JP2021135279A - Force sensor - Google Patents

Abstract

To provide a force sensor capable of improving the detection accuracy.SOLUTION: Strain generating bodies 30A-30D of a force sensor 1 according to the present invention each includes a tilt structure 31 disposed between a force receiver 10 and a support 20, a force receiver-side deformable body 33 for connecting the force receiver 10 and the tilt structure 31, and a support-side deformable body 34 for connecting the tilt structure 31 and the support 20. The tilt structure 31 includes a first tilt body 35 extending in a second direction orthogonal to a first direction, and elastically deformable by action of force in the first direction.SELECTED DRAWING: Figure 4

Description

The present invention relates to a force sensor.

Conventionally, a force sensor that outputs a force acting in a predetermined axial direction and a moment (torque) acting around a predetermined rotating axis as an electric signal has been known. This force sensor is widely used for force control of various robots such as industrial robots, collaborative robots, life support robots, medical robots, and service robots. Therefore, it is required to improve the performance as well as the safety.

For example, in a general force sensor, when a force or a moment is input, the strain-causing body constituting the force sensor is elastically deformed to cause distortion and displacement. By detecting the magnitude of the displacement as an electric signal, the magnitude of the input force or moment can be obtained. There are various detection methods such as a capacitance method and a strain gauge method.

While the strain-causing body is elastically deformed, stress is applied to the strain-causing body. When the elastic deformation of the strain-causing body due to the applied stress is small, the displacement is small. In this case, the detection sensitivity of the force or moment may decrease. When the detection sensitivity decreases, the detection accuracy may decrease.

Japanese Patent No. 6257017

The present invention has been made in consideration of such a point, and an object of the present invention is to provide a force sensor capable of improving detection accuracy.

The present invention
A receiving body that is affected by the force or moment to be detected,
A support that is arranged on one side of the receiving body in the first direction and supports the receiving body,
A strain-causing body that connects the receiving body and the supporting body and elastically deforms due to the action of a force or moment received by the receiving body.
A detection element that detects the displacement caused by the elastic deformation of the strain-causing body, and
A detection circuit that outputs an electric signal indicating a force or moment acting on the strain-causing body based on the detection result of the detection element is provided.
The strain-causing body is a tilting structure arranged between the receiving body and the supporting body, and a receiving body-side deformed body that connects the receiving body and the tilting structure, and is the receiving body. A force-bearing body-side deformable body that can be elastically deformed by the action of a force or moment received by a force body, and a support-side deformable body that connects the tilting structure and the support body, and the force received by the force-bearing body. Alternatively, it has a support-side deformable body that can be elastically deformed by the action of a moment.
The tilting structure is elastically deformed by the action of a force in the first direction, which is arranged on a plane including the first direction and a second direction orthogonal to the first direction and extends in a direction different from the first direction. Force sensor, including possible first tilting body,
I will provide a.

In the above-mentioned force sensor,
The receiving body side deformed body extends in the first direction.
You may do so.

Further, in the above-mentioned force sensor,
The support side deformed body extends in the first direction.
You may do so.

Further, in the above-mentioned force sensor,
The first tilting body extends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The first tilting body is formed on both sides of the first receiving body side facing surface facing the receiving body and the first receiving body side facing surface in the second direction to which the receiving body side deforming body is connected. Includes a second receiving body side facing surface facing the receiving body, which is arranged.
The first receiving body side facing surface is located closer to the support than the second receiving body side facing surface.
You may do so.

Further, in the above-mentioned force sensor,
The central portion of the first tilting body in the second direction is located closer to the support than both ends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The central portion of the first tilting body in the second direction is located closer to the receiving body than both ends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The tilting structure is arranged between the first tilting body and the support, is arranged on a plane including the first direction and the second direction, and extends in a direction different from the first direction. A second tilting body which is a tilting body and can be elastically deformed by the action of a force in the first direction, one end of both ends of the first tilting body in the second direction, and the second. Further including a pair of connecting bodies connecting the corresponding ends of both ends of the tilting body in the second direction.
The receiving body side deformed body is connected to the first tilting body, and is connected to the first tilting body.
The support side deformed body is connected to the second tilting body.
You may do so.

Further, in the above-mentioned force sensor,
The receiving body side deformed body is located between both ends of the first tilting body in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The support side deformed body is located between both ends of the second tilting body in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The receiving body side deformed body and the support body side deformed body are arranged at positions where they overlap each other when viewed in the first direction.
You may do so.

Further, in the above-mentioned force sensor,
The tilting structure is formed symmetrically with respect to the receiving body side deformed body and the support body side deformed body in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The spring constant for the force acting on the first direction of the second tilting body is different from the spring constant for the force acting on the first direction of the first tilting body.
You may do so.

Further, in the above-mentioned force sensor,
The second tilting body extends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The second tilting body is arranged on both sides of the first support side facing surface facing the support and the first support side facing surface in the second direction to which the support side deforming body is connected. Including a second support side facing surface facing the support,
The first support side facing surface is located closer to the receiving body than the second support side facing surface.
You may do so.

Further, in the above-mentioned force sensor,
The central portion of the second tilting body in the second direction is located closer to the receiving body than both ends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The central portion of the second tilting body in the second direction is located closer to the support than both ends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The receiving body and the first tilting body are connected by two receiving body side deformed bodies.
The support side deformed body connects the first tilting body and the support.
You may do so.

Further, in the above-mentioned force sensor,
The two receiving body side deformed bodies are located at both ends of the first tilting body in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The support side deformed body is located between the two receiving body side deformed bodies in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The strain-causing body is formed symmetrically with respect to the support-side deformed body in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The first tilting body extends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The first tilting body is arranged on both sides of the first support side facing surface facing the support and the first support side facing surface in the second direction to which the support side deforming body is connected. Including a second support side facing surface facing the support,
The first support side facing surface is located closer to the receiving body than the second support side facing surface.
You may do so.

Further, in the above-mentioned force sensor,
The central portion of the first tilting body in the second direction is located closer to the receiving body than both ends in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The receiving body side deformed body is connected to the receiving body via the receiving body side pedestal, and is connected to the receiving body.
The support side deformed body is connected to the support via a support side pedestal.
You may do so.

Further, in the above-mentioned force sensor,
The detection element has a fixed electrode substrate provided on the receiving body or the support, and a displacement electrode substrate facing the fixed electrode substrate and provided on the tilting structure.
The displacement electrode substrates are arranged at both ends of the tilting structure in the second direction.
You may do so.

Further, in the above-mentioned force sensor,
The displacement electrode substrate is provided on the tilting structure via a columnar member.
You may do so.

Further, in the above-mentioned force sensor,
The displacement electrode substrate is provided on the columnar member via a reinforcing substrate.
You may do so.

Further, in the above-mentioned force sensor,
The detection element has a strain gauge provided on the detection strain generator.
You may do so.

Further, in the above-mentioned force sensor,
The receiving body and the supporting body are connected by the four strain generating bodies.
The four strain generators include a first strain generator, a second strain generator, a third strain generator, and a fourth strain generator.
The first direction is the Z-axis direction in the XYZ three-dimensional coordinate system.
The first straining body is arranged on the negative side in the Y-axis direction with respect to the center of the receiving body, and the second straining body is arranged on the positive side in the X-axis direction with respect to the center of the receiving body. The third strain generating body is arranged on the positive side in the Y-axis direction with respect to the center of the receiving body, and the fourth straining body is arranged on the negative side in the X-axis direction with respect to the center of the receiving body.
The second direction of the first strain-causing body and the third strain-causing body is defined as the X-axis direction.
The second direction of the second strain-generating body and the fourth strain-causing body is the Y-axis direction.
You may do so.

Further, in the above-mentioned force sensor,
At least one of the planar shape of the receiving body and the planar shape of the support is circular.
You may do so.

Further, in the above-mentioned force sensor,
At least one of the planar shape of the receiving body and the planar shape of the support is rectangular.
You may do so.

Further, in the above-mentioned force sensor,
The tilting structure of the strain-causing body is formed linearly along the second direction when viewed in the first direction.
You may do so.

Further, in the above-mentioned force sensor,
The tilting structure of the strain-causing body may be formed in a curved shape when viewed in the first direction.

Further, in the above-mentioned force sensor,
Further provided with an exterior body that covers the strain-causing body from the outside when viewed in the first direction.
You may do so.

Further, in the above-mentioned force sensor,
The exterior body is fixed to the support body and separated from the receiving body.
You may do so.

Further, in the above-mentioned force sensor,
A cushioning member is interposed between the exterior body and the receiving body.
You may do so.

According to the present invention, the detection accuracy can be improved.

FIG. 1 is a perspective view showing an example of a robot to which the force sensor according to the first embodiment is applied. FIG. 2 is a cross-sectional view showing the force sensor according to the first embodiment, and is a view corresponding to the cross-sectional view taken along the line AA of FIG. 3 described later. FIG. 3 is a plan view showing the force sensor of FIG. FIG. 4 is a front view showing the strain-causing body of FIG. FIG. 5 is a plan view of the strain-causing body of the force sensor shown in FIG. FIG. 6 is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 4 receives a force on the positive side in the X-axis direction. FIG. 7A is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 4 receives a force on the positive side in the Z-axis direction. FIG. 7B is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 4 receives a force on the negative side in the Z-axis direction. FIG. 8 is a table showing changes in the capacitance value of each capacitive element in the strain-causing body of FIG. FIG. 9 is a table showing changes in the capacitance value of each capacitance element in the force sensor of FIG. FIG. 10 is a table showing the main axis sensitivity and the other axis sensitivity based on the change in the capacitance value of FIG. FIG. 11 is a front view showing a modified example of the strain-causing body of FIG. FIG. 12 is a plan view showing another modification of the strain-causing body of FIG. FIG. 13 is a plan view showing another modification of the strain-causing body of FIG. FIG. 14 is a partially enlarged front view showing another modification of the strain-causing body of FIG. FIG. 15 is a partially enlarged front view showing another modified example of the strain-causing body of FIG. FIG. 16 is a front view showing another modified example of the strain-causing body of FIG. FIG. 17 is a front view showing another modified example of the strain-causing body of FIG. FIG. 18 is a front view showing another modified example of the strain-causing body of FIG. FIG. 19 is a plan view showing another modification of the force sensor of FIG. FIG. 20 is a plan view showing another modification of the force sensor of FIG. FIG. 21A is a front view of a strain-causing body showing a modified example of the detection element of FIG. 21B is a plan view showing the detection element of FIG. 21A. 21C is a plan view showing a modification of FIG. 21B. FIG. 22A is a diagram showing a Wheatstone bridge circuit for a detection element provided in the first tilting body shown in FIG. 21A. FIG. 22B is a diagram showing a Wheatstone bridge circuit for a detection element provided in the second tilting body shown in FIG. 21A. FIG. 23A is a schematic view showing a deformed state of the strain-causing body when the strain-causing body of FIG. 21A receives a force on the positive side in the X-axis direction. FIG. 23B is a schematic view showing a deformed state of the strain-causing body when the strain-causing body of FIG. 21A receives a force on the positive side in the Z-axis direction. FIG. 24 is a front view showing a strain-causing body of the force sensor according to the second embodiment. FIG. 25 is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 24 receives a force on the positive side in the X-axis direction. FIG. 26A is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 24 receives a force on the positive side in the Z-axis direction. FIG. 26B is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 24 receives a force on the negative side in the Z-axis direction. FIG. 27 is a plan view showing a modified example of the strain-causing body of FIG. 24. FIG. 28 is a plan view showing another modification of the strain-causing body of FIG. 24. FIG. 29 is a plan view showing another modification of the strain-causing body of FIG. 24. FIG. 30 is a plan view showing another modification of the strain-causing body of FIG. 24. FIG. 31 is a plan view showing another modification of the strain-causing body of FIG. 24.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, the scale, the aspect ratio, etc. are appropriately changed from those of the actual product and exaggerated for the convenience of illustration and comprehension.

It should be noted that, as used in the present specification, the values of terms, dimensions, and physical characteristics such as "parallel", "orthogonal", and "equal" that specify the shape, geometric conditions, physical characteristics, and their degrees are specified. Etc. shall be interpreted including the range in which similar functions can be expected without being bound by the strict meaning.

(First Embodiment)
First, the force sensor according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 23B.

Before explaining the force sensor according to the present embodiment, an example of application of the force sensor to a robot will be described with reference to FIG. FIG. 1 is a diagram showing an example of a robot to which a force sensor according to the present embodiment is applied.

As shown in FIG. 1, the industrial robot 1000 includes a robot main body 1100, an end effector 1200, an electric cable 1300, a control unit 1400, and a force sensor 1. The robot body 1100 includes an arm portion of the robot. A force sensor 1 is provided between the robot body 1100 and the end effector 1200.

The electric cable 1300 extends inside the robot body 1100. The electric cable 1300 is connected to a connector (not shown) of the force sensor 1.

Although the control unit 1400 is arranged inside the robot main body 1100 in FIG. 1, it may be arranged in another place (for example, a control panel outside the robot). Further, the mounting mode of the force sensor 1 on the robot is not limited to that shown in FIG.

The force sensor 1 detects a force or moment acting on the end effector 1200 that functions as a gripper. An electric signal indicating the detected force or moment is transmitted to the control unit 1400 of the industrial robot 1000 via the electric cable 1300. The control unit 1400 controls the operations of the robot body 1100 and the end effector 1200 based on the received electric signal.

The force sensor 1 is not limited to industrial robots, but can be applied to various robots such as collaborative robots, life support robots, medical robots, and service robots.

Hereinafter, the force sensor according to the embodiment of the present invention will be described with reference to FIGS. 2 to 5. FIG. 2 is a cross-sectional view showing the force sensor according to the first embodiment, and is a view corresponding to the cross-sectional view taken along the line AA of FIG. FIG. 3 is a plan view showing the force sensor of FIG. FIG. 4 is a front view showing the strain-causing body of FIG. FIG. 5 is a plan view of the strain-causing body of the force sensor shown in FIG.

In the following description, a force is defined so that the XYZ three-dimensional coordinate system is defined, the Z-axis direction (first direction) is the vertical direction, the receiving body 10 is arranged on the upper side, and the support 20 is arranged on the lower side. The description will be given with the sensor 1 placed. Therefore, the force sensor 1 in the present embodiment is not limited to being used in a posture in which the Z-axis direction is the vertical direction. Further, it is arbitrary whether either the receiving body 10 or the support 20 is arranged on the upper side or the lower side.

The force sensor 1 has a function of outputting a force acting in a predetermined axial direction and a moment (torque) acting around a predetermined rotation axis as an electric signal. However, the present invention is not limited to this, and it may be configured to output only one of the force and the moment as an electric signal, and further, at least one axial component of the force or the moment is output as an electric signal. It may be configured as follows.

As shown in FIGS. 2 and 3, the force sensor 1 includes a receiving body 10, a support 20, strain generating bodies 30A to 30D, a detecting element 50, a detecting circuit 60, and an exterior body 80. It has. Hereinafter, each component will be described in more detail.

The receiving body 10 is affected by a force or moment to be detected. By receiving this action, the receiving body 10 moves relative to the support 20. In the example of FIG. 1 described above, the receiving body 10 is fixed to the end effector 1200 with a bolt or the like, and receives a force or a moment from the end effector 1200. Distortion bodies 30A to 30D are connected to the receiving body 10.

As shown in FIG. 3, in the present embodiment, the planar shape of the receiving body 10 is circular. Further, the receiving body 10 may be formed in a flat plate shape.

As shown in FIG. 2, the support body 20 supports the receiving body 10. The support 20 is arranged on the negative side of the receiving body 10 in the Z-axis direction. The receiving body 10 and the supporting body 20 are arranged at different positions in the Z-axis direction, and the supporting body 20 is separated from the receiving body 10. In the example of FIG. 1, the support 20 is fixed to the tip of the robot body 1100 (arm portion) with bolts or the like, and is supported by the robot body 1100. Distortion members 30A to 30D are connected to the support 20.

As shown in FIG. 3, in the present embodiment, the planar shape of the support 20 is circular like the receiving body 10. Further, the support 20 may be formed in a flat plate shape. At least one of the planar shape of the receiving body 10 and the planar shape of the support 20 may be circular. In this case, one of the planar shape of the receiving body 10 and the planar shape of the support 20 may be circular, and the other may be a shape other than circular.

As shown in FIGS. 2 and 3, the strain generating bodies 30A to 30D connect the receiving body 10 and the support body 20. More specifically, the strain generating bodies 30A to 30D are arranged between the receiving body 10 and the supporting body 20, and the straining bodies 30A to 30D are connected to the receiving body 10 and the supporting body. It is connected to 20. The receiving body 10 is supported by the support 20 via these strain generating bodies 30A to 30D.

In the present embodiment, the receiving body 10 and the supporting body 20 are connected by four strain generating bodies 30A to 30D. The four straining bodies 30A to 30D include a first straining body 30A, a second straining body 30B, a third straining body 30C, and a fourth straining body 30D. As shown in FIG. 3, when viewed in the Z-axis direction, the first strain generating body 30A is arranged on the negative side in the Y-axis direction with respect to the center O of the receiving body 10. Similarly, when viewed in the Z-axis direction, the second strain generating body 30B is arranged on the positive side in the X-axis direction with respect to the center O of the receiving body 10, and is in the Y-axis direction with respect to the center O of the receiving body 10. The third strain generating body 30C is arranged on the positive side. The fourth strain generating body 30D is arranged on the negative side in the X-axis direction with respect to the center O of the receiving body 10. In other words, the center O of the receiving body 10 is arranged between the first straining body 30A and the third straining body 30C, and between the second straining body 30B and the fourth straining body 30D, The center O of the receiving body 10 is arranged. The number of strain-causing bodies connecting the receiving body 10 and the support 20 is not limited to four, but may be two or three, or five or more, and is arbitrary. Further, the receiving body 10 and the supporting body 20 may be connected by only one strain generating body. In this case, if the detecting element 50 is composed of two capacitive elements as shown in FIG. 4A, a force is applied. Biaxial component of can be detected. The detection element 50 may be composed of only one capacitive element to detect a uniaxial component of force.

As shown in FIG. 3, the tilting structures 31 (described later) of the four strain generating bodies 30A to 30D according to the present embodiment are arranged in an annular shape. That is, as described above, the receiving body 10 and the supporting body 20 are formed in a circular shape when viewed in the Z-axis direction, and the tilting structures 31 of the four strain generating bodies 30A to 30D are rectangular annular bodies. It is arranged so as to form. The tilting structures 31 of the strain generating bodies 30A to 30D are formed linearly along the second direction when viewed in the Z-axis direction. That is, the second direction of the first strain generating body 30A and the second direction of the third strain generating body 30C correspond to the X-axis direction. The tilting structure 31 of the first straining body 30A and the tilting structure 31 of the third straining body 30C are formed linearly along the X-axis direction. The second direction of the second strain generating body 30B and the second direction of the fourth strain generating body 30D correspond to the Y-axis direction. The tilting structure 31 of the second straining body 30B and the tilting structure 31 of the fourth straining body 30D are formed linearly along the Y-axis direction. The arrangement of the four strain generating bodies 30A to 30D is not limited to the annular arrangement, and each of them may be arranged irregularly at an arbitrary position.

Next, the strain-causing bodies 30A to 30D according to the present embodiment will be described more specifically. The strain-causing bodies 30A to 30D according to the present embodiment are configured to elastically deform due to the action of the force or moment received by the receiving body 10 to cause strain and displace. Here, among the four strain generating bodies 30A to 30D described above, the first strain generating body 30A having the X-axis direction as the second direction will be described as an example. Since the second straining body 30B, the third straining body 30C, and the fourth straining body 30D have the same configuration, detailed description thereof will be omitted here.

As shown in FIGS. 2 and 4, the first strain generating body 30A includes a tilting structure 31 arranged between the receiving body 10 and the supporting body 20, and the receiving body 10 and the tilting structure 31. It has a receiving body side deformed body 33 to be connected, and a support body side deformed body 34 connecting the tilting structure 31 and the support body 20.

The tilting structure 31 is arranged in a plane (XZ plane) including the Z-axis direction and the X-axis direction (the second direction of the first strain generating body 30A) orthogonal to the Z-axis direction, and is arranged in a direction different from the Z-axis direction. Includes a first tilting body 35 that extends. The first tilting body 35 according to the present embodiment extends in the X-axis direction (corresponding to the second direction of the first strain generating body 30A). The first tilting body 35 is arranged between the receiving body 10 and the supporting body 20, and is separated from the receiving body 10 and the supporting body 20. In the present embodiment, the first tilting body 35 extends in the X-axis direction. More specifically, as shown in FIG. 4, it extends linearly from one end 35a of the first tilting body 35 in the X-axis direction to the other end 35b, and extends linearly from the X-axis of the first tilting body 35. The central portion 35c in the direction is located at the same position as both end portions 35a and 35b in the Z-axis direction. The surface of the first tilting body 35 on the side of the receiving body 10 is formed to be flat as a whole.

In the present embodiment, as shown in FIGS. 2 and 4, the tilting structure 31 includes a second tilting body 36 arranged between the first tilting body 35 and the support 20, and a first tilting body. It further includes a pair of connecting bodies 37, 38 that connect the 35 and the second tilting body 36.

The second tilting body 36 is arranged in a plane (XZ plane) including the Z-axis direction and the X-axis direction orthogonal to the Z-axis direction (the second direction of the first strain generating body 30A), and is in a direction different from the Z-axis direction. Includes a second tilting body 36 extending to. The second tilting body 36 according to the present embodiment extends in the X-axis direction. The second tilting body 36 is separated from the first tilting body 35 in the Z-axis direction and is separated from the support 20. In the present embodiment, the second tilting body 36 extends in the X-axis direction. More specifically, as shown in FIG. 4, it extends linearly from one end 36a of the second tilting body 36 in the X-axis direction to the other end 36b, and extends linearly from the other end 36b to the X-axis of the second tilting body 36. The central portion 36c in the direction is located at the same position as both end portions 36a and 36b in the Z-axis direction. The surface of the second tilting body 36 on the side of the receiving body 10 is formed to be flat as a whole.

The pair of connecting bodies 37 and 38 includes one end of both ends 35a and 35b of the first tilting body 35 in the X-axis direction and both ends 36a and 36b of the second tilting body 36 in the X-axis direction. It is connected to the corresponding end of. More specifically, as shown in FIG. 4, the connecting body 37 arranged on the negative side in the X-axis direction is the end portion 35a on the negative side in the X-axis direction of the first tilting body 35 and the second tilting body 36. It is connected to the end 36a on the negative side in the X-axis direction. The connecting body 38 arranged on the positive side in the X-axis direction connects the end portion 35b on the positive side in the X-axis direction of the first tilting body 35 and the end portion 36b on the positive side in the X-axis direction of the second tilting body 36. ing. Each of the connecting bodies 37 and 38 extends in the Z-axis direction.

In this way, the tilting structure 31 according to the present embodiment is formed in a rectangular frame shape as shown in FIG. 4 when viewed in the Y-axis direction (direction orthogonal to the Z-axis direction and the X-axis direction). Has been done.

The first tilting body 35 can be elastically deformed by the action of a force in the Z-axis direction. The second tilting body 36 can be elastically deformed by the action of a force in the Z-axis direction. The spring constant for the force acting on the Z-axis direction of the first tilting body 35 may be equal to the spring constant for the force acting on the Z-axis direction of the second tilting body 36. The spring constant can be adjusted mainly by the Z-axis dimension of the member or the type of material used. For example, the spring constant may be adjusted as in the first modification shown in FIG. 11 described later.

The receiving body side deformed body 33 extends in the Z-axis direction and is connected to the first tilting body 35 of the tilting structure 31. More specifically, the upper end of the receiving body side deformed body 33 is connected to the receiving body 10, and the lower end is connected to the first tilting body 35. As a result, the receiving body 10 and the first tilting body 35 are connected by one receiving body side deformed body 33. In the present embodiment, the receiving body side deformed body 33 is located between both end portions 35a and 35b of the first tilting body 35 in the X-axis direction. That is, the receiving body side deformed body 33 is located between the pair of connecting bodies 37 and 38. More specifically, the receiving body side deformed body 33 is located at the center of the first tilting body 35 in the X-axis direction, and is connected to the central portion 35c of the first tilting body 35.

The support side deformed body 34 extends in the Z-axis direction and is connected to the second tilting body 36 of the tilting structure 31. More specifically, the lower end of the support side deformed body 34 is connected to the support 20, and the upper end is connected to the second tilting body 36. As a result, the support 20 and the second tilting body 36 are connected by one support side deformed body 34. In the present embodiment, the support side deformed body 34 is located between both end portions 36a and 36b of the second tilting body 36 in the X-axis direction. That is, the support side deformed body 34 is located between the pair of connecting bodies 37 and 38. More specifically, the support side deformed body 34 is located at the center of the second tilting body 36 in the X-axis direction, and is connected to the central portion 36c of the second tilting body 36.

The receiving body side deformed body 33 and the support body side deformed body 34 are arranged at positions where they overlap each other when viewed in the Z-axis direction. That is, the receiving body side deformed body 33 and the support body side deformed body 34 are arranged at the same positions in the X-axis direction. In the present embodiment, the receiving body side deformed body 33 and the support body side deformed body 34 are arranged at the center of the tilting structure 31 in the X-axis direction. In this way, the tilting structure 31 is formed symmetrically with respect to the receiving body side deformed body 33 and the support body side deformed body 34 in the X-axis direction.

The receiving body side deforming body 33 can be elastically deformed by the action of the force or moment received by the receiving body 10. The receiving body side deforming body 33 may be elastically deformable mainly with respect to a force acting in the X-axis direction. The spring constant for the force acting in the X-axis direction of the receiving body side deformed body 33 may be smaller than the spring constant for the force acting in the X-axis direction of the connecting bodies 37 and 38.

The support side deformable body 34 can be elastically deformed by the action of the force or moment received by the receiving body 10. The support side deformable body 34 may be elastically deformable mainly with respect to a force acting in the X-axis direction. The spring constant with respect to the force acting on the support side deformed body 34 in the X-axis direction may be smaller than the spring constant with respect to the force acting on the connecting bodies 37 and 38 in the X-axis direction. The spring constant for the force acting on the support body side deformed body 34 in the X-axis direction may be equal to the spring constant for the force acting on the receiving body side deformed body 33 in the X-axis direction.

The first strain generating body 30A configured in this way may be formed by machining from a plate material made of a metal material such as an aluminum alloy or an iron alloy, or may be formed by casting. When formed by machining, the tilting structure 31, the receiving body side deformed body 33, and the support side deformed body 34 are formed in a plate shape so that the Y-axis direction is the thickness direction, and are integrally formed from a continuous plate material. It is formed. As a result, the first strain generating body 30A can be easily produced. The first strain generating body 30A formed in this way may be fixed to the receiving body 10 and the supporting body 20 with bolts, adhesives or the like, respectively. Alternatively, the receiving body 10, the supporting body 20, and the strain generating bodies 30A to 30D may be integrally formed from a continuous block material by machining (for example, cutting), or may be formed by casting. May be good.

The detection element 50 is configured to detect the displacement caused by the elastic deformation generated in the first strain generating body 30A described above. The detection element 50 according to the present embodiment is configured as an element for detecting capacitance. As shown in FIG. 4, the detection element 50 has a fixed electrode substrate provided on the support 20 or the receiving body 10 and a displacement electrode substrate provided on the tilting structure 31. In the example shown in FIG. 4, the detection element 50 has two fixed electrode substrates Ef1 and Ef2 and two displacement electrode substrates Ed1 and Ed2 as electrodes for the first strain generating body 30A.

The two fixed electrode substrates Ef1 and Ef2 have a first fixed electrode substrate Ef1 arranged on the negative side in the X-axis direction and a second fixed electrode substrate Ef2 arranged on the positive side in the X-axis direction. In the present embodiment, the fixed electrode substrates Ef1 and Ef2 are provided on the surface of the support 20 on the side of the receiving body 10. The fixed electrode substrates Ef1 and Ef2 may be joined to the surface of the support 20 on the side of the receiving body 10 with an adhesive, or may be fixed with bolts or the like. The fixed electrode substrates Ef1 and Ef2 include a fixed electrode Ef facing the corresponding displacement electrode substrates Ed1 and Ed2, and an insulator IBf (see FIG. 4) interposed between the fixed electrode Ef and the support 20. I'm out. The fixed electrode substrates Ef1 and Ef2 may be provided on the surface of the receiving body 10 on the side of the support 20.

The two displacement electrode substrates Ed1 and Ed2 have a first displacement electrode substrate Ed1 arranged on the negative side in the X-axis direction and a second displacement electrode substrate Ed2 arranged on the positive side in the X-axis direction. In the present embodiment, the displacement electrode substrates Ed1 and Ed2 are provided on the surface of the tilting structure 31 on the side of the support 20 in the second tilting body 36. The displacement electrode substrates Ed1 and Ed2 may be joined to the surface of the second tilting body 36 on the side of the support 20 with an adhesive, or may be fixed with 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, an insulator IBd (see FIG. 4) interposed between the displacement electrode Ed and the second tilting body 36, and the same. Includes. When the fixed electrode substrates Ef1 and Ef2 are provided on the surface of the receiving body 10 on the side of the support 20, the displacement electrode substrates Ed1 and Ed2 are the receiving bodies in the first tilting body 35 of the tilting structure 31. It may be provided on the surface on the side of 10.

The first fixed electrode substrate Ef1 faces the first displacement electrode substrate Ed1, and the second fixed electrode substrate Ef2 faces the second displacement electrode substrate Ed2. The first fixed electrode substrate Ef1 and the first displacement electrode substrate Ed1 constitute the first capacitance element C1, and the second fixed electrode substrate Ef2 and the second displacement electrode substrate Ed2 constitute the second capacitance element C2. The first capacitance element C1 and the second capacitance element C2 are configured as the detection element 50 for the first strain generating body 30A.

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 on the negative side in the X-axis direction with respect to the support side deformed body 34, and the second displacement electrode substrate Ed2 is positive in the X-axis direction with respect to the support side deformed body 34. It is placed on the side. When the dimension of the tilting structure 31 (second tilting body 36) in the X-axis direction is L, the displacement electrode substrate is in the range of L / 4 or more and L / 2 or less from the center of the tilting structure 31 in the X-axis direction. Ed1 and Ed2 may be arranged.

In the present embodiment, the displacement electrode substrates Ed1 and Ed2 are arranged at both ends of the tilting structure 31 in the X-axis direction. More specifically, the first displacement electrode substrate Ed1 is arranged at the end 36a on the negative side in the X-axis direction of the second tilting body 36, and the second displacement electrode substrate Ed2 is the second tilting body of the tilting structure 31. It is arranged at the end portion 36b on the positive side in the X-axis direction of 36.

The first fixed electrode substrate Ef1 is arranged at a position facing the first displacement electrode substrate Ed1 and is arranged below the first displacement electrode substrate Ed1. The second fixed electrode substrate Ef2 is arranged at a position facing the second displacement electrode substrate Ed2, and is arranged below the second displacement electrode substrate Ed2.

The first capacitance element C1 and the second capacitance 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. Is located in.

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 displacement electrode substrates Ed1 and Ed2 are not limited to a rectangle, and may be other shapes such as a circle, a polygon, and an ellipse.

When viewed in the Z-axis direction, the first fixed electrode substrate Ef1 may be larger than the first displacement electrode substrate Ed1. For example, the planar shape of the first fixed electrode substrate Ef1 may be larger than the planar shape of the first displacement electrode substrate Ed1. Even when the first displacement electrode substrate Ed1 is displaced in the X-axis direction, the Y-axis direction, or the Z-axis direction, the first displacement electrode substrate Ed1 is fixed as a whole when viewed in the Z-axis direction. It may overlap with the electrode substrate Ef1. In other words, even when the first displacement electrode substrate Ed1 is displaced in the X-axis direction, the Y-axis direction, or the Z-axis direction, the displacement electrode Ed constituting the first capacitance element C1 and the fixed electrode Ef overlap each other. , The size of the displacement electrode Ed and the size of the fixed electrode Ef may be set. In this way, even when the first displacement electrode substrate Ed1 is displaced, it is possible to prevent the facing area of the displacement electrode Ed and the fixed electrode Ef from changing, and to face the change in the capacitance value. It is possible to prevent the influence of the change in area. Therefore, the capacitance value can be changed according to the change in the distance between the displacement electrode Ed and the fixed electrode Ef. Here, the facing area means the area where the displacement electrode Ed and the fixed electrode Ef overlap when viewed in the Z-axis direction. When the tilting structure 31 is tilted, the displacement electrode Ed smaller than the fixed electrode Ef is tilted and the facing area may fluctuate, but the tilt angle of the displacement electrode Ed in this case is small. As a result, the distance between the displacement electrode Ed and the fixed electrode Ef is dominant in the change in the capacitance value. Therefore, in the present specification, the fluctuation of the facing area due to the inclination of the displacement electrode Ed is not considered, and the change in the capacitance value is considered to be due to the change in the distance between the displacement electrode Ed and the fixed electrode Ef. In addition, in FIG. 6 and the like described later, the inclination of the tilting structure 31 is exaggerated in order to clarify the drawing. Further, the planar shape of the first fixed electrode substrate Ef1 is not limited to being larger than the planar shape of the first displacement electrode substrate Ed1, and the planar shape of the first displacement electrode substrate Ed1 is the first fixed electrode. It may be larger than the planar shape of the substrate Ef1.

Similarly, when viewed in the Z-axis direction, the planar shape of the second fixed electrode substrate Ef2 may be larger than the planar shape of the second displacement electrode substrate Ed2. The planar shape of the second displacement electrode substrate Ed2 may be larger than the planar shape of the second fixed electrode substrate Ef2.

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 be the same size. However, the present invention is not limited to this, and the planar shape of the fixed electrode Ef and the planar shape of the insulator IBf may have different sizes. 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.

As shown in FIG. 4, the first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 may be formed separately and separated from each other. However, the present invention is not limited to this, and the first fixed electrode substrate Ef1 and the second fixed electrode substrate Ef2 may be integrated and composed of one common fixed electrode substrate. Alternatively, 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 are integrated and 1 It may be composed of two common displacement electrode substrates.

The configuration of the first straining body 30A and the detection element 50 corresponding thereto can be similarly applied to the second straining body 30B, the third straining body 30C, and the fourth straining body 30D.

That is, as shown in FIG. 5, the detection element 50 has two fixed electrode substrates Ef3 and Ef4 provided on the support 20 and a second tilt of the tilt structure 31 as electrodes for the second straining body 30B. It further has two displacement electrode substrates Ed3 and Ed4 provided on the body 36. The two fixed electrode substrates Ef3 and Ef4 have a third fixed electrode substrate Ef3 and a fourth fixed electrode substrate Ef4. The two displacement electrode substrates Ed3 and Ed4 have a third displacement electrode substrate Ed3 and a fourth displacement electrode substrate Ed4. The third fixed electrode substrate Ef3 faces the third displacement electrode substrate Ed3, and the fourth fixed electrode substrate Ef4 faces the fourth displacement electrode substrate Ed4. The third fixed electrode substrate Ef3 and the third displacement electrode substrate Ed3 constitute the third capacitance element C3, and the fourth fixed electrode substrate Ef4 and the fourth displacement electrode substrate Ed4 constitute the fourth capacitance element C4.

The third displacement electrode substrate Ed3 and the third fixed electrode substrate Ef3 are arranged on the negative side in the Y-axis direction with respect to the support side deformed body 34. The fourth displacement electrode substrate Ed4 and the fourth fixed electrode substrate Ef4 are arranged on the positive side in the Y-axis direction with respect to the support side deformed body 34. The third capacitance element C3 and the fourth capacitance element C4 are arranged at the same position in the X-axis direction. The fixed electrode substrates Ef3 and Ef4 have the same configurations as the fixed electrode substrates Ef1 and Ef2 described above. The displacement electrode substrates Ed3 and Ed4 have the same configuration as the displacement electrode substrates Ed1 and Ed2 described above.

Further, the detection element 50 is provided on the two fixed electrode substrates Ef5 and Ef6 provided on the support 20 and the second tilting body 36 of the tilting structure 31 as electrodes for the third strain generating body 30C. It further has two displacement electrode substrates Ed5 and Ed6. The two fixed electrode substrates Ef5 and Ef6 have a fifth fixed electrode substrate Ef5 and a sixth fixed electrode substrate Ef6. The two displacement electrode substrates Ed5 and Ed6 have a fifth displacement electrode substrate Ed5 and a sixth displacement electrode substrate Ed6. The fifth fixed electrode substrate Ef5 faces the fifth displacement electrode substrate Ed5, and the sixth fixed electrode substrate Ef6 faces the sixth displacement electrode substrate Ed6. The fifth fixed electrode substrate Ef5 and the fifth displacement electrode substrate Ed5 constitute the fifth capacitance element C5, and the sixth fixed electrode substrate Ef6 and the sixth displacement electrode substrate Ed6 constitute the sixth capacitance element C6.

The fifth displacement electrode substrate Ed5 and the fifth fixed electrode substrate Ef5 are arranged on the positive side in the X-axis direction with respect to the support side deformed body 34. The sixth displacement electrode substrate Ed6 and the sixth fixed electrode substrate Ef6 are arranged on the negative side in the X-axis direction with respect to the support side deformed body 34. The fifth capacitance element C5 and the sixth capacitance element C6 are arranged at the same position in the Y-axis direction. The fixed electrode substrates Ef5 and Ef6 have the same configurations as the fixed electrode substrates Ef1 and Ef2 described above. The displacement electrode substrates Ed5 and Ed6 have the same configuration as the displacement electrode substrates Ed1 and Ed2 described above.

Further, the detection element 50 is provided on the two fixed electrode substrates Ef7 and Ef8 provided on the support 20 and the second tilting body 36 of the tilting structure 31 as electrodes for the fourth strain generating body 30D. It further has two displacement electrode substrates Ed7 and Ed8. The two fixed electrode substrates Ef7 and Ef8 have a seventh fixed electrode substrate Ef7 and an eighth fixed electrode substrate Ef8. The two displacement electrode substrates Ed7 and Ed8 have a seventh displacement electrode substrate Ed7 and an eighth displacement electrode substrate Ed8. The seventh fixed electrode substrate Ef7 faces the seventh displacement electrode substrate Ed7, and the eighth fixed electrode substrate Ef8 faces the eighth displacement electrode substrate Ed8. The seventh fixed electrode substrate Ef7 and the seventh displacement electrode substrate Ed7 constitute the seventh capacitance element C7, and the eighth fixed electrode substrate Ef8 and the eighth displacement electrode substrate Ed8 constitute the eighth capacitance element C8.

The seventh displacement electrode substrate Ed7 and the seventh fixed electrode substrate Ef7 are arranged on the positive side in the Y-axis direction with respect to the support side deformed body 34. The eighth displacement electrode substrate Ed8 and the eighth fixed electrode substrate Ef8 are arranged on the negative side in the Y-axis direction with respect to the support side deformed body 34. The seventh capacitance element C7 and the eighth capacitance element C8 are arranged at the same position in the X-axis direction. The fixed electrode substrates Ef7 and Ef8 have the same configurations as the fixed electrode substrates Ef1 and Ef2 described above. The displacement electrode substrates Ed7 and Ed8 have the same configuration as the displacement electrode substrates Ed1 and Ed2 described above.

The fixed electrode substrates Ef1 to Ef8 described above may be composed of a ceramic substrate, a glass epoxy substrate, or an FPC substrate (flexible printed circuit board) on which electrode materials are laminated. The FPC substrate is a printed circuit board that is formed in the form of a thin film and has flexibility, but may be bonded to the support 20 as a whole. The fixed electrode substrates Ef1 to Ef8 may be adhered to the support 20 with an adhesive. The same applies to the displacement electrode substrates Ed1 to Ed8. The displacement electrode substrates Ed1 to Ed8 may be adhered to the second tilting body 36 with an adhesive.

The detection element 50 is not limited to being configured as a capacitance element for detecting capacitance. For example, the detection element 50 may be composed of a strain gauge that detects the strain generated by the action of the force or moment received by the receiving body 10. Further, the detection element 50 may be composed of a piezoelectric element that generates an electric charge when distortion occurs. Further, the detection element 50 may be composed of an optical sensor that detects displacement by utilizing light reflection, a sensor that detects displacement by utilizing eddy current, or a Hall effect. It may be composed of a sensor that detects displacement. In particular, optical sensors that detect displacement, sensors that use eddy currents, and sensors that use the Hall effect are similar to the principle of capacitance detection, so they can be easily replaced with capacitive elements that detect capacitance. Can be done. As an example, an example in which the detection element 50 is composed of a strain gauge will be described later.

As shown in FIG. 2, the detection circuit 60 outputs an electric signal indicating a force or moment acting on the strain generating elements 30A to 30D based on the detection result of the detection element 50. The detection circuit 60 may have an arithmetic function configured by, for example, a microprocessor. Further, the detection circuit 60 may have an A / D conversion function for converting an analog signal received from the detection element 50 described above into a digital signal, and a function for amplifying the signal. The detection circuit 60 may include a terminal for outputting an electric signal, and the electric signal is transmitted from this terminal to the control unit 1400 described above via the electric cable 1300 (see FIG. 1).

As shown in FIGS. 2 and 3, the exterior body 80 is configured to cover the four strain generating bodies 30A to 30D from the outside when viewed in the Z-axis direction. The exterior body 80 is a tubular housing that constitutes the force sensor 1. The strain generating bodies 30A to 30D are housed in the exterior body 80. In the present embodiment, the planar cross-sectional shape of the exterior body 80 (the shape in the cross section along the XY plane) is a circular frame shape.

As shown in FIG. 2, the exterior body 80 is fixed to the support body 20 and separated from the receiving body 10. The receiving body 10 is arranged in one opening (upper opening in FIG. 2) of the exterior body 80, and the support 20 is arranged in the other opening (lower opening in FIG. 2).

More specifically, the support 20 is fixed to the exterior body 80 so as to close the opening on the lower side of the exterior body 80. The exterior body 80 may be manufactured integrally with the support 20. On the other hand, a gap is provided between the receiving body 10 and the exterior body 80, and the receiving body 10 can be displaced according to the action of the force or moment received from the end effector 1200. A cushioning member 81 may be interposed in the gap between the receiving body 10 and the exterior body 80 in order to ensure waterproofness and dustproofness. The cushioning member 81 may be made of an elastically deformable flexible material such as rubber or sponge. The exterior body 80 may be integrally manufactured with the receiving body 10 instead of the support body 20. In this case, a gap may be provided between the exterior body 80 and the support body 20. Alternatively, the portion of the exterior body 80 on the side of the receiving body 10 may be integrally manufactured with the receiving body 10, and the portion of the exterior body 80 on the side of the support 20 may be integrally manufactured with the support 20. .. In this case, the exterior body 80 is composed of a portion on the side of the receiving body 10 and a portion on the side of the support 20 as separate bodies. A gap may be provided between the portion on the side of the receiving body 10 and the portion on the side of the support 20.

Next, a method in which a force or moment acts on the force sensor 1 according to the present embodiment having such a configuration and the force or moment is detected will be described with reference to FIGS. 6 to 7B. FIG. 6 is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 4 receives a force on the positive side in the X-axis direction. FIG. 7A is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 4 receives a force on the positive side in the Z-axis direction. FIG. 7B is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 4 receives a force on the negative side in the Z-axis direction.

When the receiving body 10 is subjected to the action of a force or a moment, the force or the moment is transmitted to the first straining body 30A to the fourth straining body 30D. More specifically, the force or moment is transmitted to the receiving body side deforming body 33, the tilting structure 31 and the supporting body side deforming body 34, and is transmitted to the receiving body side deforming body 33, the supporting body side deforming body 34, and the tilting structure 31. Elastic deformation occurs. As a result, the tilting structure 31 is displaced. Therefore, the distance between the fixed electrode substrates Ef1 to Ef8 of the detection element 50 and the corresponding displacement electrode substrates Ed1 to Ed8 changes, and the capacitance values of the capacitance elements C1 to C8 change. This change in capacitance value is detected by the detection element 50 as the displacement generated in the strain generating bodies 30A to 30D. In this case, the change in the capacitance value of each capacitance element C1 to C8 may be different. Therefore, the detection circuit 60 detects the direction and magnitude of the force or moment acting on the receiving body 10 based on the change in the capacitance value of each of the capacitance elements C1 to C8 detected by the detection element 50. be able to.

Here, first, taking the first straining body 30A as an example, the first capacitance element C1 and the second capacitance element when the force Fx in the X-axis direction, the force Fy in the Y-axis direction, and the force Fz in the Z-axis direction act. The change in the capacitance value of C2 will be described.

(When + Fx acts)
When a force Fx acts on the first straining body 30A on the positive side in the X-axis direction, as shown in FIG. 6, the receiving body side deforming body 33 and the supporting body side deforming body 34 of the first straining body 30A are X. Elastically deforms in the axial direction. Since the tilting structure 31 according to the present embodiment is connected to the receiving body 10 via one receiving body side deforming body 33 and connected to the supporting body 20 via one supporting body side deforming body 34. The receiving body side deformed body 33 and the support body side deformed body 34 can be elastically deformed to the same extent. Further, since the first tilting body 35 and the second tilting body 36 of the tilting structure 31 according to the present embodiment are connected via two connecting bodies 37 and 38 extending in the Z-axis direction, the connecting body 37, The receiving body side deformed body 33 and the support body side deformed body 34 can be elastically deformed more than 38. More specifically, the upper end of the receiving body side deformed body 33 is displaced to the positive side in the X-axis direction from the lower end. As a result, the receiving body side deformed body 33 is elastically deformed and tilted with respect to the Z-axis direction so as to fall to the positive side in the X-axis direction. Further, the upper end of the support side deformed body 34 is displaced to the positive side in the X-axis direction from the lower end. As a result, the support-side deformed body 34 is elastically deformed and tilted with respect to the Z-axis direction so as to fall to the positive side in the X-axis direction. Therefore, as shown in FIG. 6, the tilting structure 31 (first tilting body 35, second tilting body 36, and connecting bodies 37, 38) can be tilted as a whole. In this case, the tilting structure 31 rotates clockwise around the Y-axis when viewed toward the positive side in the Y-axis direction (when viewed toward the paper surface of FIG. 6), and is relative to the Z-axis direction. Tilt. In this way, the receiving body side deformed body 33 and the support side deformed body 34 of the first strain generating body 30A can be elastically deformed by the force Fx on the positive side in the X-axis direction. Although minute elastic deformation can occur in the tilting structure 31, elastic deformation of a magnitude similar to that of the elastic deformation of the receiving body side deforming body 33 and the supporting body side deforming body 34 does not occur. In this case, the end portion 36a on the negative side in the X-axis direction of the second tilting body 36 rises, and the end portion 36b on the positive side in the X-axis direction descends.

As shown in FIG. 6, when the tilting structure 31 of the first strain generating body 30A rotates clockwise, the first displacement electrode substrate Ed1 moves away from the first fixed electrode substrate Ef1. As a result, the distance between the electrodes (distance in the Z-axis direction) between the first displacement electrode substrate Ed1 and the first fixed electrode substrate Ef1 increases, and the capacitance value of the first capacitance element C1 decreases. On the other hand, the second displacement electrode substrate Ed2 approaches the second fixed electrode substrate Ef2. As a result, the distance between the electrodes of 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.

(When -Fx acts)
When a force Fx acts on the first strain generating body 30A on the negative side in the X-axis direction, a phenomenon opposite to the case shown in FIG. 6 occurs, although not shown. That is, the capacitance value of the first capacitance element C1 increases, and the capacitance value of the second capacitance element C2 decreases.

(When + Fy acts)
When a force Fy acts on the first strain-generating body 30A on the positive side in the Y-axis direction (not shown), the first strain-generating body 30A rotates around the X-axis (counterclockwise toward the positive side in the X-axis direction). To rotate. As a result, the first strain generating body 30A is elastically deformed so as to fall in the positive side in the Y-axis direction and incline in the Z-axis direction. Therefore, the first strain generating body 30A is elastically deformed so as to bend in the thickness direction. However, as described above, the first capacitance element C1 and the second capacitance element C2 are arranged at the same position in the Y-axis direction. Therefore, even if the first strain generating body 30A rotates around the X-axis, the capacitance value increases in a part of the first capacitance element C1 and the capacitance value increases in a part of the other regions. The capacity value decreases. Therefore, the capacitance value does not change as a whole of the first capacitance element C1. Similarly, the change in the capacitance value does not appear in the second capacitance element C2 as a whole.

(When -Fy acts)
Similarly, when a force Fy acts on the first strain generating body 30A on the negative side in the Y-axis direction, the capacitance value does not change as a whole of the first capacitance element C1 and as a whole of the second capacitance element C2. ..

(When + Fz acts)
Further, when a force Fz acts on the first strain generating body 30A on the positive side in the Z-axis direction, as shown in FIG. 7A, the first tilting body 35 and the second tilting body 36 of the tilting structure 31 are elastically deformed. do. More specifically, while the first tilting body 35 is elastically deformed, the receiving body side deformed body 33 is pulled up to the positive side in the Z-axis direction. As a result, the first tilting body 35 is pulled up to the receiving body side deformed body 33 at the central portion 35c in the X-axis direction, as shown in FIG. 7A. At this time, the connecting bodies 37 and 38 are pulled up to the positive side in the Z-axis direction while the first tilting body 35 is elastically deformed so as to be convex upward (for example, an inverted V shape). Therefore, the second tilting body 36 is pulled up at both ends 36a and 36b in the X-axis direction as shown in FIG. 7A. At this time, the second tilting body 36 is elastically deformed so as to be convex downward (for example, V-shaped).

As shown in FIG. 7A, when the first tilting body 35 and the second tilting body 36 are elastically deformed, the first displacement electrode substrate Ed1 moves away from the first fixed electrode substrate Ef1. Therefore, the capacitance value of the first capacitance element C1 is reduced. Further, the second displacement electrode substrate Ed2 moves away from the second fixed electrode substrate Ef2. Therefore, the capacitance value of the second capacitance element C2 is reduced.

(When -Fz acts)
When a force Fz acts on the first straining body 30A on the negative side in the Z-axis direction, the first tilting body 35 and the second tilting body 36 of the tilting structure 31 are elastically deformed as shown in FIG. 7B. More specifically, while the first tilting body 35 is elastically deformed, the receiving body side deforming body 33 is pushed down to the negative side in the Z-axis direction. As a result, the first tilting body 35 is pushed down by the receiving body side deformed body 33 at the central portion 35c in the X-axis direction, as shown in FIG. 7B. At this time, the connecting bodies 37 and 38 are pushed down to the negative side in the Z-axis direction while the first tilting body 35 is elastically deformed so as to be convex downward (for example, V-shaped). Therefore, the second tilting body 36 is pushed down at both end portions 36a and 36b in the X-axis direction as shown in FIG. 7B. At this time, the second tilting body 36 is elastically deformed so as to be convex upward (for example, an inverted V shape).

As shown in FIG. 7B, when the first tilting body 35 and the second tilting body 36 are elastically deformed, the first displacement electrode substrate Ed1 approaches the first fixed electrode substrate Ef1. Therefore, the capacitance value of the first capacitance element C1 increases. Further, the second displacement electrode substrate Ed2 approaches the second fixed electrode substrate Ef2. Therefore, the capacitance value of the second capacitance element C2 increases.

Here, the change in the capacitance value of each of the capacitance elements C1 and C2 provided in the first strain generating body 30A shown in FIG. 4 is shown in FIG. FIG. 8 is a table showing changes in the capacitance values of the capacitance elements C1 and C2 in the first strain generating body 30A of FIG.

FIG. 8 shows changes in the capacitance values of the capacitance elements C1 and C2 with respect to the force Fx in the X-axis direction, the force Fy in the Y-axis direction, and the force Fz in the Z-axis direction. In FIG. 8, the case where the capacitance value decreases is indicated by “− (minus)”, and the case where the capacitance value increases is indicated by “+ (plus)”. For example, "-" is shown in C1 of the Fx row in the table shown in FIG. 8, which is the capacitance of the first capacitance element C1 when the force of + Fx acts as described above. It shows that the value decreases. On the other hand, "+" is shown in C2 of the Fx row in the table shown in FIG. 8, which is the capacitance of the second capacitance element C2 when the force of + Fx acts as described above. It shows that the value increases. In FIG. 8, the numerical value “0 (zero)” indicates that the capacitance value does not change in the capacitance elements C1 and C2.

From the table shown in FIG. 8, in the force sensor 1 in which the receiving body 10 and the supporting body 20 are connected only by the first straining body 30A, the forces Fx and Fz acting on the receiving body 10 are as follows. It can be calculated by the formula. In the following equation, for convenience, the force or moment and the amount of change in the capacitance value are connected by "=". However, since the force or moment and the capacitance value are different physical quantities from each other, the force is actually calculated by converting the amount of change in the capacitance value. C1 and C2 in the following equations indicate the amount of change in the capacitance value in each capacitance element.
[Equation 1]
Fx = -C1 + C2
[Equation 2]
Fz = -C1-C2

Next, in the force sensor 1 shown in FIG. 5, the force Fx in the X-axis direction, the force Fy in the Y-axis direction, the force Fz in the Z-axis direction, the moment Mx around the X-axis, the moment My around the Y-axis, and the Z-axis Changes in the capacitance values of the capacitive elements C1 to C8 when the surrounding moment Mz acts will be described with reference to FIGS. 9 and 10. FIG. 9 is a table showing changes in the capacitance value of each capacitance element in the force sensor of FIG. FIG. 10 is a table showing the main axis sensitivity and the other axis sensitivity based on the change in the capacitance value of FIG.

(When + Fx acts)
First, a case where a force Fx acts on the receiving body 10 on the positive side in the X-axis direction will be described.

In this case, the first strain generating body 30A is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 6, the capacitance value of the first capacitance element C1 is reduced, and the electrostatic capacitance of the second capacitance element C2 is reduced. The capacity value increases. This is shown as "-(minus)" in C1 of the Fx row in the table shown in FIG. 9 and as "+ (plus)" in C2.

The second strain generating body 30B rotates around the Y axis (clockwise toward the positive side in the Y axis direction). However, as described above, the third capacitance element C3 and the fourth capacitance element C4 are arranged at the same position in the X-axis direction. Therefore, as in the case of the first strain generating body 30A when the above-mentioned force Fy in the Y-axis direction is applied, the change in the capacitance value of the third capacitance element C3 as a whole and the fourth capacitance element C4 as a whole changes. It does not appear. This is indicated as "0 (zero)" in C3 and C4 of the Fx row in the table shown in FIG.

The third strain generating body 30C is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. Therefore, the capacitance value of the fifth capacitance element C5 increases and the capacitance value of the sixth capacitance element C6 decreases. This is indicated as "+" in C5 of the Fx row in the table shown in FIG. 9 and as "-" in C6.

The fourth strain generating body 30D rotates around the Y axis in the same manner as the second strain generating body 30B. However, as described above, the 7th capacitance element C7 and the 8th capacitance element C8 are arranged at the same position in the X-axis direction. Therefore, the capacitance value does not change as a whole of the 7th capacitance element C7 and as a whole of the 8th capacitance element C8. This is indicated as "0 (zero)" in C7 and C8 of the Fx row in the table shown in FIG.

(When + Fy acts)
Next, a case where a force Fy acts on the receiving body 10 on the positive side in the Y-axis direction will be described. Also in the following description, the reference numerals in the table of FIG. 9 are determined according to the change in the capacitance value as described above.

In this case, the first strain generating body 30A rotates around the X axis (counterclockwise toward the positive side in the X axis direction). However, as described above, the first capacitance element C1 and the second capacitance element C2 are arranged at the same position in the Y-axis direction. Therefore, the change in the capacitance value does not appear in the first capacitance element C1 as a whole and in the second capacitance element C2 as a whole.

The second strain generating body 30B is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 6, the capacitance value of the third capacitance element C3 is reduced, and the capacitance value of the fourth capacitance element C4 is reduced. Increase.

The third strain generating body 30C rotates about the X axis in the same manner as the first strain generating body 30A. However, the fifth capacitance element C5 and the sixth capacitance element C6 are arranged at the same position in the Y-axis direction. Therefore, the change in the capacitance value does not appear in the fifth capacitance element C5 as a whole and in the sixth capacitance element C6 as a whole.

The fourth strain generating body 30D is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 6, and the capacitance value of the seventh capacitance element C7 increases and the capacitance value of the eighth capacitance element C8 increases. Decrease.

(When + Fz acts)
Next, a case where a force Fz acts on the receiving body 10 on the positive side in the Z-axis direction will be described. Also in the following description, the reference numerals in the table of FIG. 9 are determined according to the change in the capacitance value as described above.

In this case, the strain-generating bodies 30A to 30D are elastically deformed in the same manner as the first strain-causing body 30A shown in FIG. 7A. As a result, the capacitance values of the capacitance elements C1 to C8 are reduced.

(When + Mx acts)
Next, a case where a moment Mx (see FIG. 5) around the X-axis (clockwise toward the positive side in the X-axis direction) acts on the receiving body 10 will be described. Also in the following description, the reference numerals in the table of FIG. 9 are determined according to the change in the capacitance value as described above.

In this case, the first strain generating body 30A is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 7B, the capacitance value of the first capacitance element C1 is increased, and the capacitance of the second capacitance element C2 is increased. The capacity value increases.

In the second straining body 30B, the receiving body side deforming body 33 is located at the center O of the receiving body 10 in the Y-axis direction, so that the elastic deformation of the second straining body 30B is the first straining. It is smaller than the body 30A and the third straining body 30C. Here, for the sake of simplification of the description, it is considered that the second strain generating body 30B does not elastically deform. Therefore, the capacitance value of the third capacitance element C3 does not change, and the capacitance value of the fourth capacitance element C4 does not change either.

The third strain generating body 30C is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 7A, the capacitance value of the fifth capacitance element C5 is reduced, and the capacitance value of the sixth capacitance element C6 is increased. Decrease.

In the fourth straining body 30D, the receiving body side deforming body 33 is located at the center O of the receiving body 10 in the Y-axis direction, so that the elastic deformation of the fourth straining body 30D is the first straining. It is smaller than the body 30A and the third straining body 30C. Here, for the sake of simplification of the description, it is considered that the fourth strain generating body 30D does not elastically deform. Therefore, the capacitance value of the 7th capacitance element C7 does not change, and the capacitance value of the 8th capacitance element C8 does not change either.

(When + My works)
Next, a case where a moment My (see FIG. 5) around the Y-axis (clockwise toward the positive side in the Y-axis direction) acts on the receiving body 10 will be described. Also in the following description, the reference numerals in the table of FIG. 9 are determined according to the change in the capacitance value as described above.

In this case, in the first strain generating body 30A, since the receiving body side deforming body 33 is located at the center O of the receiving body 10 in the X-axis direction, the elastic deformation of the first strain generating body 30A is the first. It is smaller than the 2nd strainer 30B and the 4th strainer 30D. Here, for the sake of simplification of the description, it is considered that the first strain generating body 30A does not elastically deform. Therefore, the capacitance value of the first capacitance element C1 does not change, and the capacitance value of the second capacitance element C2 does not change either.

The second strain generating body 30B is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 7B, and the capacitance value of the third capacitance element C3 is increased and the capacitance value of the fourth capacitance element C4 is increased. Increase.

In the third strain-generating body 30C, the deformed body 33 on the receiving body side is located at the center O of the receiving body 10 in the X-axis direction, so that the elastic deformation of the third strain-generating body 30C is the second strain-causing strain. It is smaller than the body 30B and the fourth straining body 30D. Here, in order to simplify the explanation, it is considered that the third strain generating body 30C does not elastically deform. Therefore, the capacitance value of the fifth capacitance element C5 does not change, and the capacitance value of the sixth capacitance element C6 does not change either.

The fourth strain generating body 30D is elastically deformed in the same manner as the first strain generating body 30A shown in FIG. 7A, the capacitance value of the seventh capacitance element C7 is reduced, and the capacitance value of the eighth capacitance element C8 is reduced. Decreases.

(When + Mz acts)
Next, a case where a moment Mz (see FIG. 5) around the Z axis (clockwise toward the positive side in the Z axis direction) acts on the receiving body 10 will be described. Also in the following description, the reference numerals in the table of FIG. 9 are determined according to the change in the capacitance value as described above.

In this case, the first strain generating body 30A is elastically deformed in the same manner as when a force Fx on the positive side in the X-axis direction is applied. As a result, the first strain element 30A is elastically deformed in the same manner as the first strain element 30A shown in FIG. 6, the capacitance value of the first capacitance element C1 is reduced, and the static electricity of the second capacitance element C2 is static. The capacitance value increases.

The second straining body 30B elastically deforms in the same manner as when a force Fy on the positive side in the Y-axis direction acts. As a result, the second strain element 30B is elastically deformed in the same manner as the first strain element 30A shown in FIG. 6, the capacitance value of the third capacitance element C3 is reduced, and the static electricity of the fourth capacitance element C4 is reduced. The capacitance value increases.

In the third strain generating body 30C, elastic deformation occurs in the same manner as when a force Fx on the negative side in the X-axis direction acts. As a result, the capacitance value of the fifth capacitance element C5 decreases, and the capacitance value of the sixth capacitance element C6 increases.

In the fourth strain generating body 30D, elastic deformation occurs in the same manner as when a force Fy on the negative side in the Y-axis direction acts. As a result, the capacitance value of the 7th capacitance element C7 decreases, and the capacitance value of the 8th capacitance element C8 increases.

In this way, when the change in the capacitance value of each of the capacitance elements C1 to C8 is detected, the direction and magnitude of the force or moment acting on the receiving body 10 are detected. Then, as shown in FIG. 9, the capacitance value of each capacitance element C1 to C8 changes.

From the table shown in FIG. 9, the forces Fx, Fy, Fz and the moments Mx, My, Mz acting on the receiving body 10 can be calculated by the following formulas. Thereby, the 6-axis component of the force can be detected. In the following equation, for convenience, the force or moment and the amount of change in the capacitance value are connected by "=". However, since the force or moment and the capacitance value are different physical quantities from each other, the force or moment is actually calculated by converting the amount of change in the capacitance value. C1 to C8 in the following formula indicate the amount of change in the capacitance value in each capacitance element.
[Equation 3]
Fx = -C1 + C2 + C5-C6
[Equation 4]
Fy = -C3 + C4 + C7-C8
[Equation 5]
Fz = -C1-C2-C3-C4-C5-C6-C7-C8
[Equation 6]
Mx = + C1 + C2-C5-C6
[Equation 7]
My = + C3 + C4-C7-C8
[Equation 8]
Mz = -C1 + C2-C3 + C4-C5 + C6-C7 + C8

As described above, the force sensor 1 shown in FIG. 5 detects the forces Fx, Fy, Fz, and the moments Mx, My, Mz as shown in the above-mentioned [Equation 3] to [Equation 8]. Therefore, it is possible to detect the 6-axis component of the force. However, the number of force axis components that can be detected by the force sensor 1 is not limited to six, and the detectable axis component is arbitrary depending on the number, structure, and shape of the strain generating elements. Is. For example, when the receiving body 10 and the support 20 are connected only by the first straining body 30A shown in FIG. 4, as shown in the above-mentioned [Equation 1] and [Equation 2], the force Fx and Since Fz can be detected, it becomes possible to detect a biaxial component of force.

When the change in the capacitance value of each of the capacitance elements C1 to C8 shown in FIG. 9 is applied to the above-mentioned [Equation 3] to [Equation 8], a table showing the spindle sensitivity and the other axis sensitivity of FIG. 10 is obtained. VFx shown in FIG. 10 is an output when a force Fx in the X-axis direction is applied, VFy is an output when a force Fy in the Y-axis direction is applied, and VFz is an output when a force Fz in the Z-axis direction is applied. Is the output of. Further, VMx is the output when the moment Mx around the X axis acts, VMy is the output when the moment My around the Y axis acts, and VMz is the output when the moment Mz around the Z axis acts. Is.

The numerical values shown in the table of FIG. 10 refer to the capacitive elements marked with “+” for each force Fx, Fy, Fz and each moment Mx, My, Mz shown in the table of FIG. 9 as “+1”. , And the capacitive element with the sign of "-" is designated as "-1", and it is a numerical value obtained by substituting it on the right side of the above-mentioned [Equation 3] to [Equation 8]. For example, the numerical value "4" in the square where the column of Fx and the row of VFx intersect is "+1" in C2 and C5 based on the row of Fx in FIG. 9 in [Equation 3] indicating Fx. Is substituted, and "-1" is substituted for C1 and C6 to obtain a numerical value. Further, the numerical value "0" described in the square where the column of Fx and the row of VFy intersect is changed to C1, C2, C5 and C6 based on the row of Fy in FIG. 9 in [Equation 3] indicating Fx. It is a numerical value obtained by substituting 0.

As shown in FIG. 10, for the force Fx, VFx is a numerical value of "4", but VFy, VFz, VMx, VMy, and VMz are numerical values of "0". From this, with respect to the force Fx, there is no sensitivity on the other axis, and only the sensitivity on the spindle can be detected. Similarly, the forces Fy and Fz and the moments Mx, My and Mz have no other axis sensitivity, and only the spindle sensitivity can be detected. That is, it is possible to obtain a force sensor 1 capable of suppressing the occurrence of sensitivity of other axes.

It is also possible that sensitivity to other axes occurs. For example, when a force Fz acts on the positive side of the first strain generating body 30A in the Z-axis direction, the amount of change in the capacitance value of the first capacitance element C1 and the amount of change in the capacitance value of the second capacitance element C2. May differ from. In this case, sensitivity to the other axis may occur with respect to the force Fz. Further, when the forces Fz, the moments Mx, and My act on the receiving body 10, the first strain-causing body 30A is displaced in the Z-axis direction, so that the Fz row and the Mx row in the table shown in FIG. 9 In the My line, the amount of change in the capacitance value may be different even if the same reference numerals are given. In this case, the sensitivity of the other axis may be generated with respect to the force Fz, the moment Mx, and My. Similarly, the sensitivity of other axes can be generated for the forces Fx, Fy, and the moment Mz. For example, when the moment Mx acts on the receiving body 10, as shown in FIG. 9, the capacitance values of the third capacitance element C3, the fourth capacitance element C4, the seventh capacitance element C7, and the eighth capacitance element C8 are different. Since it does not change, the numerical value "0" is described, but the capacitance value may change and other axis sensitivity may occur. The same applies to the moments My and Mz. Further, even for a capacitive element in which a numerical value of "0" is described in the lines of forces Fx and Fy, the capacitance value may change and sensitivity to other axes may occur.

However, even when the sensitivity of the other axis occurs, the inverse matrix of the matrix of the sensitivity of the other axis (the matrix of 6 rows and 6 columns corresponding to the table shown in FIG. 10, also called the characteristic matrix) is obtained, and this inverse matrix is used. The correction calculation can be performed by multiplying the output (characteristic matrix) of the force sensor. As a result, the sensitivity of the other axis can be reduced, and the occurrence of the sensitivity of the other axis can be suppressed.

As described above, according to the present embodiment, the strain generating bodies 30A to 30D connecting the receiving body 10 and the supporting body 20 have a tilting structure connected to the receiving body side deformed body 33 and the support body side deformed body 34. A first tilting body 35 having a body 31 and a tilting structure 31 arranged in a plane including a Z-axis direction and an X-axis direction orthogonal to the Z-axis direction and extending in a direction different from the Z-axis direction is included. .. The first tilting body 35 can be elastically deformed by the action of a force in the Z-axis direction. As a result, the tilting structure 31 can be easily elastically deformed by the action of the force in the Z-axis direction. Therefore, the displacement of the displacement electrode substrates Ed1 to Ed8 can be increased, and the force or moment detection sensitivity can be increased. As a result, the detection accuracy of the force sensor 1 can be improved.

Further, according to the present embodiment, the configuration of the strain generating bodies 30A to 30D can be simplified. Further, the 6-axis component can be detected only by connecting at least three strain-causing bodies to the receiving body 10 and the support body 20. Therefore, the price of the force sensor 1 can be reduced.

Further, according to the present embodiment, the receiving body side deformed body 33 extends in the Z-axis direction. As a result, when a force or a moment acts on the receiving body 10, the receiving body side deformable body 33 can be further elastically deformed. Therefore, the strain generating bodies 30A to 30D can be more easily elastically deformed, and the displacement of the displacement electrode substrates Ed1 to Ed8 provided on the strain generating bodies 30A to 30D can be increased. Therefore, the detection sensitivity of the force or the moment can be further increased, and the detection accuracy of the force sensor 1 can be further improved.

Further, according to the present embodiment, the support side deformed body 34 extends in the Z-axis direction. As a result, when a force or a moment acts on the receiving body 10, the support side deformed body 34 can be further elastically deformed. Therefore, the strain generating bodies 30A to 30D can be more easily elastically deformed, and the displacement of the displacement electrode substrates Ed1 to Ed8 provided on the strain generating bodies 30A to 30D can be increased. Therefore, the detection sensitivity of the force or the moment can be further increased, and the detection accuracy of the force sensor 1 can be further improved.

Further, according to the present embodiment, the first tilting body 35 of the strain generating bodies 30A to 30D extends in the second direction. That is, the first tilting body 35 of the strain generating bodies 30A and 30C extends in the X-axis direction, and the first tilting body 35 of the strain generating bodies 30B and 30D extends in the Y-axis direction. As a result, the first tilting body 35 can be more easily elastically deformed when subjected to the action of a force in the Z-axis direction. Therefore, the displacement of the displacement electrode substrates Ed1 to Ed8 can be further increased, and the detection sensitivity of the force or moment can be further increased.

Further, according to the present embodiment, the receiving body side deformed body 33 is connected to the first tilting body 35, and the second tilting body 36 connected to the first tilting body 35 via the connecting bodies 37 and 38. The support side deformed body 34 is connected. The second tilting body 36 can be elastically deformed by the action of a force in the X-axis direction. As a result, the tilting structure 31 can be more easily elastically deformed by the action of the force in the Z-axis direction. Therefore, the displacement of the displacement electrode substrates Ed1 to Ed8 can be further increased, and the detection sensitivity of the force or moment can be further increased. As a result, the detection accuracy of the force sensor 1 can be further improved.

Further, according to the present embodiment, the receiving body side deformed body 33 is located between both end portions 35a and 35b of the first tilting body 35 in the X-axis direction. As a result, the first tilting body 35 can be easily elastically deformed by the action of the force in the Z-axis direction. Therefore, it is possible to easily increase the displacement of the displacement electrode substrates Ed1 to Ed8, and it is possible to increase the detection sensitivity of the force or the moment.

Further, according to the present embodiment, the support side deformed body 34 is located between both end portions 36a and 36b of the second tilting body 36 in the X-axis direction. As a result, the second tilting body 36 can be easily elastically deformed by the action of the force in the Z-axis direction. Therefore, it is possible to easily increase the displacement of the displacement electrode substrates Ed1 to Ed8, and it is possible to increase the detection sensitivity of the force or the moment.

Further, according to the present embodiment, the receiving body side deformed body 33 and the support body side deformed body 34 are arranged at positions where they overlap each other when viewed in the Z-axis direction. As a result, the receiving body side deformed body 33 and the support body side deformed body 34 can be arranged at the same position in the second direction. Therefore, when a force Fz in the Z-axis direction acts on the receiving body 10, it is possible to prevent the receiving body 10 from being displaced in the direction orthogonal to the Z-axis direction (X-axis direction or Y-axis direction). The receiving body 10 can be displaced along the Z-axis direction. In this case, it is possible to suppress the occurrence of the other axis sensitivity described above.

Further, according to the present embodiment, the tilting structure 31 is formed symmetrically with respect to the receiving body side deformed body 33 and the support body side deformed body in the second direction. As a result, the inclination of the tilting structure 31 can be increased. Therefore, the displacement of the displacement electrode substrates Ed1 to Ed8 can be further increased, and the detection sensitivity of the force or moment can be further increased. Further, when a force in the Z-axis direction is applied, the displacement of the first displacement electrode substrate Ed1 and the displacement of the second displacement electrode substrate Ed2 can be made equal. Therefore, the calculation of the force or the moment can be facilitated.

Further, according to the present embodiment, the displacement electrode substrates Ed1 to Ed8 of the detection element 50 are arranged at both ends of the tilting structure 31 in the second direction. As a result, the displacement of the displacement electrode substrates Ed1 to Ed8 can be further increased, and the detection sensitivity of the force or moment can be further increased.

Further, according to the present embodiment, the first strain generating body 30A is arranged on the negative side in the Y-axis direction with respect to the center O of the receiving body 10, and the second strain generating body 30B is arranged on the positive side in the X-axis direction. The third straining element 30C is arranged on the positive side in the Y-axis direction, and the fourth straining element 30D is arranged on the negative side in the X-axis direction. The second direction of the first straining body 30A and the third straining body 30C is the X-axis direction, and the second direction of the second straining body 30B and the fourth straining body 30D is the Y-axis direction. As a result, the first strain-generating body 30A to the fourth strain-causing body 30D can be arranged in an annular shape with respect to the center O of the receiving body 10 when viewed in the Z-axis direction. Further, the first strain-generating body 30A to the fourth strain-causing body 30D can be evenly arranged around the center O of the receiving body 10. Therefore, the detection accuracy of the force or the moment in an arbitrary direction can be improved, and it is possible to suppress the decrease in the detection accuracy of the force or the moment depending on the direction.

Further, according to the present embodiment, the planar shape of the receiving body 10 and the planar shape of the support 20 are circular. As a result, the receiving body 10 and the support body 20 can be formed along the shape of the arm portion of the robot main body 1100 and the end effector 1200.

Further, according to the present embodiment, the tilting structures 31 of the strain generating bodies 30A to 30D are formed linearly along the second direction when viewed in the Z-axis direction. As a result, the tilting structure 31 can be formed in a plate shape. For example, the tilting structure 31 can be easily manufactured from a plate material.

(First modification)
In the present embodiment described above, an example will be described in which the spring constant for the force acting on the Z-axis direction of the first tilting body 35 is equal to the spring constant for the force acting on the Z-axis direction of the second tilting body 36. bottom. However, the present invention is not limited to this, and for example, as shown in FIG. 11, the spring constant with respect to the force acting in the Z-axis direction of the second tilting body 36 acts in the Z-axis direction of the first tilting body 35. It may be different from the spring constant with respect to the force. For example, the spring constant for the force acting on the Z-axis direction of the second tilting body 36 may be smaller than the spring constant for the force acting on the Z-axis direction of the first tilting body 35. FIG. 11 is a front view showing a modified example of the strain-causing body of FIG.

According to the first deformation example shown in FIG. 11, when a force in the Z-axis direction acts on the tilting structure 31, the elastic deformation of the first tilting body 35 can be suppressed and the elasticity of the second tilting body 36 can be suppressed. The deformation can be increased. Therefore, the second tilting body 36 is greatly pulled up at both end portions 36a and 36b in the X-axis direction, and the displacement of the displacement electrode substrates Ed1 and Ed2 provided on the second tilting body 36 can be increased. Therefore, the detection sensitivity of force or moment can be further increased.

FIG. 11 shows an example in which the dimension of the first tilting body 35 in the Z-axis direction is increased in order to increase the above-mentioned spring constant of the first tilting body 35. The method of increasing the spring constant is arbitrary. Further, the above-mentioned spring constant of the second tilting body 36 may be reduced. The spring constant for the force acting on the Z-axis direction of the second tilting body 36 may be larger than the spring constant for the force acting on the Z-axis direction of the first tilting body 35. In this case, the fixed electrode substrates Ef1 and Ef2 are provided on the surface of the receiving body 10 on the side of the support 20, and the displacement electrode substrates Ed1 and Ed2 are the receiving bodies in the first tilting body 35 of the tilting structure 31. It may be provided on the surface on the side of 10.

(Second modification)
Further, in the above-described embodiment, the surface of the first straining body 30A on the side of the receiving body 10 of the first tilting body 35 is formed to be flat as a whole, and the second tilting body 36 is formed. An example in which the surface on the side of the support 20 of the above is formed to be flat as a whole has been described. However, it is not limited to this. For example, as shown in FIG. 12, the surface of the first tilting body 35 on the side of the receiving body 10 may be formed in a concave shape around the receiving body side deformed body 33. Further, the surface of the second tilting body 36 on the side of the support 20 may be formed in a concave shape around the support side deformed body 34. FIG. 12 is a plan view showing another modification of the strain-causing body of FIG.

More specifically, as shown in FIG. 12, the first tilting body 35 may include a first receiving body side facing surface 41 and a second receiving body side facing surface 42 facing the receiving body 10. .. The receiving body side deformed body 33 is connected to the first receiving body side facing surface 41. The second receiving body side facing surfaces 42 are arranged on both sides of the first receiving body side facing surfaces 41 in the X-axis direction. The first receiving body side facing surface 41 is located closer to the support 20 than the second receiving body side facing surface 42. A first receiving body side facing surface 41 is formed around the receiving body side deformed body 33. The first receiving body side facing surface 41 is farther from the receiving body 10 than the second receiving body side facing surface 42. In this way, the surface of the first tilting body 35 on the side of the receiving body 10 is formed in a concave shape, and the receiving body side deformed body 33 is connected to the concavely formed portion. The first receiving body side facing surface 41 is formed over the central portion 35c of the first tilting body 35 and a portion in the vicinity thereof, and is formed around the receiving body side deformed body 33 (in the example shown in FIG. 12, in the X-axis direction). Grooves G are formed on both sides). The first receiving body side facing surface 41 and the second receiving body side facing surface 42 may be formed flat, respectively. In the example shown in FIG. 12, the receiving body side deformed body 33 and the first tilting body 35 of the tilting structure 31 are integrally and continuously formed, and the first receiving body side facing surface 41 is on the receiving body side. It is shown on both sides of the variant 33.

As described above, according to the second modification, the first tilting body 35 includes the first receiving body side facing surface 41 located closer to the support 20 than the second receiving body side facing surface 42, and the first receiving body 35. The receiving body side deformed body 33 is connected to the force body side facing surface 41. As a result, the dimension of the receiving body side deformed body 33 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without reducing the dimension of the receiving body side deformed body 33 in the Z-axis direction, and the size can be reduced.

When the first tilting body 35 includes the first receiving body side facing surface 41 located closer to the support body 20 than the second receiving body side facing surface 42, although not shown, the support of the second tilting body 36 is not shown. The surface on the side of the body 20 may be formed flat as a whole.

Similarly, the second tilting body 36 may include a first support side facing surface 43 and a second support side facing surface 44 facing the support 20. The support side deformed body 34 is connected to the first support side facing surface 43. The second support side facing surfaces 44 are arranged on both sides of the first support side facing surfaces 43 in the X-axis direction. The first support side facing surface 43 is located closer to the receiving body 10 than the second support side facing surface 44. A first support side facing surface 43 is formed around the support side deformed body 34. The first support side facing surface 43 is farther from the support 20 than the second support side facing surface 44. In this way, the surface of the second tilting body 36 on the side of the support 20 is formed in a concave shape, and the support side deformed body 34 is connected to the concavely formed portion. The first support side facing surface 43 is formed over the central portion 36c of the second tilting body 36 and a portion in the vicinity thereof, and is formed around the support side deformed body 34 (in the example shown in FIG. 12, both sides in the X-axis direction). ), The groove G is formed. The first support side facing surface 43 and the second support side facing surface 44 may be formed flat, respectively. In the example shown in FIG. 12, the support side deformed body 34 and the second tilted body 36 of the tilted structure 31 are integrally and continuously formed, and the first support side facing surface 43 is the support side deformed body 34. Shown on both sides of.

As described above, according to the second modification, the second tilting body 36 includes the first support side facing surface 43 located closer to the receiving body 10 than the second support side facing surface 44, and includes the first support side facing surface 43. The support side deformed body 34 is connected to the facing surface 43. As a result, the dimension of the support side deformed body 34 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without shortening the dimension of the support side deformed body 34 in the Z-axis direction, and the size can be reduced.

When the second tilting body 36 includes the first support side facing surface 43 located closer to the receiving body 10 than the second support side facing surface 44, as shown in FIG. 13, the first tilting body 35 The surface on the side of the receiving body 10 may be formed to be flat as a whole. In the example shown in FIG. 13, the first tilting body 35 does not include the above-mentioned first receiving body side facing surface 41, and the groove portion G is not formed around the receiving body side deformed body 33. The groove portion G is formed around the support body side deformed body 34 on the surface of the second tilting body 36 on the side of the support body 20. FIG. 13 is a plan view showing another modification of the strain-causing body of FIG.

(Third modification example)
Further, in the above-described embodiment, the displacement electrode substrates Ed1 and Ed2 of the first strain generating body 30A are provided on the surface of the tilting structure 31 on the side of the receiving body 10 in the second tilting body 36. An example has been described. However, it is not limited to this. For example, as shown in FIG. 14, the displacement electrode substrates Ed1 and Ed2 may be provided on the surface of the second tilting body 36 on the side of the receiving body 10 via the columnar member 45. FIG. 14 is a partially enlarged front view showing another modification of the strain-causing body of FIG.

In the example shown in FIG. 14, the planar shape of the columnar member 45 may be smaller than the planar shape of the displacement electrode substrates Ed1 and Ed2. The planar shape of the columnar member 45 may be rectangular or circular, and is arbitrary. The columnar member 45 may be joined to the second tilting body 36 with an adhesive, or may be fixed with a bolt or the like. The displacement electrode substrates Ed1 and Ed2 may be joined to the columnar member 45 with an adhesive, or may be fixed with bolts or the like.

As described above, according to the third modification, the displacement electrode substrates Ed1 and Ed2 are provided on the second tilting body 36 via the columnar member 45. This makes it possible to stabilize the detection of displacement. That is, when a force acts on the first strain-causing body 30A, the second tilting body 36 of the tilting structure 31 is elastically deformed, and stress is applied to the portion of the second tilting body 36 in the vicinity of the displacement electrode substrates Ed1 and Ed2. Can occur. When such stress is generated, it causes hysteresis and drift of the zero point voltage (output voltage when no load is applied). On the other hand, as shown in FIG. 14, by providing the displacement electrode substrates Ed1 and Ed2 on the second tilting body 36 via the columnar member 45, the displacement electrode substrates Ed1 and Ed2 are attached to the second tilting body 36. The influence of the generated stress can be reduced. Therefore, the displacement detection can be stabilized.

(Fourth modification)
Further, as shown in FIG. 15, the displacement electrode substrates Ed1 and Ed2 may be provided on the columnar member 45 described above via the reinforcing substrate 46. FIG. 15 is a partially enlarged front view showing another modified example of the strain-causing body of FIG.

In the example shown in FIG. 15, the planar shape of the reinforcing substrate 46 may be equal to the planar shape of the displacement electrode substrates Ed1 and Ed2. The reinforcing substrate 46 may be joined to the columnar member 45 with an adhesive, or may be fixed with bolts or the like. In this case, the displacement electrode substrates Ed1 and Ed2 may be bonded to the reinforcing substrate 46 with an adhesive. The spring constant with respect to the force acting on the reinforcing substrate 46 in the Z-axis direction may be larger than the spring constant with respect to the force acting on the displacement electrode substrates Ed1 and Ed2 in the Z-axis direction. As a result, deformation of the displacement electrode substrates Ed1 and Ed2 can be suppressed. The reinforcing substrate 46 may be made of a metal material, and may be made of the same material as the receiving body 10, the support 20, and the strain generating bodies 30A to 30D in order to suppress deformation due to a temperature change, for example. .. In this case, the reinforcing substrate 46 may be made of an aluminum alloy or an iron alloy. The reinforcing substrate 46 may be manufactured integrally with the columnar member 45 described above. By using such a reinforcing substrate 46, deformation of the displacement electrode substrates Ed1 and Ed2 can be suppressed. For example, even when the FPC substrate is used for the displacement electrode substrates Ed1 and Ed2, the deformation of the displacement electrode substrates Ed1 and Ed2 can be effectively suppressed.

(Fifth modification)
Further, in the above-described embodiment, an example in which the first tilting body 35 and the second tilting body 36 extend linearly in the X-axis direction (the second direction of the strain generating body 30A) has been described. However, the present invention is not limited to this, and the first tilting body 35 and the second tilting body 36 are arranged in a plane including the Z-axis direction (first direction), the Z-axis direction, and the X-axis direction. Any shape can be used as long as it extends in a direction different from the axial direction. For example, the shape shown in FIG. 16 may be used. Here, FIG. 16 is a front view showing another modified example of the strain-causing body of FIG. The first straining body 30A shown in FIG. 16 has the same shape as the first straining body 30A when a force Fz on the negative side in the Z-axis direction is received as shown in FIG. 7B. In No. 16, it is shown as the first straining body 30A in a state where it is not affected by a force or a moment.

In the first straining body 30A shown in FIG. 16, the central portion 35c of the first tilting body 35 in the X-axis direction is closer to the support 20 (or the second tilting body) than both end portions 35a and 35b in the X-axis direction. It is located on the side of the body 36). More specifically, the first tilting body 35 is arranged on the negative side of the first tilting body 35d in the X-axis direction with respect to the central portion 35c and on the positive side in the X-axis direction with respect to the central portion 35c. The first tilting body positive side portion 35e and the like are included. The first tilting body negative side portion 35d is a portion connecting the negative side end portion 35a and the central portion 35c, and is inclined so as to proceed toward the positive side in the X-axis direction and toward the negative side in the Z-axis direction. .. The first tilting body negative side portion 35d extends in a direction inclined with respect to the Z-axis direction (a direction different from the Z-axis direction) in the XZ plane. The first tilting body positive side portion 35e is a portion connecting the positive end portion 35b and the central portion 35c, and is inclined so as to proceed toward the positive side in the X-axis direction toward the positive side in the Z-axis direction. .. The first tilting body positive side portion 35e extends in a direction inclined with respect to the Z-axis direction (a direction different from the Z-axis direction) in the XZ plane. In this way, the first tilting body 35 in the modified example shown in FIG. 16 is substantially formed in a V shape.

The central portion 36c of the second tilting body 36 in the X-axis direction is located closer to the receiving body 10 (or to the side of the first tilting body 35) than both end portions 36a and 36b in the X-axis direction. More specifically, the second tilting body 36 is arranged on the negative side of the second tilting body 36d arranged on the negative side in the X-axis direction with respect to the central portion 36c and on the positive side in the X-axis direction with respect to the central portion 36c. The second tilting body positive side portion 36e and the like are included. The second tilting body negative side portion 36d is a portion connecting the negative side end portion 36a and the central portion 36c, and is inclined so as to proceed toward the positive side in the X-axis direction toward the positive side in the Z-axis direction. .. The second tilting body negative side portion 36d extends in a direction inclined with respect to the Z-axis direction (a direction different from the Z-axis direction) in the XZ plane. The second tilting body positive side portion 36e is a portion connecting the positive end portion 36b and the central portion 36c, and is inclined so as to proceed toward the positive side in the X-axis direction and the negative side in the Z-axis direction. .. The second tilting body positive side portion 36e extends in a direction inclined with respect to the Z-axis direction (a direction different from the Z-axis direction) in the XZ plane. In this way, the second tilting body 36 in the modified example shown in FIG. 16 is substantially formed in an inverted V shape.

As described above, according to the modified example shown in FIG. 16, the central portion 35c of the first tilting body 35 in the X-axis direction is located closer to the support 20 than both end portions 35a and 35b in the X-axis direction. As a result, the central portion 35c of the first tilting body 35 in the X-axis direction can be kept away from the receiving body 10, and the dimension of the receiving body-side deformed body 33 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without reducing the dimension of the receiving body side deformed body 33 in the Z-axis direction, and the size can be reduced.

Further, according to the modified example shown in FIG. 16, the central portion 36c of the second tilting body 36 in the X-axis direction is located closer to the receiving body 10 than the both end portions 36a and 36b in the X-axis direction. As a result, the central portion 36c of the second tilting body 36 in the X-axis direction can be kept away from the support 20, and the dimension of the support-side deformed body 34 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without reducing the dimensions of the support side deformed body 34 in the Z-axis direction, and the size can be reduced.

(6th modification)
Further, in the above-described embodiment, an example in which the first tilting body 35 and the second tilting body 36 extend linearly in the X-axis direction (the second direction of the strain generating body 30A) has been described. However, the present invention is not limited to this, and the first tilting body 35 and the second tilting body 36 are arranged in a plane including the Z-axis direction (first direction), the Z-axis direction, and the X-axis direction. Any shape can be used as long as it extends in a direction different from the axial direction. For example, the shape shown in FIG. 17 may be used. Here, FIG. 17 is a front view showing another modified example of the strain-causing body of FIG. The first straining body 30A shown in FIG. 17 has the same shape as the first straining body 30A when a force Fz on the positive side in the Z-axis direction is received as shown in FIG. 7A. In 17, it is shown as the first straining body 30A in a state where it is not affected by a force or a moment.

In the first straining body 30A shown in FIG. 17, the central portion 35c of the first tilting body 35 in the X-axis direction is closer to the receiving body 10 (or the second tilting body 10 than both end portions 35a and 35b in the X-axis direction. It is located on the opposite side of the body 36). More specifically, the above-mentioned first tilting body negative side portion 35d of the first tilting body 35 is inclined so as to proceed toward the positive side in the X-axis direction and toward the positive side in the Z-axis direction. The first tilting body positive side portion 35e is inclined so as to proceed toward the positive side in the X-axis direction and the negative side in the Z-axis direction. In this way, the first tilting body 35 in the modified example shown in FIG. 17 is substantially formed in an inverted V shape.

The central portion 36c of the second tilting body 36 in the X-axis direction is located on the side of the support 20 (or the side opposite to the first tilting body 35) with respect to both end portions 36a and 36b in the X-axis direction. More specifically, the above-mentioned second tilting body negative side portion 36d of the second tilting body 36 is inclined so as to proceed toward the positive side in the X-axis direction and toward the negative side in the X-axis direction. The second tilting body positive side portion 36e is inclined so as to advance to the positive side in the Z-axis direction toward the positive side in the X-axis direction. In this way, the second tilting body 36 in the modified example shown in FIG. 17 is substantially formed in a V shape.

As described above, according to the modified example shown in FIG. 17, the central portion 35c of the first tilting body 35 in the X-axis direction is located closer to the receiving body 10 than the both end portions 35a and 35b in the X-axis direction. .. As a result, the height of the force sensor 1 can be increased without increasing the dimension of the receiving body side deformed body 33 in the Z-axis direction.

Further, according to the modified example shown in FIG. 17, the central portion 36c of the second tilting body 36 in the X-axis direction is located closer to the support 20 than both end portions 36a and 36b in the X-axis direction. As a result, the height of the force sensor 1 can be increased without increasing the dimension of the support side deformed body 34 in the Z-axis direction.

(7th modification)
Further, in the above-described embodiment, an example in which the upper end of the receiving body side deformed body 33 is connected to the receiving body 10 has been described. However, the present invention is not limited to this, and for example, as shown in FIG. 18, the receiving body side deformed body 33 may be connected to the receiving body 10 via the receiving body side pedestal 39. As a result, the receiving body side deformed body 33 can be stably attached to the receiving body 10 by the receiving body side pedestal 39. For example, the receiving body side pedestal 39, the receiving body side deformed body 33, and the first tilting body 35 may be integrally formed. In this case, the receiving body side pedestal 39 receives with a bolt, an adhesive, or the like. It may be fixed to the force body 10. Alternatively, the receiving body side pedestal 39 and the receiving body side deformed body 33 may be formed separately and fixed to each other with bolts, adhesives, or the like.

Similarly, the lower end of the support side deformed body 34 is not limited to being connected to the support 20. For example, as shown in FIG. 18, the support side deformed body 34 is connected to the support side pedestal 40. It may be connected to the support 20. As a result, the support side deformed body 34 can be stably attached to the support 20 by the support side pedestal 40. For example, the support side pedestal 40, the support side deformed body 34, and the second tilting body 36 may be integrally formed. In this case, the support side pedestal 40 is fixed to the support 20 with a bolt, an adhesive, or the like. It may have been done. Alternatively, the support side pedestal 40 and the support side deformed body 34 may be formed separately and fixed to each other with bolts, adhesives, or the like.

Further, the receiving body side pedestal 39, the receiving body side deformed body 33, the tilting structure 31, the support body side deformed body 34, and the support body side pedestal 40 may be integrally formed. In this case, the receiving body side pedestal 39 may be fixed to the receiving body 10 with a bolt or an adhesive, and the support body side pedestal 40 may be fixed to the support 20 with a bolt or an adhesive or the like. ..

The receiving body side pedestal and the support side pedestal are not limited to being applied to the first straining body 30A shown in FIG. 18, and other strains such as the first straining body 30A shown in FIG. 11 are generated. It can also be applied to bodies 30A to 30D.

(8th modification)
Further, in the above-described embodiment, the planar shape of the receiving body 10 is circular, and the tilting structure 31 is formed linearly along the second direction when viewed in the Z-axis direction. The example that has been done has been explained. However, it is not limited to this.

For example, as shown in FIG. 19, the tilting structure 31 may be formed in a curved shape when viewed in the Z-axis direction. FIG. 19 is a plan view showing another modification of the force sensor of FIG. In this case, the tilting structure 31 may be formed in a curved shape concentrically with the receiving body 10. That is, the tilting structures 31 of the four strain generating bodies 30A to 30D may be arranged so as to form a circular ring shape. When the tilting structures 31 of the strain generating bodies 30A to 30D are formed in a curved shape, the planar shape of the receiving body 10 may be rectangular as shown in FIG. 20 described later. In this case, the planar shape of the support 20 may be rectangular.

Further, for example, as shown in FIG. 20, the planar shape of the receiving body 10 may be rectangular. In this case, the planar shape of the support 20 may also be rectangular. As a result, the force receiving body 10 and the support body 20 can be formed along the arrangement of the strain generating bodies 30A to 30D, and the force sensor 1 having good space efficiency can be obtained. Further, the plane cross-sectional shape of the exterior body 80 may be the shape of a rectangular frame. That is, at least one of the planar shape of the receiving body 10 and the planar shape of the support 20 may be rectangular. In this case, one of the planar shape of the receiving body 10 and the planar shape of the support 20 may be rectangular, and the other may be a shape other than a rectangle. The planar shape of the receiving body 10 may be another shape such as a polygon or an ellipse in addition to the rectangular shape. The same applies to the support 20. The planar cross-sectional shape of the exterior body 80 may also be another shape such as a polygonal frame or an elliptical frame, corresponding to the planar shape of the receiving body 10 and the planar shape of the support 20.

(9th modification)
Further, in the above-described embodiment, an example in which the detection element 50 is configured as an element for detecting the capacitance has been described. However, the present invention is not limited to this, and the detection element 50 may be composed of a strain gauge that detects the strain generated by the action of the force or moment received by the receiving body 10. For example, as shown in FIG. 21A, the detection element 50 may have a strain gauge provided on the first strain generating body 30A. FIG. 21A is a front view of a strain-causing body showing a modified example of the detection element of FIG. 21B is a plan view showing the detection element of FIG. 21A. 21C is a plan view showing a modification of FIG. 21B. 22A is a diagram showing a Wheatstone bridge circuit for a detection element provided in the first tilting body shown in FIG. 21A. FIG. 22B is a diagram showing a Wheatstone bridge circuit for a detection element provided in the second tilting body shown in FIG. 21A. FIG. 23A is a schematic view showing a deformed state of the strain-causing body when the strain-causing body of FIG. 21A receives a force on the positive side in the X-axis direction. FIG. 23B is a schematic view showing a deformed state of the strain-causing body when the strain-causing body of FIG. 21A receives a force on the positive side in the Z-axis direction.

As shown in FIG. 21A, the strain gauges R1 to R8 may be provided on the tilting structure 31. As shown in FIGS. 23A and 23B, the dimensions of the connecting bodies 37 and 38 of the tilting structure 31 according to the present embodiment in the X-axis direction are the X of the connecting bodies 37 and 38 of the tilting structure 31 in FIG. It may be larger than the axial dimension. In other words, the spring constant for the force acting in the X-axis direction of the connecting bodies 37 and 38 according to the present embodiment is larger than the spring constant for the force acting in the X-axis direction of the connecting bodies 37 and 38 in FIG. You may.

More specifically, the strain gauges R1 to R4 may be attached to the surface of the tilting structure 31 on the side of the receiving body 10 of the first tilting body 35. For example, two strain gauges R1 and R2 are attached to the upper surface of the first tilt body negative side portion 35d of the first tilt body 35, and two strain gauges R3 and R4 are attached to the upper surface of the first tilt body positive side portion 35e. May be attached. In the first tilting body negative side portion 35d, one strain gauge R1 is located on the side of the end portion 35a on the negative side in the X-axis direction (the side of the connecting body 37), and the other strain gauge R2 is located on the central portion 35c. It may be located on the side (the side of the receiving body side deformed body 33). In the first tilting body positive side portion 35e, one strain gauge R3 is located on the side of the central portion 35c (the side of the receiving body side deformed body 33), and the other strain gauge R4 is the end on the positive side in the X-axis direction. It may be located on the side of the portion 35b (the side of the connecting body 38). As shown in FIG. 21B, the four strain gauges R1 to R4 provided on the first tilting body 35 may be located at the center of the first tilting body 35 in the Y-axis direction.

Further, as shown in FIG. 22A, the detection circuit 60 includes a Wheatstone bridge circuit 61 that outputs an electric signal based on the detection results of the four strain gauges R1 to R4 attached to the first tilting body 35. May be good. In this Wheatstone bridge circuit 61, by applying a predetermined voltage from the bridge voltage source E1, a bridge voltage as an electric signal corresponding to the distortion detected by each distortion gauge R1 to R4 is generated between the output terminals T11 and T12. It is configured to occur. In the Wheatstone bridge circuit 61, the strain gauge R1 and the strain gauge R3 face each other, and the strain gauge R2 and the strain gauge R4 face each other. As a result, as will be described later, the force Fx in the X-axis direction can be detected, and it is possible to prevent the force Fz in the Z-axis direction from affecting the detection of the force Fx. That is, the force Fx as the main axis sensitivity can be detected, and it is possible to prevent the other axis sensitivity from being generated.

Further, as shown in FIG. 21A, the strain gauges R5 to R8 may be attached to the surface of the tilting structure 31 on the side of the support 20 of the second tilting body 36. For example, two strain gauges R5 and R6 are attached to the lower surface of the second tilt body negative side portion 36d of the second tilt body 36, and two strain gauges R7 and R8 are attached to the lower surface of the second tilt body positive side portion 36e. May be attached. In the second tilting body negative side portion 36d, one strain gauge R5 is located on the side of the end portion 36a on the negative side in the X-axis direction (the side of the connecting body 37), and the other strain gauge R6 is located on the central portion 36c. It may be located on the side (the side of the support side deformed body 34). In the second tilting body positive side portion 36e, one strain gauge R7 is located on the side of the central portion 36c (the side of the support side deformed body 34), and the other strain gauge R8 is the end portion on the positive side in the X-axis direction. It may be located on the side of 36b (the side of the connecting body 38). The strain gauges R5 to R8 provided on the second tilting body 36 may be arranged in the same manner as the strain gauges R1 to R4 provided on the first tilting body 35 shown in FIG. 21B.

Further, as shown in FIG. 22B, the detection circuit 60 further includes a Wheatstone bridge circuit 62 that outputs an electric signal based on the detection results of the four strain gauges R5 to R8 attached to the second tilting body 36. You may. In this Wheatstone bridge circuit 62, by applying a predetermined voltage from the bridge voltage source E2, a bridge voltage as an electric signal corresponding to the distortion detected by each distortion gauge R5 to R8 is generated between the output terminals T21 and T22. It is configured to occur. In the Wheatstone bridge circuit 62, the strain gauge R5 and the strain gauge R8 face each other, and the strain gauge R6 and the strain gauge R7 face each other. As a result, as will be described later, the force Fz in the Z-axis direction can be detected, and it is possible to prevent the force Fx in the X-axis direction from affecting the detection of the force Fz. That is, the force Fz as the main axis sensitivity can be detected, and the occurrence of other axis sensitivity can be prevented.

The strain gauges R5 to R8 provided on the second tilting body 36 may be provided on the first tilting body 35. That is, the first tilting body 35 may be provided with eight strain gauges R1 to R8. In this case, as shown in FIG. 21C, two rows of strain gauges along the X-axis direction may be formed on the surface of the first tilting body 35 on the side of the receiving body 10. This eliminates the need to mount the eight strain gauges R1 to R8 on the surface of the second tilting body 36 on the side of the support 20, and eliminates the need to mount the eight strain gauges R1 to R8 on the surface of the first tilting body 35 on the side of the receiving body 10. It can be done only by itself, and the efficiency of manufacturing work can be improved. Alternatively, eight strain gauges R1 to R8 may be provided on the surface of the second tilting body 36 on the side of the support 20. In this case, the eight strain gauges R1 to R8 may be provided on the surface of the first tilting body 35 on the side of the receiving body 10. This can be done only on the surface of the second tilting body 36 on the side of the support 20, and the efficiency of the manufacturing work can be improved.

With such a configuration, when the receiving body 10 is subjected to the action of a force or a moment, the tilting structure 31 and the support side deforming body 34 are mainly elastically deformed, but the first tilting body 35 and the first tilting body 35 of the tilting structure 31 The two tilting body 36 also elastically deforms. When the first tilting body 35 is elastically deformed, a strain is generated in the first tilting body 35, and this strain is detected by strain gauges R1 to R4 provided on the first tilting body 35.

For example, when a force Fx acts on the positive side in the X-axis direction, as shown in FIG. 6, the receiving body-side deformed body 33 and the support-side deformed body 34 of the tilting structure 31 are tilted with respect to the Z-axis direction. Then, the tilting structure 31 can be tilted as a whole. More specifically, as shown in FIG. 23A, the first tilting body 35 and the second tilting body 36 are elastically deformed so as to be curved. Of the negative side portion 35d of the first tilting body, a compressive stress is generated at the portion 35a on the negative side in the X-axis direction, and the strain gauge R1 located at that portion has a resistance value corresponding to the compressive strain. Decrease. Tensile stress is generated in the portion of the negative side portion 35d of the first tilting body on the side of the central portion 35c, and the resistance value of the strain gauge R2 located at the portion increases in accordance with the tensile strain. Further, a compressive stress is generated in a portion of the first tilting body positive side portion 35e on the side of the central portion 35c, and the resistance value of the strain gauge R3 located at the portion decreases in accordance with the compressive strain. Tensile stress is generated in the portion of the first tilting body positive side portion 35e on the side of the end portion 35b on the positive side in the X-axis direction, and the strain gauge R4 located at that portion has a resistance value corresponding to the tensile strain. Increase.

In this way, the resistance values change in the strain gauges R1 to R4, and the forces Fx in the X-axis direction acting on the first strain generating body 30A are shown from the output terminals T11 and T12 of the Wheatstone bridge circuit 61 shown in FIG. 22A. An electric signal is output.

In the strain gauges R5 to R8 provided on the second tilting body 36, stresses in opposite directions to the strain gauges R1 to R4 provided on the first tilting body 35 are generated, and the resistance value changes. However, no electric signal is output from the output terminals T21 and T22 of the Wheatstone bridge circuit 62 shown in FIG. 22B.

Further, for example, when a force Fz acts on the positive side in the Z-axis direction, as shown in FIG. 7A, the first tilting body 35 and the second tilting body 36 of the tilting structure 31 are elastically deformed. More specifically, as shown in FIG. 23B, the first tilting body 35 and the second tilting body 36 are elastically deformed so as to be curved. Of the second tilting body negative side portion 36d, a compressive stress is generated at the portion on the side of the end portion 36a on the negative side in the X-axis direction, and the strain gauge R5 located at that portion has a resistance value corresponding to the compressive strain. Decrease. Tensile stress is generated in the portion of the negative side portion 36d of the second tilting body on the side of the central portion 36c, and the resistance value of the strain gauge R6 located at the portion increases in accordance with the tensile strain. Further, tensile stress is generated in the portion of the second tilting body positive side portion 36e on the side of the central portion 36c, and the resistance value of the strain gauge R7 located at the portion increases in accordance with the tensile strain. Compressive stress is generated in the portion of the second tilting body positive side portion 36e on the side of the end portion 36b on the positive side in the X-axis direction, and the strain gauge R8 located at that portion has a resistance value corresponding to the compressive strain. Decrease.

In this way, the resistance value changes in the strain gauges R5 to R8, and the electricity indicating the Z-axis direction force Fz acting on the first strain generating body 30A from the output terminals T21 and T22 of the Wheatstone bridge circuit 62 shown in FIG. 22B. A signal is output.

In the strain gauges R1 to R4 provided on the first tilting body 35, stresses in the same directions as the strain gauges R5 to R8 provided on the second tilting body 36 are generated, and the resistance value changes. However, no electric signal is output from the output terminals T11 and T12 of the Wheatstone bridge circuit 61 shown in FIG. 22A.

By using the strain gauges R1 to R8 provided on the first straining body 30A shown in FIG. 21A, the force Fx in the X-axis direction and the force Fz in the Z-axis direction can be detected, and the biaxial component of the force can be detected. Can be detected. Further, for example, by providing a strain gauge on each of the strain generating bodies 30A to 30D shown in FIG. 5, the forces Fx, Fy, Fz and the moments Mx, My, Mz can be detected, and the 6-axis components of the force can be detected. Can be detected.

In addition, in FIGS. 21A, 23A and 23B, the example in which the strain gauges R1 to R4 are attached to the surface of the first tilting body 35 on the side of the receiving body 10 has been described. However, the present invention is not limited to this, and as shown by the broken lines in FIGS. 23A and 23B, the strain gauges R1 to R4 are the surfaces of the first tilting body 35 on the side of the support 20 (of the second tilting body 36). It may be attached to the side surface). In this case, the relationship between the compression and the tension of the strain gauges R1 to R4 is opposite, but the force Fz in the Z-axis direction can be detected in the same manner. Further, an example in which the strain gauges R5 to R8 are attached to the surface of the second tilting body 36 on the side of the support 20 has been described. However, the present invention is not limited to this, and as shown by the broken lines in FIGS. 23A and 23B, the strain gauges R5 to R8 are the surfaces of the second tilting body 36 on the side of the receiving body 10 (the first tilting body 35). It may be attached to the side surface). In this case, the relationship between the compression and the tension of the strain gauges R5 to R8 is opposite, but the force Fx in the X-axis direction can be detected in the same manner.

Further, in the examples shown in FIGS. 21A to 23B, the Wheatstone bridge circuit 61 shown in FIG. 22A is formed by the four strain gauges R1 to R4 attached to the first tilting body 35, whereby the force Fx in the X-axis direction is used. An example of detecting is described. However, the present invention is not limited to this, and the force Fz in the Z-axis direction may be detected by the four strain gauges R1 to R4. In this case, for example, in the Wheatstone bridge circuit 61 shown in FIG. 22A, the strain gauge R3 and the strain gauge R4 may be interchanged. Similarly, in the examples shown in FIGS. 21A to 23B, the four strain gauges R5 to R8 attached to the second tilting body 36 form the Wheatstone bridge circuit 62 shown in FIG. 22B to form a force in the Z-axis direction. An example of detecting Fz has been described. However, the present invention is not limited to this, and the four strain gauges R5 to R8 may detect the force Fx in the X-axis direction. In this case, for example, in the Wheatstone bridge circuit 62 shown in FIG. 22B, the strain gauge R7 and the strain gauge R8 may be interchanged.

(Second Embodiment)
Next, the force sensor according to the second embodiment of the present invention will be described with reference to FIGS. 24 to 28.

In the second embodiment shown in FIGS. 24 to 28, the receiving body and the first tilting body are connected by two receiving body side deformed bodies, and the support side deformed body is the first tilting body and the support body. The other configurations are substantially the same as those of the first embodiment shown in FIGS. 1 to 23B. In FIGS. 24 to 28, the same parts as those in the first embodiment shown in FIGS. 1 to 23B are designated by the same reference numerals, and detailed description thereof will be omitted.

First, the force sensor 1 according to the present embodiment will be described with reference to FIG. 24. FIG. 24 is a front view showing a strain-causing body of the force sensor according to the second embodiment.

In the force sensor 1 according to the present embodiment, as shown in FIG. 24, the tilting structure 31 of the first strain generating body 30A is composed of one first tilting body 35. The tilting structure 31 according to the present embodiment does not have the second tilting body 36 and the connecting bodies 37 and 38 as shown in FIG. In the present embodiment, the first tilting body 35 extends in the X-axis direction. More specifically, the first tilting body 35 extends linearly from one end 35a in the X-axis direction to the other end 35b, and the central portion 35c of the first tilting body 35 in the X-axis direction is formed. Both ends 35a and 35b are located at the same position in the Z-axis direction. The surface of the first tilting body 35 on the side of the receiving body 10 is formed to be flat as a whole. Further, the surface of the first tilting body 35 on the side of the support 20 is formed to be flat as a whole.

The receiving body 10 and the first tilting body 35 are connected by two receiving body side deformed bodies 33 extending in the Z-axis direction. The two receiving body side deformed bodies 33 are arranged at different positions in the X-axis direction. In the example shown in FIG. 24, the two receiving body side deformed bodies 33 are located at both ends 35a and 35b of the first tilting body 35 in the X-axis direction. In the present embodiment, the upper end of each receiving body side deformed body 33 is connected to the receiving body 10, and the lower end is connected to the first tilting body 35.

The support side deformed body 34 is located between the two receiving body side deformed bodies 33 in the X-axis direction. More specifically, the support side deformed body 34 is located at the center of the first tilting body 35 in the X-axis direction, and is connected to the central portion 35c of the first tilting body 35. In the present embodiment, the lower end of the support side deformed body 34 is connected to the support body 20, and the upper end is connected to the first tilting body 35.

In this way, the first strain generating body 30A is formed symmetrically with respect to the support side deformed body 34 in the X-axis direction.

Next, a method in which a force or moment acts on the force sensor 1 according to the present embodiment having such a configuration and the force or moment is detected will be described with reference to FIGS. 25 to 26B. FIG. 25 is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 24 receives a force on the positive side in the X-axis direction. FIG. 26A is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 24 receives a force on the positive side in the Z-axis direction. FIG. 26B is a front view schematically showing a deformed state of the strain-causing body when the strain-causing body of FIG. 24 receives a force on the negative side in the Z-axis direction.

Here, taking the first straining body 30A as an example, the first capacitance element C1 and the second capacitance element C2 when a force Fx in the X-axis direction, a force Fy in the Y-axis direction, and a force Fz in the Z-axis direction act. The change in the capacitance value will be described.

(When + Fx acts)
When a force Fx acts on the first straining body 30A on the positive side in the X-axis direction, as shown in FIG. Is elastically deformed in the X-axis direction. The first tilting body 35 of the tilting structure 31 according to the present embodiment is connected to the receiving body 10 via two receiving body side deforming bodies 33 and the supporting body 20 via one supporting body side deforming body 34. Since the deformed body 34 is connected to the receiving body side deformed body 33, the support body side deformed body 34 can be elastically deformed more than the receiving body side deformed body 33. More specifically, the upper end of the support side deformed body 34 is displaced relatively larger on the positive side in the X-axis direction than the lower end. As a result, as shown in FIG. 25, the two receiving body side deformed bodies 33 and the first tilting body 35 can be tilted as a whole together with the receiving body 10. At this time, although not shown in FIG. 25, each receiving body side deformed body 33 is also elastically deformed, and the upper end of each receiving body side deformed body 33 can be displaced to the positive side in the X-axis direction from the lower end. In this way, the support side deformed body 34 of the first strain generating body 30A can be elastically deformed mainly by the force Fx on the positive side in the X-axis direction. In this case, the end portion 35a on the negative side in the X-axis direction of the first tilting body 35 rises, and the end portion 35b on the positive side in the X-axis direction descends.

As a result, the first displacement electrode substrate Ed1 moves away from the first fixed electrode substrate Ef1, and the capacitance value of the first capacitance element C1 decreases. Further, the second displacement electrode substrate Ed2 approaches the second fixed electrode substrate Ef2, and the capacitance value of the second capacitance element C2 increases.

(When -Fx acts)
When a force Fx acts on the first strain generating body 30A on the negative side in the X-axis direction, a phenomenon opposite to that shown in FIG. 25 occurs, although not shown. That is, the capacitance value of the first capacitance element C1 increases, and the capacitance value of the second capacitance element C2 decreases.

(When + Fy acts)
When a force Fy acts on the first strain-generating body 30A on the positive side in the Y-axis direction (not shown), the first strain-generating body 30A rotates around the X-axis (counterclockwise toward the positive side in the X-axis direction). To rotate. As described above, the first capacitance element C1 and the second capacitance element C2 are arranged at the same position in the Y-axis direction. Therefore, even if the first strain generating body 30A rotates around the X-axis, the capacitance value increases in a part of the first capacitance element C1 and the capacitance value increases in a part of the other regions. The capacity value decreases. Therefore, the capacitance value does not change as a whole of the first capacitance element C1. Similarly, the change in the capacitance ground does not appear in the second capacitance element C2 as a whole.

(When -Fy acts)
Similarly, when a force Fy acts on the first strain generating body 30A on the negative side in the Y-axis direction, the capacitance value does not change as a whole of the first capacitance element C1 and as a whole of the second capacitance element C2. ..

(When + Fz acts)
Further, when a force Fz acts on the first strain generating body 30A on the positive side in the Z-axis direction, the first tilting body 35 of the tilting structure 31 is elastically deformed as shown in FIG. 26A. More specifically, while the first tilting body 35 is elastically deformed, the two receiving body side deformed bodies 33 are pulled up to the positive side in the Z-axis direction. As a result, the first tilting body 35 is pulled up to the receiving body side deformed body 33 at both end portions 35a and 35b in the X-axis direction, as shown in FIG. 26A. On the other hand, since the central portion 35c of the first tilting body 35 in the X-axis direction is connected to the support side deformed body 34, it is not substantially pulled up. Therefore, the first tilting body 35 is elastically deformed so as to be convex downward (for example, V-shaped).

As shown in FIG. 26A, when the first tilting body 35 is elastically deformed, the first displacement electrode substrate Ed1 moves away from the first fixed electrode substrate Ef1. Therefore, the capacitance value of the first capacitance element C1 is reduced. Further, the second displacement electrode substrate Ed2 moves away from the second fixed electrode substrate Ef2. Therefore, the capacitance value of the second capacitance element C2 is reduced.

(When -Fz acts)
When a force Fz acts on the first straining body 30A on the negative side in the Z-axis direction, the first tilting body 35 of the tilting structure 31 is elastically deformed as shown in FIG. 26B. More specifically, while the first tilting body 35 is elastically deformed, the receiving body side deforming body 33 is pushed down to the negative side in the Z-axis direction. As a result, the first tilting body 35 is pushed down by the receiving body side deformed body 33 at both end portions 35a and 35b in the X-axis direction, as shown in FIG. 26B. On the other hand, since the central portion 35c of the first tilting body 35 in the X-axis direction is connected to the support side deformed body 34, it is not substantially pushed down. Therefore, the first tilting body 35 is elastically deformed so as to be convex upward (for example, an inverted V shape).

As shown in FIG. 26B, when the first tilting body 35 is elastically deformed, the first displacement electrode substrate Ed1 approaches the first fixed electrode substrate Ef1. Therefore, the capacitance value of the first capacitance element C1 increases. Further, the second displacement electrode substrate Ed2 approaches the second fixed electrode substrate Ef2. Therefore, the capacitance value of the second capacitance element C2 increases.

As described above, according to the present embodiment, the receiving body 10 and the first tilting body 35 are connected by the two receiving body side deformed bodies 33, and the support side deformed body 34 is the first tilting body 35 and the support body. 20 is connected. As a result, the dimension of the tilting structure 31 in the Z-axis direction can be reduced. Therefore, the height of the force sensor 1 can be reduced, and the size can be reduced.

Further, according to the present embodiment, the two receiving body side deformed bodies 33 of the first strain generating body 30A are located at both ends 35a and 35b of the first tilting body 35 in the X-axis direction. As a result, the first tilting body 35 can be easily elastically deformed by the action of the force in the Z-axis direction. Therefore, it is possible to easily increase the displacement of the displacement electrode substrates Ed1 to Ed8, and it is possible to increase the detection sensitivity of the force or the moment.

Further, according to the present embodiment, the support side deformed body 34 of the first strain generating body 30A is located between the two receiving body side deformed bodies 33 in the X-axis direction. As a result, the first tilting body 35 can be easily elastically deformed by the action of the force in the Z-axis direction. Therefore, it is possible to easily increase the displacement of the displacement electrode substrates Ed1 to Ed8, and it is possible to increase the detection sensitivity of the force or the moment.

Further, according to the present embodiment, the strain generating bodies 30A to 30D are formed symmetrically with respect to the support side deformed body 34 in the second direction. As a result, when a force in the Z-axis direction is applied, the displacement of the first displacement electrode substrate Ed1 and the displacement of the second displacement electrode substrate Ed2 can be made equal. Therefore, the calculation of the force or the moment can be facilitated.

(10th modification)
Further, in the above-described embodiment, an example has been described in which the surface of the first straining body 30A on the side of the support 20 of the first tilting body 35 is formed to be flat as a whole. However, it is not limited to this. For example, as shown in FIG. 27, the surface of the first tilting body 35 on the side of the support 20 may be formed in a concave shape around the support side deformed body 34. FIG. 27 is a plan view showing a modified example of the strain-causing body of FIG. 24.

More specifically, the first tilting body 35 may include a first support side facing surface 47 and a second support side facing surface 48 facing the support 20. The support side deformed body 34 is connected to the first support side facing surface 47. The second support side facing surfaces 48 are arranged on both sides of the first support side facing surfaces 47 in the X-axis direction. The first support side facing surface 47 is located closer to the receiving body 10 than the second support side facing surface 48. A first support side facing surface 47 is formed around the support side deformed body 34. The first support side facing surface 47 is farther from the support 20 than the second support side facing surface 48. In this way, the surface of the first tilting body 35 on the side of the support 20 is formed in a concave shape, and the support side deformed body 34 is connected to the concave portion. The first support side facing surface 47 is formed over the central portion 35c of the first tilting body 35 and a portion in the vicinity thereof, and is formed around the support side deformed body 34 (in the example shown in FIG. 27, both sides in the X-axis direction). ), The groove G is formed. The first support side facing surface 47 and the second support side facing surface 48 may be formed flat, respectively. In the example shown in FIG. 27, the support side deformed body 34 and the first tilted body 35 of the tilted structure 31 are integrally and continuously formed, and the first support side facing surface 47 is the support side deformed body 34. Shown on both sides of.

As described above, according to the tenth modification, the first tilting body 35 includes the first support side facing surface 47 located closer to the receiving body 10 than the second support side facing surface 48, and is on the first support side. The support side deformed body 34 is connected to the facing surface 47. As a result, the dimension of the support side deformed body 34 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without shortening the dimension of the support side deformed body 34 in the Z-axis direction, and the size can be reduced.

(11th modification)
Further, in the above-described embodiment, an example in which the first tilting body 35 extends linearly in the X-axis direction (the second direction of the strain generating body 30A) has been described. However, the present invention is not limited to this, and the first tilting body 35 and the second tilting body 36 are arranged on a plane including the Z-axis direction (first direction) and the X-axis direction and are different from the Z-axis direction. Any shape can be used as long as it extends in the direction. For example, the shape shown in FIG. 28 may be used. Here, FIG. 28 is a front view showing another modification of the strain-causing body of FIG. 24. The straining body 30A shown in FIG. 28 has the same shape as the straining body when a force Fz on the negative side in the Z-axis direction is received as shown in FIG. 26B. It is shown as a strain generating body 30A in a state where it is not affected by a moment.

In the strain-causing body 30A shown in FIG. 28, the central portion 35c of the first tilting body 35 in the X-axis direction is located closer to the receiving body 10 than the both end portions 35a and 35b in the X-axis direction. More specifically, the first tilting body 35 includes a first tilting body negative side portion 35d arranged on the negative side in the X-axis direction and a first tilting body positive side portion 35e arranged on the positive side in the X-axis direction. , Including. The first tilting body negative side portion 35d is a portion connecting the negative side end portion 35a and the central portion 35c, and is inclined so as to proceed toward the positive side in the X-axis direction toward the positive side in the Z-axis direction. .. The first tilting body negative side portion 35d extends in a direction inclined with respect to the Z-axis direction (a direction different from the Z-axis direction) in the XZ plane. The first tilting body positive side portion 35e is a portion connecting the positive end portion 35b and the central portion 35c, and is inclined so as to proceed toward the positive side in the X-axis direction and the negative side in the Z-axis direction. .. The first tilting body positive side portion 35e extends in a direction inclined with respect to the Z-axis direction (a direction different from the Z-axis direction) in the XZ plane. In this way, the first tilting body 35 in the modified example shown in FIG. 28 is substantially formed in an inverted V shape.

As described above, according to the modified example shown in FIG. 28, both end portions 35a and 35b of the first tilting body 35 in the X-axis direction are located closer to the support 20 than the central portion 35c in the X-axis direction. As a result, both ends 35a and 35b of the first tilting body 35 in the X-axis direction can be separated from the receiving body 10, and the dimension of the receiving body-side deformed body 33 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without reducing the dimension of the receiving body side deformed body 33 in the Z-axis direction, and the size can be reduced.

Further, according to the modified example shown in FIG. 28, the central portion 35c of the first tilting body 35 in the X-axis direction is located closer to the receiving body 10 than the both end portions 35a and 35b in the X-axis direction. As a result, the central portion 35c of the first tilting body 35 in the X-axis direction can be kept away from the support 20, and the dimension of the support-side deformed body 34 in the Z-axis direction can be lengthened. Therefore, the height of the force sensor 1 can be reduced without reducing the dimensions of the support side deformed body 34 in the Z-axis direction, and the size can be reduced.

The form of the first tilting body 35 is not limited to the example shown in FIG. 28. For example, although not shown, the central portion 35c of the first tilting body 35 in the X-axis direction is a both end portion in the X-axis direction. It may be located closer to the support 20 than the 35a and 35b. In this case, the first tilting body 35 is generally formed in a V shape. In this way, the height of the force sensor 1 can be increased without increasing the dimensions of the receiving body-side deformed body 33 in the Z-axis direction and the dimensions of the support-side deformed body 34 in the Z-axis direction.

(12th modification)
Further, in the above-described embodiment, an example in which the receiving body side deformed body 33 extends in the Z-axis direction has been described. However, it is not limited to this. For example, as shown in FIGS. 29 and 30, the receiving body side deformed body 33 may be inclined with respect to the Z-axis direction when viewed in the Y-axis direction. FIG. 29 is a plan view showing another modification of the strain-causing body of FIG. 24. FIG. 30 is a plan view showing another modification of the strain-causing body of FIG. 24.

In the modified example shown in FIG. 29, the two receiving body side deforming bodies 33 are inclined with respect to the Z-axis direction so as to move away from each other toward the receiving body 10. More specifically, the receiving body side deformed body 33 located on the negative side in the X-axis direction is inclined with respect to the Z-axis direction so that the upper end is located on the negative side in the X-axis direction with respect to the lower end. On the other hand, the receiving body side deformed body 33 located on the positive side in the X-axis direction is inclined with respect to the Z-axis direction so that the upper end is located on the positive side in the X-axis direction with respect to the lower end. In this way, the receiving body 10, the two receiving body side deformed bodies 33, and the first tilting body 35 are arranged in an inverted trapezoidal shape when viewed in the Y-axis direction.

As described above, according to the modified example shown in FIG. 29, the height of the force sensor 1 can be reduced without reducing the longitudinal dimension of the receiving body side deformed body 33, and the compactness can be achieved. Can be done.

In the modified example shown in FIG. 30, the two receiving body side deforming bodies 33 are inclined with respect to the Z-axis direction so as to approach each other toward the receiving body 10. More specifically, the receiving body side deformed body 33 located on the negative side in the X-axis direction is inclined with respect to the Z-axis direction so that the upper end is located on the positive side in the X-axis direction with respect to the lower end. On the other hand, the receiving body side deformed body 33 located on the positive side in the X-axis direction is inclined with respect to the Z-axis direction so that the upper end is located on the negative side in the X-axis direction with respect to the lower end. In this way, the receiving body 10, the two receiving body side deformed bodies 33, and the first tilting body 35 are arranged in a trapezoidal shape when viewed in the Y-axis direction.

As described above, according to the modified example shown in FIG. 30, the height of the force sensor 1 can be reduced without reducing the longitudinal dimension of the receiving body side deformed body 33, and the compactness can be achieved. Can be done.

(13th modification)
Further, in the above-described embodiment, an example in which the upper end of each receiving body side deformed body 33 is connected to the receiving body 10 has been described. However, the present invention is not limited to this, and for example, as shown in FIG. 31, each receiving body side deformed body 33 may be connected to the receiving body 10 via the receiving body side pedestal 39. As a result, each of the receiving body side deformed bodies 33 can be stably attached to the receiving body 10 by the receiving body side pedestal 39. For example, the receiving body side pedestal 39, the receiving body side deformed body 33, and the first tilting body 35 may be integrally formed, and in this case, each receiving body side pedestal 39 is made of bolts, adhesives, or the like. It may be fixed to the receiving body 10. Alternatively, the receiving body side pedestal 39 and the receiving body side deformed body 33 may be formed separately and fixed to each other with bolts, adhesives, or the like.

Similarly, the lower end of the support side deformed body 34 is not limited to being connected to the support 20. For example, as shown in FIG. 31, the support side deformed body 34 is connected to the support side pedestal 40. It may be connected to the support 20. As a result, the support side deformed body 34 can be stably attached to the support 20 by the support side pedestal 40. For example, the support side pedestal 40, the support side deformed body 34, and the first tilting body 35 may be integrally formed. In this case, the support side pedestal 40 is attached to the support 20 with a bolt, an adhesive, or the like. It may be fixed. Alternatively, the support side pedestal 40 and the support side deformed body 34 may be formed separately and fixed to each other with bolts, adhesives, or the like.

Further, the receiving body side pedestal 39, the receiving body side deformed body 33, the tilting structure 31, the support body side deformed body 34, and the support body side pedestal 40 may be integrally formed. In this case, the receiving body side pedestal 39 may be fixed to the receiving body 10 with a bolt or an adhesive, and the support body side pedestal 40 may be fixed to the support 20 with a bolt or an adhesive or the like. ..

The receiving body side pedestal and the support side pedestal are not limited to being applied to the first straining body 30A shown in FIG. 31, and other strains such as the first straining body 30A shown in FIG. 24 are generated. It can also be applied to bodies 30A to 30D.

(14th modification)
Further, in the above-described embodiment, an example in which the detection element 50 is configured as an element for detecting the capacitance has been described. However, the present invention is not limited to this, and the detection element 50 may be composed of a strain gauge (see FIGS. 21A to 23B) that detects the strain generated by the action of the force or moment received by the receiving body 10. good. For example, the strain gauges R1 to R4 are attached to the surface of the tilting structure 31 on the side of the receiving body 10 of the first tilting body 35, and the strain gauges R5 to R8 are attached to the support 20 of the first tilting body 35. It may be attached to the side surface. In this case, the strain gauges R1 to R4 and the strain gauges R5 to R8 may be arranged as shown in FIG. 21B. Further, for example, even if the strain gauges R1 to R8 are attached to the surface of the first tilting body 35 on the side of the receiving body 10 or the surface on the side of the support 20 and arranged as shown in FIG. 21C. good.

The present invention is not limited to the above-described embodiment and modification as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by appropriately combining the plurality of components disclosed in the above-described embodiments and modifications. Some components may be removed from all the components shown in the embodiments and modifications. In addition, components spanning different embodiments and variants may be combined as appropriate.

1 Force sensor 10 Force receiving body 20 Supporting body 30A 1st straining body 30B 2nd straining body 30C 3rd straining body 30D 4th straining body 31 Tilt structure 33 Force receiving body side deformed body 34 Supporter side deformed body 35 1st tilting body 35a, 35b End 35c Central part 35d 1st tilting body negative side part 35e 1st tilting body positive side part 36 2nd tilting body 36a, 36b End part 36c Central part 36d 2nd tilting body negative side part 36e 2nd tilting body positive side portions 37, 38 Connecting body 39 Receiving body side pedestal 40 Supporting body side pedestal 41 1st receiving body side facing surface 42 2nd receiving body side facing surface 43 1st supporting body side facing surface 44 2nd support side Facing surface 45 Columnar member 46 Reinforcing substrate 47 First support side facing surface 48 Second support side facing surface 50 Detection element 60 Detection circuit 61, 62 Wheatstone bridge circuit 80 Exterior body 1000 Industrial robot 1100 Robot body 1200 End effector 1300 Electric cable 1400 Control unit C1 to C8 Capacitive elements E1, E2 Bridge voltage source Ed1 to Ed8 Displacement electrode substrate Ef1 to Ef8 Fixed electrode substrate Ed Displacement electrode Ef Fixed electrode G Groove IBd Insulator IBf Insulator R1 to R8 Strain gauges T11, T12, T21 , T22 output terminal

Claims (37)

A receiving body that is affected by the force or moment to be detected,
A support that is arranged on one side of the receiving body in the first direction and supports the receiving body,
A strain-causing body that connects the receiving body and the supporting body and elastically deforms due to the action of a force or moment received by the receiving body.
A detection element that detects the displacement caused by the elastic deformation of the strain-causing body, and
A detection circuit that outputs an electric signal indicating a force or moment acting on the strain-causing body based on the detection result of the detection element is provided.
The strain-causing body is a tilting structure arranged between the receiving body and the supporting body, and a receiving body-side deformed body that connects the receiving body and the tilting structure, and is the receiving body. A force-bearing body-side deformable body that can be elastically deformed by the action of a force or moment received by a force body, and a support-side deformable body that connects the tilting structure and the support body, and the force received by the force-bearing body. Alternatively, it has a support-side deformable body that can be elastically deformed by the action of a moment.
The tilting structure is elastically deformed by the action of a force in the first direction, which is arranged on a plane including the first direction and a second direction orthogonal to the first direction and extends in a direction different from the first direction. A force sensor that includes a possible first tilting body. The force sensor according to claim 1, wherein the force receiving body side deformed body extends in the first direction. The force sensor according to claim 1 or 2, wherein the support-side deformed body extends in the first direction. The force sensor according to any one of claims 1 to 3, wherein the first tilting body extends in the second direction. The first tilting body is formed on both sides of the first receiving body side facing surface facing the receiving body and the first receiving body side facing surface in the second direction to which the receiving body side deforming body is connected. Includes a second receiving body side facing surface facing the receiving body, which is arranged.
The force sensor according to claim 4, wherein the first receiving body side facing surface is located closer to the support than the second receiving body side facing surface. The force sensor according to any one of claims 1 to 3, wherein the central portion of the first tilting body in the second direction is located closer to the support than both ends in the second direction. Sensor. The force according to any one of claims 1 to 3, wherein the central portion of the first tilting body in the second direction is located closer to the receiving body than both ends in the second direction. Sensory sensor. The tilting structure is arranged between the first tilting body and the support, is arranged on a plane including the first direction and the second direction, and extends in a direction different from the first direction. A second tilting body which is a tilting body and can be elastically deformed by the action of a force in the first direction, one end of both ends of the first tilting body in the second direction, and the second. Further including a pair of connecting bodies connecting the corresponding ends of both ends of the tilting body in the second direction.
The receiving body side deformed body is connected to the first tilting body, and is connected to the first tilting body.
The force sensor according to any one of claims 1 to 5, wherein the support-side deformed body is connected to the second tilting body. The force sensor according to claim 8, wherein the force receiving body side deformed body is located between both ends of the first tilting body in the second direction. The force sensor according to claim 8 or 9, wherein the support-side deformed body is located between both ends of the second tilting body in the second direction. The force sensor according to any one of claims 8 to 10, wherein the force receiving body side deformed body and the support body side deformed body are arranged at positions where they overlap each other when viewed in the first direction. The force sensor according to claim 11, wherein the tilting structure is formed symmetrically with respect to the receiving body side deformed body and the support body side deformed body in the second direction. Any one of claims 8 to 12, wherein the spring constant for the force acting on the first direction of the second tilting body is different from the spring constant for the force acting on the first direction of the first tilting body. The force sensor described in the section. The force sensor according to any one of claims 8 to 13, wherein the second tilting body extends in the second direction. The second tilting body is arranged on both sides of the first support side facing surface facing the support and the first support side facing surface in the second direction to which the support side deforming body is connected. Including a second support side facing surface facing the support,
The force sensor according to claim 14, wherein the first support side facing surface is located closer to the receiving body than the second support side facing surface. The force according to any one of claims 8 to 13, wherein the central portion of the second tilting body in the second direction is located closer to the receiving body than both ends in the second direction. Sensory sensor. The force sensor according to any one of claims 8 to 13, wherein the central portion of the second tilting body in the second direction is located closer to the support than both ends in the second direction. Sensor. The receiving body and the first tilting body are connected by two receiving body side deformed bodies.
The force sensor according to any one of claims 1 to 4, wherein the support-side deformed body connects the first tilting body and the support. The force sensor according to claim 18, wherein the two force receiving body side deformed bodies are located at both ends of the first tilting body in the second direction. The force sensor according to claim 19, wherein the support side deformed body is located between the two receiving body side deformed bodies in the second direction. The force sensor according to claim 20, wherein the strain-causing body is formed symmetrically with respect to the support-side deformed body in the second direction. The force sensor according to any one of claims 18 to 21, wherein the first tilting body extends in the second direction. The first tilting body is arranged on both sides of the first support side facing surface facing the support and the first support side facing surface in the second direction to which the support side deforming body is connected. Including a second support side facing surface facing the support,
The force sensor according to claim 22, wherein the first support-side facing surface is located closer to the receiving body than the second support-side facing surface. The force according to any one of claims 18 to 21, wherein the central portion of the first tilting body in the second direction is located closer to the receiving body than both ends in the second direction. Sensory sensor. The receiving body side deformed body is connected to the receiving body via the receiving body side pedestal, and is connected to the receiving body.
The force sensor according to any one of claims 1 to 24, wherein the support side deformed body is connected to the support via a support side pedestal. The detection element has a fixed electrode substrate provided on the receiving body or the support, and a displacement electrode substrate facing the fixed electrode substrate and provided on the tilting structure.
The force sensor according to any one of claims 1 to 25, wherein the displacement electrode substrate is arranged at both ends of the tilting structure in the second direction. The force sensor according to claim 26, wherein the displacement electrode substrate is provided on the tilting structure via a columnar member. The force sensor according to claim 27, wherein the displacement electrode substrate is provided on the columnar member via a reinforcing substrate. The force sensor according to any one of claims 1 to 25, wherein the detection element has a strain gauge provided on the strain-causing body. The receiving body and the supporting body are connected by the four strain generating bodies.
The four strain generators include a first strain generator, a second strain generator, a third strain generator, and a fourth strain generator.
The first direction is the Z-axis direction in the XYZ three-dimensional coordinate system.
The first straining body is arranged on the negative side in the Y-axis direction with respect to the center of the receiving body, and the second straining body is arranged on the positive side in the X-axis direction with respect to the center of the receiving body. The third strain generating body is arranged on the positive side in the Y-axis direction with respect to the center of the receiving body, and the fourth straining body is arranged on the negative side in the X-axis direction with respect to the center of the receiving body.
The second direction of the first strain-causing body and the third strain-causing body is defined as the X-axis direction.
The force sensor according to any one of claims 1 to 29, wherein the second direction of the second strain-generating body and the fourth strain-causing body is the Y-axis direction. The force sensor according to claim 30, wherein at least one of the planar shape of the receiving body and the planar shape of the support is circular. The force sensor according to claim 30, wherein at least one of the planar shape of the receiving body and the planar shape of the support is rectangular. The force sensor according to claim 31 or 32, wherein the tilting structure of the strain-causing body is formed linearly along the second direction when viewed in the first direction. The force sensor according to claim 31 or 32, wherein the tilting structure of the strain-causing body is formed in a curved shape when viewed in the first direction. The force sensor according to any one of claims 1 to 34, further comprising an exterior body that covers the strain-causing body from the outside when viewed in the first direction. The force sensor according to claim 35, wherein the exterior body is fixed to the support and is separated from the receiving body. The force sensor according to claim 36, wherein a cushioning member is interposed between the exterior body and the force receiving body.

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