolysiloxane (e.g., PDMS)), acrylic-based resin, rotaxane-based resin, and urethane-based resin. The rubber material used for the conductive elastic body 83 is at least one rubber material selected from the group consisting of, for example, silicone rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, chloroprene rubber, nitrile rubber, polyisobutylene, ethylene propylene rubber, chlorosulfonated polyethylene, acrylic rubber, fluororubber, epichlorohydrin rubber, urethane rubber, and natural rubber.

[0037] The conductive filler used in the conductive elastic body 83 may be, for example, Au (gold), Ag (silver), Cu (copper), C (carbon), ZnO (zinc oxide), In ２ O ３(indium(III) oxide), and SnO ２ The conductive material is at least one material selected from the group consisting of metal materials such as tin (IV) oxide, conductive polymer materials such as PEDOT:PSS (i.e., a composite of poly3,4-ethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS)), and conductive fibers such as metal-coated organic fibers and metal wires (in a fibrous state).

[0038] In this embodiment, a region where one conductive elastic body 83 intersects one wire 81 at right angles is one detection region where a change in capacitance can be detected. Therefore, the second load sensor 8 can have, for example, a maximum of 3 × 15 = 45 detection regions.

[0039] Electrical signals (detection signals) from each of the 15 wires 81 and the three conductive elastic bodies 83 can be transmitted to, for example, a control system that controls a robot hand via the conductor pattern of the substrate 6, the connecting connector E1, and the flexible printed wiring board C2.

[0040] The second load sensor 8 is not limited to being a capacitance-type load sensor having the above configuration. The second load sensor 8 may be a capacitance-type load sensor having another configuration. Alternatively, the second load sensor 8 may be a resistive film-type or piezoelectric element-type load sensor.

[0041] As shown in FIG. 12 , the anti-slip member A1 is a rectangular plate elongated in the front-rear direction. The anti-slip member A1 is integrally formed with three conductive elastic bodies 83 and disposed on the upper side of the substrate 6. The anti-slip member A1 prevents the object M1 from slipping off due to its own weight when sandwiched between the pair of load detectors 1. The anti-slip member A1 is made of a highly tacky (sticky) material such as rubber. Therefore, by bringing the highly tacky anti-slip member A1 into contact with the object M1, a load corresponding to the weight of the object M1 is easily transmitted to the first load sensor 4 and the second load sensor 8. As a result, the weight, slippage, and gripping force (of the robot hand) of the object M1 can be accurately detected from the loads detected by the first load sensor 4 and the second load sensor 8.

[0042] [Detection Operation of Second Load Sensor] Here, the detection operation of the second load sensor 8 will be described. When a load is applied to the surface of the anti-slip member A1 along the Z-axis direction (vertical direction), one or more of the three conductive elastic bodies 83 may be brought closer to one or more of the fifteen wires 81 (coated with the dielectric layer 82). As a result, one or more conductive elastic bodies 83 move so that the one or more wires 81 bite into the one or more conductive elastic bodies 83. As a result, the contact area between the one or more conductive elastic bodies 83 and the one or more wires 81 (coated with the dielectric layer 82) increases. This causes a change in capacitance between the one or more conductive elastic bodies 83 and the one or more wires 81. By detecting this change in capacitance, the load in the thickness direction D1 (vertical direction) is acquired. In other words, by detecting a change in capacitance in one or more detection regions out of the 45 detection regions of the second load sensor 8, the load in the thickness direction D1 (vertical direction) is acquired (calculated).

[0043] The load calculation may be performed, for example, by a control system (one or more processors thereof) that controls the robot hand. The load detector 1 is communicably connected to the control system via flexible printed wiring boards C1 and C2. The control system receives a detection signal from the second load sensor 8 and calculates the load in the thickness direction D1 (vertical direction) based on the change in capacitance.

[0044] The support body 3 has a rectangular box shape that is flat in the vertical direction. The support body 3 is made of, for example, a resin member. The top surface of the support body 3 is open, and a recess 30 is formed therein. The recess 30 is configured to accommodate the movable body 2 so that the movable body 2 can move in a direction D2 (a direction parallel to the X-Y plane) perpendicular to the thickness direction D1 of the movable body 2. When viewed from the vertical direction, the bottom surface 3B of the recess 30 has substantially the same shape (rectangular) as the movable body 2. When viewed from the vertical direction, the opening area of ​​the recess 30 is slightly larger than the surface area of ​​the movable body 2, to the extent that the first load sensor 4 can be interposed between the inner surface 3A of the recess 30 and the movable body 2. The recess 30 has a certain depth. As shown in FIGS. 13 and 14 , the depth of the recess 30 is substantially the same as the thickness of the movable body 2 (excluding the restricting protrusion 200).

[0045] The support body 3 has a through hole 3C penetrating the bottom surface 3B of the recess 30. Specifically, as shown in FIGS. 4 , 9 , and 11 , the support body 3 has one or more (eight in this example) through holes 3C penetrating the support body 3 in the up-down direction near both the front and rear ends and the left and right ends of the bottom surface 3B of the recess 30. Two through holes 3C are provided at each of the front and rear ends and the left and right ends of the bottom surface 3B. Each through hole 3C is slit-shaped. A plurality of first protrusions 51 and a plurality of second protrusions 52 of the holding substrate 5 (described later) are inserted into the plurality of through holes 3C from the back side (lower side) of the support body 3 and exposed within the recess 30. Each of the plurality of first protrusions 51 and the plurality of second protrusions 52 is provided with a conductive elastic body 43, which is the second component 4B of the first load sensor 4. In short, the through hole 3C is a hole for leading the conductive elastic body 43 from the back side (lower side) of the support body 3 into the recess 30.

[0046] As shown in FIG. 10 , the support 3 has a back surface area 3D recessed upward on its back surface (lower surface). The back surface area 3D is located behind the recess 30. When viewed from the top-bottom direction, the bottom surface of the back surface area 3D has substantially the same shape (rectangular) as the bottom surface 3B of the recess 30. When viewed from the top-bottom direction, the opening area of ​​the back surface area 3D is substantially the same as the opening area of ​​the recess 30. The back surface area 3D is a space for accommodating the holding substrate 5. As shown in FIG. 10 , a cylindrical protrusion 3G having a threaded hole 3E formed therein is provided on the bottom surface of the back surface area 3D. In addition, a cylindrical protrusion 3H having a threaded hole 3E formed therein is also provided in an area on the lower surface of the support 3 forward of the back surface area 3D. Two hexagon socket head bolts G1 are screwed into these two threaded holes 3E to fix the load detector 1 to a fixture H1 of the robot hand.

[0047] The support body 3 also has a plurality of (six in the illustrated example) protrusions 3F on its outer surfaces on the front, rear, left, and right sides. Each protrusion 3F fits into a hole 7C of a corresponding hook 7B of the cover 7, thereby fixing the cover 7 to the support body 3.

[0048] One or more (eight in the illustrated example) first load sensors 4 (load sensors) are, for example, capacitance sensors. As shown in FIGS. 1, 13, and 14, each first load sensor 4 is interposed between the outer surface 2A of the movable body 2 and the inner surface 3A of the recess 30, and detects a load acting on the movable body 2 in a vertical direction D2 (a direction parallel to the X-Y plane). Each first load sensor 4 is composed of a first component 4A held on the movable body 2 side and a second component 4B held on the support body 3 side. However, the first component 4A is shared among the eight first load sensors 4.

[0049] The first component 4A has either a linear first electrode or a sheet-like second electrode facing the first electrode. In the present embodiment, as an example, the first component 4A has a single conductive wire 41 (see FIGS. 1, 4, 6, 7, 13, and 14) as the linear first electrode. The wire 41 is used as one pole (e.g., an anode) of a capacitor. The wire 41 is, for example, a single copper wire. However, the wire 41 may also be a twisted wire formed by twisting together multiple core wires. In the present embodiment, the first component 4A has a first electrode (wire 41) and a dielectric layer 42 provided on the surface of the first electrode. The wire 41, with its surface covered with the electrically insulating dielectric layer 42, is wound around the outer surface 2A of the movable body 2 in three turns and fixed with an adhesive or the like, thereby being held to the movable body 2. The dielectric layer 42 is made of, for example, a resin material, a ceramic material, a metal oxide material, or the like. The four corners of the outer surface 2A of the movable body 2, front, rear, left, and right, are rounded in the lower half in the vertical direction, and steps are provided between the upper and lower halves in the vertical direction. Therefore, the wire 41 can be caught on the steps at the four corners, thereby stably winding the wire 41 around the outer surface 2A of the movable body 2. In addition, of the four corners of the outer surface 2A of the movable body 2, a recess 2B (see FIGS. 6 and 7) is provided in the front right corner. The recess 2B extends in a groove shape in the vertical direction.

[0050] The first outgoing wiring W1 is accommodated in the recess 2B in the front right corner. The first outgoing wiring W1 is electrically connected to the first component 4A. The first outgoing wiring W1 is connected to a conductor portion of a substrate 6 disposed on the movable body 2. In this embodiment, the first outgoing wiring W1 includes a pair of electric wires. The wire 41 is wound around the outer surface 2A of the movable body 2 so that both ends (first end and second end) of the wire 41 in the longitudinal direction are located in the recess 2B. The pair of electric wires (first outgoing wiring W1) are connected to the first end and second end of the wire 41, respectively, and are arranged to pass through the recess 2B and head toward a conductor portion (conductor pattern) of the substrate 6 disposed above the movable body 2.

[0051] An electrical signal (detection signal) from the wire 41 can be transmitted to, for example, a control system that controls a robot hand via the conductor portion (conductor pattern) of the substrate 6, the connector E1, and the flexible printed wiring board C2.

[0052] The pair of electric wires (first outgoing wiring W1) may be made of the same material as the wire 41. In other words, the first end and second end (first outgoing wiring W1) of the wire 41 may be arranged to pass through the recess 2B and face the conductor portion of the substrate 6. In this case, the first end and second end of the wire 41 may not be covered with the dielectric layer 42.

[0053] The second component 4B has the other of a linear first electrode and a sheet-like second electrode. In the present embodiment, as an example, the second component 4B has a conductive elastic body 43 (see FIGS. 1, 4, 8, 9, 11, 13, and 14) as the second electrode. In other words, in the present embodiment, the second component 4B has a second electrode (conductive elastic body 43) in contact with or close to the dielectric layer 42. In the present embodiment, a plurality of conductive elastic bodies 43 (eight in the illustrated example) are provided. Each conductive elastic body 43 is used as the other pole (e.g., a cathode) of a capacitor. The eight conductive elastic bodies 43 are supported by a support substrate 5. The conductive elastic body 43 is configured as a thin carbon film.

[0054] The holding substrate 5 has an overall rectangular box shape with an open top. The holding substrate 5 holds the conductive elastic body 43. The holding substrate 5 is an electrically insulating substrate. The holding substrate 5 is, for example, a rubber substrate. As shown in FIGS. 8 and 11 , the holding substrate 5 has a main body 50, a plurality of (e.g., four) first protrusions 51, and a plurality of (e.g., four) second protrusions 52.

[0055] The main body 50 is a rectangular plate. When viewed from the top-bottom direction, the main body 50 has substantially the same shape (rectangular) as the bottom surface of the back surface area 3D. When viewed from the top-bottom direction, the area of ​​the main body 50 is slightly smaller than the area of ​​the bottom surface of the back surface area 3D. The main body 50 is accommodated in the back surface area 3D from below.

[0056] The four first protrusions 51 are arranged two on each of the left and right edges of the main body 50. Each first protrusion 51 is a plate-shaped portion that protrudes upward from the edge of the main body 50. Each first protrusion 51 is elongated in the front-to-rear direction. The thickness direction of each first protrusion 51 is parallel to the left-to-right direction. Each first protrusion 51 is arranged to face the first protrusion 51 on the opposite edge. A conductive elastic body 43, which is a thin carbon film, is provided on the inner surface of each first protrusion 51. For example, the conductive elastic body 43 is formed by applying carbon printing to the surface of each first protrusion 51. The material of the conductive elastic body 43 may be the same as the material of each conductive elastic body 83 described above.

[0057] The four second protrusions 52 are arranged two on each of the front and rear edges of the main body 50. Each second protrusion 52 is a plate-shaped portion that protrudes upward from the edge of the main body 50. Each second protrusion 52 is elongated in the left-right direction. The longitudinal dimension of each second protrusion 52 is shorter than the longitudinal dimension of the first protrusion 51. The thickness direction of each second protrusion 52 is parallel to the front-to-rear direction. Each second protrusion 52 is arranged to face the second protrusion 52 on the opposite edge. A conductive elastic body 43 is also provided on the inner surface of each second protrusion 52. For example, the conductive elastic body 43 is formed by applying carbon printing to the surface of each second protrusion 52.

[0058] With the main body 50 accommodated in the back surface region 3D from below the support 3, the four first protrusions 51 and four second protrusions 52, each having a conductive elastic body 43 on its surface, are disposed in the recess 30 through eight slit-shaped through-holes 3C in the support 3 (see FIG. 9 ). That is, with at least a portion (e.g., all) of each conductive elastic body 43 disposed in the recess 30 via the (corresponding) through-hole 3C, the holding substrate 5 is held on the back surface of the support 3.

[0059] In this embodiment, eight conductive elastic bodies 43 are provided, and each conductive elastic body 43 (second electrode) is positioned opposite a common wire 41 (first electrode), making it possible to detect a change in capacitance for each conductive elastic body 43. In other words, it can be said that the load detector 1 of this embodiment includes a plurality of first load sensors 4 including the first load sensor 4 (load sensor), and the plurality of first load sensors 4 are respectively disposed at a plurality of positions between the outer surface 2A of the movable body 2 and the inner surface 3A of the recess 30.

[0060] In each first load sensor 4 configured in this manner, when a load is applied to the movable body 2 in a direction parallel to the X-Y plane, the movable body 2 moves within the recess 30 of the support body 3. As the movable body 2 moves within the recess 30 of the support body 3, the first electrode (wire 41) moves relative to the second electrode (conductive elastic body 43). More specifically, the wire 41, the surface of which is coated with a dielectric layer 42, moves so as to bite into one or more of the eight conductive elastic bodies 43 that are located further ahead in the direction of movement.

[0061] The first load sensor 4 is not limited to being a capacitance-type load sensor having the above configuration. The first load sensor 4 may be a capacitance-type load sensor having another configuration. Alternatively, the first load sensor 4 may be a resistive film-type or piezoelectric element-type load sensor.

[0062] As shown in Figures 8, 10, and 11, the main body 50 has holes 5A and 5B penetrating through it in the thickness direction. Hole 5A is a long hole that is long in the left-right direction and located approximately in the center in the front-rear direction. Hole 5B is a circular hole located in front of hole 5A. Hole 5A is a hole for inserting the flexible printed wiring board C1 (see Figure 10). In other words, the holding substrate 5 has hole 5A through which the flexible printed wiring board C1 is passed. Hole 5B is a hole for inserting a cylindrical protrusion 3G having a screw hole 3E and located on the bottom surface of the back surface region 3D of the support body 3 (see Figure 10).

[0063] Here, the wiring of the eight conductive elastic bodies 43 provided on the surfaces of the eight protrusions (first protrusions 51, second protrusions 52) will be described. Each conductive elastic body 43 is electrically connected to the flexible printed wiring board C1 (see FIG. 8) via a second lead-out wiring W2 (see FIG. 8). In other words, the second lead-out wiring W2 is electrically connected to the second component 4B (the conductive elastic bodies 43).

[0064] The second outgoing wiring W2 is arranged in a region different from the recess 30 of the support 3. Specifically, the second outgoing wiring W2 includes eight conductor portions arranged on the upper surface 500 of the main body 50 of the holding substrate 5 (see FIG. 8 ). The eight conductive elastic bodies 43 are connected to the eight conductor portions of the second outgoing wiring W2, respectively. That is, in this example, the second outgoing wiring W2 is arranged in the back surface region 3D on the opposite side of the support 3 from the recess 30, and is connected to the conductive elastic bodies 43. Therefore, it can be said that the second outgoing wiring W2 is arranged in a region different from the recess 30.

[0065] The flexible printed wiring board C1 is electrically connected to the second lead-out wiring W2. A portion of the flexible printed wiring board C1 is disposed on the surface of the holding substrate 5 and extends to the outside through the hole 5A. Specifically, the flexible printed wiring board C1 has a rear end region C100 (see FIG. 8 ) whose left-right dimension is slightly shorter than the left-right dimension of the main body 50 of the holding substrate 5. The flexible printed wiring board C1 is disposed such that the rear end region C100 is interposed between the main body 50 of the holding substrate 5 and the bottom surface of the rear region 3D of the support 3. The eight conductor portions of the second lead-out wiring W2 are joined to conductor patterns formed in the rear end region C100. The flexible printed wiring board C1 also has a central region C101 (see FIG. 8 ) that is continuous with the rear end region C100 and whose left-right dimension is shorter than the left-right dimension of the rear end region C100. The central region C101 passes through the hole 5A of the main body 50 and is positioned below the main body 50. In other words, the rear end region C100 of the flexible printed wiring board C1 is positioned above the main body 50, and the central region C101 is positioned below the main body 50 via the hole 5A. The central region C101 has a central hole C10 (see FIG. 8) that is long in the front-to-rear direction. The central hole C10 is a hole for inserting two cylindrical protrusions 3G, 3H with screw holes 3E on the support body 3 (see FIG. 10). The two cylindrical protrusions 3G, 3H are led out through the hole 5B of the holding substrate 5 and the central hole C10.

[0066] An electrical signal (detection signal) from each of the eight conductive elastic bodies 43 can be transmitted to, for example, a control system that controls a robot hand via the second lead wire W2 and the flexible printed wiring board C1.

[0067] As shown in Fig. 11, the upper plate Q1 is a rectangular plate. The upper plate Q1 is a reinforcing plate provided at the joint between the flexible printed wiring board C1 and another member. Specifically, the upper plate Q1 is disposed so as to cover the upper surface of the rear end region C100 and protects the electrical joint between the flexible printed wiring board C1 and the second lead wiring W2. The upper plate Q1 is, for example, a resin plate.

[0068] As shown in FIG. 10 , the pressure plate 9 is a rectangular plate. The pressure plate 9 is arranged to press the holding substrate 5 against the support 3 from the back side (lower side) of the holding substrate 5. The pressure plate 9 is made of, for example, metal. The pressure plate 9 has an outlet hole 90 (see FIG. 10 ) located forward from the center. The outlet hole 90 is a hole for inserting a cylindrical protrusion 3G having a screw hole 3E located in the back surface region 3D of the support 3 (see FIG. 10 ). The cylindrical protrusion 3G is led out through the hole 5B of the holding substrate 5, the central hole C10 of the flexible printed wiring board C1, and the outlet hole 90.

[0069] As shown in FIG. 10 , the back plate P1 is a rectangular plate. The back plate P1 is disposed below the presser plate 9 so as to cover the lead-out hole 90 of the presser plate 9. The back plate P1 is, for example, a metal plate. The back plate P1 has two insertion holes P10. The two insertion holes P10 are disposed so as to face the screw holes 3E of the two cylindrical protrusions 3G, 3H, respectively. Two hexagon socket head bolts G1 are inserted into two holes in the fixture H1 of the robot hand, and further inserted into the two insertion holes P10 of the back plate P1 and screwed into the two screw holes 3E. As a result, the back plate P1, presser plate 9, holding substrate 5, and flexible printed wiring board C1 are assembled to the support body 3, and the load detector 1 is fixed to the fixture H1 of the robot hand.

[0070] [Detection Operation of First Load Sensor] Here, the detection operation of the first load sensor 4 will be described. When a load is applied to the surface of the anti-slip member A1 in a direction parallel to the X-Y plane, the movable body 2 moves along the X-Y plane within the recess 30. Then, the wire 41 (coated with the dielectric layer 42) held by the movable body 2 may be brought closer to one or more of the eight conductive elastic bodies 43 on the support body 3 side. As a result, the wire 41 moves so as to bite into one or more conductive elastic bodies 43. As a result, the contact area between the wire 41 (coated with the dielectric layer 42) and the one or more conductive elastic bodies 43 increases. This changes the capacitance between the wire 41 and the one or more conductive elastic bodies 43. By detecting this change in capacitance, the load in the direction parallel to the X-Y plane is obtained. In other words, by detecting a change in capacitance in one or more of the eight first load sensors 4 located around the front, back, left and right of the moving body 2, the load in a direction parallel to the X-Y plane is obtained (calculated).

[0071] The load calculation may be performed, for example, by one or more processors in a control system that controls the robot hand. The control system receives detection signals from the eight first load sensors 4 and calculates the load in a direction parallel to the XY plane based on changes in capacitance.

[0072] (2) Advantages: According to the load detector 1 of this embodiment, the first component 4A and the second component 4B constituting the first load sensor 4 (load sensor) are separately held on the movable body 2 side, which is the movable part, and on the support body 3 side, which is the fixed part. Therefore, compared to a configuration in which the first load sensor 4 (as a whole) is held on either the movable body 2 side or the support body 3 side, it is easier to realize a configuration that reduces frictional resistance caused by contact with the support body 3 when the movable body 2 moves due to an external force along the direction D2 (X-Y plane) perpendicular to the thickness direction D1. Specifically, if the entire load sensor configuration were located on the movable body side, which is the movable part, it would likely result in a structure in which the movable body and the load sensor make flat-surface contact with the support body. Similarly, if the entire load sensor configuration were located on the support body side, which is the fixed part, it would likely result in a structure in which the movable body makes flat-surface contact with the load sensor on the support body. In contrast, by separating the first component 4A and the second component 4B from the movable body 2 side and the support body 3 side, it is easier to realize a structure that reduces the contact area. As a result, the load detector 1 can reduce the frictional resistance and suppress the deterioration of the detection performance of the load sensor 4.

[0073] Furthermore, if the entire load sensor configuration is located on the moving body side or the support side, it may be necessary to package the load sensor. However, packaging the load sensor may lead to an increase in the size of the recess in the support that houses the moving body. In this regard, the load detector 1 has the first component 4A and the second component 4B of the first load sensor 4 separately held on the moving body 2 side and the support 3 side, respectively, thereby eliminating the need for packaging and preventing the recess 30 in the support 3 from becoming larger.

[0074] Furthermore, in the load detector 1 according to this embodiment, the first component 4A has the wire 41, and the second component 4B has the conductive elastic body 43. As the movable body 2 moves within the recess 30 of the support 3, the wire 41 moves relative to the conductive elastic body 43. As a result, a flat surface and a wire come into contact, and the contact area can be reduced compared to when flat surfaces contact each other. In other words, the contact area between the first component 4A and the second component 4B can be further reduced. As a result, the frictional resistance that affects the detection performance of the load sensor 4 can be further reduced.

[0075] Furthermore, the first outgoing wiring W1 electrically connected to the first component 4A (wire 41) is connected to a conductor portion of the substrate 6 disposed on the moving body 2. In other words, the first outgoing wiring W1 is not fixed to the support body 3 (for example, the inner surface 3A of the recess 30, etc.). Therefore, it is possible to reduce external forces acting on the first component 4A.

[0076] Furthermore, the conductive elastic body 43 arranged on the protrusions (first protrusion 51, second protrusion 52) of the holding substrate 5 is arranged in the recess 30 via the through hole 3C, and the holding substrate 5 is held on the back side of the support 3. Therefore, compared to when the holding substrate 5 is arranged in the recess 30, for example, it is easier to ensure sufficient space for arranging the holding substrate 5, and the degree of freedom in design can be improved.

[0077] Furthermore, the second lead-out wiring W2 electrically connected to the second component 4B (conductive elastic body 43) is arranged in a region different from the recess 30 of the support body 3. In other words, the second lead-out wiring W2 does not pass through the recess 30 of the support body 3. The second lead-out wiring W2 is arranged in the back surface region 3D on the opposite side of the support body 3 from the recess 30. Therefore, compared to when the second lead-out wiring W2 is arranged in a region within the recess 30, for example, it is easier to ensure a sufficient region that can be used for the second lead-out wiring W2, thereby improving the degree of freedom in design.

[0078] Furthermore, the multiple load sensors 4 are disposed at multiple positions between the outer surface 2A of the movable body 2 and the inner surface 3A of the recess 30. Therefore, it is possible to detect the moment around the Z axis, for example, from the output balance of adjacent load sensors 4.

[0079] The movable body 2 is preferably accommodated in the recess 30 with almost no play in the direction parallel to the X-Y plane. If there is play, the movable body 2 can move within the recess 30 by a stroke calculated by adding the play and the amount of elastic deformation of the conductive elastic body 43 due to the wire 41 of the first load sensor 4 being dug in by a load in the direction parallel to the X-Y plane. By minimizing this play, the first load sensor 14 can detect the load generated by the movement of the movable body 32 with high response. In this regard, in this embodiment, each first load sensor 4 is divided into a first component 4A held on the movable body 2 side and a second component 4B held on the support body 3 side. Therefore, it is sufficient to accommodate the movable body 2 in the recess 30 so that the first component 4A and the second component 4B are in slight contact with each other. Therefore, the load detector 1 has a structure that easily minimizes the play. In other words, the load detector 1 also has the advantage of being compact.

[0080] (3) Modifications Modifications are listed below. Each of the modifications described below can be applied in appropriate combination with the above embodiment or other modifications.

[0081] (3.1) Modification 1 Fig. 15 is a perspective view, seen from above, of the support body 3 and its peripheral configuration in a load detector 1 according to Modification 1. As shown in Fig. 15, the load detector 1 according to Modification 1 further includes an adjustment structure Z1 that adjusts the distance between the second component 4B and the first component 4A.

[0082] The adjustment structure Z1 includes multiple pairs (eight pairs in this example) of cylindrical members Z11 and plate members Z12. The cylindrical members Z11 are, for example, set screws. The plate members Z12 are, for example, rigid, rectangular thin plates (preferably made of resin). These eight pairs are arranged on each of the four walls (front wall 301, rear wall 302, left wall 303, and right wall 304) surrounding the recess 30. For convenience, only four pairs (the rear wall 302 and the left wall 303) are shown in FIG. 15 . Each pair of plate members Z12 is inserted into a gap SP1 between a corresponding one of the eight protrusions (first protrusion 51, second protrusion 52) on which the conductive elastic body 43 is disposed and the inner surface 3A of the recess 30. The four walls, ie, the front wall 301, the rear wall 302, the left wall 303, and the right wall 304, are provided with screw holes for passing through the respective sets of cylindrical members Z11 (set screws). Each set of cylindrical members Z11 (set screws) is screwed into the corresponding screw holes and positioned so that its tip presses the corresponding plate member Z12 from the rear surface. As a result, each protrusion on which the conductive elastic body 43 is positioned is pressed by the plate member Z12.

[0083] In short, the adjustment structure Z1 adjusts the dimension of the gap SP1 between the eight protrusions (first protrusion 51, second protrusion 52) and the inner surface 3A of the recess 30, and adjusts the balance of the initial load between the first component 4A and the second component 4B.

[0084] When the moving object 2 moves due to a force parallel to the X-Y plane, the protrusions (first protrusion 51, second protrusion 52) on which the conductive elastic body 43 facing the wire 41 is provided may elastically deform, causing a decrease in pressure. As a result, a problem of differential pressure loss may occur. In response to this, the provision of the adjustment structure Z1 allows the plate member Z12 to act as a support, suppressing elastic deformation of the first protrusion 51 and the second protrusion 52 and preventing a loss of differential pressure. Furthermore, the provision of the adjustment structure Z1 allows the plate member Z12 to press down on the first protrusion 51 and the second protrusion 52, making it possible to adjust the positions of the first protrusion 51 and the second protrusion 52 slightly inward to minimize the aforementioned "play." As a result, the provision of the adjustment structure Z1 further suppresses a decrease in the detection performance of the load sensor 4.

[0085] (3.2) Other Modifications In the above embodiment, the first component 4A held on the moving body 2 side has a linear first electrode (wire 41) and a dielectric layer 42, and the second component 4B held on the support body 3 side has a sheet-like second electrode (conductive elastic body 43). However, conversely, the first component 4A held on the moving body 2 side may have a sheet-like second electrode (conductive elastic body 43), and the second component 4B held on the support body 3 side may have a linear first electrode (wire 41) and a dielectric layer 42.

[0086] In the above embodiment, the first load sensor 4 is a capacitance-type load sensor. However, the first load sensor 4 may also be a resistive film-type load sensor. In this case, the first load sensor 4 may have two planar electrodes (a first planar electrode and a second planar electrode) and a resistor disposed therebetween. The size of the resistor in a planar view may be approximately the same as that of each of the first and second planar electrodes. For example, the first component 4A may have a first planar electrode and a resistor, and the second component 4B may have a second planar electrode. The first planar electrode and the resistor may be held on the mobile object 2 side, and the second planar electrode may be held on the support 3 side. In this resistive film-type load sensor, when a load is applied, the resistor's film thickness decreases and its resistance value decreases, and the load is detected based on the change in resistance value.

[0087] Alternatively, the first load sensor 4 may be a capacitance-type sensor in which the thickness of the dielectric changes. In this case, the first load sensor 4 may have two planar electrodes (a first planar electrode and a second planar electrode) and a dielectric disposed therebetween. The size of the dielectric in a planar view may be approximately the same as that of each of the first and second planar electrodes. For example, the first component 4A may have the first planar electrode and the dielectric, and the second component 4B may have the second planar electrode. The first planar electrode and the dielectric may be held on the mobile object 2 side, and the second planar electrode may be held on the support 3 side. In this capacitance-type load sensor, when a load is applied, the thickness of the dielectric decreases and the capacitance increases, and therefore the load is detected based on the change in capacitance.

[0088] Alternatively, the first load sensor 4 may be a piezoelectric load sensor. In this case, the first load sensor 4 may have two planar electrodes (a first planar electrode and a second planar electrode) and a piezoelectric body disposed therebetween. For example, the first component 4A (or the second component 4B) may have a first planar electrode, a second planar electrode, and a piezoelectric body. The first planar electrode, the second planar electrode, and the piezoelectric body may be held on the moving body 2 side (or the support body 3 side).

[0089] (Summary) The above-described embodiments and the like disclose the following aspects.

[0090] A load detector (1) according to a first aspect includes a moving body (2), a support (3), and a load sensor (4). The moving body (2) has a predetermined thickness. The support (3) has a recess (30) that accommodates the moving body (2) so that the moving body (2) can move in a direction (D2) perpendicular to the thickness direction (D1) of the moving body (2). The load sensor (4) is interposed between an outer surface (2A) of the moving body (2) and an inner surface (3A) of the recess (30) and detects a load acting on the moving body (2) in the perpendicular direction (D2). The load sensor (4) includes a first component (4A) held on the moving body (2) side and a second component (4B) held on the support (3) side.

[0091] According to the above aspect, there is an advantage that the deterioration of the detection performance of the load sensor (4) can be suppressed.

[0092] The load detector (1) according to the second aspect includes a plurality of load sensors (4) including the load sensor (4) in the first aspect. The plurality of load sensors (4) are respectively arranged at a plurality of positions between the outer surface (2A) of the moving body (2) and the inner surface (3A) of the recess (30).

[0093] According to the above aspect, it is possible to suppress a decrease in the detection performance of the multiple load sensors 4. Furthermore, by arranging the multiple load sensors 4, it is also possible to detect, for example, the moment around the Z axis from the output balance of the adjacent load sensors 4.

[0094] The load detector (1) according to the third aspect is the load detector (1) according to the first or second aspect, further comprising a first lead-out wiring (W1) electrically connected to the first component (4A). The first lead-out wiring (W1) is connected to a conductor portion of a substrate (6) disposed on the moving body (2).

[0095] According to the above aspect, the external force acting on the first component (4A) can be reduced compared to when the first lead wire (W1) is disposed on the support (3) side, for example.

[0096] The load detector (1) according to a fourth aspect is any one of the first to third aspects, further comprising a second lead-out wiring (W2) electrically connected to the second component (4B). The second lead-out wiring (W2) is arranged in a region different from the recess (30) of the support (3).

[0097] According to the above aspect, it is easier to secure a sufficient area available for the second lead-out wiring (W2), compared to when the second lead-out wiring (W2) is placed in an area within the recess (30), for example, thereby improving design freedom.

[0098] In the fourth aspect of the load detector (1) according to the fifth aspect, the second component (4B) has a conductive elastic body (43). The load detector (1) further includes a holding substrate (5) that holds the conductive elastic body (43). The support (3) has a through-hole (3C) that penetrates the bottom surface (3B) of the recess (30). The holding substrate (5) is held on the back side of the support (3) with at least a portion of the conductive elastic body (43) disposed within the recess (30) via the through-hole (3C).

[0099] According to the above-described embodiment, it is easier to secure sufficient space for placing the holding substrate (5), compared to, for example, placing the holding substrate (5) in a recess (30), thereby improving design freedom.

[0100] Regarding the load detector (1) of the sixth aspect, in the fifth aspect, the second lead wiring (W2) is arranged in the back surface area (3D) opposite the recess (30) in the support (3) and is connected to the conductive elastic body (43).

[0101] According to the above aspect, it is easier to secure a sufficient area available for the second lead-out wiring (W2), compared to when the second lead-out wiring (W2) is placed in an area within the recess (30), for example, thereby improving design freedom.

[0102] The load detector (1) according to a seventh aspect is the sixth aspect, further comprising a flexible printed wiring board (C1) electrically connected to the second lead wire (W2). The holding substrate (5) has a hole (5A) through which the flexible printed wiring board (C1) passes. A portion of the flexible printed wiring board (C1) is disposed on the surface of the holding substrate (5) and is led out to the outside through the hole (5A).

[0103] According to the above embodiment, it becomes easier to lead out the flexible printed wiring board (C1) to the outside.

[0104] Regarding the load detector (1) according to the eighth aspect, in any one of the first to seventh aspects, the movable body (2) and the support (3) are in contact with each other directly or via another member in the thickness direction (D1) of the movable body (2), and the contact area between the movable body (2) and the support (3) is smaller than the projected area of ​​the movable body (2).

[0105] According to the above aspect, the contact resistance due to contact between the moving body (2) and the support (3) in the thickness direction (D1) of the moving body (2) can be reduced, and the deterioration of the detection performance of the load sensor (4) can be further suppressed.

[0106] In the load detector (1) according to the ninth aspect, in the eighth aspect, the moving body (2) has a plurality of contact surfaces with the support body (3).

[0107] According to the above aspect, compared to the case where there is one contact surface, for example, it is possible to realize stable movement (sliding) of the moving body (2) relative to the support body (3) while reducing contact resistance.

[0108] With respect to the load detector (1) according to the tenth aspect, in the ninth aspect, each of the plurality of contact surfaces is a curved surface.

[0109] According to the above aspect, the contact resistance can be further reduced compared to when each of the plurality of contact surfaces is a flat surface, for example.

[0110] Regarding the load detector (1) according to the eleventh aspect, in any one of the eighth to tenth aspects, the movable body (2) has one or more contact members (21) that contact the bottom surface (3B) of the recess (30). The movable body (2) is supported by the support (3) via the one or more contact members (21) so as to be movable within the recess (30).

[0111] According to the above aspect, the contact area between the moving body (2) and the support (3) can be made smaller than the projected area of ​​the moving body (2) with a simple configuration.

[0112] The load detector (1) according to the twelfth aspect is any one of the first to eleventh aspects, and further includes an adjustment structure (Z1) that adjusts the distance of the second component (4B) relative to the first component (4A).

[0113] According to the above aspect, the deterioration of the detection performance of the load sensor (4) can be further suppressed.

[0114] Regarding the load detector (1) according to the thirteenth aspect, in any one of the first to twelfth aspects, the first component (4A) has either a linear first electrode (wire 41) or a sheet-like second electrode (conductive elastic body 43) facing the first electrode (wire 41). The second component (4B) has the other of the first electrode (wire 41) or the second electrode (conductive elastic body 43). As the movable body (2) moves within the recess (30) of the support body (3), the first electrode (wire 41) moves relative to the second electrode (conductive elastic body 43).

[0115] According to the above aspect, the contact area between the first component (4A) and the second component (4B) can be reduced, thereby further reducing frictional resistance that affects the detection performance of the load sensor (4).

[0116] Regarding the load detector (1) according to the fourteenth aspect, in the thirteenth aspect, the load sensor (4) is a capacitance-type sensor. The first component (4A) has a first electrode (wire 41) and a dielectric layer (42) provided on the surface of the first electrode (wire 41). The second component (4B) has a second electrode (conductive elastic body 43) in contact with or in close proximity to the dielectric layer (42).

[0117] According to the above aspect, it is possible to suppress a decrease in the detection performance of the capacitance type load sensor (4).

[0118] The configurations according to the second to fourteenth aspects are not essential for the load detector (1) and may be omitted as appropriate.

[0119] REFERENCE SIGNS LIST 1 Load detector 2 Moving body 21 Contact member 2A Outer surface 3 Support 30 Recess 3A Inner surface 3B Bottom surface 3C Through hole 3D Back surface area 4 Load sensor 41 Wire (first electrode) 42 Dielectric layer 43 Conductive elastic body (second electrode) 4 Load sensor 4A First component 4B Second component 5 Holding substrate 5A Hole 6 Substrate C1 Flexible printed wiring board D1 Thickness direction D2 Vertical direction M1 Measurement object W1 First lead-out wiring W2 Second lead-out wiring Z1 Adjustment structure

Claims

1. A load detector comprising: a movable body having a predetermined thickness; a support having a recess that accommodates the movable body so that the movable body can move in a direction perpendicular to the thickness direction of the movable body; and a load sensor interposed between the outer surface of the movable body and the inner surface of the recess and detecting a load applied to the movable body in the perpendicular direction, wherein the load sensor is composed of a first component held on the movable body side and a second component held on the support side.

2. The load detector according to claim 1, comprising a plurality of load sensors including the load sensor, the plurality of load sensors being respectively arranged at a plurality of positions between the outer surface of the movable body and the inner surface of the recess.

3. A load detector as set forth in claim 1 or 2, further comprising a first lead-out wiring electrically connected to the first component, the first lead-out wiring being connected to a conductor portion of a substrate disposed on the moving body.

4. A load detector as claimed in any one of claims 1 to 3, further comprising a second lead-out wiring electrically connected to the second component, the second lead-out wiring being arranged in a region of the support body different from the recess.

5. A load detector as described in claim 4, wherein the second component has a conductive elastic body, the load detector further comprises a holding substrate that holds the conductive elastic body, the support has a through hole that penetrates the bottom surface of the recess, and the holding substrate is held on the back side of the support with at least a portion of the conductive elastic body positioned within the recess via the through hole.

6. The load detector according to claim 5, wherein the second lead wiring is arranged in a back surface area of ​​the support member opposite the recess, and is connected to the conductive elastic body.

7. A load detector as described in claim 6, further comprising a flexible printed wiring board electrically connected to the second lead-out wiring, the holding substrate having a hole through which the flexible printed wiring board is passed, and a portion of the flexible printed wiring board being disposed on the surface of the holding substrate and being led out to the outside through the hole.

8. A load detector according to any one of claims 1 to 7, wherein the movable body and the support are in contact with each other directly or via another member in the thickness direction of the movable body, and the contact area between the movable body and the support is smaller than the projected area of ​​the movable body.

9. The load detector according to claim 8, wherein the movable body has a plurality of contact surfaces with the support body.

10. The load detector according to claim 9, wherein each of the plurality of contact surfaces is a curved surface.

11. A load detector according to any one of claims 8 to 10, wherein the movable body has one or more contact members that come into contact with the bottom surface of the recess, and the movable body is supported by the support body so as to be movable within the recess via the one or more contact members.

12. A load detector according to any one of claims 1 to 11, further comprising an adjustment structure for adjusting the distance of the second component relative to the first component.

13. A load detector as claimed in any one of claims 1 to 12, wherein the first component has either a linear first electrode or a sheet-like second electrode facing the first electrode, the second component has the other of the first electrode and the second electrode, and the first electrode moves relative to the second electrode as the movable body moves within the recess of the support.

14. A load detector as described in claim 13, wherein the load sensor is a capacitance type sensor, the first component has the first electrode and a dielectric layer provided on the surface of the first electrode, and the second component has the second electrode in contact with or in close proximity to the dielectric layer.

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