Independent force sensor and force sensor

Abstract

This independent force sensor is provided with: a first independent sensor body; a second independent sensor body; a first strain body that connects the first independent sensor body and the second independent sensor body; and a detection element that detects the displacement of the first strain body due to elastic deformation. The first strain body includes a first connection body extending in a first direction from a first end portion connected to the first independent sensor body to a second end portion connected to the second independent sensor body, and a displacement body protruding from the first connection body in a second direction orthogonal to the first direction. The detection element includes a fixed electrode substrate provided on the second independent sensor body, and a displacement electrode substrate provided on the displacement body and facing the fixed electrode substrate.

Description

Technical Field

[0001] The present invention relates to an independent force sensor and a force sensor. Background Art

[0002] Conventionally, a force sensor that outputs, as an electric signal, a force acting in a predetermined axial direction and a moment (torque) acting about a predetermined rotation axis has been known. Force sensors are widely used for force control of various robots such as industrial robots, collaborative robots, life assistance robots, medical robots, and service robots. For example, when a robotic arm comes into contact with a person, the force sensor detects the contact with the person. Thereby, the operation of the robotic arm is stopped urgently, or the operation is performed in such a way as to avoid contact with the person.

[0003] Since a plurality of force sensors are built in one robot, cost reduction of each force sensor is required. In addition, the force sensor is arranged between the tip of the robotic arm and a tool such as an end effector (gripper). When the height of the force sensor is high, the distance from the tip of the robotic arm to the tip of the tool becomes long, and high-precision control of the workpiece may become difficult. Therefore, reduction of the height of the force sensor is also required.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 6257017 Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] The present invention has been made in view of such points, and an object thereof is to provide an independent force sensor and a force sensor that can achieve cost reduction and height reduction.

[0009] Technical Solution for Solving the Technical Problem

[0010] [1] The present disclosure may be an independent force sensor including:

[0011] a first independent sensor body that is acted on by a force or a moment to be detected;

[0012] a second independent sensor body that is arranged at a position different from that of the first independent sensor body in a first direction;

[0013] a first strain body that connects the first independent sensor body and the second independent sensor body, and elastically deforms due to the force or moment acting on the first independent sensor body; and

[0014] The detection element detects the displacement generated by the elastic deformation of the first strain body.

[0015] The first strain body includes: a first connecting body extending from a first end connected to the first independent sensor body to a second end connected to the second independent sensor body in the first direction; and a displacement body protruding from the first connecting body in a second direction orthogonal to the first direction.

[0016] The detection element includes: a fixed electrode substrate disposed on the second independent sensor body; and a displacement electrode substrate disposed on the displacement body and opposed to the fixed electrode substrate.

[0017] [2] The present disclosure may also be the independent force sensor described in [1],

[0018] Taking the direction orthogonal to both the first direction and the second direction as the third direction,

[0019] The first connecting body is formed along each of the first direction and the third direction.

[0020] [3] The present disclosure may also be the independent force sensor described in [2],

[0021] When viewed from the first direction, the dimension of the first connecting body in the second direction is smaller than the dimension of the first connecting body in the third direction.

[0022] [4] The present disclosure may also be the independent force sensor described in any one of [1] to [3],

[0023] The first independent sensor body, the second independent sensor body, and the displacement body are formed along a plane orthogonal to the first direction.

[0024] [5] The present disclosure may also be the independent force sensor described in any one of [1] to [4],

[0025] The second independent sensor body and the displacement body protrude more in the third direction than the first independent sensor body.

[0026] [6] The present disclosure may also be the independent force sensor described in any one of [1] to [5],

[0027] The first strain body includes two displacement bodies protruding in the second direction on both sides of the first connecting body,

[0028] The detection element includes two fixed electrode substrates and two displacement electrode substrates opposed to the corresponding fixed electrode substrates.

[0029] The displacement electrode substrates are provided on the respective displacement bodies.

[0030] [7] The present disclosure may also be an independent force sensor according to any one of [1] to [6],

[0031] The first independent sensor body, the second independent sensor body, and the first strain body are integrally formed of a continuous material.

[0032] [8] The present disclosure may also be an independent force sensor according to any one of [1] to [7],

[0033] The first strain body includes a first thinning portion that is formed along a plane orthogonal to the first direction and connects the first independent sensor body to the first end portion of the first connection body.

[0034] The first thinning portion is thinner than the first independent sensor body.

[0035] [9] The present disclosure may also be the independent force sensor according to [8],

[0036] The first strain body includes a first protruding portion that protrudes from the first thinning portion in the first direction.

[0037]

[10] The present disclosure may also be an independent force sensor according to any one of [1] to [9],

[0038] The first strain body includes a second thinning portion that is formed along a plane orthogonal to the first direction and connects the second independent sensor body to the second end portion of the first connection body.

[0039] The second thinning portion is thinner than the second independent sensor body.

[0040]

[11] The present disclosure may also be the independent force sensor according to

[10] ,

[0041] The first strain body includes a second protruding portion that protrudes from the second thinning portion in the first direction.

[0042]

[12] The present disclosure may also be an independent force sensor according to any one of [1] to

[11] ,

[0043] The independent force sensor includes a detection circuit that outputs an electrical signal representing the force or torque received by the first independent sensor body based on the detection result of the detection element.

[0044]

[13] The present disclosure may also be an independent force sensor, comprising:

[0045] A first independent sensor body, which is acted upon by a force or torque to be detected;

[0046] A second independent sensor body, which is disposed at a position different from that of the first independent sensor body in a first direction;

[0047] A first strain body, which connects the first independent sensor body and the second independent sensor body, and elastically deforms due to the force or torque acting on the first independent sensor body; and

[0048] A detection element, which detects the displacement generated by the elastic deformation of the first strain body,

[0049] The first strain body includes a first connecting body, and the first connecting body extends from a first end connected to the first independent sensor body to a second end connected to the second independent sensor body in the first direction,

[0050] The detection element includes: two first strain gauges, which are disposed at the first end; and two second strain gauges, which are disposed at the second end,

[0051] A Wheatstone bridge circuit is formed by the two first strain gauges and the two second strain gauges.

[0052]

[14] The present disclosure may also be a force sensor, comprising:

[0053] Multiple independent force sensors as described in any one of [1] to

[12] ;

[0054] A first sensor body, which supports the first independent sensor bodies of the respective independent force sensors, and the first sensor body is acted upon by a force or torque to be detected;

[0055] A second sensor body, which supports the second independent sensor bodies of the respective independent force sensors;

[0056] Multiple second strain bodies, which connect the first sensor body and the second sensor body, and elastically deform due to the force or torque acting on the first sensor body; and

[0057] A detection circuit, which outputs an electrical signal representing the force or torque acting on the first sensor body based on the detection results of the detection elements of the respective independent force sensors,

[0058] The second strain body includes a second connecting body, and the second connecting body extends in the first direction from a third end connected to the first sensor body to a fourth end connected to the second sensor body.

[0059]

[15] The present disclosure may also be, in the force sensor described in

[14] ,

[0060] When viewed from the first direction, the second connecting body is formed along a radial direction with respect to the center point of the first sensor body.

[0061]

[16] The present disclosure may also be, in the force sensor described in

[15] ,

[0062] When viewed from the first direction, the dimension of the second connecting body in a direction orthogonal to the radial direction is smaller than the dimension of the second connecting body in the radial direction.

[0063]

[17] The present disclosure may also be, in the force sensor described in any one of

[14] to

[16] ,

[0064] The first sensor body and the second sensor body are formed along a plane orthogonal to the first direction.

[0065]

[18] The present disclosure may also be, in the force sensor described in any one of

[14] to

[17] ,

[0066] The first sensor body includes a first opening, and the first connecting body is inserted into the first opening.

[0067]

[19] The present disclosure may also be, in the force sensor described in

[18] ,

[0068] The first sensor body includes a first recess, the first recess opens toward a side opposite to the second sensor body and communicates with the first opening,

[0069] The first independent sensor body is accommodated in the first recess.

[0070]

[20] The present disclosure may also be, in the force sensor described in any one of

[14] to

[19] ,

[0071] The second sensor body includes a second opening, and the first connecting body is inserted into the second opening.

[0072]

[21] The present disclosure may also be, in the force sensor described in

[20] ,

[0073] The second sensor body includes a second recess, the second recess opens toward a side opposite to the first sensor body and communicates with the second opening,

[0074] The second independent sensor body is received in the second recess.

[0075]

[22] The present disclosure may also be a force sensor according to any one of

[14] to

[21] ,

[0076] The second connecting body has higher rigidity than the first connecting body with respect to a moment about an axis along the first direction.

[0077]

[23] The present disclosure may also be a force sensor according to any one of

[14] to

[22] ,

[0078] The first sensor body, the second sensor body, and the second strain body are integrally formed of a continuous material.

[0079]

[24] The present disclosure may also be a force sensor according to any one of

[14] to

[23] ,

[0080] The second strain body includes a third thinning portion that is formed along a plane orthogonal to the first direction and connects the first sensor body and the third end portion of the second connecting body,

[0081] The third thinning portion is thinner than the first sensor body.

[0082]

[25] The present disclosure may also be a force sensor according to

[24] ,

[0083] The second strain body includes a third protruding portion that protrudes in the first direction from the third thinning portion.

[0084]

[26] The present disclosure may also be a force sensor according to any one of

[14] to

[24] ,

[0085] The second strain body includes a fourth thinning portion that is formed along a plane orthogonal to the first direction and connects the second sensor body and the fourth end portion of the second connecting body,

[0086] The fourth thinning portion is thinner than the second sensor body.

[0087]

[27] The present disclosure may also be a force sensor according to

[25] ,

[0088] The second strain body includes a fourth protruding portion that protrudes in the first direction from the fourth thinning portion.

[0089]

[28] The present disclosure may also be a force sensor including:

[0090] A plurality of independent force sensors, each of the independent force sensors including a first independent sensor body, a second independent sensor body, a first strain body, and a detection element, wherein the first independent sensor body is subjected to a force or torque to be detected, the second independent sensor body is disposed at a position different from that of the first independent sensor body in a first direction, the first strain body connects the first independent sensor body and the second independent sensor body, the first strain body elastically deforms due to the force or torque applied to the first independent sensor body, and the detection element detects the displacement generated by the elastic deformation of the first strain body;

[0091] A first sensor body that supports the first independent sensor body of each of the independent force sensors, and the first sensor body is subjected to a force or torque to be detected;

[0092] A second sensor body that supports the second independent sensor body of each of the independent force sensors;

[0093] A plurality of second connectors that extend in the first direction from a third end connected to the first sensor body to a fourth end connected to the second sensor body; and

[0094] A detection circuit that outputs an electrical signal representing the force or torque applied to the first sensor body based on the detection results of the detection elements of each of the independent force sensors.

[0095] The strain body includes a first connector that extends in the first direction from a first end connected to the first independent sensor body to a second end connected to the second independent sensor body.

[0096] The detection element includes: two first strain gauges disposed at the first end; and two second strain gauges disposed at the second end.

[0097] The detection circuit includes a Wheatstone bridge circuit that outputs an electrical signal based on the detection results of the first strain gauges and the second strain gauges.

[0098] When viewed from the first direction, the second connector is formed radially with respect to the center point of the first sensor body.

[0099] Advantages of the Invention

[0100] According to the present invention, cost reduction can be achieved and the height can be reduced. Description of the Drawings

[0101] Figure 1It is a perspective view showing an example of a robot.

[0102] Figure 2 It is a longitudinal sectional view showing an independent force sensor according to the first embodiment.

[0103] Figure 3 It shows Figure 2 The top view of the independent force sensor shown.

[0104] Figure 4 It schematically shows Figure 2 The longitudinal sectional view of the deformation state of the first strain body when the independent force-receiving body of the independent force sensor shown is subjected to a force on the positive side in the X-axis direction.

[0105] Figure 5 It is a perspective view showing an independent force sensor according to the second embodiment.

[0106] Figure 6 It shows Figure 5 The side view of the independent force sensor shown.

[0107] Figure 7 It shows Figure 5 The top view of the independent force sensor shown.

[0108] Figure 8 It is a longitudinal sectional view showing an independent force sensor according to the third embodiment.

[0109] Figure 9A It shows Figure 8 The top view of the independent force-receiving body shown.

[0110] Figure 9B It shows Figure 8 The bottom view of the independent fixing body shown.

[0111] Figure 10 It schematically shows Figure 8 The longitudinal sectional view of the deformation state of the first strain body when the independent force-receiving body of the independent force sensor shown is subjected to a force on the positive side in the X-axis direction.

[0112] Figure 11 It schematically shows Figure 8 The longitudinal sectional view of the deformation state of the first strain body when the independent force-receiving body of the independent force sensor shown is subjected to a force on the positive side in the Z-axis direction.

[0113] Figure 12 It schematically shows Figure 8 The longitudinal sectional view of the deformation state of the first strain body when the independent force-receiving body of the independent force sensor shown is subjected to a force on the negative side in the Z-axis direction.

[0114] Figure 13 It showsFigure 9A Top view of a modified example of the independent force sensor shown.

[0115] Figure 14 Is a longitudinal sectional view of a force sensor according to the fourth embodiment.

[0116] Figure 15 Is Figure 14 P-direction view of.

[0117] Figure 16 Is Figure 14 Q-direction view of.

[0118] Figure 17 Is Figure 15 And Figure 16 Longitudinal sectional view of the second strain body shown.

[0119] Figure 18 Is a view showing Figure 14 Enlarged longitudinal sectional view of the independent force sensor shown.

[0120] Figure 19 Is an enlarged longitudinal sectional view of an independent force sensor according to the fifth embodiment.

[0121] Figure 20 Is a view showing Figure 19 Diagram of the Wheatstone bridge circuit for the detection element shown.

[0122] Figure 21 Schematically shows Figure 19 Longitudinal sectional view of the deformation state of the first strain body when the independent force-receiving body of the independent force sensor shown is subjected to a force on the positive side in the X-axis direction.

[0123] Figure 22 Is a view showing the application of Figure 19 Longitudinal sectional view of the force sensor of the independent force sensor shown.

[0124] Figure 23 Is Figure 22 R-direction view of.

[0125] Figure 24 Is a longitudinal sectional view of a force sensor according to the sixth embodiment.

[0126] Figure 25 Is a view showing Figure 24 Top view of the force sensor shown.

[0127] Figure 26 Is Figure 25 Longitudinal sectional view of the second strain body shown.

[0128] Figure 27 Is a view showing Figure 24Table of changes in electrostatic capacitance values of respective capacitance elements in the force sensor shown

[0129] Figure 28 is a table showing the principal axis sensitivity and the other axis sensitivity based on Figure 27 the changes in the electrostatic capacitance values shown

[0130] Figure 29 is a longitudinal sectional view showing an independent force sensor according to the seventh embodiment

[0131] Figure 30 is Figure 29 a sectional view taken along line A-A of

[0132] Figure 31 is a top view of a force sensor including an independent force sensor shown Figure 29 in

[0133] Figure 32 is a longitudinal sectional view showing Figure 29 a modified example of the independent force sensor shown

[0134] Figure 33 is a longitudinal sectional view showing Figure 29 another modified example of the independent force sensor shown

[0135] Figure 34 is a longitudinal sectional view showing Figure 29 another modified example of the independent force sensor shown

[0136] Figure 35 is a longitudinal sectional view showing Figure 31 a modified example of the force sensor shown

[0137] Figure 36 is Figure 35 a longitudinal sectional view of the second strain body shown DETAILED DESCRIPTION OF THE INVENTION

[0138] Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that in the drawings attached to this specification, for the sake of easy illustration and understanding, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are appropriately changed and exaggerated compared to the actual object

[0139] It should be noted that terms such as "parallel", "orthogonal", "equal", etc. used in this specification for determining shapes, geometric conditions, physical properties, and their degrees, dimensions, values of physical properties, etc. are not bound by strict meanings and should be interpreted as including ranges of degrees expected to achieve the same functions

[0140] (First Embodiment)

[0141] UsingFigures 1 to 4 , the independent force sensor in the first embodiment of the present invention will be described.

[0142] First, for the robot 1 according to this embodiment, reference is made to Figure 1 for description. Figure 1 is a perspective view showing an example of the robot 1 according to this embodiment. An independent force sensor 10 according to this embodiment or a force sensor 110 according to the fourth embodiment or the like is mounted on the robot 1. As an example of the robot 1, various robots such as industrial robots, collaborative robots, life assistance robots, medical robots, and service robots can be cited. Hereinafter, for convenience, an industrial robot equipped with the force sensor 110 will be described as an example.

[0143] As Figure 1 shown, the industrial robot 1 includes: a robot main body 2, a tool 3, a force sensor 110, and a controller 5. The robot main body 2 includes a robotic arm 4. The robotic arm 4 has a multi-joint arm structure.

[0144] A force sensor 110 is mounted at the front end of the robotic arm 4. More specifically, a force sensor 110 is mounted between the robotic arm 4 and the tool 3. The force sensor 110 is electrically connected to the controller 5 via a cable (not shown). As an example of the tool 3, an end effector (gripper) and a tool changer (both not shown) can be cited. When the force sensor 110 is configured as a torque sensor described later, the torque sensor is housed inside the robotic arm and is arranged between a speed reducer (not shown) built in the robotic arm and the front end of the robotic arm.

[0145] The controller 5 performs force control of the robot 1 based on the electrical signal output from the force sensor 110. Thereby, the operations of the robot main body 2 and the tool 3 are controlled.

[0146] The force sensor 110 mounted on the above-mentioned robot 1 can also be replaced with the independent force sensor 10 according to this embodiment according to the application. The independent force sensor 10 according to this embodiment is different from the force sensor 110 according to the fourth embodiment or the like in that it is mainly composed of a single strain body, but like the force sensor 110, it is configured to detect force or torque.

[0147] Hereinafter, reference is made to Figure 2 and Figure 3 to describe the independent force sensor 10 according to this embodiment. Figure 2 is a longitudinal sectional view showing the independent force sensor 10 according to the first embodiment. Figure 3 is a top view showing Figure 2 the independent force sensor 10.

[0148] In the following description, an XYZ three-dimensional coordinate system is defined, and the Z-axis direction is set as the vertical direction. The Z-axis direction is an example of the first direction. The X-axis direction is an example of the second direction, and the Y-axis direction is an example of the third direction. The X-axis direction and the Y-axis direction are orthogonal to each other, the X-axis direction and the Z-axis direction are orthogonal to each other, and the Y-axis direction and the Z-axis direction are orthogonal to each other. In the following description, the independent force sensor 10 will be described in a state where the independent force-receiving body 20 to be described later is arranged on the upper side and the independent fixing body 30 to be described later is arranged on the lower side. Therefore, the independent force sensor 10 according to the present embodiment is not limited to being used in an attitude with the Z-axis direction as the vertical direction. In addition, it is arbitrary which of the independent force-receiving body 20 and the independent fixing body 30 is arranged on the upper side or the lower side. The same applies to the force sensor 110 to be described later.

[0149] The independent force sensor 10 has a function of outputting, as an electric signal, a force acting in a specified axial direction and a torque (twisting moment) acting around a specified rotation axis. However, it is not limited thereto, and it may be configured to output only one of the force and the torque as an electric signal. Furthermore, it may be configured to output at least one axial component of the force or the torque as an electric signal.

[0150] The independent force sensor 10, as shown in Figure 2 and Figure 3 may also include an independent force-receiving body 20, an independent fixing body 30, a first strain body 40, a detection element 60, and a detection circuit 70. Hereinafter, each component will be described in more detail.

[0151] The independent force-receiving body 20 is an example of the first independent sensor body. The independent force-receiving body 20 is subjected to a force or a torque to be detected. By being subjected to this action, the independent force-receiving body 20 is displaced relative to the independent fixing body 30. For example, the independent force-receiving body 20 may be fixed to the tool 3 inserted into a bolt hole (not shown) using a bolt or the like. In this case, the independent force-receiving body 20 may receive a force or a torque from the tool 3. Figure 1 as shown in

[0152] The independent force-receiving body 20 is formed along a plane orthogonal to the Z-axis direction. That is, the independent force-receiving body 20 is formed along each of the X-axis direction and the Y-axis direction. The independent force-receiving body 20 may be formed in a flat plate shape. As shown in Figure 3 , the planar shape of the independent force-receiving body 20 may be rectangular (for example, rectangular or square), or may be circular, and is arbitrary.

[0153] As shown in Figure 2As shown, the independent fixing body 30 is an example of the second independent sensor body and supports the independent force-bearing body 20. The independent fixing body 30 is arranged on the negative side of the independent force-bearing body 20 in the Z-axis direction. The independent force-bearing body 20 and the independent fixing body 30 are arranged at different positions in the Z-axis direction, and the independent fixing body 30 is separated from the independent force-bearing body 20. For example, the independent fixing body 30 can also be fixed to Figure 1 the front end of the robotic arm 4 shown by inserting a bolt into a bolt hole (not shown). In this case, the independent fixing body 30 can also be supported by the robotic arm 4.

[0154] The independent fixing body 30 is formed along a plane orthogonal to the Z-axis direction. That is, the independent fixing body 30 is formed along each of the X-axis direction and the Y-axis direction. The independent fixing body 30 can also be formed in a flat plate shape. As Figure 3 shown, the planar shape of the independent fixing body 30 can be rectangular (for example, a rectangle or a square), or circular, and is arbitrary. When viewed from the Z-axis direction, the independent fixing body 30 can entirely overlap with the independent force-bearing body 20, or can have the same planar shape as the independent force-bearing body 20. More specifically, the independent fixing body 30 can have an X-axis dimension that is the same as the X-axis dimension of the independent force-bearing body 20, or can have a Y-axis dimension that is the same as the Y-axis dimension of the independent force-bearing body 20.

[0155] As Figure 2 and Figure 3 shown, the first strain body 40 connects the independent force-bearing body 20 and the independent fixing body 30. The first strain body 40 is arranged between the independent force-bearing body 20 and the independent fixing body 30. In the present embodiment, the independent force-bearing body 20 and the independent fixing body 30 are connected by one first strain body 40.

[0156] The first strain body 40 will be described in more detail. The first strain body 40 according to the present embodiment is configured to elastically deform and generate strain and displace due to the action of a force or a moment received by the independent force-bearing body 20.

[0157] As Figure 2 shown, the first strain body 40 includes a first connecting body 41 and a displacement body 42.

[0158] The first connecting body 41 extends in the Z-axis direction. The first connecting body 41 includes a force-bearing body side end portion 43 (an example of a first end portion) connected to the independent force-bearing body 20 and a fixing body side end portion 44 (an example of a second end portion) connected to the independent fixing body 30. When viewed from the Y-axis direction, the first connecting body 41 extends from the force-bearing body side end portion 43 to the fixing body side end portion 44 along the Z-axis direction.

[0159] The first connecting body 41 according to the present embodiment may also be elastically deformable by the action of a force in the second direction. More specifically, the first connecting body 41 may be formed in each direction along the Y-axis direction and the Z-axis direction. The first connecting body 41 may be formed in a flat plate shape. As Figure 3 shown, when viewed from the Z-axis direction, the dimension of the first connecting body 41 in the X-axis direction (corresponding to the thickness t1 of the first connecting body 41) is smaller than the dimension of the first connecting body 41 in the Y-axis direction L1. Thus, the spring constant of the first connecting body 41 with respect to the action of the force Fx in the X-axis direction is smaller than the spring constant with respect to the action of the force Fy in the Y-axis direction. Therefore, the first connecting body 41 is easily elastically deformed by the action of the force Fx in the X-axis direction.

[0160] The displacement body 42 protrudes from the first connecting body 41 in the X-axis direction. The first strain body 40 according to the present embodiment includes two displacement bodies 42 protruding in the X-axis direction on both sides of the first connecting body 41. One displacement body 42 protrudes from the first connecting body 41 to the negative side in the X-axis direction, and the other displacement body 42 protrudes from the first connecting body 41 to the positive side in the X-axis direction. The displacement body 42 may also extend from the first connecting body 41 in the X-axis direction. Each displacement body 42 may be configured as a cantilever beam supported by the first connecting body 41.

[0161] Each displacement body 42 may also be formed along a plane orthogonal to the Z-axis direction. That is, each displacement body 42 may be formed in each direction along the X-axis direction and the Y-axis direction. The displacement body 42 may be formed in a flat plate shape. As Figure 3 shown, the planar shape of the displacement body 42 may be rectangular. When viewed from the Z-axis direction, the entire displacement body 42 may overlap with the independent force-receiving body 20, or may overlap with the independent fixing body 30. The displacement body 42 may have a Y-axis dimension that is the same as the Y-axis dimension of the independent force-receiving body 20, or may have a Y-axis dimension that is the same as the Y-axis dimension of the independent fixing body 30.

[0162] As Figure 2 shown, the displacement body 42 is separated from the independent force-receiving body 20 in the Z-axis direction and is also separated from the independent fixing body 30. The displacement body 42 may be disposed at an intermediate position between the force-receiving body side end portion 43 and the fixing body side end portion 44. Alternatively, the displacement body 42 may be disposed at a position closer to the independent force-receiving body 20 than the intermediate position, or may be disposed at a position closer to the independent fixing body 30. The displacement body 42 faces the independent fixing body 30.

[0163] The independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 may also be formed integrally from a continuous material. The independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 may also constitute an independent sensor structure 50. The independent sensor structure 50 may be formed by machining (e.g., cutting) a single block of material, or may also be formed by casting. In this case, the R-shaped portion 50R as described later may be provided at the connection point of the first connecting body 41 between the independent force-receiving body 20 and the first strain body 40, i.e., the force-receiving body side end portion 43. Figure 5 As shown. Similarly, the R-shaped portion 50R may also be provided at the connection point of the first connecting body 41 between the independent fixing body 30 and the first strain body 40, i.e., the fixing body side end portion 44, and the R-shaped portion 50R may also be provided at the connection point of the first connecting body 41 and the displacement body 42. The independent sensor structure 50 may also be made of a metal material such as aluminum alloy or ferroalloy.

[0164] However, the independent force sense sensor 10 according to the present embodiment is not limited thereto. For example, at least two of the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 may be formed integrally, and the other components may be formed as separate bodies. For example, the independent force-receiving body 20 and the first strain body 40 may be formed integrally and fixed to the independently formed independent fixing body 30 by bolts (not shown) or adhesives. For example, the independent fixing body 30 and the first strain body 40 may be formed integrally and fixed to the independently formed independent force-receiving body 20 by bolts or adhesives. Or, the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 may be formed separately and fixed by bolts or adhesives.

[0165] The detection element 60 will be described.

[0166] The detection element 60 is configured to detect the displacement generated by the elastic deformation of the first strain body 40. The detection element 60 according to the present embodiment may also include a capacitance element for detecting electrostatic capacitance. As Figure 2 shown, the capacitance element includes a fixed electrode substrate provided on the independent fixing body 30 and a displacement electrode substrate provided on the displacement body 42. The displacement electrode substrate faces the fixed electrode substrate. In the present embodiment, the detection element 60 includes a first capacitance element C1 and a second capacitance element C2.

[0167] In Figure 2In the example shown, the detection element 60 includes two fixed electrode substrates Ef1 and Ef2, and two displacement electrode substrates Ed1 and Ed2. One displacement electrode substrate Ed1 is disposed on one displacement body 42 of the first strain body 40, and the other displacement electrode substrate Ed2 is disposed on the other displacement body 42. One displacement electrode substrate is disposed on one displacement body 42. Each of the fixed electrode substrates Ef1 and Ef2 is disposed on the independent fixing body 30 at a position opposed to the corresponding displacement electrode substrates Ed1 and Ed2.

[0168] The two fixed electrode substrates Ef1 and Ef2 include a first fixed electrode substrate Ef1 and a second fixed electrode substrate Ef2. The first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 are disposed at different positions in the X-axis direction. In the present embodiment, the first fixed electrode substrate Ef1 is disposed at a position more negative in the X-axis direction than the first connecting body 41, and the second fixed electrode substrate Ef2 is disposed at a position more positive in the X-axis direction than the first connecting body 41.

[0169] In the present embodiment, the fixed electrode substrates Ef1 and Ef2 are disposed on the surface of the independent fixing body 30 on the side of the independent force-receiving body 20. The fixed electrode substrates Ef1 and Ef2 can be joined to the independent fixing body 30 by an adhesive, or can also be fixed by bolts or the like. The fixed electrode substrates Ef1 and Ef2 include: a fixed electrode Ef opposed to the corresponding displacement electrode substrates Ed1 and Ed2, and an insulator IBf interposed between the fixed electrode Ef and the independent fixing body 30. The fixed electrode Ef can also be formed of a conductive material. The insulator IBf can also be formed of an insulating material such as glass epoxy resin or ceramic. Alternatively, the fixed electrode substrates Ef1 and Ef2 can also be constituted by an FPC substrate (flexible printed circuit board). The FPC substrate is a printed substrate formed in a thin film shape and having flexibility, and a metal thin film constituting electrodes and wirings is formed on the upper surface of the polyimide film. The portions of the FPC substrate corresponding to the fixed electrode substrates Ef1 and Ef2 can also be joined to the independent fixing body 30. The FPC substrate can also include a wiring connecting the fixed electrode Ef to the detection circuit 70.

[0170] As Figure 2As shown, the two displacement electrode substrates Ed1 and Ed2 include a first displacement electrode substrate Ed1 and a second displacement electrode substrate Ed2. The first displacement electrode substrate Ed1 and the second displacement electrode substrate Ed2 are arranged at different positions in the X-axis direction. In the present embodiment, the first displacement electrode substrate Ed1 is arranged at a position on the negative side of the X-axis direction with respect to the first connector 41, and a displacement body 42 protruding from the first connector 41 in the negative X-axis direction is arranged. The second displacement electrode substrate Ed2 is arranged at a position on the positive side of the X-axis direction with respect to the first connector 41, and a displacement body 42 protruding from the first connector 41 in the positive X-axis direction is arranged. The first displacement electrode substrate Ed1 may also be arranged at the end on the negative side of the X-axis direction of the displacement body 42. The second displacement electrode substrate Ed2 may also be arranged at the end on the positive side of the X-axis direction of the displacement body 42.

[0171] In the present embodiment, the displacement electrode substrates Ed1 and Ed2 are provided on the surface of the displacement body 42 on the side of the independent fixing body 30. The displacement electrode substrates Ed1 and Ed2 may be joined to the displacement body 42 by an adhesive, or may be fixed by bolts or the like. The displacement electrode substrates Ed1 and Ed2 include: a displacement electrode Ed facing the corresponding fixed electrode substrates Ef1 and Ef2, and an insulator IBd interposed between the displacement electrode Ed and the displacement body 42. The displacement electrode Ed may also be formed of a conductive material. The insulator IBd may also be formed of an insulating material such as glass epoxy resin or ceramic. Alternatively, the displacement electrode substrates Ed1 and Ed2 may be constituted by FPC substrates. The portions of the FPC substrates corresponding to the displacement electrode substrates Ed1 and Ed2 may also be joined to the displacement body 42. The FPC substrates may also include wirings connecting the displacement electrode Ed to the detection circuit 70. Each of the displacement electrode substrates Ed1 and Ed2 may also be bonded to the displacement body 42 by an adhesive.

[0172] The first fixed electrode substrate Ef1 faces the first displacement electrode substrate Ed1. The first capacitor element C1 is constituted by the first fixed electrode substrate Ef1 and the first displacement electrode substrate Ed1. The second fixed electrode substrate Ef2 faces the second displacement electrode substrate Ed2. The second capacitor element C2 is constituted by the second fixed electrode substrate Ef2 and the second displacement electrode substrate Ed2. The first capacitor element C1 and the second capacitor element C2 are configured as a detection element 60 for the first strain body 40.

[0173] As Figure 3As shown, the first capacitive element C1 and the second capacitive element C2 are arranged at the same position in the Y-axis direction. That is, the first displacement electrode substrate Ed1 and the second displacement electrode substrate Ed2 are arranged at the same position in the Y-axis direction, and the first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 are also arranged at the same position in the Y-axis direction. The first capacitive element C1 and the second capacitive element C2 may also be arranged at the same position as the first connecting body 41 in the Y-axis direction.

[0174] In the present embodiment, the planar shapes of the fixed electrode substrates Ef1 and Ef2 are rectangular. The planar shapes of the displacement electrode substrates Ed1 and Ed2 are also rectangular. However, the planar shapes of the fixed electrode substrates Ef1 and Ef2 and the planar shapes of the displacement electrode substrates Ed1 and Ed2 are not limited to rectangular, and may also be other shapes such as circular, polygonal, elliptical, etc.

[0175] As Figure 2 and Figure 3 shown, when viewed from the Z-axis direction, the first fixed electrode substrate Ef1 may also be larger than the first displacement electrode substrate Ed1. For example, the planar shape of the first fixed electrode substrate Ef1 may also be larger than the planar shape of the first displacement electrode substrate Ed1. In addition, it may be that when the first displacement electrode substrate Ed1 is displaced in the X-axis direction, Y-axis direction, or Z-axis direction, when viewed from the Z-axis direction, the first displacement electrode substrate Ed1 as a whole overlaps with the first fixed electrode substrate Ef1. In other words, the sizes of the displacement electrode Ed and the fixed electrode Ef may be set such that even when the first displacement electrode substrate Ed1 is displaced in the X-axis direction, Y-axis direction, or Z-axis direction, the displacement electrode Ed overlaps with the fixed electrode Ef. Thereby, it is possible to prevent the change in the facing area between the displacement electrode Ed and the fixed electrode Ef, and it is possible to prevent the change in the facing area from affecting the change in the electrostatic capacitance value. Therefore, the electrostatic capacitance value can be changed according to the change in the electrode distance (distance in the Z-axis direction) between the displacement electrode Ed and the fixed electrode Ef. Here, the facing area refers to the area where the displacement electrode Ed overlaps with the fixed electrode Ef when viewed from the Z-axis direction. When the displacement body 42 tilts, the displacement electrode Ed smaller than the fixed electrode Ef may tilt to cause a change in the facing area, but the tilt angle of the displacement electrode Ed in this case is small. Therefore, in the change of the electrostatic capacitance value, the electrode distance between the displacement electrode Ed and the fixed electrode Ef becomes dominant. Therefore, in this specification, the change in the facing area caused by the tilt of the displacement electrode Ed is not considered, and it is considered that the change in the electrostatic capacitance value is caused by the change in the electrode distance between the displacement electrode Ed and the fixed electrode Ef. It should be noted that in the following Figure 4In the following, for the sake of clarity of the drawings, the inclination of the displacement body 42 is exaggerated. In addition, it is not limited that the planar shape of the first fixed electrode substrate Ef1 is larger than the planar shape of the first displacement electrode substrate Ed1. It may also be that the planar shape of the first displacement electrode substrate Ed1 is larger than the planar shape of the first fixed electrode substrate Ef1.

[0176] Similarly, it may also be that, when viewed from the Z-axis direction, the planar shape of the second fixed electrode substrate Ef2 is larger than the planar shape of the second displacement electrode substrate Ed2. It should be noted that the planar shape of the second displacement electrode substrate Ed2 may also be larger than the planar shape of the second fixed electrode substrate Ef2.

[0177] The planar shape of the fixed electrode Ef of the fixed electrode substrates Ef1 and Ef2 and the planar shape of the insulator IBf may also be of the same size. However, it is not limited to this. The planar shape of the fixed electrode Ef may also be smaller than the planar shape of the insulator IBf. The same applies to the planar shape of the displacement electrode Ed of the displacement electrode substrates Ed1 and Ed2 and the planar shape of the insulator IBd.

[0178] The first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2, as Figure 2 and Figure 3 shown, may also be formed separately and separated from each other. However, it is not limited to this. It may also be that, when the first displacement electrode substrate Ed1 and the second displacement electrode substrate Ed2 are formed separately, the first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 are integrally formed by a common fixed electrode substrate. By reducing the size of the first connector 41 in the Y-axis direction, the first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 can be connected and integrated. In this case, the insulator IBf and the fixed electrode Ef may also be integrated separately. Or, it may also be that, even when the fixed electrodes Ef are configured to be separated from each other, the insulator IBf is integrated.

[0179] The first displacement electrode substrate Ed1 and the second displacement electrode substrate Ed2, as Figure 2 and Figure 3As shown, they may also be formed separately and separated from each other. However, not limited thereto, when the first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 are formed separately, the first displacement electrode substrate Ed1 and the second displacement electrode substrate Ed2 may be integrally formed by a common displacement electrode substrate. By reducing the size of the first connector 41 in the Y-axis direction, the two displacement bodies 42 can be connected, and thus, the first displacement electrode substrate Ed1 and the second displacement electrode substrate Ed2 can be connected and integrated. In this case, the insulator IBd and the displacement electrode Ed may also be integrated respectively. Alternatively, even when the displacement electrodes Ed are configured to be separated from each other, the insulator IBd may be integrated.

[0180] As Figure 2 shown, the detection circuit 70 according to the present embodiment outputs an electrical signal representing the force or torque applied to the independent force-receiving body 20 based on the detection result of the detection element 60. For example, the detection circuit 70 may have an arithmetic function constituted by a microprocessor. In addition, the detection circuit 70 may have an A / D conversion function for converting the analog signal received from the detection element 60 into a digital signal, a function for amplifying the signal, and various correction functions. The detection circuit 70 may also include a terminal for outputting an electrical signal, and the electrical signal is sent from this terminal to the above-mentioned controller 5 via a cable. The electrical signal sent to the controller 5 may be a digital signal, but may also be an analog signal.

[0181] Next, a method for detecting force or torque in the independent force sensor 10 according to the present embodiment having such a configuration will be described.

[0182] If a force or torque acts on the independent force-receiving body 20, the force or torque is transmitted to the first strain body 40. More specifically, the force or torque is transmitted to the first connector 41, and elastic deformation occurs in the first connector 41. As a result, the displacement body 42 tilts and displaces. Therefore, the inter-electrode distance between each fixed electrode substrate Ef1, Ef2 of the detection element 60 and the corresponding displacement electrode substrate Ed1, Ed2 changes, and the capacitance values of the respective capacitor elements C1, C2 change. The change in the capacitance value is detected by the detection element 60 as the displacement generated in the first strain body 40. In this case, the changes in the capacitance values of the respective capacitor elements C1, C2 may be different. Therefore, the detection circuit 70 can detect the direction and magnitude of the force or torque applied to the independent force-receiving body 20 based on the changes in the capacitance values of the respective capacitor elements C1, C2 detected by the detection element 60.

[0183] Here, first, as an example, use Figure 4Describe the changes in the capacitance values of the first capacitor element C1 and the second capacitor element C2 when the independent force-bearing body 20 is subjected to a force Fx in the X-axis direction. Figure 4 It is a longitudinal sectional view schematically showing the deformation state of the first strain body 40 when the independent force-bearing body 20 is subjected to a force Fx on the positive side in the X-axis direction.

[0184] When the independent force-bearing body 20 is subjected to a force Fx on the positive side in the X-axis direction, as Figure 4 shown, the first connecting body 41 of the first strain body 40 elastically deforms. In this case, the force-bearing body side end portion 43 of the first connecting body 41 is displaced toward the positive side in the X-axis direction, and the first connecting body 41 elastically deforms in a manner of deflecting toward the positive side in the X-axis direction. When observing toward the positive side in the Y-axis direction, the first connecting body 41 elastically deforms in a manner of deflecting in the clockwise direction. In Figure 4 , for the sake of simplifying the drawings, the state where the first connecting body 41 tilts is shown. The displacement body 42 tilts and displaces. As a result, the first displacement electrode substrate Ed1 rises and moves away from the first fixed electrode substrate Ef1. The electrode distance between the first displacement electrode substrate Ed1 and the first fixed electrode substrate Ef1 increases, and the capacitance value of the first capacitor element C1 decreases. On the other hand, the second displacement electrode substrate Ed2 descends and approaches the second fixed electrode substrate Ef2. The electrode distance between the second displacement electrode substrate Ed2 and the second fixed electrode substrate Ef2 decreases, and the capacitance value of the second capacitor element C2 increases.

[0185] The force Fx applied to the independent force-bearing body 20 can also be calculated as Fx1 by the following formula. It should be noted that in the following formula, for convenience, the force or moment and the change amount of the capacitance value are connected by "=". However, the force or moment and the capacitance value are different physical quantities, so actually Fx1 is calculated by converting the change amount of the capacitance value. C1 and C2 in the following formula represent the change amounts of the capacitance values in the respective capacitor elements C1 and C2.

[0186] [Equation 1]

[0187] Fx1 = -C1 + C2

[0188] Although not shown in Figures 2 to 4 , according to the detection element 60 of the present embodiment, it may also further include a third capacitor element C3 and a fourth capacitor element C4 (refer to Figure 6 and Figure 7). For example, the first capacitor element C1 and the third capacitor element C3 may also be arranged at the same position in the X-axis direction. The second capacitor element C2 and the fourth capacitor element C4 may also be arranged at the same position in the X-axis direction. The third capacitor element C3 and the fourth capacitor element C4 may also be arranged at the same position in the Y-axis direction. The third capacitor element C3 may also be arranged at a position more on the positive side of the Y-axis direction than the first capacitor element C1, and the fourth capacitor element C4 may also be arranged at a position more on the positive side of the Y-axis direction than the second capacitor element C2. In this case, the force Fx can also be calculated as Fx2 by the following formula.

[0189] [Formula 2]

[0190] Fx2 = -C3 + C4

[0191] Alternatively, the first capacitor element C1 to the fourth capacitor element C4 can also be used to calculate the force Fx as Fx3 (= Fx1 + Fx2) by the following formula.

[0192] [Formula 3]

[0193] Fx3 = -C1 + C2 - C3 + C4

[0194] Fault diagnosis can also be performed by comparing Fx1 of the above [Formula 1] with Fx2 of [Formula 2]. Alternatively, fault diagnosis can also be performed by comparing Fx3 of [Formula 3] with the sum of Fx1 and Fx2. Alternatively, fault diagnosis can also be performed by multiplying Fx1 of [Formula 1] by a specified magnification and then comparing it with Fx3 of [Formula 3]. Alternatively, fault diagnosis can also be performed by multiplying Fx2 of [Formula 2] by a specified magnification and then comparing it with Fx3 of [Formula 3]. Fault diagnosis can be performed by the above detection circuit 70, or can also be performed by the controller 5 of the robot 1.

[0195] When the independent force-receiving body 20 is subjected to a moment My about the Y-axis, the first connecting body 41 also Figure 4 elastically deforms in the same way. The electrostatic capacitance value of the first capacitor element C1 decreases, and the electrostatic capacitance value of the second capacitor element C2 increases. Therefore, in the same way as the above [Formula 1], the moment My is calculated by the following [Formula 4].

[0196] [Formula 4]

[0197] My = -C1 + C2

[0198] When the independent force-receiving body 20 is subjected to a force Fy in the Y-axis direction, the changes in the electrostatic capacitance values of the respective capacitor elements C1 and C2 can be regarded as negligible. As described above, the dimension L1 of the first connecting body 41 in the Y-axis direction is larger than the thickness t1. Therefore, the spring constant of the first connecting body 41 with respect to the force Fy in the Y-axis direction is large, and it substantially functions as a rigid body. Thus, it can be regarded that the first connecting body 41 does not elastically deform in the Y-axis direction. Similarly, when a moment Mx about the X-axis acts on the first strain body 40, the changes in the electrostatic capacitance values of the respective capacitor elements C1 and C2 can be regarded as negligible.

[0199] When the independent force-receiving body 20 is subjected to a force Fz in the Z-axis direction, the changes in the electrostatic capacitance values of the respective capacitor elements C1 and C2 can be regarded as negligible. As described above, the first connecting body 41 extends from the force-receiving body side end portion 43 connected to the independent force-receiving body 20 to the fixed body side end portion 44 in the Z-axis direction. Therefore, the spring constant of the first connecting body 41 with respect to the force Fz in the Z-axis direction is large, and it substantially functions as a rigid body. Thus, it can be regarded that the first connecting body 41 does not elastically deform in the Z-axis direction.

[0200] In this way, the independent force sensor 10 in which the independent force-receiving body 20 and the independent fixing body 30 are connected by a first strain body 40 can detect the force Fx and the moment My. This independent force sensor 10 can be used in an environment where only one of the force Fx and the moment My acts, or can be used as a sensor for detecting one-axis component.

[0201] In this way, according to the present embodiment, the first strain body 40 connecting the independent force-receiving body 20 and the independent fixing body 30 includes a first connecting body 41. The first connecting body 41 extends from the force-receiving body side end portion 43 connected to the independent force-receiving body 20 to the fixed body side end portion 44 connected to the independent fixing body 30 in the Z-axis direction. Thereby, the shape of the first strain body 40 can be made pure, and the structure of the first strain body 40 can be simplified. In addition, the interval between the independent force-receiving body 20 and the independent fixing body 30 can be reduced. As a result, the cost reduction of the independent force sensor 10 can be achieved, and the height of the independent force sensor 10 ( Figure 2 the Z-axis direction dimension h0 shown) can be reduced.

[0202] In addition, according to the present embodiment, the first strain body 40 includes a displacement body 42 protruding from the first connecting body 41 in the X-axis direction orthogonal to the Z-axis direction, and displacement electrode substrates Ed1 and Ed2 opposed to the fixed electrode substrates Ef1 and Ef2 are provided on the displacement body 42. Thereby, while preventing the shape or the structure of the first strain body 40 from being complicated, the displacement body 42 can be displaced by the elastic deformation of the first connecting body 41.

[0203] In addition, according to the present embodiment, the first connecting body 41 is formed along each of the Y-axis direction and the Z-axis direction. Thereby, the shape of the first connecting body 41 can be made pure. In addition, the interval between the independent force-receiving body 20 and the independent fixing body 30 can be reduced.

[0204] In addition, according to the present embodiment, when viewed from the Z-axis direction, the dimension of the first connecting body 41 in the X-axis direction is smaller than the dimension in the Y-axis direction. Thereby, the spring constant of the force Fx acting on the first connecting body 41 in the X-axis direction can be made smaller than the spring constant of the action with respect to the force Fy in the Y-axis direction. Therefore, it can be more easily elastically deformed by the action of the force Fx, and the detection sensitivity of the force Fx can be improved.

[0205] In addition, according to the present embodiment, the independent force-receiving body 20, the independent fixing body 30, and the displacement body 42 are formed along each of the X-axis direction and the Y-axis direction. Thereby, the shapes of the independent force-receiving body 20, the independent fixing body 30, and the displacement body 42 can be made pure, and the structure of the first strain body 40 can be simplified. In addition, the interval between the independent force-receiving body 20 and the independent fixing body 30 can be reduced. As a result, the independent force sensor 10 can be made inexpensive, and the height of the independent force sensor 10 can be reduced.

[0206] In addition, according to the present embodiment, displacement electrode substrates Ed1 and Ed2 are provided on the displacement bodies 42 protruding from both sides of the first connecting body 41. Thereby, when the independent force-receiving body 20 receives the force Fx in the X-axis direction, one of the displacement electrode substrates Ed1 and Ed2 can be moved away from the corresponding fixed electrode substrate Ef1 and Ef2, and the other displacement electrode substrate Ed1 and Ed2 can be moved closer to the corresponding fixed electrode substrate Ef1 and Ef2. Therefore, the detection sensitivity of the force Fx can be improved.

[0207] In addition, according to the present embodiment, the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 are integrally formed of a continuous material. Thereby, the structure of the independent force sensor 10 can be simplified. For example, when the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 are formed separately and fixed by bolts or adhesives, etc., the structure becomes complicated in order to enable such fixing, and a space for optimizing workability is required. Therefore, the cost reduction of the independent force sensor 10 may be limited, and the reduction of the height of the independent force sensor 10 may be limited. In contrast, according to the present embodiment, since the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 are integrally formed of a continuous material, the structure can be further simplified. In addition, the interval between the independent force-receiving body 20 and the independent fixing body 30 can be further reduced. As a result, the independent force sensor 10 can be further made inexpensive, and the height of the independent force sensor 10 can be further reduced.

[0208] (Second Embodiment)

[0209] Next, use Figures 5 to 7 to describe the independent force sensor according to the second embodiment of the present invention.

[0210] In Figures 5 to 7 the second embodiment shown, it is mainly different in that the independent fixing body and the displacement body protrude more in the Y-axis direction than the independent force-receiving body, and other configurations are substantially the same as those in Figures 1 to 4 the first embodiment shown. It should be noted that in Figures 5 to 7 , the same reference numerals are given to the parts that are the same as those in Figures 1 to 4 the first embodiment shown, and detailed descriptions thereof are omitted. Figure 5 is a perspective view showing the independent force sensor according to the second embodiment. Figure 6 is a side view showing the Figure 5 independent force sensor shown, Figure 7 is a top view showing the Figure 5 independent force sensor shown.

[0211] As Figures 5 to 7 shown, in the present embodiment, the independent fixing body 30 and the displacement body 42 may also protrude more in the Y-axis direction than the independent force-receiving body 20. The displacement body 42 may also protrude more in the Y-axis direction than the first connecting body 41. As Figure 7 shown, the portion of the displacement body 42 that is closer to the positive side in the Y-axis direction than the first connecting body 41 ( Figure 7 the upper portion of

[0212] As Figure 5 and Figure 6 shown, in the present embodiment, the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 may also be constituted by the above-described independent sensor structure body 50. In this case, as Figure 5As shown, an R-shaped portion 50R may also be provided at the connection point of the independent force-receiving body 20 and the first connecting body 41 of the first strain body 40, i.e., the force-receiving body side end portion 43. Similarly, an R-shaped portion 50R may also be provided at the connection point of the independent fixing body 30 and the first connecting body 41 of the first strain body 40, i.e., the fixing body side end portion 44. An R-shaped portion 50R may also be provided at the connection point of the first connecting body 41 and the displacement body 42.

[0213] As Figure 6 well as Figure 7 shown, the detection element 60 may also further include a third capacitor element C3 and a fourth capacitor element C4. For example, the third capacitor element C3 includes a third fixed electrode substrate Ef3 and a third displacement electrode substrate Ed3. The fourth capacitor element C4 includes a fourth fixed electrode substrate Ef4 and a fourth displacement electrode substrate Ed4.

[0214] The first capacitor element C1 and the third capacitor element C3 are arranged at the same position in the X-axis direction. The second capacitor element C2 and the fourth capacitor element C4 are arranged at the same position in the X-axis direction. The first capacitor element C1 and the second capacitor element C2 are arranged at the same position in the Y-axis direction. The third capacitor element C3 and the fourth capacitor element C4 are arranged at the same position in the Y-axis direction. The third capacitor element C3 may also be arranged at a position more on the positive side of the Y-axis direction than the first capacitor element C1, and the fourth capacitor element C4 may also be arranged at a position more on the positive side of the Y-axis direction than the second capacitor element C2.

[0215] Thus, according to the present embodiment, the independent fixing body 30 and the displacement body 42 protrude more in the Y-axis direction than the independent force-receiving body 20. As a result, the planar area of the independent fixing body 30 and the planar area of the displacement body 42 can be increased. Therefore, not only can the first capacitor element C1 and the second capacitor element C2 be easily arranged, but also the third capacitor element C3 and the fourth capacitor element C4 can be easily arranged. That is, the number of capacitor elements constituting the detection element 60 can be increased. In addition, the electrodes of each capacitor element can be enlarged, and the detection sensitivity can be improved.

[0216] It should be noted that in the above-described embodiment, an example in which the detection element 60 includes the first capacitor element C1, the second capacitor element C2, the third capacitor element C3, and the fourth capacitor element C4 has been described. However, the present embodiment is not limited thereto. For example, the detection element 60 may not include the third capacitor element C3 and the fourth capacitor element C4. Alternatively, the detection element 60 may not include the first capacitor element C1 and the second capacitor element C2. Or, it may be that the first capacitor element C1 and the third capacitor element C3 are integrated, and the second capacitor element C2 and the fourth capacitor element C4 are integrated. For example, it may be that by connecting the fixed electrodes Ef of the first capacitor element C1 and the third capacitor element C3 in parallel, and connecting the displacement electrodes Ed of the first capacitor element C1 and the third capacitor element C3 in parallel, the first capacitor element C1 and the third capacitor element C3 are integrated. Similarly, it may be that by connecting the fixed electrodes Ef of the second capacitor element C2 and the fourth capacitor element C4 in parallel, and connecting the displacement electrodes Ed of the second capacitor element C2 and the fourth capacitor element C4 in parallel, the second capacitor element C2 and the fourth capacitor element C4 are integrated. When the first capacitor element C1 and the third capacitor element C3 are integrated, the capacitance value of the first capacitor element C1 and the capacitance value of the third capacitor element C3 are added together, which can improve the sensitivity. By integrating the second capacitor element C2 and the fourth capacitor element C4, the capacitance value of the second capacitor element C2 and the capacitance value of the fourth capacitor element C4 are added together, which can improve the sensitivity.

[0217] (Third Embodiment)

[0218] Next, use Figures 8 to 13 , to describe the independent force sensor according to the third embodiment of the present invention.

[0219] In Figures 8 to 13 shown in the third embodiment, it is mainly different in that the first strain body includes a first thinning portion connecting the independent force receiving body and the first connecting body and a second thinning portion connecting the independent fixing body and the first connecting body, and other configurations are substantially the same as those in Figures 1 to 4 shown in the first embodiment. It should be noted that in Figures 8 to 13 , the same reference numerals are assigned to the parts that are the same as those in Figures 1 to 4 shown in the first embodiment, and detailed descriptions thereof are omitted.

[0220] First, use Figure 8 , Figure 9A and Figure 9B , to describe the independent force sensor 10 according to the present embodiment. Figure 8 is a longitudinal sectional view showing the independent force sensor 10 according to the third embodiment.Figure 9A is a top view showing Figure 8 the independent force-bearing body 20 shown in the figure, Figure 9B is a bottom view showing Figure 8 the independent fixed body 30 shown in the figure.

[0221] As Figure 8 shown, the first strain body 40 according to the present embodiment includes a first force-bearing thinning portion 45. The first force-bearing thinning portion 45 is an example of the first thinning portion. The first force-bearing thinning portion 45 is formed along a plane orthogonal to the Z-axis direction. That is, the first force-bearing thinning portion 45 is formed along each of the X-axis direction and the Y-axis direction.

[0222] The independent force-bearing body 20 includes an independent force-bearing main body portion 21. The independent force-bearing main body portion 21 is formed around the first force-bearing thinning portion 45.

[0223] The first force-bearing thinning portion 45 is interposed between the independent force-bearing body 20 and the first connecting body 41, and connects the independent force-bearing main body portion 21 and the force-bearing body side end portion 43 of the first connecting body 41. The first force-bearing thinning portion 45 is thinner than the independent force-bearing main body portion 21 of the independent force-bearing body 20. More specifically, the thickness t2 (Z-axis direction dimension) of the first force-bearing thinning portion 45 is thinner than the thickness t3 of the independent force-bearing main body portion 21. The first force-bearing thinning portion 45 has flexibility and can be elastically deformed by the action of force or torque.

[0224] Although the planar shape of the first force-bearing thinning portion 45 is not particularly limited, as Figure 9A shown, it may also be circular. It may also be that by forming the first force-bearing thinning portion 45, an independent force-bearing recess 22 is formed on the surface ( Figure 8 the upper surface in the figure) of the independent force-bearing body 20 on the side opposite to the independent fixed body 30.

[0225] The first connecting body 41 according to the present embodiment may also be formed in a circular shape when viewed from the Z-axis direction. The first connecting body 41 may also be formed in a cylindrical shape extending in the Z-axis direction. When viewed from the Z-axis direction, the first connecting body 41 may be arranged concentrically with the first force-bearing thinning portion 45, or may be arranged concentrically with the first fixed thinning portion 46 described later.

[0226] As Figure 8 shown, the first strain body 40 according to the present embodiment includes a first fixed thinning portion 46. The first fixed thinning portion 46 is an example of the second thinning portion. The first fixed thinning portion 46 is formed along a plane orthogonal to the Z-axis direction. That is, the first fixed thinning portion 46 is formed along each of the X-axis direction and the Y-axis direction.

[0227] The independent fixing body 30 includes an independent fixing main body portion 31. The independent fixing main body portion 31 is formed around the first fixing thinning portion 46. The above-mentioned fixing electrode substrates Ef1 and Ef2 can also be fixed to the independent fixing main body portion 31.

[0228] The first fixing thinning portion 46 is interposed between the independent fixing body 30 and the first connecting body 41, and connects the independent fixing main body portion 31 and the fixing body side end portion 44 of the first connecting body 41. The first fixing thinning portion 46 is thinner than the independent fixing main body portion 31 of the independent fixing body 30. More specifically, the thickness t4 (Z-axis direction dimension) of the first fixing thinning portion 46 is thinner than the thickness t5 of the independent fixing main body portion 31. The first fixing thinning portion 46 has flexibility and can be elastically deformed by the action of force or torque.

[0229] Although the planar shape of the first fixing thinning portion 46 is not particularly limited, as Figure 9B shown, it can also be circular like the first force-receiving thinning portion 45. By forming the first fixing thinning portion 46, an independent fixing recess 32 can be formed on the surface of the independent fixing body 30 on the side opposite to the independent force-receiving body 20 ( Figure 8 the lower surface in ).

[0230] In the present embodiment, the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 can also be integrally formed of a continuous material. The independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 can also constitute an independent sensor structure 50.

[0231] However, the independent force sense sensor 10 according to the present embodiment is not limited to this. For example, at least two of the independent force-receiving body 20, the independent fixing body 30, and the first strain body 40 can be integrally formed, and the other components can be formed as separate bodies.

[0232] For example, the independent force-receiving main body portion 21 and the first force-receiving thinning portion 45 can be integrally formed, and the first force-receiving thinning portion 45 and the first connecting body 41 can be formed separately. In this case, a bolt hole for inserting a bolt (not shown) for fixing the first force-receiving thinning portion 45 and the first connecting body 41 can also be formed in the first force-receiving thinning portion 45. Thereby, the bolt head can be accommodated in the independent force-receiving recess 22. Therefore, it is possible to prevent the bolt head from protruding from the independent force-receiving body 20, and the height of the independent force sense sensor 10 can be reduced.

[0233] For example, it is also possible that the independent fixing main body portion 31 and the first fixing thinning portion 46 are formed integrally, and the first fixing thinning portion 46 and the first connecting body 41 are formed separately. In this case, a bolt hole for inserting a bolt for fixing the first fixing thinning portion 46 and the first connecting body 41 may be formed in the first fixing thinning portion 46. Thereby, the bolt head of the bolt can be accommodated in the independent fixing recess 32. Therefore, it is possible to prevent the bolt head from protruding from the independent fixing body 30, and the height of the independent force sensor 10 can be reduced.

[0234] For example, it is also possible that, when the independent force-bearing main body portion 21 and the first force-bearing thinning portion 45 are formed integrally and the first force-bearing thinning portion 45 and the first connecting body 41 are formed separately, the independent fixing main body portion 31 and the first fixing thinning portion 46 are formed integrally, and the first fixing thinning portion 46 and the first connecting body 41 are formed separately. The first force-bearing thinning portion 45 and the first connecting body 41 may be fixed with a bolt as described above. The first fixing thinning portion 46 and the first connecting body 41 may be fixed with a bolt as described above.

[0235] Next, a method for detecting a force or a torque in the independent force sensor 10 according to the present embodiment having such a configuration will be described.

[0236] Use Figure 10 A case where the independent force-bearing body 20 according to the present embodiment is subjected to a force Fx in the X-axis direction will be described. Figure 10 FIG. is a longitudinal sectional view schematically showing a deformed state of the first strain body 40 when the independent force-bearing body 20 is subjected to a force Fx on the positive side in the X-axis direction.

[0237] As Figure 10 shown, it is also possible that, when the independent force-bearing body 20 is subjected to the force Fx, the first connecting body 41 elastically deforms. The first connecting body 41 may elastically deform in the same manner as the first connecting body 41 shown in Figure 4 FIG. In the present embodiment, by interposing the first force-bearing thinning portion 45 between the independent force-bearing main body portion 21 of the independent force-bearing body 20 and the first connecting body 41, the first force-bearing thinning portion 45 also elastically deforms. Similarly, by interposing the first fixing thinning portion 46 between the independent fixing main body portion 31 of the independent fixing body 30 and the first connecting body 41, the first fixing thinning portion 46 also elastically deforms. It should be noted that if the first force-bearing thinning portion 45 and the first fixing thinning portion 46 elastically deform, the first connecting body 41 may not substantially elastically deform.

[0238] When the independent force-bearing body 20 is subjected to the force Fx, the capacitance value of the first capacitor element C1 decreases, and the capacitance value of the second capacitor element C2 increases. In this case, the force Fx is calculated by the above [Equation 1].

[0239] When the independent force-receiving body 20 according to the present embodiment is subjected to a moment My about the Y-axis, similar to the Figure 4 independent force sensor 10 shown, the electrostatic capacitance value of the first capacitor element C1 decreases, and the electrostatic capacitance value of the second capacitor element C2 increases. In this case, the moment My is represented by the above [Equation 4].

[0240] When the independent force-receiving body 20 is subjected to a force Fy in the Y-axis direction, the change in the electrostatic capacitance value in each of the capacitor elements C1 and C2 can be regarded as negligible. This is because the first capacitor element C1 and the second capacitor element C2 are arranged at the same position as the first connecting body 41 in the Y-axis direction. Similarly, when the independent force-receiving body 20 is subjected to a moment Mx about the X-axis, the change in the electrostatic capacitance value in each of the capacitor elements C1 and C2 can be regarded as negligible.

[0241] Next, use Figure 11 and Figure 12 to illustrate the case where the independent force-receiving body 20 is subjected to a force Fz on the positive side in the Z-axis direction. Figure 11 is a longitudinal sectional view schematically showing the deformation state of the first strain body 40 when the independent force-receiving body 20 of the independent force sensor 10 is subjected to a force Fz on the positive side in the Z-axis direction. Figure 12 is a longitudinal sectional view schematically showing the deformation state of the first strain body 40 when the independent force-receiving body 20 of the independent force sensor 10 is subjected to a force Fz on the negative side in the Z-axis direction.

[0242] As Figure 11 shown, when the independent force-receiving body 20 is subjected to a force Fz on the positive side in the Z-axis direction, the first force-reducing portion 45 and the first fixed-reducing portion 46 elastically deform. The independent force-receiving body 20 is displaced toward the positive side in the Z-axis direction, and the first connecting body 41 and the displacement body 42 are displaced toward the positive side in the Z-axis direction. The first connecting body 41 does not substantially elastically deform in the Z-axis direction. As a result, the first displacement electrode substrate Ed1 rises and moves away from the first fixed electrode substrate Ef1. The electrode distance between the first displacement electrode substrate Ed1 and the first fixed electrode substrate Ef1 increases, and the electrostatic capacitance value of the first capacitor element C1 decreases. Similarly, the second displacement electrode substrate Ed2 also rises and moves away from the second fixed electrode substrate Ef2. The electrode distance between the second displacement electrode substrate Ed2 and the second fixed electrode substrate Ef2 increases, and the electrostatic capacitance value of the second capacitor element C2 decreases.

[0243] The force Fz received by the independent force-receiving body 20 can also be calculated by the following formula.

[0244] [Equation 5]

[0245] Fz = -C1 - C2

[0246] As Figure 12As shown, when the independent force-receiving body 20 is subjected to a force Fz in the negative Z-axis direction, the first force-receiving thinning portion 45 and the first fixed thinning portion 46 elastically deform. The independent force-receiving body 20 is displaced in the negative Z-axis direction, and the first connecting body 41 and the displacement body 42 are displaced in the negative Z-axis direction. The first connecting body 41 does not substantially elastically deform in the Z-axis direction. As a result, the first displacement electrode substrate Ed1 descends and approaches the first fixed electrode substrate Ef1. The electrode distance between the first displacement electrode substrate Ed1 and the first fixed electrode substrate Ef1 decreases, and the capacitance value of the first capacitance element C1 increases. Similarly, the second displacement electrode substrate Ed2 also descends and approaches the second fixed electrode substrate Ef2. The electrode distance between the second displacement electrode substrate Ed2 and the second fixed electrode substrate Ef2 decreases, and the capacitance value of the second capacitance element C2 increases.

[0247] Thus, the independent force sensor 10 according to the present embodiment can detect the force Fx, the force Fz, and the torque My. The independent force sensor 10 can be used in an environment where only either the force Fx or the torque My acts together with the force Fz, or can be used as a sensor for detecting two-axis components.

[0248] Thus, according to the present embodiment, the first strain body 40 includes the first force-receiving thinning portion 45, and the first force-receiving thinning portion 45 connects the independent force-receiving body 20 and the force-receiving body side end portion 43 of the first connecting body 41. The first force-receiving thinning portion 45 is thinner than the independent force-receiving body 20. Thus, the first force-receiving thinning portion 45 can elastically deform due to the action of a force or a torque. For example, when the independent force-receiving body 20 is subjected to a force Fz in the Z-axis direction, the independent force-receiving body 20 can be displaced in the Z-axis direction. Therefore, the displacement body 42 of the first strain body 40 can be displaced, and the capacitance values of the capacitance elements C1 and C2 can be changed. As a result, while achieving the simplicity of the shape and structure of the first strain body 40, the number of detectable axis components can be increased, and the versatility can be improved.

[0249] In addition, according to the present embodiment, the first strain body 40 includes the first fixed thinning portion 46, and the first fixed thinning portion 46 connects the independent fixing body 30 and the fixing body side end portion 44 of the first connecting body 41. The first fixed thinning portion 46 is thinner than the independent fixing body 30. Thus, the first fixed thinning portion 46 can elastically deform due to the action of a force or a torque. For example, when the independent force-receiving body 20 is subjected to a force Fz in the Z-axis direction, the independent force-receiving body 20 can be displaced in the Z-axis direction. Therefore, the displacement body 42 of the first strain body 40 can be displaced, and the capacitance values of the capacitance elements C1 and C2 can be changed. As a result, while achieving the simplicity of the shape and structure of the first strain body 40, the number of detectable axis components can be increased, and the versatility can be improved.

[0250] It should be noted that, in the above-described embodiment, an example in which the first strain body 40 includes the first force-receiving thinning portion 45 and the first fixed thinning portion 46 has been described. However, the present embodiment is not limited thereto. For example, if the first strain body 40 includes the first fixed thinning portion 46, it may not include the first force-receiving thinning portion 45. In this case, the first force-receiving thinning portion 45 may not be formed, and similar to the force-receiving body side end portion 43 shown in Figure 2 , the first connecting body 41 is directly connected to the independent force-receiving main body portion 21 of the independent force-receiving body 20.

[0251] In addition, in the above-described embodiment, an example in which the detection element 60 includes the first capacitor element C1 and the second capacitor element C2 has been described. However, the present embodiment is not limited thereto. For example, the detection element 60 may also further include a third capacitor element C3 and a fourth capacitor element C4 (refer to Figure 6 and Figure 7 ). In this case, as described above, the detection circuit 70 or the controller 5 may also perform a fault diagnosis.

[0252] In addition, in the above-described embodiment, an example in which the planar shape of the first force-receiving thinning portion 45 is circular and the independent force-receiving main body portion 21 of the independent force-receiving body 20 is formed around the first force-receiving thinning portion 45 has been described. However, the present embodiment is not limited thereto. For example, as shown in Figure 13 , the planar shape of the first force-receiving thinning portion 45 may also be rectangular. In this case, similar to the first connecting body 41 shown in Figure 3 , the first connecting body 41 is formed in a flat plate shape, and the dimension of the first connecting body 41 in the X-axis direction is smaller than the dimension of the first connecting body 41 in the Y-axis direction. The independent force-receiving main body portion 21 may also be formed on both sides in the X-axis direction of the first force-receiving thinning portion 45. It may also be that the independent force-receiving main body portion 21 further extends on both sides in the Y-axis direction of the first force-receiving thinning portion 45, and the independent force-receiving main body portion 21 is formed around the first force-receiving thinning portion 45. The same applies to the first fixed thinning portion 46.

[0253] In addition, in the above-described embodiment, a plurality of through-holes (not shown) may be provided in the first force-reducing and thinning portion 45. In this case, the flexibility of the first force-reducing and thinning portion 45 can be increased. Alternatively, when the first force-reducing and thinning portion 45 includes a through-hole, the thickness t2 of the first force-reducing and thinning portion 45 can be increased. When the independent sensor structure 50 is manufactured by casting, by increasing the thickness of the first force-reducing and thinning portion 45, the flow of the molten metal can be ensured in the portion corresponding to the first force-reducing and thinning portion 45 in the mold. As the planar shape of the through-hole, any shape such as a circle, a semi-circle, an ellipse, a sector, a triangle, and a rectangle can be adopted as long as the first force-reducing and thinning portion 45 can have flexibility. The same applies to the first fixed and thinned portion 46.

[0254] (Fourth Embodiment)

[0255] Next, Figures 14 to 18 will be used to describe the force sensor according to the fourth embodiment of the present invention.

[0256] In Figures 14 to 18 shown in the fourth embodiment, it is mainly different in that the force sensor is constituted by a plurality of independent force sensors, and other configurations are substantially the same as those in Figures 5 to 7 shown in the second embodiment. It should be noted that in Figures 14 to 18 , the same reference numerals are given to the parts that are the same as those in Figures 5 to 7 shown in the second embodiment, and the detailed description thereof is omitted. Figure 14 is a longitudinal sectional view showing the force sensor according to the fourth embodiment. Figure 15 is Figure 14 's P-direction view, Figure 16 is Figure 14 's Q-direction view. Figure 17 is Figure 15 and Figure 16 shown longitudinal sectional view of the second connecting body, Figure 18 is a longitudinal sectional view showing an enlarged view of the independent force sensor shown in Figure 14 .

[0257] In Figures 14 to 16 the force sensor 110 according to the present embodiment is shown. The force sensor 110 according to the present embodiment is constituted by a plurality of independent force sensors 10 and includes a plurality of first strain bodies 40. More specifically, the force sensor 110 includes: a force-receiving body 120, a plurality of independent force sensors 10, a fixing body 130, a plurality of second strain bodies 140, and a detection circuit 170. The independent force sensor 10 according to the present embodiment may also be briefly described in Figures 5 to 7The independent force sensor 10 shown is configured in the same way. The detection element 60 of each independent force sensor 10 may also include four capacitive elements. The number of independent force sensors 10 that make up the force sensor 110 according to the present embodiment is two, but may also be three or more, and is arbitrary. In the present embodiment, when viewed from the Z-axis direction, the two independent force sensors 10 are arranged with a pitch of 180° with respect to the center point O of the force-receiving body 120 described later. In other words, the plurality of independent force sensors 10 may also be arranged at equal intervals with respect to the center point O of the force-receiving body 120. When viewed from the Z-axis direction, the first connecting body 41 of each independent force sensor 10 is formed along the radial direction with respect to the center point O of the force-receiving body 120. In the present embodiment, the first connecting body 41 is arranged along the Y-axis direction. When viewed from the Z-axis direction, the outer edges of the independent force-receiving body 20, the independent fixing body 30, and the displacement body 42 on the positive side or the negative side in the Y-axis direction may also be formed in an arc shape so as to be continuous with the outer edges of the force-receiving body 120 and the fixing body 130, respectively.

[0258] The force-receiving body 120 is an example of a first sensor body. The force-receiving body 120 is subjected to a force or torque that is the object to be detected. As Figure 14 and Figure 15 shown, the force-receiving body 120 is configured to support the independent force-receiving bodies 20 of the respective independent force sensors 10. Each independent force sensor 10 is detachably mounted on the force-receiving body 120. The independent force sensors 10 are arranged on the outer edge 120c described later of the force-receiving body 120. The force-receiving body 120 is formed along a plane orthogonal to the Z-axis direction. That is, the force-receiving body 120 is formed along each of the X-axis direction and the Y-axis direction. The force-receiving body 120 may also be formed substantially in a flat plate shape. The force-receiving body 120 may also be fixed to the Figure 1 tool 3 shown using a bolt or the like inserted into the bolt hole 126. In this case, the force-receiving body 120 may also receive a force or torque from the tool 3. As Figure 15 shown, the force-receiving body 120 may also include a force-receiving body center opening 120a. In this case, the planar shape of the force-receiving body 120 may also be substantially in an annular shape.

[0259] The fixing body 130 is an example of a second sensor body. As Figure 14 and Figure 16As shown, the fixing body 130 is configured to support the independent fixing bodies 30 of the respective independent force sensors 10. Each independent force sensor 10 is detachably attached to the fixing body 130. The independent force sensors 10 are arranged at the outer edge 130c of the fixing body 130 described later. The fixing body 130 is formed along a plane orthogonal to the Z-axis direction. That is, the fixing body 130 is formed along each direction of the X-axis direction and the Y-axis direction. The fixing body 130 may be substantially formed in a flat plate shape. The fixing body 130 may also be fixed to Figure 1 the front end of the robotic arm 4 shown by using a bolt or the like inserted into the bolt hole 136. In this case, the fixing body 130 may also be supported by the robotic arm 4. As Figure 16 shown, the fixing body 130 may also include a fixing body central opening 130a similar to the force receiving body central opening 120a described above. In this case, the planar shape of the fixing body 130 may also be substantially in an annular shape. When viewed from the Z-axis direction, the fixing body central opening 130a may overlap with the force receiving body central opening 120a. The fixing body 130 and the force receiving body 120 may be arranged concentrically.

[0260] As Figure 15 and Figure 16 shown, at least one of the planar shape of the force receiving body 120 and the planar shape of the fixing body 130 may be a planar shape other than an annular shape. In this case, it may be that one of the planar shape of the force receiving body 120 and the planar shape of the fixing body 130 is circular and the other is a shape other than circular. For example, the planar shape of the force receiving body 120 may be a circular shape that does not include the force receiving body central opening 120a. Alternatively, the planar shape of the force receiving body 120 may be a rectangular shape (for example, a rectangle or a square). The same applies to the planar shape of the fixing body 130.

[0261] As Figures 14 to 17 shown, the second strain body 140 connects the force receiving body 120 and the fixing body 130. The second strain body 140 is arranged between the force receiving body 120 and the fixing body 130. In the present embodiment, the force receiving body 120 and the fixing body 130 are connected by four second strain bodies 140.

[0262] The second strain body 140 will be described in more detail. The second strain body 140 according to the present embodiment is configured to elastically deform due to the action of a force or a moment received by the force receiving body 120, generate a strain, and displace.

[0263] The second strain body 140 includes a second connecting body 141.

[0264] As Figure 14As shown, the second connector 141 connects the force-receiving body 120 and the fixed body 130. The second connector 141 is disposed between the force-receiving body 120 and the fixed body 130. In the present embodiment, the force-receiving body 120 and the fixed body 130 are connected by a plurality of second connectors 141. In the present embodiment, the force-receiving body 120 and the fixed body 130 are connected by four second connectors 141. The number of the second connectors 141 is not limited to four and can be arbitrary.

[0265] As Figure 15 and Figure 16 shown, when viewed from the Z-axis direction, the second connector 141 is formed along a radial direction with respect to the center point O of the force-receiving body 120 and extends radially. The four second connectors 141 can also be arranged at an interval of 90° with respect to the center point O of the force-receiving body 120 when viewed from the Z-axis direction. In other words, the plurality of second connectors 141 can also be arranged at equal intervals with respect to the center point O of the force-receiving body 120. The second connector 141 can also be arranged at a position that does not overlap with the independent force sensor 10 when viewed from the Z-axis direction. The second connector 141 can also extend from the inner edge 120b to the outer edge 120c of the force-receiving body 120 having an annular shape in the radial direction, or extend from the inner edge 130b to the outer edge 130c of the fixed body 130 having an annular shape in the radial direction when viewed from the Z-axis direction. However, it is not limited thereto. The second connector 141 may not extend to the inner edge 120b of the force-receiving body 120, and may not extend to the inner edge 130b of the fixed body 130. The second connector 141 can be separated from the inner edge 120b of the force-receiving body 120, and can also be separated from the inner edge 130b of the fixed body 130. The second connector 141 may not extend to the outer edge 120c of the force-receiving body 120, and may not extend to the outer edge 130c of the fixed body 130. The second connector 141 can be separated from the outer edge 120c of the force-receiving body 120, and can also be separated from the outer edge 130c of the fixed body 130. The inner edge 120b of the force-receiving body 120 can also be defined by the force-receiving body center opening 120a, and the inner edge 130b of the fixed body 130 can also be defined by the fixed body center opening 130a.

[0266] As Figure 14 and Figure 17 shown, the second connector 141 extends in the Z-axis direction. As Figure 17As shown, the second connecting body 141 includes a force-receiving body side end portion 143 (an example of a third end portion) connected to the force-receiving body 120 and a fixed body side end portion 144 (an example of a fourth end portion) connected to the fixed body 130. The second connecting body 141 extends from the force-receiving body side end portion 143 to the fixed body side end portion 144 along the Z-axis direction. That is, the second connecting body 141 is formed along each of the Z-axis direction and the radial direction. The second connecting body 141 may also be formed in a flat plate shape.

[0267] As Figure 15 shown, when viewed from the Z-axis direction, the dimension in the direction orthogonal to the radial direction of the second connecting body 141 (corresponding to the thickness t6 of the second connecting body 141) is smaller than the dimension in the radial direction of the second connecting body 141. Accordingly, the spring constant of the second connecting body 141 with respect to the action of a force in the direction orthogonal to the radial direction is smaller than the spring constant with respect to the action of a force in the radial direction. Therefore, the second connecting body 141 is liable to elastically deform due to the action of the moment Mz about the Z-axis.

[0268] With respect to the moment Mz about the Z-axis, the rigidity of the second connecting body 141 is higher than the rigidity of the first connecting body 41. More specifically, as Figure 15 shown, the thickness t6 of the second connecting body 141 is larger than the thickness t1 of the first connecting body 41 of the independent force sensor 10. Accordingly, the spring constant of the second connecting body 141 with respect to the action of a force in the direction orthogonal to the radial direction is larger than the spring constant of the first connecting body 41 with respect to the action of a force in the direction orthogonal to the radial direction. Therefore, the second connecting body 141 is less liable to elastically deform due to the action of the moment Mz about the Z-axis than the first connecting body 41. In other words, when the force sensor 110 according to the present embodiment is subjected to the moment Mz, the displacement of the force-receiving body 120 is dominated by the elastic deformation of the second connecting body 141. The first connecting body 41 has a lower rigidity than the second connecting body 141 with respect to the moment Mz, and thus follows the displacement of the force-receiving body 120 caused by the second connecting body 141. The influence of the elastic deformation of the first connecting body 41 on the displacement of the force-receiving body 120 can be substantially regarded as nil. In this case, the load imposed on the first connecting body 41 by the moment Mz received by the force-receiving body 120 can be reduced. Thereby, the size of the bolt for attaching the independent force sensor 10 to the force-receiving body 120 can be reduced, and the size of the bolt for attaching the independent force sensor 10 to the fixed body 130 can be reduced. Accordingly, miniaturization of the independent force sensor 10 can be achieved, and hysteresis can be alleviated and accuracy can be improved.

[0269] The force-receiving body 120, the fixed body 130, and the second strain body 140 may also be integrally formed of a continuous material. The force-receiving body 120, the fixed body 130, and the second strain body 140 may also form a sensor structure 150. The sensor structure 150 may also be formed from a single block by machining (e.g., cutting), or may also be formed by casting. In this case, an R-shaped portion 50R as shown in Figure 5 may be provided at the connection point of the second connection body 141 of the force-receiving body 120 and the second strain body 140, i.e., the force-receiving body side end portion 143. Similarly, an R-shaped portion 50R may be provided at the connection point of the second connection body 141 of the fixed body 130 and the second strain body 140, i.e., the fixed body side end portion 144, and the sensor structure 150 may be made of a metal material such as aluminum alloy or ferroalloy.

[0270] However, the force sensor 110 according to the present embodiment is not limited thereto. For example, at least two of the force-receiving body 120, the fixed body 130, and the second strain body 140 may be integrally formed, and the other components may be formed as separate bodies. For example, the force-receiving body 120 and the second strain body 140 may be integrally formed and fixed to the separately formed fixed body 130 by bolts (not shown) or an adhesive. For example, the fixed body 130 and the second strain body 140 may be integrally formed and fixed to the separately formed force-receiving body 120 by bolts or an adhesive. Or, the force-receiving body 120, the fixed body 130, and the second strain body 140 may be separately formed and fixed by bolts or an adhesive.

[0271] In Figure 15 , the detection element 60 of the independent force sensor 10 on the positive side in the Y-axis direction is the same as Figure 6 and Figure 7 the independent force sensor 10 shown, and includes a first capacitor element C1, a second capacitor element C2, a third capacitor element C3, and a fourth capacitor element C4. In Figure 15 , the detection element of the independent force sensor 10 at the position on the negative side in the Y-axis direction includes a fifth capacitor element C5, a sixth capacitor element C6, a seventh capacitor element C7, and an eighth capacitor element C8. The fifth capacitor element C5 corresponds to the first capacitor element C1 and is configured in the same manner as the first capacitor element C1. The sixth capacitor element C6 corresponds to the second capacitor element C2 and is configured in the same manner as the second capacitor element C2. The seventh capacitor element C7 corresponds to the third capacitor element C3 and is configured in the same manner as the third capacitor element C3. The eighth capacitor element C8 corresponds to the fourth capacitor element C4 and is configured in the same manner as the fourth capacitor element C4.

[0272] As Figure 14As shown, the detection circuit 170 according to the present embodiment outputs an electrical signal representing the force or torque applied to the force-receiving body 120 based on the detection results of the detection elements 60 of the respective independent force sensors 10. The independent force sensor 10 according to the present embodiment may not include Figure 2 the detection circuit 70 shown. The detection circuit 170 according to the present embodiment may also have, for example, an arithmetic function constituted by a microprocessor. In addition, the detection circuit 170 may have an A / D conversion function for converting an analog signal received from the detection element 60 of each independent force sensor 10 into a digital signal, a function for amplifying the signal, and various correction functions. The detection circuit 170 may also include a terminal for outputting an electrical signal, and a connector 171 (see Figure 15 ) is connected to this terminal, and an electrical signal is sent from the connector 171 to the above-mentioned controller 5 via a cable. The electrical signal sent to the controller 5 may be a digital signal, but may also be an analog signal.

[0273] Next, the fixing structure of the independent force sensor 10 will be described.

[0274] As Figure 15 and Figure 18 shown, the force-receiving body 120 includes a force-receiving opening 121, and the first connecting body 41 of the independent force sensor 10 is inserted into the force-receiving opening 121. The force-receiving opening 121 is an example of the first opening. The force-receiving openings 121 are arranged at an interval of 180° with respect to the center point O of the force-receiving body 120. The force-receiving openings 121 open at the outer edge 120c of the force-receiving body 120.

[0275] As Figure 18 shown, the force-receiving body 120 may also include a force-receiving recess 122. The force-receiving recess 122 is an example of the first recess. The force-receiving recess 122 is provided on the surface of the force-receiving body 120 opposite to the fixing body 130 and opens toward the side opposite to the fixing body 130. In Figure 18 the example shown, the force-receiving recess 122 opens toward the positive side in the Z-axis direction. The force-receiving recess 122 communicates with the above-mentioned force-receiving opening 121. The independent force-receiving body 20 of the independent force sensor 10 is accommodated in the force-receiving recess 122. The first connecting body 41 is arranged in the force-receiving opening 121.

[0276] The dimension of the force-receiving recess 122 in the Z-axis direction (corresponding to the depth h1 of the force-receiving recess 122) may be larger than the dimension of the independent force-receiving body 20 in the Z-axis direction (corresponding to the thickness t7 of the independent force-receiving body 20), or may be equal to the dimension of the independent force-receiving body 20 in the Z-axis direction. Thereby, it is possible to prevent the independent force-receiving body 20 from protruding from the force-receiving body 120, and it is possible to reduce the height of the force sensor 110 ( Figure 14 the Z-axis direction dimension h3 shown). As Figure 16As shown, the planar shape of the force-receiving recess 122 may also have the same shape as the independent force-receiving body 20, but as long as the independent force-receiving body 20 can be accommodated, the planar shape of the force-receiving recess 122 can be arbitrary.

[0277] As Figure 18 shown, the force-receiving body 120 may also include a force-receiving main body portion 123 and a force-receiving support portion 124. The force-receiving main body portion 123 is the thicker part of the force-receiving body 120. The force-receiving support portion 124 is the thinner part of the force-receiving body 120. The force-receiving support portion 124 is configured to support the independent force-receiving body 20 accommodated in the force-receiving recess 122. The independent force-receiving body 20 may also abut against the force-receiving support portion 124. The surface of the force-receiving main body portion 123 on the side of the fixing body 130 and the surface of the force-receiving support portion 124 on the side of the fixing body 130 may form a continuous surface, or may be arranged at the same position in the Z-axis direction. Through the force-receiving support portion 124 configured in this way, the above-mentioned force-receiving recess 122 is formed.

[0278] The above-mentioned force-receiving opening 121 is formed in the force-receiving support portion 124. In the present embodiment, the force-receiving support portions 124 are formed on both sides of the force-receiving opening 121. As Figure 15 shown, a plurality of bolt holes 125 for fixing the independent force-receiving body 20 may also be provided in the force-receiving support portion 124. The bolt holes 125 are arranged on both sides of the force-receiving opening 121. By inserting bolts (not shown) into the bolt holes 125 and the bolt holes 24 provided in the independent force-receiving body 20 to fasten the independent force-receiving body 20 and the force-receiving body 120, the independent force-receiving body 20 can be detachably mounted on the force-receiving support portion 124. A counterbore (not shown) may also be provided in the bolt hole 24 of the independent force-receiving body 20. In this case, it is possible to prevent the bolt head from protruding from the independent force-receiving body 20. The bolts for fixing are not particularly limited. For example, countersunk head bolts may also be used.

[0279] As Figure 16 and Figure 18 shown, the fixing body 130 includes a fixing opening 131, and the first connecting body 41 of the independent force sensor 10 is inserted into the fixing opening 131. The fixing opening 131 is an example of the second opening. The fixing openings 131 are arranged at an interval of 180° with respect to the center point O of the force-receiving body 120. The fixing opening 131 opens at the outer edge 130c of the fixing body 130.

[0280] As Figure 18 shown, the fixing body 130 may also include a fixing recess 132. The fixing recess 132 is an example of the second recess. The fixing recess 132 is provided on the surface of the fixing body 130 opposite to the force-receiving body 120 and opens toward the side opposite to the force-receiving body 120. In Figure 18In the example shown, the fixing recess 132 opens toward the negative side in the Z-axis direction. The fixing recess 132 communicates with the above-described fixing opening 131. An independent fixing body 30 of the independent force sensor 10 is accommodated in the fixing recess 132. When viewed from the Z-axis direction, a first connecting body 41 and fixing electrode substrates Ef1 and Ef2 are arranged in the fixing opening 131.

[0281] The dimension of the fixing recess 132 in the Z-axis direction (corresponding to the depth h2 of the fixing recess 132) may also be larger than the dimension of the independent fixing body 30 in the Z-axis direction (corresponding to the thickness t8 of the independent fixing body 30), or may be equal to the dimension of the independent fixing body 30 in the Z-axis direction. Thereby, it is possible to prevent the independent fixing body 30 from protruding from the fixing body 130, and it is possible to reduce the height of the force sensor 110 ( Figure 14 the dimension h3 in the Z-axis direction shown). As Figure 16 shown, the planar shape of the fixing recess 132 may also have the same shape as the independent fixing body 30, but as long as the independent fixing body 30 can be accommodated, the planar shape of the fixing recess 132 is arbitrary.

[0282] As Figure 18 shown, the fixing body 130 may also include a fixing main body portion 133 and a fixing support portion 134. The fixing main body portion 133 is the thicker part of the fixing body 130. The fixing support portion 134 is the thinner part of the fixing body 130. The fixing support portion 134 is configured to support the independent fixing body 30 accommodated in the fixing recess 132. The independent fixing body 30 may also abut against the fixing support portion 134. The surface of the fixing main body portion 133 on the side of the force receiving body 120 and the surface of the fixing support portion 134 on the side of the force receiving body 120 may form a continuous surface, or may be arranged at the same position in the Z-axis direction. Through the fixing support portion 134 configured in this way, the above-described fixing recess 132 is formed.

[0283] The above-described fixing opening 131 is formed in the fixing support portion 134. In the present embodiment, the fixing support portions 134 are formed on both sides of the fixing opening 131. As Figure 16 shown, a plurality of bolt holes 135 for fixing the independent fixing body 30 may also be provided in the fixing support portion 134. The bolt holes 135 are arranged on both sides of the fixing opening 131. By inserting bolts (not shown) into the bolt holes 135 and the bolt holes 34 provided in the independent fixing body 30 and fastening the independent fixing body 30 and the fixing body 130, the independent fixing body 30 can be detachably attached to the fixing support portion 134. A counterbore (not shown) may also be provided in the bolt holes 34 of the independent fixing body 30. In this case, it is possible to prevent the bolt heads from protruding from the independent fixing body 30. The bolts for fixing are not particularly limited. For example, countersunk head bolts may also be used.

[0284] Next, a method for detecting a force or a torque in the force sensor 110 according to the present embodiment having such a configuration will be described.

[0285] When the force-receiving body 120 is subjected to a torque Mz about the Z-axis, due to the action of the force or torque, the second connecting bodies 141 of the respective second strain bodies 140 elastically deform, and the force-receiving body 120 is displaced about the Z-axis.

[0286] At this time, each independent force-receiving body 20 of the independent force sensor 10 is subjected to a force Fx in the X-axis direction. The independent force-receiving body 20 located on the negative side of the Y-axis direction with respect to the center point O is subjected to a force Fx on the positive side in the X-axis direction. The independent force-receiving body 20 located on the positive side of the Y-axis direction with respect to the center point O is subjected to a force Fx on the negative side in the X-axis direction. As a result, the first connecting bodies 41 of the respective independent force sensors 10 elastically deform, and the displacement body 42 is displaced. Therefore, the electrostatic capacitance values of the first capacitor element C1 and the third capacitor element C3 decrease, and the electrostatic capacitance values of the second capacitor element C2 and the fourth capacitor element C4 increase. The electrostatic capacitance values of the fifth capacitor element C5 and the seventh capacitor element C7 decrease, and the electrostatic capacitance values of the sixth capacitor element C6 and the eighth capacitor element C8 increase.

[0287] The torque Mz received by the force-receiving body 120 can also be calculated using the electrostatic capacitance values of the first capacitor element C1 to the fourth capacitor element C4. For example, the torque Mz can also be calculated as T1 using the electrostatic capacitance values of the first capacitor element C1 and the second capacitor element C2 by the following formula.

[0288] [Equation 5]

[0289] T11 = -C1 + C2

[0290] Alternatively, the electrostatic capacitance values of the third capacitor element C3 and the fourth capacitor element C4 can be used, and the torque Mz can be calculated as T2 by the following formula.

[0291] [Equation 6]

[0292] T21 = -C3 + C4

[0293] Alternatively, the electrostatic capacitance values of the first capacitor element C1 to the fourth capacitor element C4 can be used, and the torque Mz can be calculated as T3 by the following formula.

[0294] [Equation 7]

[0295] T31 = -C1 + C2 - C3 + C4

[0296] Fault diagnosis can also be performed by comparing T11 in [Equation 5] above with T21 in [Equation 6]. Alternatively, fault diagnosis can also be performed by comparing T31 in [Equation 7] with the sum of T11 and T21. Alternatively, fault diagnosis can also be performed by multiplying T11 in [Equation 5] by a specified magnification factor and then comparing it with T31 in [Equation 7]. Alternatively, fault diagnosis can also be performed by multiplying T21 in [Equation 6] by a specified magnification factor and then comparing it with T31 in [Equation 3]. The fault diagnosis can be performed by the above-described detection circuit 170, or alternatively, it can also be performed by the controller 5 of the robot 1.

[0297] Alternatively, the torque Mz applied to the force-receiving body 120 can also be calculated using the fifth capacitor element C5 to the eighth capacitor element C8. For example, the torque Mz can also be calculated as T12 using the capacitance values of the fifth capacitor element C5 and the sixth capacitor element C6 by the following equation.

[0298] [Equation 8]

[0299] T12 = -C5 + C6

[0300] Alternatively, the torque Mz can also be calculated as T22 using the capacitance values of the seventh capacitor element C7 and the eighth capacitor element C8 by the following equation.

[0301] [Equation 9]

[0302] T22 = -C7 + C8

[0303] Alternatively, the torque Mz can also be calculated as T32 using the capacitance values of the fifth capacitor element C5 to the eighth capacitor element C8 by the following equation.

[0304] [Equation 10]

[0305] T32 = -C5 + C6 - C7 + C8

[0306] Fault diagnosis can also be performed by comparing T12 in [Equation 8] above with T22 in [Equation 9]. Alternatively, fault diagnosis can also be performed by comparing T32 in [Equation 10] with the sum of T12 and T22. Alternatively, fault diagnosis can also be performed by multiplying T12 in [Equation 8] by a specified magnification factor and then comparing it with T32 in [Equation 10]. Alternatively, fault diagnosis can also be performed by multiplying T22 in [Equation 9] by a specified magnification factor and then comparing it with T32 in [Equation 10].

[0307] Alternatively, the torque Mz applied to the force-receiving body 120 can also be calculated using the first capacitor element C1 to the eighth capacitor element C8. For example, the torque Mz can also be calculated as T33 by the following [Equation 11]. When calculating the torque Mz using the capacitance values of eight capacitor elements, the detection sensitivity of the torque Mz can be improved.

[0308] [Equation 11]

[0309] T33 = -C1 + C2 - C3 + C4 - C5 + C6 - C7 + C8

[0310] Alternatively, the torque Mz applied to the force-receiving body 120 can also be calculated as T34 by the following [Equation 12] using the first capacitor element C1, the second capacitor element C2, the fifth capacitor element C5, and the sixth capacitor element C6 arranged on the outer side in the radial direction. When calculating the torque Mz using the capacitance values of four capacitor elements, the number of capacitor elements is reduced, so that the force sensor 110 can be made compact.

[0311] [Equation 12]

[0312] T34 = -C1 + C2 - C5 + C6

[0313] Alternatively, the torque Mz can also be calculated as T35 by the following [Equation 13] using the third capacitor element C3, the fourth capacitor element C4, the seventh capacitor element C7, and the eighth capacitor element C8 arranged on the inner side in the radial direction.

[0314] [Equation 13]

[0315] T35 = -C3 + C4 - C7 + C8

[0316] In this way, various combinations of capacitor elements used in the calculation of the torque Mz can be considered. If the combination is such that the number of +-sign capacitor elements is the same as the number of --sign capacitor elements, the combination of capacitor elements can be arbitrary.

[0317] According to the force sensor 110 of the present embodiment, when the force-receiving body 120 is subjected to a force Fx in the X-axis direction, a force Fy in the Y-axis direction, a force Fz in the Z-axis direction, a torque Mx about the X-axis, and a torque My about the Y-axis, the changes in the capacitance values of the respective capacitor elements C1 to C8 can be regarded as negligible. This is because, as Figure 15 and Figure 16 shown, the four second connectors 141 are arranged at intervals of 90° with respect to the center point O of the force-receiving body 120 when viewed from the Z-axis direction.

[0318] Thus, the force sensor 110 according to the present embodiment can detect only the torque Mz about the Z axis, and can also be referred to as a torque sensor. The force sensor 110 can also be used in an environment where only the torque Mz about the Z axis acts.

[0319] Thus, according to the present embodiment, the force-receiving body 120 that supports the independent force-receiving bodies 20 of the respective independent force sensors 10, and the fixing body 130 that supports the independent fixing bodies 30 of the respective independent force sensors 10 are supported by the second strain body 140. The second strain body 140 includes a second connecting body 141, and the second connecting body 141 extends in the Z-axis direction from the force-receiving body-side end portion 143 connected to the force-receiving body 120 to the fixing body-side end portion 144 connected to the fixing body 130.

[0320] Thus, the independent force sensor 10 supported by the force-receiving body 120 and the fixing body 130 includes the first strain body 40 and the detection element 60. As a result, the shapes of the force-receiving body 120, the fixing body 130, and the second connecting body 141 can be made pure, and the structure of the second connecting body 141 can be simplified. In addition, the distance between the force-receiving body 120 and the fixing body 130 can be reduced. As a result, the cost of the force sensor 110 can be reduced, and the height of the force sensor 110 ( Figure 14 the Z-axis direction dimension h3 shown) can be reduced.

[0321] In addition, according to the present embodiment, when viewed from the Z-axis direction, the first connecting body 41 and the second connecting body 141 of the independent force sensor 10 are formed along the radial direction with respect to the center point O of the force-receiving body 120. As a result, the shape of the second connecting body 141 can be made pure. In addition, the distance between the force-receiving body 120 and the fixing body 130 can be reduced. In addition, when the force-receiving body 120 is subjected to the torque Mz about the Z axis, the first connecting body 41 and the second connecting body 141 can elastically deform, and the displacement body 42 can be displaced. Thus, the detection element 60 of each independent force sensor 10 can detect the force received by the independent force-receiving body 20, and based on the detection results of the respective detection elements 60, the detection circuit 170 can output an electrical signal representing the torque Mz received by the force-receiving body 120. As a result, the force sensor 110 can detect the torque Mz and can function as a torque sensor.

[0322] In addition, according to the present embodiment, when viewed from the Z-axis direction, the dimension t6 of the second connecting body 141 in the direction orthogonal to the radial direction is smaller than the dimension L2 of the second connecting body 141 in the radial direction. Thereby, the spring constant of the force exerted by the second connecting body 141 in the direction orthogonal to the radial direction can be made smaller than the spring constant of the force exerted in the radial direction. Therefore, due to the action of the moment Mz about the Z-axis on the force-receiving body 120, the second connecting body 141 can be easily elastically deformed, and the detection sensitivity of the moment Mz can be improved.

[0323] In addition, according to the present embodiment, the force-receiving body 120 and the fixing body 130 are formed along a plane orthogonal to the Z-axis direction. Thereby, the shapes of the force-receiving body 120 and the fixing body 130 can be made pure. In addition, the interval between the force-receiving body 120 and the fixing body 130 can be reduced. As a result, cost reduction of the force sensor 110 can be achieved, and the height of the force sensor 110 can be reduced.

[0324] In addition, according to the present embodiment, the force-receiving body 120 includes a force-receiving opening 121, and the first connecting body 41 of the independent force sensor 10 is inserted into the force-receiving opening 121. Thereby, it is possible to prevent the independent force sensor 10 from protruding outward from the force-receiving body 120 when viewed from the Z-axis direction, and the interval between the force-receiving body 120 and the fixing body 130 can be reduced. Therefore, miniaturization of the force sensor 110 can be achieved, and the height of the force sensor 110 can be reduced.

[0325] In addition, according to the present embodiment, the force-receiving body 120 includes a force-receiving recess 122, the force-receiving recess 122 opens toward the side opposite to the fixing body 130, and communicates with the force-receiving opening 121. The independent force-receiving body 20 of the independent force sensor 10 is accommodated in the force-receiving recess 122. Thereby, it is possible to prevent the independent force-receiving body 20 from protruding from the force-receiving body 120, and the height of the force sensor 110 can be reduced.

[0326] In addition, according to the present embodiment, the fixing body 130 includes a fixing opening 131, and the first connecting body 41 of the independent force sensor 10 is inserted into the fixing opening 131. Thereby, it is possible to prevent the independent force sensor 10 from protruding outward from the fixing body 130 when viewed from the Z-axis direction, and the interval between the force-receiving body 120 and the fixing body 130 can be reduced. Therefore, miniaturization of the force sensor 110 can be achieved, and the height of the force sensor 110 can be reduced.

[0327] In addition, according to the present embodiment, the fixing body 130 includes a fixing recess 132 that opens toward a side opposite to the force receiving body 120 and communicates with the fixing opening 131. The independent fixing body 30 of the independent force sensor 10 is accommodated in the fixing recess 132. Thereby, it is possible to prevent the independent fixing body 30 from protruding from the fixing body 130, and the height of the force sensor 110 can be reduced.

[0328] In addition, according to the present embodiment, with respect to the moment Mz about the Z axis, the rigidity of the second connecting body 141 is higher than the rigidity of the first connecting body 41 of the independent force sensor 10. Thereby, it is possible to make the second connecting body 141 more difficult to elastically deform with respect to the moment Mz than the first connecting body 41. Therefore, when the force receiving body 120 is subjected to the moment Mz, the displacement of the force receiving body 120 can be controlled by the second connecting body 141.

[0329] In addition, according to the present embodiment, the force receiving body 120, the fixing body 130, and the second connecting body 141 are integrally formed of a continuous material. Thereby, the structure of the force sensor 110 can be simplified. For example, when the force receiving body 120, the fixing body 130, and the second connecting body 141 are formed separately and fixed by bolts or adhesives, etc., the structure becomes complicated in order to enable such fixing, and a space for optimizing workability is required. Therefore, it may limit the cost reduction of the force sensor 110 and may limit the reduction of the height of the force sensor 110. In contrast, according to the present embodiment, since the force receiving body 120, the fixing body 130, and the second connecting body 141 are integrally formed of a continuous material, the structure can be further simplified. In addition, the interval between the force receiving body 120 and the fixing body 130 can be further reduced. As a result, further cost reduction of the force sensor 110 can be achieved, and the height of the force sensor 110 can be further reduced.

[0330] In addition, according to the present embodiment, it may be that the force receiving body 120, the fixing body 130, and the second connecting body 141 are integrally formed of a continuous material, and the independent force receiving body 20, the independent fixing body 30, and the first strain body 40 are integrally formed of a continuous material. In this case, by mounting the independent force sensor 10 on the force receiving body 120 and the fixing body 130, the force sensor 110 according to the present embodiment can be easily manufactured. Therefore, cost reduction of the force sensor 110 can be achieved, and the height of the force sensor 110 ( Figure 14 the Z-axis direction dimension h3 shown) can be reduced.

[0331] It should be noted that in the above-described present embodiment, for the independent force sensor 10 having Figures 5 to 7An example has been described in which the independent force sensor 10 shown has the same configuration, and the detection element 60 of each independent force sensor 10 includes four capacitive elements. However, the present embodiment is not limited to this. For example, the detection element 60 of the independent force sensor 10 may also be composed of two capacitive elements, namely, the first capacitive element C1 and the second capacitive element C2, or may be composed of two capacitive elements, namely, the third capacitive element C3 and the fourth capacitive element C4.

[0332] In addition, in the above-described present embodiment, an example has been described in which the independent force sensor 10 is disposed on the outer edge 120c of the force-receiving body 120 and on the outer edge 130c of the fixed body 130. However, the present embodiment is not limited to this. For example, the independent force sensor 10 may also be disposed on the inner edge 120b of the force-receiving body 120, or the independent force sensor 10 may also be disposed on the inner edge 130b of the fixed body 130. In this case, the force-receiving opening 121 may also open on the inner edge 120b of the force-receiving body 120, and the fixing opening 131 may also open on the inner edge 130b of the fixed body 130.

[0333] In addition, in the above-described present embodiment, an example has been described in which the spring constant of the second connecting body 141 with respect to the action of the force in the direction orthogonal to the radial direction is greater than the spring constant of the first connecting body 41 with respect to the action of the force in the direction orthogonal to the radial direction. However, the present embodiment is not limited to this. It may also be that the sum of the spring constants of the respective second connecting bodies 141 with respect to the action of the force in the direction orthogonal to the radial direction is greater than the sum of the spring constants of the respective first connecting bodies 14 acting on the force in the direction orthogonal to the radial direction. In this case, the thickness t6 of the second connecting body 141 may be greater than the thickness t1 of the first connecting body 41, or may be smaller, or may also be equal to the thickness t1. For example, the number of the second connecting bodies 141 may also be increased.

[0334] In addition, in the above-described present embodiment, an example has been described in which the independent force sensor 10 is detachably mounted on the force-receiving body 120 and the fixed body 130. However, the present embodiment is not limited to this. For example, the independent force sensor 10 may also be integrated with the force-receiving body 120 and the fixed body 130. More specifically, it may also be that the independent force-receiving body 20, the independent fixed body 30, the first strain body 40, the force-receiving body 120, the fixed body 130, and the second strain body 140 are formed integrally from a continuous material to constitute a sensor structure 150.

[0335] (Fifth Embodiment)

[0336] Next, use Figures 19 to 23 , to describe the independent force sensor and the force sensor according to the fifth embodiment of the present invention.

[0337] In Figures 19 to 23 the fifth embodiment shown, it is different mainly in that the detection element is composed of a strain gauge, and other configurations are substantially the same as those of Figures 1 to 4 the first embodiment shown. It should be noted that, in Figures 19 to 23 , for the parts that are the same as those of Figures 1 to 4 the first embodiment shown, the same reference numerals are given and detailed descriptions are omitted. Figure 19 FIG. is a partially enlarged top view showing an independent force sensor according to the fifth embodiment. Figure 20 FIG. is a diagram showing Figure 19 the Wheatstone bridge circuit for the detection element shown. Figure 21 FIG. is a longitudinal sectional view schematically showing the deformation state of the first strain body.

[0338] As Figure 19 shown, the first strain body 40 of the independent force sensor 10 according to the present embodiment may not include the displacement body 42. In this case, the structure of the first strain body 40 can be simplified.

[0339] The detection element 60 of the independent force sensor 10 according to the present embodiment does not include a capacitive element, but includes a first strain gauge R11, R12 and a second strain gauge R21, R22. Each strain gauge R11, R12, R21, R22 is configured to detect the strain generated by the action of a force or torque on the independent force receiving body 20. For example, four strain gauges R11, R12, R21, R22 constituting the detection element 60 may be pasted on the first connecting body 41. The first strain gauges R11, R12 may also be provided at the force receiving body side end portion 43 of the first connecting body 41 and pasted on the force receiving body side end portion 43. The second strain gauges R21, R22 may also be provided at the fixed body side end portion 44 of the first connecting body 41 and pasted on the fixed body side end portion 44. The strain gauges R11, R21 may also be pasted on the surface of the first connecting body 41 facing the negative side of the X-axis direction. The strain gauges R12, R22 may also be pasted on the surface of the first connecting body 41 facing the positive side of the X-axis direction. The first strain gauges R11, R12 may also be arranged at the same position in the Z-axis direction, and the second strain gauges R21, R22 may also be arranged at the same position in the Z-axis direction. Each of the strain gauges R11 to R22 may also be arranged at the same position in the Y-axis direction. The Y-axis direction is equivalent to the direction perpendicular to the Figure 19 paper surface of

[0340] The detection circuit 70 according to the present embodiment may also include Figure 20The Wheatstone bridge circuit WB shown. The Wheatstone bridge circuit WB outputs an electrical signal based on the detection results of four strain gauges R11 to R22 provided on the first connecting body 41. The Wheatstone bridge circuit WB is configured such that by applying a prescribed voltage from the bridge voltage source E1, a bridge voltage as an electrical signal corresponding to the strain detected by each of the strain gauges R11 to R22 is generated between the output terminals T11 and T12. In the Wheatstone bridge circuit WB, the strain gauge R11 and the strain gauge R22 face each other, and the strain gauge R21 and the strain gauge R12 face each other. Thereby, the force Fx in the X-axis direction can be detected.

[0341] For example, when the independent force-receiving body 20 is subjected to a force Fx on the positive side in the X-axis direction, as Figure 21 shown, at the positions where the strain gauges R11 and R22 are pasted, a compressive stress is detected, and at the positions where the strain gauges R21 and R12 are pasted, a tensile stress is detected. In the strain gauges R11 and R22, the resistance value decreases according to the compressive strain. In the strain gauges R21 and R12, the resistance value increases according to the tensile strain. Then, based on the output value obtained from the Wheatstone bridge circuit WB, the force Fx received by the independent force-receiving body 20 is calculated.

[0342] Thus, according to the present embodiment, the first strain body 40 that connects the independent force-receiving body 20 and the independent fixing body 30 includes the first connecting body 41. The first connecting body 41 extends in the Z-axis direction from the force-receiving body side end portion 43 connected to the independent force-receiving body 20 to the fixing body side end portion 44 connected to the independent fixing body 30. Thereby, the shape of the first strain body 40 can be made pure, and the structure of the first strain body 40 can be simplified. In addition, the interval between the independent force-receiving body 20 and the independent fixing body 30 can be reduced. As a result, the independent force sensor 10 can be made inexpensive, and the height of the independent force sensor 10 ( Figure 2 the Z-axis direction dimension h0 shown) can be reduced.

[0343] In addition, according to the present embodiment, the detection element 60 includes: first strain gauges R11 and R12 provided at the force-receiving body side end portion 43 of the first connecting body 41, and second strain gauges R21 and R22 provided at the fixing body side end portion 44. Thereby, the detection element 60 can detect the displacement generated due to the elastic deformation of the first strain body 40. Therefore, the force received by the independent force-receiving body 20 can be detected.

[0344] It should be noted that the detection element 60 composed of strain gauges according to the present embodiment can also be applied to the independent force sensor 10 according to the second embodiment.

[0345] In addition, Figure 19 the independent force sensor 10 shown as Figure 22 and Figure 23As shown, it can also be applied to the force sensor 110. In this case, the moment Mz about the Z-axis acting on the force-receiving body 120 is calculated. Figure 22 is a longitudinal sectional view of the force sensor 110 to which the Figure 19 shown independent force sensor 10 is applied, Figure 23 and is Figure 22 the R-direction view of Figure 22 and Figure 23 the force sensor 110 shown and Figures 14 to 18 the force sensor 110 shown are different in that the independent force sensor 10 is replaced with Figure 19 the independent force sensor 10 shown. In other respects, Figure 22 and Figure 23 the force sensor 110 shown has the same configuration as Figures 14 to 18 the force sensor 110 shown. The configuration Figure 22 and Figure 23 the number of independent force sensors 10 that make up the force sensor 110 shown is two, but it can also be three or more, and can be arbitrary. When viewed from the Z-axis direction, the independent force-receiving body 20 and the independent fixing body 30 can be formed in an arc shape continuously with the outer edges of the force-receiving body 120 and the fixing body 130, respectively, on the positive side or the negative side of the Y-axis direction.

[0346] In Figure 23 , the detection element 60 of the independent force sensor 10 located on the positive side of the Y-axis direction includes the first strain gauges R11, R12 and the second strain gauges R21, R22. The arrangement of each strain gauge R11 to R22 in the independent force sensor 10 is shown in Figure 19 . The first strain gauges R11, R12 are provided at the force-receiving body side end portion 43 of the first connecting body 41, and the second strain gauges R21, R22 are provided at the fixing body side end portion 44 of the first connecting body 41. The strain gauges R11, R21 can also be arranged on the surface of the first connecting body 41 facing the positive side of the X-axis direction as shown in Figure 23 , and the strain gauges R12, R22 can also be arranged on the surface of the first connecting body 41 facing the negative side of the X-axis direction. The first strain gauges R11, R12 can also be arranged at the same position in the Z-axis direction, and the second strain gauges R21, R22 can also be arranged at the same position in the Z-axis direction. Each strain gauge R11 to R22 can also be arranged at the same position in the Y-axis direction.

[0347] In Figure 23 , the detection element 60 of the independent force sensor 10 located on the negative side of the Y-axis direction includes the first strain gauges R13, R14 and the second strain gauges R23, R24. The arrangement of each strain gauge R13 to R24 in the independent force sensor 10 is shown in Figure 19is shown. The first strain gauges R13 and R14 are provided at the end portion 43 on the force-receiving body side of the first connecting body 41, and the second strain gauges R23 and R24 are provided at the end portion 44 on the fixed body side of the first connecting body 41. The strain gauges R13 and R23 can also be arranged on the surface of the first connecting body 41 facing the negative side in the X-axis direction as shown in Figure 23 . The strain gauges R14 and R24 can also be arranged on the surface of the first connecting body 41 facing the positive side in the X-axis direction. The first strain gauges R13 and R14 can also be arranged at the same position in the Z-axis direction, and the second strain gauges R23 and R24 can also be arranged at the same position in the Z-axis direction. Each of the strain gauges R13 to R24 can also be arranged at the same position in the Y-axis direction.

[0348] Figure 22 The detection circuit 170 shown in Figure 20 includes the Wheatstone bridge circuit WB shown in Figure 22 . That is, the independent force sensor 10 shown in Figure 19 may not include the detection circuit 70 shown in Figure 22 . In this case, the Wheatstone bridge circuit WB can also be a part of the configuration of the detection circuit 170 shown in Figure 22 . The detection circuit 170 can also include a plurality of Wheatstone bridge circuits WB corresponding to each independent force sensor 10. More specifically, the detection circuit 170 can include a Wheatstone bridge circuit WB corresponding to the strain gauges R11, R12, R21, and R22, and a Wheatstone bridge circuit WB corresponding to the strain gauges R13, R14, R23, and R24.

[0349] For the method of detecting force or torque in the force sensor 110 shown in Figure 22 and Figure 23 , an explanation will be given.

[0350] If the force-receiving body 120 is subjected to the action of a torque Mz about the Z axis, due to the action of this force or torque, the second connecting body 141 of the second strain body 140 elastically deforms, and the force-receiving body 120 is displaced about the Z axis.

[0351] At this time, each independent force-receiving body 20 of the independent force sensor 10 is subjected to a force Fx in the X-axis direction. The independent force-receiving body 20 located on the negative side in the Y-axis direction with respect to the center point O is subjected to a force Fx in the positive side in the X-axis direction. The independent force-receiving body 20 located on the positive side in the Y-axis direction with respect to the center point O is subjected to a force Fx in the negative side in the X-axis direction. As a result, the first connecting body 41 of each independent force sensor 10 elastically deforms. Therefore, in the same manner as the case where the independent force sensor 10 shown in Figure 19 is subjected to a force Fx in the positive side in the X-axis direction, stress is detected by each strain gauge.

[0352] More specifically, as shown in Figure 21As shown, at the positions where strain gauges R11 and R22 are pasted on the independent force sensor 10 on the positive side in the Y-axis direction, compressive stress is detected, and at the positions where strain gauges R21 and R12 are pasted, tensile stress is detected. In strain gauges R11 and R22, the resistance value decreases according to the compressive strain. In strain gauges R21 and R12, the resistance value increases according to the tensile strain. Then, based on the output value obtained from the Wheatstone bridge circuit WB, the force Fx1 received by the independent force-receiving body 20 is calculated.

[0353] Similarly, as Figure 21 shown, at the positions where strain gauges R13 and R24 are pasted on the independent force sensor 10 on the negative side in the Y-axis direction, compressive stress is detected, and at the positions where strain gauges R14 and R23 are pasted, tensile stress is detected. In strain gauges R13 and R24, the resistance value decreases according to the compressive strain. In strain gauges R14 and R23, the resistance value increases according to the tensile strain. Then, based on the output value obtained from the Wheatstone bridge circuit WB, the force Fx2 received by the independent force-receiving body 20 is calculated.

[0354] The torque Mz received by the force-receiving body 120 can also be calculated using the forces received by each independent force-receiving body 20. For example, the following [Equation 14] can also be used to calculate the torque Mz as T4 through the following formula. In the following [Equation 14], for convenience, the force and the torque are connected by "=". However, since the force and the torque are different physical quantities, in fact, the torque Mz is calculated by converting the force.

[0355] [Equation 14]

[0356] T4 = Fx1 + Fx2

[0357] However, the torque Mz can be calculated using Fx1 without using Fx2, or can be calculated using Fx2 without using Fx1.

[0358] Figure 22 And Figure 23 As shown, when the force-receiving body 120 receives a force Fx in the X-axis direction, a force Fy in the Y-axis direction, a force Fz in the Z-axis direction, a torque Mx about the X-axis, and a torque My about the Y-axis, the force-sensing sensor 110 can regard the change in the resistance value of each strain gauge as none. This is because, as Figure 22 And Figure 23 shown, when viewed from the Z-axis direction, the four second connectors 141 are arranged at intervals of 90° with respect to the center point O of the force-receiving body 120.

[0359] In this way, Figure 22 And Figure 23The force sensor 110 shown can only detect the torque Mz about the Z-axis and can also be called a torque sensor. The force sensor 110 can also be used in an environment where only the torque Mz about the Z-axis acts.

[0360] Thus, according to ​ and ​ In the example shown, the body 120 that supports the independent force-receiving body 20 of each independent force sensor 10 and the fixing body 130 that supports the independent fixing body 30 of each independent force sensor 10 are supported by the second connecting body 141. The second connecting body 141 extends in the Z-axis direction from the body-side end portion 143 connected to the body 120 to the fixing-body-side end portion 144 connected to the fixing body 130. When viewed from the Z-axis direction, the first connecting body 41 and the second connecting body 141 of the independent force sensor 10 are formed along the radial direction with respect to the center point O of the body 120. When the body 120 is subjected to the torque Mz about the Z-axis, the first connecting body 41 and the second connecting body 141 can elastically deform, and the resistance value of the strain gauge can be changed. Thereby, the detection element 60 of each independent force sensor 10 can detect the force received by the independent force-receiving body 20, and based on the detection results of the respective detection elements 60, the detection circuit 170 can output an electrical signal indicating the torque Mz received by the body 120. As a result, the force sensor 110 can detect the torque Mz and can function as a torque sensor.

[0361] In addition, according to ​ and ​ In the example shown, the second connecting body 141 extends in the Z-axis direction from the body-side end portion 143 connected to the body 120 to the fixing-body-side end portion 144 connected to the fixing body 130. The independent force sensor 10 supported by the body 120 and the fixing body 130 includes the first strain body 40 and the detection element 60. Thereby, the shapes of the body 120, the fixing body 130, and the second connecting body 141 can be made pure, and the structure of the second connecting body 141 can be simplified. In addition, the interval between the body 120 and the fixing body 130 can be reduced. As a result, the cost of the force sensor 110 can be reduced, and the height (dimension in the Z-axis direction) of the force sensor 110 can be decreased.

[0362] (Sixth Embodiment)

[0363] Next, use ​ to describe the force sensor according to the sixth embodiment of the present invention.

[0364] In ​In the sixth embodiment shown, it is different mainly in that the first strain body of the independent force sensor includes a first thinning portion and a second thinning portion, and the second strain body of the force sensor includes a third thinning portion and a fourth thinning portion, and other configurations are the same as those in ​ the fourth embodiment shown. It should be noted that in ​ , the parts identical to those in ​ the fourth embodiment shown are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0365] First, use ​ to describe the force sensor 110 according to the present embodiment. ​ is a longitudinal sectional view showing the force sensor according to the sixth embodiment. ​ is a top view showing ​ the force sensor shown. In ​ , the bolt holes 126 (see ​ ) are omitted. ​ is a longitudinal sectional view of the second strain body.

[0366] As shown in ​ and ​ , each independent force sensor 10 of the force sensor 110 according to the present embodiment includes ​ and ​ and ​ shown, a first force-receiving thinning portion 45 and a first fixing thinning portion 46. The first force-receiving thinning portion 45 is formed along each of the X-axis direction and the Y-axis direction, and an independent force-receiving main body portion 21 constituting the independent force-receiving body 20 is formed around the first force-receiving thinning portion 45. The first fixing thinning portion 46 is formed along each of the X-axis direction and the Y-axis direction, and an independent fixing main body portion 31 constituting the independent fixing body 30 is formed around the first fixing thinning portion 46.

[0367] As shown in ​As shown, the force sensor 110 according to the present embodiment includes four independent force sensors 10. When viewed from the Z-axis direction, the four independent force sensors 10 are arranged at intervals of 90° with respect to the center point O of the force-receiving body 120. More specifically, the force sensor 110 includes a first independent force sensor 10A, a second independent force sensor 10B, a third independent force sensor 10C, and a fourth independent force sensor 10D. When viewed from the Z-axis direction, the first independent force sensor 10A is arranged on the positive side of the X-axis direction with respect to the center point O of the force-receiving body 120. The second independent force sensor 10B is arranged on the positive side of the Y-axis direction with respect to the center point O of the force-receiving body 120. The third independent force sensor 10C is arranged on the negative side of the X-axis direction with respect to the center point O of the force-receiving body 120. The fourth independent force sensor 10D is arranged on the negative side of the Y-axis direction with respect to the center point O of the force-receiving body 120. It should be noted that the number of independent force sensors 10 is not limited to four. For example, as long as it is two or more, it can be arbitrary.

[0368] As ​ shown, the second strain body 140 according to the present embodiment includes a second force-receiving thinning portion 145. The second force-receiving thinning portion 145 is an example of the third thinning portion. The second force-receiving thinning portion 145 is formed along a plane orthogonal to the Z-axis direction. That is, the second force-receiving thinning portion 145 is formed along each of the X-axis direction and the Y-axis direction.

[0369] The force-receiving body 120 includes a force-receiving main body portion 123. The force-receiving main body portion 123 is formed around the second force-receiving thinning portion 145.

[0370] The second force-receiving thinning portion 145 is interposed between the force-receiving body 120 and the second connecting body 141, and connects the force-receiving main body portion 123 and the force-receiving body side end portion 143 of the second connecting body 141. The second force-receiving thinning portion 145 is thinner than the force-receiving main body portion 123 of the force-receiving body 120. More specifically, as ​ shown, the thickness t9 (Z-axis direction dimension) of the second force-receiving thinning portion 145 is thinner than the thickness t10 of the force-receiving main body portion 123. The second force-receiving thinning portion 145 has flexibility and can be elastically deformed by the action of force or torque.

[0371] The planar shape of the second force-receiving thinning portion 145 is not particularly limited. As ​ shown, it may also be circular. By forming the second force-receiving thinning portion 145, a force-receiving concave portion 122 may be formed on the surface ( ​ the upper surface in this case) of the force-receiving body 120 on the side opposite to the fixed body 130.

[0372] The second connecting body 141 according to the present embodiment may also be formed in a circular shape when viewed from the Z-axis direction. The second connecting body 141 may also be formed in a cylindrical shape extending in the Z-axis direction. When viewed from the Z-axis direction, the second connecting body 141 may be arranged concentrically with the corresponding second force-reducing thinning portion 145, or may be arranged concentrically with the corresponding second fixed thinning portion 146 described later.

[0373] As ​ shown, the second strain body 140 according to the present embodiment includes a second fixed thinning portion 146. The second fixed thinning portion 146 is an example of the fourth thinning portion. The second fixed thinning portion 146 is formed along a plane orthogonal to the Z-axis direction. That is, the second fixed thinning portion 146 is formed along each direction of the X-axis direction and the Y-axis direction.

[0374] The fixing body 130 includes a fixing main body portion 133. The fixing main body portion 133 is formed around the second fixed thinning portion 146.

[0375] The second fixed thinning portion 146 is interposed between the fixing body 130 and the second connecting body 141, and connects the fixing main body portion 133 and the fixing body side end portion 144 of the second connecting body 141. The second fixed thinning portion 146 is thinner than the fixing main body portion 133 of the fixing body 130. More specifically, as ​ shown, the thickness t11 (Z-axis direction dimension) of the second fixed thinning portion 146 is thinner than the thickness t12 of the fixing main body portion 133. The second fixed thinning portion 146 has flexibility and can be elastically deformed by the action of force or moment.

[0376] The planar shape of the second fixed thinning portion 146 is not particularly limited. As ​ shown, it may also be circular like the second force-reducing thinning portion 145. By forming the second fixed thinning portion 146, a fixing concave portion 132 may be formed on the surface ( ​ the lower surface in ) of the fixing body 130 on the side opposite to the force-receiving body 120.

[0377] With respect to the force or moment in each axis component, the rigidity of the second connecting body 141 is higher than the rigidity of the first connecting body 41. More specifically, as ​ shown, the diameter φ1 of the second connecting body 141 is larger than the diameter φ2 of the first connecting body 41 of the independent force sensor 10. Thus, similar to the ​ force sensor 110 shown, the spring constant of the second connecting body 141 is larger than the spring constant of the first connecting body 41. Therefore, the second connecting body 141 is more difficult to be elastically deformed by the action of the force or moment in each axis component than the first connecting body 41.

[0378] With respect to the force or torque in each axis component, the rigidity of the second force-receiving thinning portion 145 and the rigidity of the second fixed thinning portion 146 are higher than the rigidity of the first force-receiving thinning portion 45 and the rigidity of the first fixed thinning portion 46. More specifically, the thickness t9 of the second force-receiving thinning portion 145 is larger than the thickness t2 of the first force-receiving thinning portion 45 (refer to ​ ), and the thickness t11 of the second fixed thinning portion 146 is larger than the thickness t4 of the first fixed thinning portion 46 (refer to ​ ). Thus, the spring constant of the second force-receiving thinning portion 145 is larger than the spring constant of the first force-receiving thinning portion 45, and the spring constant of the second fixed thinning portion 146 is larger than the spring constant of the first fixed thinning portion 46. Therefore, due to the action of the force or torque in each axis component, the second force-receiving thinning portion 145 is more difficult to elastically deform than the first force-receiving thinning portion 45, and the second fixed thinning portion 146 is more difficult to elastically deform than the first fixed thinning portion 46.

[0379] Thus, when the force sensor 110 according to the present embodiment receives a force or torque, the displacement of the force-receiving body 120 is dominated by the elastic deformation of the second connecting body 141, the second force-receiving thinning portion 145, and the second fixed thinning portion 146. The first connecting body 41 has a lower rigidity than the second connecting body 141, so it follows the displacement of the force-receiving body 120 based on the second connecting body 141. The first force-receiving thinning portion 45 has a lower rigidity than the second force-receiving thinning portion 145, and the first fixed thinning portion 46 has a lower rigidity than the second fixed thinning portion 146. Therefore, the first force-receiving thinning portion 45 and the first fixed thinning portion 46 follow the displacement of the force-receiving body 120 based on the second connecting body 141. The influence of the elastic deformation of the first connecting body 41 on the displacement of the force-receiving body 120 can be substantially regarded as none. The influence of the elastic deformation of the first force-receiving thinning portion 45 and the elastic deformation of the first fixed thinning portion 46 on the displacement of the force-receiving body 120 can be substantially regarded as none.

[0380] Similarly in the present embodiment, the force-receiving body 120, the fixing body 130, and the second strain body 140 may also be integrally formed of a continuous material. The force-receiving body 120, the fixing body 130, and the second strain body 140 may also constitute a sensor structure body 150.

[0381] However, the force sensor 110 according to the present embodiment is not limited thereto. For example, at least two of the force-receiving body 120, the fixing body 130, and the second strain body 140 may be integrally formed, and the other components may be formed as separate bodies.

[0382] For example, it can also be that the force-receiving main body portion 123 and the second force-receiving thinning portion 145 are formed integrally, and the second force-receiving thinning portion 145 and the second connecting body 141 are formed in a separated manner. In this case, a bolt hole for inserting a bolt (not shown) for fixing the second force-receiving thinning portion 145 and the second connecting body 141 can also be formed in the second force-receiving thinning portion 145. Thus, the bolt head of the bolt can be received in the force-receiving recess 122. Therefore, it is possible to prevent the bolt head from protruding from the force-receiving body 120, and the height of the force sense sensor 110 can be reduced.

[0383] For example, it can also be that the fixing main body portion 133 and the second fixing thinning portion 146 are formed integrally, and the second fixing thinning portion 146 and the second connecting body 141 are formed in a separated manner. In this case, a bolt hole for inserting a bolt for fixing the second fixing thinning portion 146 and the second connecting body 141 can also be formed in the second fixing thinning portion 146. Thus, the bolt head of the bolt can be received in the fixing recess 132. Therefore, it is possible to prevent the bolt head from protruding from the fixing body 130, and the height of the force sense sensor 110 can be reduced.

[0384] For example, it can also be that, in the case where the force-receiving main body portion 123 and the second force-receiving thinning portion 145 are formed integrally and the second force-receiving thinning portion 145 and the second connecting body 141 are formed in a separated manner, the fixing main body portion 133 and the second fixing thinning portion 146 are formed integrally, and the second fixing thinning portion 146 and the second connecting body 141 are formed in a separated manner. The second force-receiving thinning portion 145 and the second connecting body 141 can also be fixed using a bolt as described above. The second fixing thinning portion 146 and the second connecting body 141 can also be fixed using a bolt as described above.

[0385] Each independent force sense sensor 10A to 10D according to the present embodiment has the same configuration as the ​ and ​ and ​ above-described independent force sense sensor 10 shown, so detailed description thereof is omitted here. The detection element 60 of each independent force sense sensor 10A to 10D includes two capacitance elements.

[0386] The detection element 60 of the first independent force sense sensor 10A includes a first capacitance element C11 and a second capacitance element C12. The first capacitance element C11 corresponds to the ​ and ​ and ​ above-described first capacitance element C1 shown, and the second capacitance element C12 corresponds to the second capacitance element C2. The first capacitance element C11 is disposed on the negative side in the Y-axis direction, and the second capacitance element C12 is disposed on the positive side in the Y-axis direction.

[0387] The detection element 60 of the second independent force sensor 10B includes a third capacitance element C13 and a fourth capacitance element C14. The third capacitance element C13 is equivalent to ​ and ​ and ​ the first capacitance element C1 shown. The fourth capacitance element C14 is equivalent to the second capacitance element C2. The third capacitance element C13 is arranged on the positive side in the X-axis direction, and the fourth capacitance element C14 is arranged on the negative side in the X-axis direction.

[0388] The detection element 60 of the third independent force sensor 10C includes a fifth capacitance element C15 and a sixth capacitance element C16. The fifth capacitance element C15 is equivalent to ​ and ​ and ​ the first capacitance element C1 shown. The sixth capacitance element C16 is equivalent to the second capacitance element C2. The fifth capacitance element C15 is arranged on the positive side in the Y-axis direction, and the sixth capacitance element C16 is arranged on the negative side in the Y-axis direction.

[0389] The detection element 60 of the fourth independent force sensor 10D includes a seventh capacitance element C17 and an eighth capacitance element C18. The seventh capacitance element C17 is equivalent to ​ and ​ and Figure 9B the first capacitance element C1 shown. The eighth capacitance element C18 is equivalent to the second capacitance element C2. The seventh capacitance element C17 is arranged on the negative side in the X-axis direction, and the eighth capacitance element C18 is arranged on the positive side in the X-axis direction.

[0390] Next, a method for detecting force or torque in the force sensor 110 according to the present embodiment having such a configuration will be described using Figure 27 and Figure 28 . Figure 27 is a table showing Figure 24 the changes in the capacitance values of the capacitance elements C11 to C18 in the force sensor shown, Figure 28 is a table showing the principal axis sensitivity and the cross-axis sensitivity based on Figure 27 the changes in the capacitance values shown.

[0391] (When +Fx acts)

[0392] First, a case where a force Fx is applied to the force-receiving body 120 in the positive X-axis direction will be described. When the force Fx is applied to the force-receiving body 120, the second connecting bodies 141 of the respective second strain bodies 140 elastically deform. By interposing the second force-thinning portion 145 between the force-receiving main body portion 123 of the force-receiving body 120 and the second connecting body 141, the second force-thinning portion 145 also elastically deforms. Similarly, by interposing the second fixing-thinning portion 146 between the fixing main body portion 133 of the fixing body 130 and the second connecting body 141, the second fixing-thinning portion 146 also elastically deforms. The second force-thinning portion 145 and the second fixing-thinning portion 146 elastically deform in the same manner as Figure 10 the first force-thinning portion 45 and the first fixing-thinning portion 46 shown. In this way, the force-receiving body 120 to which the force Fx is applied is displaced in the positive X-axis direction. It should be noted that if the second force-thinning portion 145 and the second fixing-thinning portion 146 elastically deform, the second connecting body 141 may not substantially elastically deform.

[0393] In this case, the first strain body 40 of the first independent force sensor 10A rotates about the Y-axis (clockwise in the positive Y-axis direction). However, the first capacitor element C11 and the second capacitor element C12 are arranged at the same position in the X-axis direction. Therefore, it can be regarded that there is substantially no change in the electrostatic capacitance value in the first capacitor element C11 and the second capacitor element C12. This is shown as "0 (zero)" under C11 and C12 in the row of Fx in the table shown in Figure 27 .

[0394] Regarding the first strain body 40 of the second independent force sensor 10B, the electrostatic capacitance value of the third capacitor element C13 increases, and the electrostatic capacitance value of the fourth capacitor element C14 decreases. This is shown as "+ (positive)" under C13 and "- (negative)" under C14 in the row of Fx in the table shown in Figure 27 .

[0395] The first strain body 40 of the third independent force sensor 10C rotates about the Y-axis in the same manner as the first independent force sensor 10A. However, the fifth capacitor element C15 and the sixth capacitor element C16 are arranged at the same position in the X-axis direction. Therefore, it can be regarded that there is substantially no change in the electrostatic capacitance value in the fifth capacitor element C15 and the sixth capacitor element C16. This is shown as "0 (zero)" under C15 and C16 in the row of Fx in the table shown in Figure 27 .

[0396] Regarding the first strain body 40 of the fourth independent force sensor 10D, the electrostatic capacitance value of the seventh capacitor element C17 decreases, and the electrostatic capacitance value of the eighth capacitor element C18 increases. This is shown in Figure 27In the table shown, the value below C17 in the row of Fx is shown as "- (negative)", and the value below C18 is shown as "+ (positive)".

[0397] (When +Fy acts)

[0398] Next, a case where a force Fy acts on the force-receiving body 120 in the positive direction of the Y-axis will be described. When the force Fy acts on the force-receiving body 120, the second connecting body 141, the second force-receiving thinning portion 145, and the second fixed thinning portion 146 of each second strain body 140 elastically deform, and the force-receiving body 120 is displaced in the positive direction of the Y-axis. The second force-receiving thinning portion 145 and the second fixed thinning portion 146 elastically deform. It should be noted that if the second force-receiving thinning portion 145 and the second fixed thinning portion 146 elastically deform, the second connecting body 141 may not substantially elastically deform. In the following description, the symbols in the Figure 27 table are also determined based on the change in the capacitance value as described above.

[0399] In this case, regarding the first strain body 40 of the first independent force sensor 10A, the capacitance value of the first capacitor element C11 decreases, and the capacitance value of the second capacitor element C12 increases.

[0400] The first strain body 40 of the second independent force sensor 10B rotates about the X-axis. However, the third capacitor element C13 and the fourth capacitor element C14 are arranged at the same position in the Y-axis direction. Therefore, it can be regarded that there is substantially no change in the capacitance value in the third capacitor element C13 and the fourth capacitor element C14.

[0401] Regarding the first strain body 40 of the third independent force sensor 10C, the capacitance value of the fifth capacitor element C15 increases, and the capacitance value of the sixth capacitor element C16 decreases.

[0402] The first strain body 40 of the fourth independent force sensor 10D rotates about the X-axis in the same manner as the second independent force sensor 10B. However, the seventh capacitor element C17 and the eighth capacitor element C18 are arranged at the same position in the Y-axis direction. Therefore, it can be regarded that there is substantially no change in the capacitance value in the seventh capacitor element C17 and the eighth capacitor element C18.

[0403] (When +Fz acts)

[0404] Next, a case where a force Fz acts on the force-receiving body 120 in the positive direction of the Z-axis will be described. When the force Fz acts on the force-receiving body 120, the second force-receiving thinning portion 145 and the second fixed thinning portion 146 of each second strain body 140 are the same as Figure 11The first force-reducing thinned portion 45 and the first fixed thinned portion 46 shown are also elastically deformed. As a result, the force-receiving body 120 and the second connecting body 141 are displaced in the positive Z-axis direction. The second connecting body 141 is not substantially elastically deformed in the Z-axis direction. When the force-receiving body 120 is displaced in the positive Z-axis direction, the first strain bodies 40 of the respective independent force sensors 10A to 10D are elastically deformed as Figure 11 shown. As a result, the electrostatic capacitance values of the respective capacitor elements C11 to C18 decrease.

[0405] (When +Mx acts)

[0406] Next, the case where a moment Mx about the X-axis (clockwise in the positive X-axis direction) acts on the force-receiving body 120 will be described. When the moment Mx acts on the force-receiving body 120, the second connecting body 141, the second force-reducing thinned portion 145, and the second fixed thinned portion 146 of the respective second strain bodies 140 are elastically deformed, and the force-receiving body 120 is displaced about the X-axis. It should be noted that if the second force-reducing thinned portion 145 and the second fixed thinned portion 146 are elastically deformed, the second connecting body 141 may not be substantially elastically deformed.

[0407] In this case, a force Fz is applied to the first strain body 40 of the second independent force sensor 10B in the positive Z-axis direction, and a force Fz is applied to the first strain body 40 of the fourth independent force sensor 10D in the negative Z-axis direction. As a result, similar to Figure 11 the independent force sensor 10 shown, the electrostatic capacitance values of the third capacitor element C13 and the fourth capacitor element C14 of the second independent force sensor 10B decrease. Similar to Figure 12 the independent force sensor 10 shown, the electrostatic capacitance values of the seventh capacitor element C17 and the eighth capacitor element C18 of the fourth independent force sensor 10D increase.

[0408] The first strain body 40 of the first independent force sensor 10A is arranged at the same position as the center point O of the force-receiving body 120 in the Y-axis direction. Therefore, the first strain body 40 of the first independent force sensor 10A is arranged on the X-axis, and the displacement of the displacement body 42 of the first independent force sensor 10A is smaller than the displacement of the displacement body 42 of the second independent force sensor 10B and the displacement of the displacement body 42 of the fourth independent force sensor 10D. Here, for simplicity of explanation, it can be considered that the displacement body 42 of the first independent force sensor 10A does not substantially displace. Therefore, it can be considered that the electrostatic capacitance values of the first capacitance element C11 and the second capacitance element C12 of the first independent force sensor 10A do not substantially change. Similarly, the first strain body 40 of the third independent force sensor 10C is also arranged at the same position as the center point O of the force-receiving body 120 in the Y-axis direction. Therefore, the first strain body 40 of the third independent force sensor 10C is also arranged on the X-axis, and it can be considered that the electrostatic capacitance values of the fifth capacitance element C15 and the sixth capacitance element C16 of the third independent force sensor 10C do not substantially change.

[0409] (Case where +My acts)

[0410] Next, the case where a moment My about the Y-axis (clockwise in the positive Y-axis direction) acts on the force-receiving body 120 will be described. When the moment My acts on the force-receiving body 120, the second connecting body 141, the second force-reducing thinned portion 145, and the second fixed thinned portion 146 of each second strain body 140 are elastically deformed, and the force-receiving body 120 is displaced about the Y-axis. It should be noted that if the second force-reducing thinned portion 145 and the second fixed thinned portion 146 are elastically deformed, the second connecting body 141 may not substantially elastically deform.

[0411] In this case, a force Fz is applied to the first strain body 40 of the first independent force sensor 10A in the negative Z-axis direction, and a force Fz is applied to the first strain body 40 of the third independent force sensor 10C in the positive Z-axis direction. Thus, similar to the Figure 12 independent force sensor 10 shown, the electrostatic capacitance values of the first capacitance element C11 and the second capacitance element C12 of the first independent force sensor 10A increase. Similar to the Figure 11 independent force sensor 10 shown, the electrostatic capacitance values of the fifth capacitance element C15 and the sixth capacitance element C16 of the third independent force sensor 10C decrease.

[0412] The first strain body 40 of the second independent force sensor 10B is arranged at the same position as the center point O of the force receiving body 120 in the X-axis direction. Therefore, the first strain body 40 of the second independent force sensor 10B is arranged on the Y-axis, and the displacement of the displacement body 42 of the second independent force sensor 10B is smaller than the displacement of the displacement body 42 of the first independent force sensor 10A and the displacement of the displacement body 42 of the third independent force sensor 10C. Here, for simplicity of explanation, it can be regarded that the displacement body 42 of the second independent force sensor 10B does not substantially displace. Therefore, it can be regarded that the electrostatic capacitance values of the third capacitor element C13 and the fourth capacitor element C14 of the second independent force sensor 10B do not substantially change. Similarly, the first strain body 40 of the fourth independent force sensor 10D is also arranged at the same position as the center point O of the force receiving body 120 in the X-axis direction. Therefore, the first strain body 40 of the fourth independent force sensor 10D is also arranged on the Y-axis, and it can be regarded that the electrostatic capacitance values of the seventh capacitor element C17 and the eighth capacitor element C18 of the fourth independent force sensor 10D do not substantially change.

[0413] (When +Mz acts)

[0414] Next, the case where a moment Mz about the Z-axis (clockwise in the positive Z-axis direction) acts on the force receiving body 120 will be described. When the moment Mz acts on the force receiving body 120, the second connecting body 141, the second force receiving thinning part 145, and the second fixed thinning part 146 of each second strain body 140 elastically deform, and the force receiving body 120 displaces about the Z-axis. It should be noted that if the second force receiving thinning part 145 and the second fixed thinning part 146 elastically deform, the second connecting body 141 may not substantially elastically deform.

[0415] In this case, the first strain body 40 of the first independent force sensor 10A elastically deforms in the same manner as the case where a force Fy acts on the positive side in the Y-axis direction. As a result, the electrostatic capacitance value of the first capacitor element C11 of the first independent force sensor 10A decreases, and the electrostatic capacitance value of the second capacitor element C12 increases.

[0416] The first strain body 40 of the second independent force sensor 10B elastically deforms in the same manner as the case where a force Fx acts on the negative side in the X-axis direction. As a result, the electrostatic capacitance value of the third capacitor element C13 of the second independent force sensor 10B decreases, and the electrostatic capacitance value of the fourth capacitor element C14 increases.

[0417] The first strain body 40 of the third independent force sensor 10C elastically deforms in the same manner as the case where a force Fy acts on the negative side in the Y-axis direction. As a result, the electrostatic capacitance value of the fifth capacitor element C15 of the third independent force sensor 10C decreases, and the electrostatic capacitance value of the sixth capacitor element C16 increases.

[0418] The first strain body 40 of the fourth independent force sensor 10D elastically deforms in the same manner as when a force Fx in the positive side of the X-axis direction acts thereon. As a result, the electrostatic capacitance value of the seventh capacitance element C17 of the fourth independent force sensor 10D decreases, and the electrostatic capacitance value of the eighth capacitance element C18 increases.

[0419] Thus, the force sensor 110 according to the present embodiment can detect the force Fx, the force Fy, the force Fz, the torque Mx, the torque My, and the torque Mz, and can detect six-axis components. When the force Fx, the force Fy, the force Fz, the torque Mx, the torque My, and the torque Mz act on the force-receiving body 120, changes in the electrostatic capacitance values of the respective capacitance elements C11 to C18 are detected, and the direction and magnitude of the force or torque acting on the force-receiving body 120 are detected. Then, as Figure 27 shown, the electrostatic capacitance values of the respective capacitance elements C11 to C18 change.

[0420] According to Figure 27 the table shown, the Fx, the force Fy, the force Fz, the torque Mx, the torque My, and the torque Mz acting on the force-receiving body 120 can also be calculated by the following formulas. Thereby, six-axis components of the force can be detected.

[0421] [Equation 15]

[0422] Fx = +C13 - C14 - C17 + C18

[0423] [Equation 16]

[0424] Fx = -C11 + C12 + C15 - C16

[0425] [Equation 17]

[0426] Fz = -C11 - C12 - C13 - C14 - C15 - C16 - C17 - C18

[0427] [Equation 18]

[0428] Mx = -C13 - C14 + C17 + C18

[0429] [Equation 19]

[0430] Mx = C11 + C12 - C15 - C16

[0431] [Equation 20]

[0432] Mz = -C11 + C12 - C13 + C14 - C15 + C16 - C17 + C18

[0433] As described above, Figure 24 and Figure 25The force sensor 110 shown can detect the force Fx, the force Fy, the force Fz, the torque Mx, the torque My, and the torque Mz as shown in the above [Equation 15] to [Equation 20], so it can detect the six-axis components of the force. However, the axial components of the force that the force sensor 110 can detect are not limited to 6, and depending on the number, structure, and shape of the strain bodies, the detectable axial components are arbitrary. Although detailed description is omitted, for example, the six-axis components of the force and torque can also be detected by using three strain bodies.

[0434] If the changes in the electrostatic capacitance values of the respective capacitive elements C11 to C18 shown Figure 27 are applied to the above [Equation 15] to [Equation 20], then Figure 28 a table showing the principal axis sensitivity and the cross-axis sensitivity is obtained. Figure 28 The VFx shown is the output when the force Fx in the X-axis direction acts, the VFy is the output when the force Fy in the Y-axis direction acts, and the VFz is the output when the force Fz in the Z-axis direction acts. In addition, the VMx is the output when the torque Mx about the X-axis acts, the VMy is the output when the torque My about the Y-axis acts, and the VMz is the output when the torque Mz about the Z-axis acts.

[0435] Figure 28 The values shown in the table of Figure 27 are obtained by setting the capacitive elements marked with the "+" sign to "+1" and the capacitive elements marked with the "-" sign to "-1" for each of the forces Fx, Fy, Fz and each of the torques Mx, My, Mz recorded in the table of Figure 27 and substituting them into the right sides of the above [Equation 15] to [Equation 20]. For example, the value "4" recorded in the cell where the column of Fx intersects the row of VFx is the value obtained by substituting "+1" into C13 and C18 and "-1" into C14 and C17 based on the Figure 27 row of Fx in the table of

[0436] As Figure 28 shown, for the force Fx, the value of VFx is "4", while the values of VFy, VFz, VMx, VMy, and VMz are "0". Thus, for the force Fx, there is no cross-axis sensitivity, and only the principal axis sensitivity can be detected. Similarly, for the forces Fy, Fz and the torques Mx, My, Mz, there is no cross-axis sensitivity, and only the principal axis sensitivity can be detected respectively. That is, a force sensor 110 capable of suppressing the generation of cross-axis sensitivity can be obtained.

[0437] It should be noted that the situation of cross-axis sensitivity generation is also considered. For example, when a force Fz acts on the positive side in the Z-axis direction on the first independent force sensor 10A, sometimes the change amount of the electrostatic capacitance value of the first capacitor element C11 is different from the change amount of the electrostatic capacitance value of the second capacitor element C12. In this case, cross-axis sensitivity may be generated with respect to the force Fz. In addition, when the forces Fz, torque Mx, and My act on the force-receiving body 120, the first independent force sensor 10A is displaced in the Z-axis direction. Therefore, in the rows of Fz, Mx, and My in the table shown in Figure 27 , even if the same symbol is marked, the change amount of the electrostatic capacitance value may be different. In this case, cross-axis sensitivity may be generated with respect to the forces Fz, torque Mx, and My. Similarly, cross-axis sensitivity may also be generated with respect to the forces Fx, Fy, and torque Mz. For example, when the torque Mx acts on the force-receiving body 120, as shown in Figure 27 , in the first capacitor element C11, the second capacitor element C12, the fifth capacitor element C15, and the sixth capacitor element C16, the electrostatic capacitance value does not change, so the value "0" is recorded. However, sometimes the electrostatic capacitance value may change to generate cross-axis sensitivity. The same is true for the torques My and Mz. In addition, in the rows of the forces Fx and Fy, for the capacitor elements in which the value "0" is recorded, sometimes the electrostatic capacitance value may also change to generate cross-axis sensitivity.

[0438] However, even in the case where cross-axis sensitivity is generated, it is possible to perform correction calculation by obtaining the inverse matrix of the cross-axis sensitivity matrix (a 6-row and 6-column matrix corresponding to the table shown in Figure 28 , also called the characteristic matrix) and multiplying the inverse matrix by the output (characteristic matrix) of the force sensor. As a result, the cross-axis sensitivity can be reduced, and the generation of cross-axis sensitivity can be suppressed.

[0439] In this way, according to the present embodiment, the second strain body 140 includes a second force-receiving thinning portion 145, and the second force-receiving thinning portion 145 connects the force-receiving body 120 and the force-receiving body side end portion 143 of the second connecting body 141. The second force-receiving thinning portion 145 is thinner than the force-receiving body 120. Thus, the second force-receiving thinning portion 145 can be elastically deformed by the action of a force or a torque. Therefore, the force-receiving body 120 can be displaced, and the displacement bodies 42 of the respective independent force sensors 10 can be displaced. Thereby, the detection elements 60 of the respective independent force sensors 10 can detect the force received by the independent force-receiving body 20. Based on the detection results of the respective detection elements 60, the detection circuit 170 can output an electric signal indicating the force or torque received by the force-receiving body 120. As a result, the force sensor 110 can detect the force or torque. In addition, while realizing the purity of the shape and the simplification of the structure of the second strain body 140, the number of axial components that can be detected can be increased, and the versatility can be improved.

[0440] In addition, according to the present embodiment, the second strain body 140 includes a second fixed thinning portion 146 that connects the fixed body 130 to the fixed body side end portion 144 of the second connecting body 141. The second fixed thinning portion 146 is thinner than the fixed body 130. Thus, the second fixed thinning portion 146 can be elastically deformed by the action of force or torque. Therefore, the force receiving body 120 can be displaced, and the displacement bodies 42 of the respective independent force sensors 10 can be displaced. As a result, the detection elements 60 of the respective independent force sensors 10 can detect the force received by the independent force receiving body 20, and based on the detection results of the respective detection elements 60, the detection circuit 170 can output an electrical signal representing the force or torque received by the force receiving body 120. As a result, the force sensor 110 can detect force or torque. In addition, while achieving the purity of the shape and the simplification of the structure of the second strain body 140, the number of axial components that can be detected can be increased, and the versatility can be improved.

[0441] In addition, according to the present embodiment, the first strain body 40 of each independent force sensor 10 includes a first force receiving thinning portion 45 that connects the independent force receiving body 20 to the force receiving body side end portion 43 of the first connecting body 41. The first force receiving thinning portion 45 is thinner than the independent force receiving body 20. Thus, the first force receiving thinning portion 45 can be elastically deformed by the action of force or torque. Therefore, the displacement bodies 42 of the first strain bodies 40 of the respective independent force sensors 10 can be displaced, and the electrostatic capacitance values of the respective capacitor elements C11 to C18 can be changed. As a result, six-axis components can be detected.

[0442] In addition, according to the present embodiment, the first strain body 40 of each independent force sensor 10 includes a first fixed thinning portion 46 that connects the independent fixed body 30 to the fixed body side end portion 44 of the first connecting body 41. The first fixed thinning portion 46 is thinner than the independent fixed body 30. Thus, the first fixed thinning portion 46 can be elastically deformed by the action of force or torque. Therefore, the displacement bodies 42 of the first strain bodies 40 of the respective independent force sensors 10 can be displaced, and the electrostatic capacitance values of the respective capacitor elements C11 to C18 can be changed. As a result, six-axis components can be detected.

[0443] It should be noted that, in the above-described present embodiment, an example in which each second strain body 140 includes a second force receiving thinning portion 145 and a second fixed thinning portion 146 has been described. However, it is not limited thereto. For example, if each second strain body 140 includes the second fixed thinning portion 146, it may not include the second force receiving thinning portion 145.

[0444] In addition, in the above-described embodiment, an example in which the first strain body 40 of each independent force sensor 10 includes a first force-receiving thinning portion 45 and a first fixed thinning portion 46 has been described. However, it is not limited thereto. For example, if each first strain body 40 includes a first fixed thinning portion 46, it may not include a first force-receiving thinning portion 45.

[0445] In addition, in the above-described embodiment, a plurality of through holes (not shown) may be provided in the second force-receiving thinning portion 145. In this case, the flexibility of the second force-receiving thinning portion 145 can be increased. Alternatively, when the second force-receiving thinning portion 145 includes a through hole, the thickness t2 of the second force-receiving thinning portion 145 can be increased. When the sensor structure 150 is manufactured by casting, by increasing the thickness of the second force-receiving thinning portion 145, the flow of the molten metal can be ensured also in the portion corresponding to the second force-receiving thinning portion 145 in the mold. As the planar shape of the through hole, any shape such as a circle, a semicircle, an ellipse, a sector, a triangle, and a rectangle can be adopted as long as the second force-receiving thinning portion 145 can have flexibility. The same applies to the second fixed thinning portion 146.

[0446] (Seventh Embodiment)

[0447] Next, Figures 29 to 34 will be used to describe the independent force sensor and the force sensor according to the seventh embodiment of the present invention.

[0448] In Figures 29 to 34 the seventh embodiment shown, it is mainly different in that the first strain body of the independent force sensor includes a first protruding portion protruding in the Z-axis direction from the first thinning portion and a second protruding portion protruding in the Z-axis direction from the fixed thinning portion, and other configurations are substantially the same as those of Figures 24 to 28 the sixth embodiment shown. It should be noted that in Figures 29 to 34 , the same reference numerals are given to the parts that are the same as those of Figures 24 to 28 the sixth embodiment shown, and the detailed description thereof is omitted.

[0449] First, Figure 29 will be used to describe the independent force sensor 10 according to the present embodiment.

[0450] As shown in Figure 29 , the first strain body 40 according to the present embodiment includes: a first force-receiving protruding portion 47 protruding in the Z-axis direction from the first force-receiving thinning portion 45, and a first fixed protruding portion 48 protruding in the Z-axis direction from the first fixed thinning portion 46. The first force-receiving protruding portion 47 is an example of the first protruding portion, and the first fixed protruding portion 48 is an example of the second protruding portion.

[0451] As shown in Figure 30As shown, when viewed from the Z-axis direction, the first force-receiving protrusion 47 can also be disposed at a position along the second direction with respect to the first connecting body 41. In Figure 30 the independent force sensor 10 shown, the second direction corresponds to the X-axis direction. The first force-receiving protrusion 47 is disposed on the negative X-axis side of the first connecting body 41.

[0452] As Figure 29 shown, the first force-receiving protrusion 47 according to the present embodiment can also be connected to the first connecting body 41. The first force-receiving protrusion 47 can also be disposed on the surface of the independent fixing body 30 side of the first force-reducing portion 45 ( Figure 29 the lower surface shown). More specifically, the first force-receiving protrusion 47 is connected to the force-receiving body side end portion 43 of the first connecting body 41 and is formed from the first force-reducing portion 45 to the force-receiving body side end portion 43. The first force-receiving protrusion 47 can also be formed in a rib shape. The first force-receiving protrusion 47 can also extend from the first connecting body 41 toward the negative X-axis direction. However, the direction in which the first force-receiving protrusion 47 extends from the first connecting body 41 is arbitrary.

[0453] As Figure 29 shown, when viewed from the longitudinal section passing through the first force-receiving protrusion 47, the first force-reducing portion 45 includes: an inner end portion 45a located on the force-receiving body side end portion 43 side of the first connecting body 41, and an outer end portion 45b located on the independent force-receiving main body portion 21 side. The inner end portion 45a is an end portion located inside with respect to the center (corresponding to the first connecting body 41) when viewed from the Z-axis direction, and the outer end portion 45b is an end portion located outside with respect to the center. The first force-receiving protrusion 47 according to the present embodiment is disposed at the inner end portion 45a. The first force-receiving protrusion 47 can also be separated from the outer end portion 45b. Figure 29 The longitudinal section shown is a section along the X-axis direction and along the Z-axis direction.

[0454] As Figure 30 shown, when viewed from the Z-axis direction, the planar shape of the first force-receiving protrusion 47 can also be rectangular. However, the planar shape of the first force-receiving protrusion 47 can also be circular, and it is arbitrary.

[0455] When viewed from the Z-axis direction, the first fixing protrusion 48 can also be disposed at a position along the X-axis direction with respect to the first connecting body 41 in the same manner as the first force-receiving protrusion 47. The first fixing protrusion 48 is disposed from the first connecting body 41 toward the negative X-axis direction. When viewed from the Z-axis direction, the first fixing protrusion 48 can also overlap with the first force-receiving protrusion 47.

[0456] As Figure 29As shown, the first fixing protrusion 48 according to the present embodiment may also be connected to the first connecting body 41. The first fixing protrusion 48 may also be disposed on the surface of the independent force-bearing body 20 side of the first fixing thinning portion 46 ( Figure 29 the upper surface shown). More specifically, the first fixing protrusion 48 is connected to the fixing body side end portion 44 of the first connecting body 41 and is formed from the first fixing thinning portion 46 to the fixing body side end portion 44. The first fixing protrusion 48 may also be formed in a rib shape. The first fixing protrusion 48 may also extend in the negative X-axis direction from the first connecting body 41. However, the direction in which the first fixing protrusion 48 extends from the first connecting body 41 is arbitrary.

[0457] As Figure 29 shown, when viewed from a longitudinal section passing through the first fixing protrusion 48, the first fixing thinning portion 46 includes: an inner end portion 46a on the side of the fixing body side end portion 44 of the first connecting body 41, and an outer end portion 46b on the side of the independent fixing main body portion 31. The inner end portion 46a is an end portion located inside with respect to the center (corresponding to the first connecting body 41) when viewed from the Z-axis direction, and the outer end portion 46b is an end portion located outside with respect to the center. The first fixing protrusion 48 according to the present embodiment is disposed on the inner end portion 46a. The first fixing protrusion 48 may also be separated from the outer end portion 46b.

[0458] When viewed from the Z-axis direction, the planar shape of the first fixing protrusion 48 may also be rectangular. However, the planar shape of the first fixing protrusion 48 may also be circular, which is arbitrary. The planar shape of the first fixing protrusion 48 may also be the same as the planar shape of the first force-bearing protrusion 47.

[0459] Figure 31 Shows a force sensor 110 including Figure 29 the independent force sensor 10 shown. The first force-bearing protrusion 47 and the first fixing protrusion 48 of the first independent force sensor 10A are disposed on the negative Y-axis side of the first connecting body 41. The first force-bearing protrusion 47 and the first fixing protrusion 48 of the second independent force sensor 10B are disposed on the positive X-axis side of the first connecting body 41. The first force-bearing protrusion 47 and the first fixing protrusion 48 of the third independent force sensor 10C are disposed on the positive Y-axis side of the first connecting body 41. The first force-bearing protrusion 47 and the first fixing protrusion 48 of the fourth independent force sensor 10D are disposed on the negative X-axis side of the first connecting body 41.

[0460] When the independent force-receiving body 20 of the independent force sensor 10 is subjected to a force Fz on the positive side in the Z-axis direction, the elastic deformations of the first connecting body 41, the first force-receiving thinning portion 45, and the first fixed thinning portion 46 of the first strain body 40 are suppressed. That is, the first force-receiving protrusion 47 can suppress the elastic deformation of the first force-receiving thinning portion 45. The first fixed protrusion 48 can suppress the elastic deformation of the first fixed thinning portion 46. Thus, the first force-receiving protrusion 47 and the first fixed protrusion 48 can increase the resistance to the force Fz and can suppress the elastic deformation of the first strain body 40 with respect to the force Fz.

[0461] In Figure 31 In the force sensor 110 shown, when a force Fz is applied to the force-receiving body 120 on the positive side in the Z-axis direction, the elastic deformations of the first strain bodies 40 of the independent force sensors 10A to 10D are suppressed. Thus, the sensitivity of the force sensor 110 to the force Fz in the Z-axis direction can be reduced. In addition, since the elastic deformations of the first strain bodies 40 of the independent force sensors 10A to 10D are suppressed, the sensitivity of the force sensor 110 to the moment Mx about the X-axis and the moment My about the Y-axis can be reduced. Therefore, the sensitivity of the force sensor 110 to the force Fx in the X-axis direction, the force Fy in the Y-axis direction, and the moment Mz about the Z-axis can be relatively increased. More specifically, when the first force-receiving thinning portion 45 and the first fixed thinning portion 46 are formed along a plane orthogonal to the Z-axis direction, if the first force-receiving protrusion 47 and the first fixed protrusion 48 do not exist, the first force-receiving thinning portion 45 and the first fixed thinning portion 46 are likely to elastically deform with respect to the force Fz in the Z-axis direction. Thus, the sensitivity of the force sensor 110 to the force Fz, the moment Mx, and the moment My is likely to become higher than the sensitivity of the force sensor 110 to the force Fx, the force Fy, and the moment Mz. When the length of the tool becomes longer, the balance of the sensitivity of the force sensor 110 may be reduced. In contrast, according to the present embodiment, by providing the first force-receiving protrusion 47, the elastic deformation of the first strain bodies 40 of the independent force sensors 10A to 10D with respect to the force Fz can be suppressed. As a result, the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved.

[0462] Thus, according to the present embodiment, the first strain body 40 includes the first force-receiving protrusion 47 protruding from the first force-receiving thinning portion 45 in the Z-axis direction. Thus, the elastic deformation of the first force-receiving thinning portion 45 with respect to the force Fz in the Z-axis direction can be suppressed. Therefore, the sensitivity of the force sensor 110 to the force Fz in the Z-axis direction, the moment Mx about the X-axis, and the moment My about the Y-axis can be reduced, and the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved.

[0463] In addition, according to the present embodiment, the first strain body 40 includes a first fixed protruding portion 48 protruding from the first fixed thinning portion 46 in the Z-axis direction. Thereby, elastic deformation of the first fixed thinning portion 46 with respect to the force Fz in the Z-axis direction can be suppressed. Therefore, the sensitivities of the force sensor 110 with respect to the force Fz in the Z-axis direction, the moment Mx about the X-axis, and the moment My about the Y-axis can be reduced, and the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved.

[0464] It should be noted that, in the above-described present embodiment, an example in which the first force-receiving protruding portion 47 is disposed at the inner end portion 45a of the first force-receiving thinning portion 45 has been described. However, the present embodiment is not limited thereto. For example, as Figure 32 shown, the first force-receiving protruding portion 47 may also be disposed at the outer end portion 45b of the first force-receiving thinning portion 45. In this case, elastic deformation of the first force-receiving thinning portion 45 with respect to the force Fz in the Z-axis direction can also be suppressed. Therefore, the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved. Figure 32 The first force-receiving protruding portion 47 shown may also be separated from the inner end portion 45a of the first force-receiving thinning portion 45.

[0465] In addition, in the above-described present embodiment, an example in which the first fixed protruding portion 48 is disposed at the inner end portion 46a of the first fixed thinning portion 46 has been described. However, the present embodiment is not limited thereto. For example, as Figure 32 shown, the first fixed protruding portion 48 may also be disposed at the outer end portion 46b of the first fixed thinning portion 46. In this case, elastic deformation of the first fixed thinning portion 46 with respect to the force Fz in the Z-axis direction can also be suppressed. Therefore, the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved. Figure 32 The first fixed protruding portion 48 shown may also be separated from the inner end portion 46a of the first fixed thinning portion 46.

[0466] In addition, in the above-described present embodiment, an example in which the first force-receiving protruding portion 47 is disposed on the surface of the first force-receiving thinning portion 45 on the side of the independent fixing body 30 has been described. However, the present embodiment is not limited thereto. For example, the first force-receiving protruding portion 47 may also be disposed on the surface of the first force-receiving thinning portion 45 on the side opposite to the independent fixing body 30. In this case, elastic deformation of the first force-receiving thinning portion 45 with respect to the force Fz in the Z-axis direction can also be suppressed, and the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved.

[0467] In Figure 33 the example shown, the first force-receiving protruding portion 47 is disposed on the surface of the first force-receiving thinning portion 45 on the side opposite to the independent fixing body 30 ( Figure 33The upper surface shown). The first connecting body 41 extends through the first force-reducing and thinning portion 45. The first connecting body 41 includes a force-receiving connecting body protruding portion 49a that protrudes from the first force-reducing and thinning portion 45 toward the positive side in the Z-axis direction. The first force-receiving protruding portion 47 is connected to the force-receiving connecting body protruding portion 49a of the first connecting body 41 and is formed in a rib shape from the first force-reducing and thinning portion 45 to the force-receiving connecting body protruding portion 49a. Figure 33 The first force-receiving protruding portion 47 shown is disposed at the inner end portion 45a of the first force-reducing and thinning portion 45 and is separated from the outer end portion 45b.

[0468] Or, as Figure 34 shown, the first force-receiving protruding portion 47 disposed on the surface of the first force-reducing and thinning portion 45 on the side opposite to the independent fixing body 30 may also be disposed at the outer end portion 45b of the second force-reducing and thinning portion 145. In this case, the first force-receiving protruding portion 47 may also be separated from the inner end portion 45a. In this case, the first connecting body 41 may not include the force-receiving connecting body protruding portion 49a.

[0469] In addition, in the above-described embodiment of the present invention, an example in which the first fixing protruding portion 48 is disposed on the surface of the first fixing and thinning portion 46 on the side of the independent force-receiving body 20 has been described. However, the present embodiment is not limited thereto. For example, the first fixing protruding portion 48 may also be disposed on the surface of the first fixing and thinning portion 46 on the side opposite to the independent force-receiving body 20. In this case, it is also possible to suppress the elastic deformation of the first fixing and thinning portion 46 with respect to the force Fz in the Z-axis direction, and it is possible to improve the balance of the sensitivities of the respective axis components in the force sensor 110.

[0470] In Figure 33 the example shown, the first fixing protruding portion 48 is disposed on the surface of the first fixing and thinning portion 46 on the side opposite to the independent force-receiving body 20 ( Figure 33 the lower surface shown). The first connecting body 41 extends through the first fixing and thinning portion 46. The first connecting body 41 includes a fixing connecting body protruding portion 49b that protrudes from the first fixing and thinning portion 46 toward the negative side in the Z-axis direction. The first fixing protruding portion 48 is connected to the fixing connecting body protruding portion 49b of the first connecting body 41 and is formed in a rib shape from the first fixing and thinning portion 46 to the fixing connecting body protruding portion 49b. Figure 33 The first fixing protruding portion 48 shown is disposed at the inner end portion 46a of the first fixing and thinning portion 46 and is separated from the outer end portion 46b.

[0471] Or, as Figure 34As shown, the first fixed protrusion 48 disposed on the surface of the first fixed thinning portion 46 on the side opposite to the independent force-receiving body 20 may also be disposed at the outer end portion 46b of the first fixed thinning portion 46. In this case, the first fixed protrusion 48 may also be separated from the inner end portion 46a. In this case, the first connecting body 41 may not include the fixed connecting body protrusion 49b.

[0472] In addition, in the above-described embodiment of the present invention, as Figure 35 and Figure 36 shown, the second strain body 140 may also include: a second force-receiving protrusion 147 protruding in the Z-axis direction from the second force-receiving thinning portion 145, and a second fixed protrusion 148 protruding in the Z-axis direction from the second fixed thinning portion 146. The second force-receiving protrusion 147 is an example of the third protrusion, and the second fixed protrusion 148 is an example of the fourth protrusion. Figure 35 is a top view showing a modified example of the force sensor shown in Figure 31 . In Figure 35 , the bolt holes 126 (see Figure 15 ) are omitted. Figure 36 is Figure 35 a longitudinal sectional view of the second strain body 140 shown in

[0473] As Figure 35 shown, when viewed from the Z-axis direction, the second force-receiving protrusion 147 may also be disposed at a circumferential position along the center point O of the force-receiving body 120. In the example shown in Figure 35 , each second force-receiving protrusion 147 is disposed in the clockwise direction along the negative side of the Z-axis direction.

[0474] As Figure 36 shown, the second force-receiving protrusion 147 may also be connected to the second connecting body 141. The second force-receiving protrusion 147 may also be disposed on the surface of the second force-receiving thinning portion 145 on the side of the fixed body 130 ( Figure 36 the lower surface shown). More specifically, the second force-receiving protrusion 147 is connected to the force-receiving body side end portion 143 of the second connecting body 141 and is formed from the second force-receiving thinning portion 145 to the force-receiving body side end portion 143. The second force-receiving protrusion 147 may also be formed in a rib shape. The second force-receiving protrusion 147 may also extend in the circumferential direction from the second connecting body 141. However, the direction in which the second force-receiving protrusion 147 extends from the second connecting body 141 is arbitrary.

[0475] As Figure 36As shown, when observed from a cross-section passing through the second force-receiving protrusion 147, the second force-receiving thinning portion 145 includes: an inner end portion 145a located on the side of the force-receiving body side end portion 143 of the second connecting body 141, and an outer end portion 145b located on the side of the force-receiving main body portion 123. When observed from the Z-axis direction, the inner end portion 145a is an end portion located inside with respect to the center (corresponding to the second connecting body 141), and the outer end portion 145b is an end portion located outside with respect to this center. The second force-receiving protrusion 147 according to the present embodiment is disposed at the inner end portion 145a. The second force-receiving protrusion 147 may also be separated from the outer end portion 145b. Figure 36 The longitudinal section shown is a cross-section along the Z-axis direction.

[0476] As Figure 35 shown, when observed from the Z-axis direction, the planar shape of the second force-receiving protrusion 147 may also be rectangular. However, the planar shape of the second force-receiving protrusion 147 may also be circular, and it is arbitrary.

[0477] As Figure 35 shown, when observed from the Z-axis direction, the second fixing protrusion 148 may also be disposed at a circumferential position along the center point O of the force-receiving body 120. In Figure 35 the example shown, each second fixing protrusion 148 is disposed in the clockwise direction along the negative side of the Z-axis direction.

[0478] As Figure 36 shown, the second fixing protrusion 148 may also be connected to the second connecting body 141. The second fixing protrusion 148 may also be disposed on the surface of the force-receiving body 120 side of the second fixing thinning portion 146 ( Figure 36 the upper surface shown). More specifically, the second fixing protrusion 148 is connected to the fixing body side end portion 144 of the second connecting body 141, and is formed from the second fixing thinning portion 146 to the fixing body side end portion 144. The second fixing protrusion 148 may also be formed in a rib shape. The second fixing protrusion 148 may also extend in the circumferential direction from the second connecting body 141. However, the direction in which the second fixing protrusion 148 extends from the second connecting body 141 is arbitrary.

[0479] As Figure 36As shown, when viewed from a cross-section passing through the second fixed protrusion 148, the second fixed thinning portion 146 includes: an inner end portion 146a located on the side of the fixed body side end portion 144 of the second connecting body 141, and an outer end portion 146b located on the side of the fixed main body portion 133. The inner end portion 146a is an end portion located inside with respect to the center (corresponding to the second connecting body 141) when viewed from the Z-axis direction, and the outer end portion 146b is an end portion located outside with respect to this center. The second fixed protrusion 148 according to the present embodiment is disposed at the inner end portion 146a. The second fixed protrusion 148 may also be separated from the outer end portion 146b.

[0480] When viewed from the Z-axis direction, the planar shape of the second fixed protrusion 148 may also be rectangular. However, the planar shape of the second fixed protrusion 148 may also be circular, and it is arbitrary. The planar shape of the second fixed protrusion 148 may also be the same as the planar shape of the second force-receiving protrusion 147.

[0481] When the force sensor 110 receives a force Fz on the positive side in the Z-axis direction, the elastic deformation of the second connecting body 141, the second force-receiving thinning portion 145, and the second fixed thinning portion 146 of the second strain body 140 is suppressed. That is, the second force-receiving protrusion 147 can suppress the elastic deformation of the second force-receiving thinning portion 145. The second fixed protrusion 148 can suppress the elastic deformation of the second fixed thinning portion 146. Thus, the second force-receiving protrusion 147 and the second fixed protrusion 148 can increase the resistance to the force Fz and can suppress the elastic deformation of the second strain body 140 with respect to the force Fz.

[0482] In Figure 35 In the force sensor 110 shown, when a force Fz is applied to the force-receiving body 120 on the positive side in the Z-axis direction, the elastic deformation of the first strain body 40 of each independent force sensor 10A to 10D can be suppressed. Thus, the sensitivity of the force sensor 110 with respect to the force Fz in the Z-axis direction can be further reduced. In addition, since the elastic deformation of the first strain body 40 of each independent force sensor 10A to 10D is suppressed, the sensitivity of the force sensor 110 with respect to the moment Mx about the X-axis and the moment My about the Y-axis can be further reduced. Therefore, the sensitivity of the force sensor 110 with respect to the force Fx in the X-axis direction, the force Fy in the Y-axis direction, and the moment Mz about the Z-axis can be relatively further increased. As a result, the balance of the sensitivities of the respective axis components in the force sensor 110 can be further improved.

[0483] In this way, according to Figure 35 and Figure 36In the example shown, the second strain body 140 includes a second force-receiving protruding portion 147 that protrudes in the Z-axis direction from the second force-receiving thinning portion 145. Thereby, the elastic deformation of the second force-receiving thinning portion 145 with respect to the force Fz in the Z-axis direction can be suppressed. Therefore, the sensitivities of the force sensor 110 with respect to the force Fz in the Z-axis direction, the moment Mx about the X-axis, and the moment My about the Y-axis can be further reduced, and the balance of the sensitivities of the respective axis components in the force sensor 110 can be further improved.

[0484] In addition, according to Figure 35 and Figure 36 In the example shown, the second strain body 140 includes a second fixed protruding portion 148 that protrudes in the Z-axis direction from the second fixed thinning portion 146. Thereby, the elastic deformation of the second fixed thinning portion 146 with respect to the force Fz in the Z-axis direction can be suppressed. Therefore, the sensitivities of the force sensor 110 with respect to the force Fz in the Z-axis direction, the moment Mx about the X-axis, and the moment My about the Y-axis can be reduced, and the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved.

[0485] It should be noted that the arrangements of the second force-receiving protruding portion 147 and the second fixed protruding portion 148 are not limited to Figure 36 the example shown. For example, the second force-receiving protruding portion 147 and the second fixed protruding portion 148 may also be arranged in the same way as Figures 32 to 34 the first force-receiving protruding portion 47 and the first fixed protruding portion 48 shown. In the case of being arranged in the same way as Figure 33 the example shown, the second connecting body 141 may penetrate the second force-receiving thinning portion 145 and protrude in the positive Z-axis direction from the second force-receiving thinning portion 145, or may penetrate the second fixed thinning portion 146 and protrude in the negative Z-axis direction from the second fixed thinning portion 146.

[0486] In addition, when the second strain body 140 includes the second force-receiving protruding portion 147 and the second fixed protruding portion 148, the first strain body 40 may not include the first force-receiving protruding portion 47 and the first fixed protruding portion 48. When the displacement of the force-receiving body 120 is dominated by the elastic deformations of the second connecting body 141, the second force-receiving thinning portion 145, and the second fixed thinning portion 146, the balance of the sensitivities of the respective axis components in the force sensor 110 can be improved by the second force-receiving protruding portion 147 and the second fixed protruding portion 148.

[0487] The present invention is not limited to the above-described embodiments and modified examples in this way. At the implementation stage, the constituent elements can be modified within the scope of not departing from the gist thereof for concretization. In addition, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments and modified examples. It is also possible to delete several constituent elements from all the constituent elements shown in the embodiments and modified examples. Furthermore, it is also possible to appropriately combine the constituent elements related to different embodiments and modified examples.

Claims

1. An independent force sensor, comprising: A first independent sensor body, which is subjected to a force or torque to be detected; A second independent sensor body, which is arranged at a position different from that of the first independent sensor body in a first direction; A first strain body, which connects the first independent sensor body and the second independent sensor body, and elastically deforms due to the force or torque applied to the first independent sensor body; And A detection element, which detects the displacement generated by the elastic deformation of the first strain body, The first strain body includes: a first connecting body, which extends from a first end connected to the first independent sensor body to a second end connected to the second independent sensor body in the first direction; and a displacement body, which protrudes from the first connecting body in a second direction orthogonal to the first direction, The detection element includes: a fixed electrode substrate, which is arranged on the second independent sensor body; and a displacement electrode substrate, which is arranged on the displacement body and faces the fixed electrode substrate.

2. The independent force sensor according to claim 1, Wherein, Taking the direction orthogonal to the first direction and the second direction as a third direction, The first connecting body is formed along each of the first direction and the third direction.

3. The independent force sensor according to claim 2, Wherein, When viewed from the first direction, the size of the first connecting body in the second direction is smaller than the size of the first connecting body in the third direction.

4. The independent force sensor according to claim 1, Wherein, The first independent sensor body, the second independent sensor body, and the displacement body are formed along a plane orthogonal to the first direction.

5. The independent force sensor according to claim 2, Wherein, The second independent sensor body and the displacement body protrude more in the third direction than the first independent sensor body.

6. The independent force sensor according to claim 1, Wherein, The first strain body includes two displacement bodies protruding in the second direction on both sides of the first connecting body, The detection element includes two fixed electrode substrates and two displacement electrode substrates facing the corresponding fixed electrode substrates, The displacement electrode substrates are arranged on the respective displacement bodies.

7. The independent force sensor according to claim 1, Wherein, The first independent sensor body, the second independent sensor body, and the first strain body are integrally formed of a continuous material.

8. The independent force sensor according to claim 1, Wherein, The first strain body includes a first thinning portion, which is formed along a plane orthogonal to the first direction and connects the first independent sensor body and the first end of the first connecting body, The first thinning portion is thinner than the first independent sensor body.

9. The independent force sensor according to claim 8, Wherein, The first strain body includes a first protruding portion, which protrudes from the first thinning portion in the first direction.

10. The independent force sensor according to claim 1, wherein, the first strain body includes a second thinning portion which is formed along a plane orthogonal to the first direction and connects the second independent sensor body to the second end portion of the first connection body, the second thinning portion is thinner than the second independent sensor body.

11. The independent force sensor according to claim 10, wherein, the first strain body includes a second protruding portion which protrudes from the second thinning portion in the first direction.

12. The independent force sensor according to claim 1, wherein, the independent force sensor is provided with a detection circuit which outputs an electrical signal representing the force or torque received by the first independent sensor body based on the detection result of the detection element.

13. An independent force sensor, comprising: a first independent sensor body which is acted upon by a force or torque to be detected; a second independent sensor body which is arranged at a position different from that of the first independent sensor body in the first direction; a first strain body which connects the first independent sensor body and the second independent sensor body, and the first strain body elastically deforms due to the force or torque received by the first independent sensor body; and a detection element which detects the displacement generated by the elastic deformation of the first strain body, the first strain body includes a first connection body which extends from a first end portion connected to the first independent sensor body to a second end portion connected to the second independent sensor body in the first direction, the detection element includes: two first strain gauges which are arranged at the first end portion; and two second strain gauges which are arranged at the second end portion, a Wheatstone bridge circuit is formed by the two first strain gauges and the two second strain gauges.

14. A force sensor, comprising: a plurality of independent force sensors according to any one of claims 1 to 12; a first sensor body which supports the first independent sensor body of each of the independent force sensors, and the first sensor body is acted upon by a force or torque to be detected; a second sensor body which supports the second independent sensor body of each of the independent force sensors; a plurality of second strain bodies which connect the first sensor body and the second sensor body, and the plurality of second strain bodies elastically deform due to the force or torque received by the first sensor body; and a detection circuit which outputs an electrical signal representing the force or torque received by the first sensor body based on the detection results of the detection elements of the respective independent force sensors, the second strain body includes a second connection body which extends from a third end portion connected to the first sensor body to a fourth end portion connected to the second sensor body in the first direction.

15. The force sensor according to claim 14, wherein, when observed from the first direction, the second connection body is formed along a radial direction with respect to the center point of the first sensor body.

16. The force sensor according to claim 15, wherein, When viewed from the first direction, the second connecting body has a smaller dimension in a direction orthogonal to the radial direction than in the radial direction.

17. The force sensor according to claim 14, wherein, the first sensor body and the second sensor body are formed along a plane orthogonal to the first direction.

18. The force sensor according to claim 14, wherein, the first sensor body includes a first opening into which the first connecting body is inserted.

19. The force sensor according to claim 18, wherein, the first sensor body includes a first recess that opens toward a side opposite to the second sensor body and communicates with the first opening, the first independent sensor body is received in the first recess.

20. The force sensor according to claim 14, wherein, the second sensor body includes a second opening into which the first connecting body is inserted.

21. The force sensor according to claim 20, wherein, the second sensor body includes a second recess that opens toward a side opposite to the first sensor body and communicates with the second opening, the second independent sensor body is received in the second recess.

22. The force sensor according to claim 14, wherein, with respect to a moment about an axis along the first direction, the second connecting body has a higher rigidity than the first connecting body.

23. The force sensor according to claim 14, wherein, the first sensor body, the second sensor body, and the second strain body are integrally formed of a continuous material.

24. The force sensor according to claim 15, wherein, the second strain body includes a third thinning portion that is formed along a plane orthogonal to the first direction and connects the first sensor body to the third end portion of the second connecting body, the third thinning portion is thinner than the first sensor body.

25. The force sensor according to claim 24, wherein, the second strain body includes a third protruding portion that protrudes from the third thinning portion in the first direction.

26. The force sensor according to claim 15, wherein, the second strain body includes a fourth thinning portion that is formed along a plane orthogonal to the first direction and connects the second sensor body to the fourth end portion of the second connecting body, the fourth thinning portion is thinner than the second sensor body.

27. The force sensor according to claim 26, wherein, the second strain body includes a fourth protruding portion that protrudes from the fourth thinning portion in the first direction.

28. A force sensor, comprising: A plurality of independent force sensors, each of the independent force sensors including a first independent sensor body, a second independent sensor body, a first strain body, and a detection element, the first independent sensor body being subjected to a force or torque to be detected, the second independent sensor body being disposed at a position different from that of the first independent sensor body in a first direction, the first strain body connecting the first independent sensor body and the second independent sensor body, the first strain body elastically deforming due to the force or torque applied to the first independent sensor body, and the detection element detecting a displacement generated by the elastic deformation of the first strain body; A first sensor body that supports the first independent sensor body of each of the independent force sensors, the first sensor body being subjected to a force or torque to be detected; A second sensor body that supports the second independent sensor body of each of the independent force sensors; A plurality of second connectors that extend in the first direction from a third end connected to the first sensor body to a fourth end connected to the second sensor body; And A detection circuit that outputs an electrical signal representing the force or torque applied to the first sensor body based on the detection results of the detection elements of the independent force sensors; The first strain body includes a first connector that extends in the first direction from a first end connected to the first independent sensor body to a second end connected to the second independent sensor body; The detection element includes: two first strain gauges disposed at the first end; And two second strain gauges disposed at the second end; The detection circuit includes a Wheatstone bridge circuit that outputs an electrical signal based on the detection results of the first strain gauges and the second strain gauges; When viewed from the first direction, the second connector is formed radially with respect to the center point of the first sensor body.

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