JPH05312659A - Strain-generating body for detecting force and moment - Google Patents

Abstract

PURPOSE:To obtain a strain-generating body for detecting force and moment which can detect forces in X-Y-Z directions (three-dimensional directions) and moment around an axis with an improved sensitivity. CONSTITUTION:The title body is provided with mounting parts 1a and 1b which are placed upper and lower parts opposingly with a certain spacing, spindle parts 2a and 2b which are provided at either one of the mounting parts and whose tip parts oppose the other mounting part and a strain-generating part 3 which is provided between the mounting parts while surrounding the spindle parts and is provided with a recessed part 39 which is curved toward inside. A group of light receiving bodies where four light receiving bodies 4 are laid out at either the inner surface of the recessed part 39 or the outer surface of the spindle part 2a which opposes it in upper/ lower and left/right directions are laid out at 90-degree spacing and at the same time a light emitting body 5 which irradiates the center of the group of light receiving bodies with light is provided at the other. On the other hand, one group of light receiving bodies 4 which are aligned in upper/lower and left/right directions are provided at either the tip part of the spindle part 2a (2b) or a mounting part which opposes it and a light emitting body 5 which applies light to the center of the other group of light emitting bodies is provided at the other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexure element for detecting force and moment.

[0002]

2. Description of the Related Art As a flexure element of this type, for example, FIG.
There is a type as shown in FIG. 1, which is inserted into the ring-shaped first mounting portion 9a, the circular mounting plate 90, and the central portion of the first mounting portion 9a. A second mounting portion 9b having a shaft portion 91, a band-shaped strain-producing portion 92 that is easily deformable and is installed between the first mounting portion 9a and the shaft portion 91 at 90 ° angular intervals, and the strain-generating portion. It is composed of a single crystal substrate 94 having four detection elements 93 fixed to 92 and having electric resistances changed by mechanical deformation on the X and Y lines.

In this case, the first mounting portion 9 of the strain-generating body is used.
When a force (mechanical external force is applied to the a and the second mounting portion 9b,
As shown in FIG. 2, the single crystal substrate 94 is deformed along with the deformation of the strain generating portion 92, and the electric resistance value of the detection element 93 provided on the single crystal substrate 94 changes (strain in the tensile direction is detected by the detection element). The resistance value is increased by adding to the detection element, and the resistance value is decreased when the strain in the compression direction is added to the detection element).

Therefore, the above-mentioned four detection elements 94
It is possible to detect the force in the X and Y directions and the moment around the axis from the change in resistance. However, in the above flexure element, XY
Only a part of the force in the −Z direction (three-dimensional direction) and the moment about the axis can be detected, and the deformation amount of the strain generating portion 92 does not directly appear as the deformation amount of the detection element 93, but the single crystal substrate. Since it is via 94, there is a problem that the detection sensitivity of the force and moment is not good.

[0005]

Therefore, in the present invention, a strain-generating body for detecting a force and a moment capable of detecting a force in the XYZ directions (three-dimensional directions) and a moment around an axis with excellent sensitivity. The challenge is to provide.

[0006]

A strain-generating body for detecting a force and a moment according to the present invention is provided in one of the mounting portion and the mounting portion which are vertically opposed to each other with a certain space. A shaft portion having a tip portion facing the other mounting portion, and a strain-flexing portion having a recessed portion that is provided between the mounting portions and surrounds the shaft portion and that is bent inward. A group of photoconductors, in which four photoconductors are arranged vertically and horizontally on either the inner surface of the recessed portion or the outer surface of the shaft portion facing the recessed portion, is arranged at 90 ° angular intervals. On the other hand, a light-emitting body for irradiating the central portion of the light-receiving body is provided on the other side, and on the other hand, one light-receiving body arranged vertically or horizontally on either one of the tip portion of the shaft portion or the mounting portion facing this. A light source that illuminates the central part of the photoreceptor group to the other while arranging A body is provided, and when an external force is applied to the mounting portion, the strain generating portion is deformed to change the relative positional relationship between the light receiving body group and the light emitting body, whereby each light receiving body forming each light receiving body group is changed. The amount of light received by is changed.

Further, the flexure element for detecting force and moment of the present invention is provided at one of the mounting portion and the mounting portion which are vertically opposed to each other with a certain interval, and the tip portion. Includes a shaft portion facing the other mounting portion, and a strain-flexing portion having a recessed portion that is provided between the mounting portions and surrounds the shaft portion and that is bent inward. , An inner surface of the recessed portion or an outer surface of the shaft portion opposed to the recessed portion is provided with an electrode plate group in which four small electrode plates are vertically and horizontally arrayed at 90 ° angular intervals while the other is provided. A large electrode plate having substantially the same area as that of the electrode plate group, on the other hand, an electrode plate in which small electrode plates are vertically and horizontally arranged on either one of the tip end portion of the shaft portion or a mounting portion opposed thereto. And a large electrode plate having substantially the same area as the electrode plate group on the other side, When an external force is applied, the strain generating portion is deformed to change the relative positional relationship between the electrode plate group and the large electrode plate, whereby a capacitor between the large electrode plate and the small electrode plate of each electrode plate group is changed. The capacity is changed.

Incidentally, in place of the above-mentioned structure, it is possible to provide a shaft portion on both of the mounting portions and to make these end portions face each other. Further, in place of the above-mentioned configuration, four photoconductor groups and two photoconductors are arrayed vertically and horizontally on either the inner surface of the recessed portion or the outer surface of the shaft portion facing the recessed portion. Alternate 90 °
It is also possible to dispose them at angular intervals and to provide a light emitting body for irradiating the central portion of the light receiving group on the other side.

[0009]

The present invention operates as follows. (Operation of the invention according to claims 1 to 4) When an external force is applied to the mounting portion, the strain generating portion is deformed and the relative position between the light receiving body group and the light emitting body, that is, the light receiving body group and the light emitting body approach each other. · Separation,
The facing attitude of the light-receiving body group and the light-emitting body changes, and the amount of light received by each light-receiving body forming each light-receiving body group changes.

The above-mentioned light-receiving body group and light-emitting body have 9
Since they are arranged at 0 ° angular intervals, the three-dimensional (X
The force in the (-Y-Z) direction and the moment around the axis can be detected. Since the strain-generating body of the present invention directly detects the deformation amount of the strain-generating portion (not through the single crystal substrate) unlike the one described in the section of the related art, the detection accuracy is excellent. It becomes a thing. (Operation of the invention according to claims 5 to 8) When an external force acts on the mounting portion, the strain generating portion is deformed and the relative position between the electrode plate group and the large electrode plate, that is, the electrode plate group and the large electrode plate. The approaching / separating of the electrode plate and the facing attitude of the electrode group and the large electrode plate are changed, and the capacitor capacity between the small electrode plate and the large electrode plate of each electrode plate group is changed.

The above electrode plate group and large electrode plate have 90
Since the electrodes are arranged at angular intervals, the three-dimensional (XYZ) direction acting on the mounting portion due to the change in the capacitor capacity between the small electrode plate and the large electrode plate of each electrode plate group. The force and the moment around the axis can be detected. Since the strain-generating body of the present invention directly detects the deformation amount of the strain-generating part (not through the single crystal substrate) unlike the one described in the section of the conventional technique, the detection accuracy is high. Will be excellent.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below with reference to the drawings shown as embodiments. [Embodiment 1] As shown in FIGS. 1 to 3, the flexure element of this embodiment has mounting portions 1a, which are arranged facing each other with a constant interval.
1b, a long shaft portion 2a fixedly arranged on the inner surface of the mounting portion 1a, and a short shaft portion 2b fixedly arranged on the inner surface of the mounting portion 1b and facing the tip end surface of the long shaft portion 2a, The length
A recess 39 that is provided between the mounting portions 1a and 1b and surrounds the minor shafts 2a and 2b and is bent inward.
And a strain-flexing part 3 having

As shown in the figure, each of the mounting portions 1a and 1b is formed of a thin circular plate, and bolt insertion holes 10 are provided at 90 ° angular intervals. Long shaft 2a
Is formed in a prismatic shape as shown in FIGS. 1 to 3, and four photodiodes 40 (corresponding to the light receiving body in the column of means) are formed on the peripheral surface thereof as shown in FIG. Photoreceptor elements 4a, 4b, 4c, 4d arranged vertically and horizontally
(Corresponding to the photoreceptor group in the column of means) are arranged at 90 ° angular intervals, and the photoreceptor element 4e is also formed on the end face.
Is provided.

As shown in FIG. 2, the short shaft portion 2b is formed in the shape of a prism that is thicker than the long shaft portion 2a, and a small gap () is formed between the end surface of the short shaft portion 2b and the end surface of the long shaft portion 2a. The length is set to be g ± 0). Then, as shown in FIG. 2, on the end surface of the short axis portion 2b, the light receiving element 4 of the long axis portion 2a is formed.
A light emitting diode 5e (corresponding to the light emitter in the column of means) for irradiating the central portion of e is provided.

As shown in FIGS. 1 and 2, the strain-flexing portion 3 is composed of four strip-shaped plate members, and each strip-shaped plate member has a recess 39 that is bent inward in a substantially U-shape. Main body 30 and mounting seats 30a, 30b provided on both ends of the main body 30 and mounted on the mounting portions 1a, 1b described above.
It consists of and. The light emitting diode 5 (5a, 5b, 5c, 5d) is disposed on the inner surface side of the recess 39 of the strain-flexing portion 3 as shown in FIGS.
In the assembled state as shown in FIG. 5, a small gap (g ± 0) is formed between the inner surface of the recess 39 and the peripheral surface of the long shaft portion 2a, and the light emitting diode 5a is connected to the light receiving element 4
The light emitting diode 5b irradiates the center portion of the light receiving element 4b, the light emitting diode 5c irradiates the center portion of the light receiving element 4c, and the light emitting diode 5d irradiates the center portion of the light receiving element 4d. There is.

Since this flexure element is constructed as described above, when an external force acts on the mounting portions 1a, 1b,
With the deformation of the strain-flexing portion 3, the light-receiving elements 4a, 4b, 4c, 4
d, 4e and light emitting diodes 5a, 5b, 5c, 5d, 5
The relative positional relationship with e is changed so that each of the photoreceptor elements 4a, 4a
Each photodiode 4 constituting b, 4c, 4d and 4e
The amount of received light of 0 changes. Therefore, if the difference in the amount of light received by each photodiode 40 is electrically converted and arithmetic processing is performed, the force in the XYZ directions (three-dimensional direction) and the moment around the axis can be detected. The detection of the force / moment in the strain-generating body will be described in detail below with reference to FIGS. ． For detection of Fx (force in X direction) and Fy (force in Y direction)
Then , as shown in FIG. 5, when the mounting portions 1a and 1b are fixed and, for example, Fx is applied to the mounting portion 1b, the flexure element is deformed so as to be inclined with respect to the peripheral surface of the long axis portion 2b as shown in the figure. The center axis AX1 + of the photodetector element 4a and the center axis AX2 + of the photodetector element 4c are the same as the center axis AX1 + of the photodiodes 5a and 5c.
−, AX2 − are displaced in opposite directions. In this state, the amount of light received by the photodiode 40 above the light-receiving element 4a and the photodiode 4 below the light-receiving element 4c.
Since the received light amount of 0 is increasing and the received light amount of the photodiode 40 below the light receiving element 4a and the light receiving amount of the photodiode 40 above the light receiving element 4c are decreasing, Fx if converted and processed
Can be detected.

Fy can also be detected in the same manner as above from the change in the amount of light received by the photodiode 40 of each of the light receiving elements 4b and 4d. ． My (moment about Y-axis) and Mx (moment about X-axis)
Moment) When My is applied to the mounting portion 1b as shown in FIG. 6, the flexure element is deformed as shown in FIG. In this case, the amount of light received by the two photodiodes 40 of the light-receiving element 4e is increased, and the amount of light received by the other two photodiodes 40 is decreased, so that the amount of light received is electrically converted. Then, the arithmetic processing can be performed to detect My.

Mx can be detected in the same manner as My. ． Regarding the detection of Fz (force in the Y direction) When Fz is applied to the mounting portion 1b as shown in FIG. 7, the flexure element is deformed as shown in FIG. In this case, since the amount of light received by all the photodiodes 40 forming the light-receiving element 4e is increased, Fz can be detected by electrically converting the amount of light received and performing arithmetic processing. ． Regarding Mz (moment about the Z axis) When Mz is applied to the mounting portion 1b as shown in FIG. 8, the flexure element is deformed as shown in FIG. In this case, the amount of light received by the two photodiodes 40 on the clockwise side in the photodetector elements 4a, 4b, 4c, 4d, 4e decreases,
Since the amount of light received by the two photodiodes 40 on the counterclockwise side increases, Fz can be detected by electrically converting the amount of light received and performing arithmetic processing. [Embodiment 2] The flexure element of this embodiment has mounting portions 1a and 1b.
The long / short axis portions 2a and 2b, and the strain-flexing portion 3 have exactly the same configuration as in the first embodiment, but the combination of the light-receiving element 4 and the light-emitting diode 5 constitutes a parallel plate capacitor. The four electrode plates 60 are arranged vertically and horizontally, and the electrode plate group 6 and the large electrode plate 7 facing the electrode plate group and having substantially the same area as the electrode plate group 6 are used.

In the flexure element of this embodiment, when an external force acts on the mounting portion, the flexure portion is deformed, and the electrode plate group 6 and the large electrode plate 7 approach each other as described in detail in Embodiment 1. · Separation, Figure 10
As shown in, the facing attitude between the electrode plate group 6 and the large electrode plate 7 changes. In the case of this embodiment, the small electrode plates 6 of each electrode plate group 6 are
Since the capacitance between the large pole plate 7 and the large pole plate at 0 increases or decreases, if the increased or decreased capacitance is electrically converted and arithmetic processing is performed, Fx, Fy, Fz, Mx, My,
Mz can be detected.

In addition to the constructions of the above-described embodiments, the shaft portion is provided only in the mounting portion 1a, and the end portion of the shaft portion is made to face the surface of the mounting portion 1b. 1
The light-receiving element 4e (electrode plate group 6) may be provided on one side of the surface b, and the photodiode 5e (large electrode plate 7) may be provided on the other side. Further, instead of the configurations of the above-described embodiments, the strain-flexing portion 3 may be a tubular one that surrounds the mounting portion 1a and the mounting portion 1b.

Further, the cross-sectional shape of the strain-flexing portion 3 is not limited to the shape of both of the above-described embodiments, and when an external force acts on the mounting portion, the strain-generating portion 3 approaches, separates from, or tilts with respect to the shaft portion. What has a recess 39 may be used. Then, in place of the configuration of the above-described first embodiment, four photoconductor groups and two photoconductor groups arranged vertically and horizontally on either one of the inner surface of the recessed portion 39 or the peripheral surface of the shaft portion facing the recessed portion 39. It is also possible to alternately arrange light-receiver groups formed by arranging light-receivers on the left and right at 90 ° angular intervals and to provide a light-emitting body for irradiating the central part of the light-receiver group to the other.

Further, in place of the structure of the above-described second embodiment, four small electrode plates are arranged vertically and horizontally on either the inner surface of the recess or the peripheral surface of the shaft portion opposed thereto. And a photoreceptor group formed by arranging two photoreceptors on the left and right alternately at 90 ° angular intervals, and a large pole plate having substantially the same area as that of the pole group is provided on the other side. You can also do it.

[0023]

The present invention having the above-mentioned structure has the following effects. From the contents described in the action column,
It has been possible to provide a flexure element for detecting a force and a moment, which is capable of detecting a force in the XYZ directions and a moment about an axis with excellent sensitivity.

[Brief description of drawings]

FIG. 1 is a perspective view of a flexure element for detecting force and moment in an embodiment of the present invention.

FIG. 2 is a sectional view of the flexure element.

3 is a sectional view taken along line AA of FIG.

FIG. 4 is a perspective view of a light receiving element and a photodiode in the strain generating element.

FIG. 5 is a cross-sectional view when a force FX acts on the flexure element.

FIG. 6 is a cross-sectional view when a moment My about the Y-axis acts on the flexure element.

FIG. 7 is a cross-sectional view when a force FZ acts on the flexure element.

FIG. 8 is a cross-sectional view when a moment Mz about the Z axis acts on the strain body.

FIG. 9 is a perspective view of a polar plate group and a large polar plate in a flexure element of another embodiment.

FIG. 10 is a view showing a state in which the attitude of the large electrode plate is changed with respect to the electrode plate group.

FIG. 11 is a cross-sectional view of a conventional flexure element for detecting force and moment.

FIG. 12 is a cross-sectional view when a force is applied to the conventional flexure element.

[Explanation of symbols]

 1a Mounting part 1b Mounting part 2a Long axis part 2b Short axis part 3 Strain element 4 Photoreceptor element 5 Light emitting diode 6 Electrode plate group 7 Large electrode plate 39 Recessed portion 40 Photodiode 60 Small electrode plate

Claims (10)

[Claims] 1. A mounting portion which is vertically opposed to each other at a constant interval, a shaft portion which is provided in one of the mounting portions and has a tip portion facing the other mounting portion, and the shaft. A strain-flexing portion that is provided between the mounting portions in a manner to surround the portion and that has a recessed portion that is bent inward, the inner surface of the recessed portion or On one of the outer surfaces, a light-receiving body group in which four light-receiving bodies are vertically and horizontally arranged is arranged at 90 ° angular intervals, and on the other side, a light-emitting body for irradiating the central portion of the light-receiving body group is provided. On the other hand, one of the photoconductor groups arranged vertically and horizontally is disposed on either one of the tip portion of the shaft portion or the mounting portion facing the tip portion, and the other portion is irradiated with the central portion of the photoconductor group. Provided with a luminous body, the strain-causing part is deformed when an external force is applied to the mounting part. A force and moment detection device characterized in that the relative positional relationship between the light-receiving body group and the light-emitting body is changed, so that the amount of light received by each light-receiving body forming each light-receiving body group is changed. Distorted body. 2. A mounting portion vertically opposed to each other with a constant space, a shaft portion provided in one of the mounting portions and having a tip end facing the other mounting portion, and the shaft. A strain-flexing portion that is provided between the mounting portions in a manner that surrounds the portion and that has a recessed portion that is bent inward, the inner surface of the recessed portion or the shaft portion facing the inner surface of the recessed portion. On one of the outer surfaces, a photoreceptor group consisting of four photoreceptors arranged vertically and horizontally and a photoreceptor group consisting of two photoreceptors arranged laterally are alternately arranged at 90 ° angular intervals. On the other hand, a light-emitting body that irradiates the central portion of the light-receiving body group is provided on the other side, and on the other hand, one light-receiving body arranged vertically or horizontally on either one of the tip portion of the shaft portion or the mounting portion facing this. And a light-emitting body for irradiating the central portion of the light-receiving body on the other side. When an external force is applied to the mounting portion, the strain generating portion is deformed to change the relative positional relationship between the light receiving body group and the light emitting body, whereby the amount of light received by each light receiving body forming each light receiving body group is changed. A strain-generating body for detecting force and moment characterized by being changed. 3. A mounting part, which is vertically opposed to each other with a constant space, and shaft parts which are respectively provided in both of the mounting parts and whose tip parts face each other, and a mode which surrounds the shaft part. And a strain-flexing portion having a recessed portion that is provided between the mounting portions and is bent inward, which is one of the inner surface of the recessed portion and the outer surface of the shaft portion that faces the recessed portion. On one side, a group of four light receiving bodies arranged vertically and horizontally is arranged at 90 ° angular intervals, and on the other side, a light emitting body for irradiating the central portion of the light receiving group is provided. One of the tip portions of both shafts is provided with one light-receiving body group arranged vertically and horizontally, and the other is provided with a light-emitting body that irradiates the central portion of the light-receiving body group, and the above-mentioned mounting portion is provided. When an external force is applied, the strain-flexing part is deformed, and the phase Positional relationship is changed, thereby, the strain generating member for force and moment detecting the amount of light the photoreceptor receives constituting each photoreceptor group is characterized in that so as to vary. 4. A mounting part which is vertically opposed to each other with a constant space, and shaft parts which are respectively provided in both of the mounting parts and whose tip parts face each other, and a mode surrounding the shaft part. And a strain-flexing portion having a recessed portion that is provided between the mounting portions and is bent inward, which is one of the inner surface of the recessed portion and the outer surface of the shaft portion that faces the recessed portion. On one side, four light-receiving body groups arranged vertically and horizontally and on the other hand, light-receiving body groups formed by arranging two light-receiving bodies on the left and right are alternately arranged at 90 ° angular intervals, and on the other side the light-receiving body group is arranged. A light-emitting body for irradiating the central portion is provided, and on the other hand, a light-receiving element group formed by arranging four light-receiving elements vertically or horizontally in either one of the tip portions of the above-described shaft portions is arranged at 90 ° angular intervals. And the other side is provided with a light-emitting body that irradiates the central portion of the light-receiving body group, When the external force is applied, the strain-flexing portion is deformed to change the relative positional relationship between the light-receiving body group and the light-emitting body, thereby changing the amount of light received by each light-receiving body forming each light-receiving body group. A strain-generating body for detecting force and moment, which is characterized in that 5. A mounting portion vertically opposed to each other with a constant space, a shaft portion provided in one of the mounting portions and having a tip end facing the other mounting portion, and the shaft. A strain-flexing portion that is provided between the mounting portions in a manner that surrounds the portion and that has a recessed portion that is bent inward, the inner surface of the recessed portion or the shaft portion facing the inner surface of the recessed portion. On one of the outer surfaces, a group of four small plates arranged vertically and horizontally is arranged at 90 ° angular intervals, and on the other side, a large plate having substantially the same area as the group of plates is arranged. Provided, on the other hand,
A pole plate group consisting of small pole plates arranged vertically and horizontally is disposed on either one of the tip portion of the shaft portion or the mounting portion facing the tip portion, and on the other side a large pole plate having substantially the same area as the pole plate group is arranged. An electrode plate is provided, and when an external force is applied to the mounting portion, the strain generating portion is deformed to change the relative positional relationship between the electrode plate group and the large electrode plate, whereby the small electrode plate of each electrode plate group is changed. A strain-generating body for detecting force and moment, characterized in that the capacitance of the capacitor between the large pole plate and the large pole plate is changed. 6. A mounting portion which is vertically disposed to face each other with a constant interval, a shaft portion which is provided in one of the mounting portions and has a tip portion facing the other mounting portion, and the shaft. A strain-flexing portion that is provided between the mounting portions in a manner that surrounds the portion and that has a recessed portion that is bent inward, the inner surface of the recessed portion or the shaft portion facing the inner surface of the recessed portion. On one of the outer surfaces, a group of four plates arranged vertically or horizontally on either side and a group of photoreceptors composed of two photoreceptors arranged on the left and right are alternately arranged at 90 ° angular intervals. And a large electrode plate having substantially the same area as the electrode plate group is provided on the other side, and on the other hand,
A pole plate group consisting of small pole plates arranged vertically and horizontally is disposed on either one of the tip portion of the shaft portion or the mounting portion facing the tip portion, and on the other side a large pole plate having substantially the same area as the pole plate group is arranged. An electrode plate is provided, and when an external force is applied to the mounting portion, the strain generating portion is deformed to change the relative positional relationship between the electrode plate group and the large electrode plate, whereby the small electrode plate of each electrode plate group is changed. A strain-generating body for detecting force and moment, characterized in that the capacitance of the capacitor between the large pole plate and the large pole plate is changed. 7. A mounting part, which is vertically opposed to each other with a constant space, and a shaft part which is provided in both of the mounting parts and whose tip parts face each other, and a mode that surrounds the shaft part. And a strain-flexing portion having a recessed portion which is provided between the mounting portions and is bent inward, wherein, of the inner surface of the recessed portion or the outer surface of the shaft portion facing the inner surface, An electrode plate group composed of four small electrode plates arranged vertically and horizontally on either side is arranged at 90 ° angular intervals, and on the other side, a large electrode plate having substantially the same area as the electrode plate group is provided, On the other hand, a pole plate group consisting of small pole plates arranged vertically and horizontally is arranged on either one of the tip ends of the above-mentioned both shaft portions, and on the other side a big pole plate having substantially the same area as the pole plate group is arranged. And the relative position between the electrode group and the large electrode plate due to deformation of the strain-generating part when an external force acts on the mounting part. Engagement is changed, thereby, force and strain body for moment detection capacitor capacity is characterized in that so as to vary between the large electrode plate in the small plates of the electrode plate group. 8. A mode in which mounting portions are arranged to face each other at a certain interval in the vertical direction, and shaft portions which are provided in both of the mounting portions and whose tip portions face each other, and which surround the shaft portion. And a strain-flexing portion having a recessed portion which is provided between the mounting portions and is bent inward, wherein, of the inner surface of the recessed portion or the outer surface of the shaft portion facing the inner surface, An electrode plate group formed by arranging four small electrode plates vertically and horizontally on either side and a light receiver group formed by arranging two light receiving members on the left and right are alternately arranged at 90 ° angular intervals, and Is provided with a large electrode plate having substantially the same area as that of the electrode plate group, and on the other hand, an electrode plate group in which small electrode plates are vertically and horizontally arranged is provided at either one of the tip ends of the both shaft portions. At the same time, a large electrode plate having approximately the same area as the electrode plate group is provided on the other side, and is started when an external force acts on the mounting portion. The parts are deformed so that the relative positional relationship between the electrode group and the large electrode plate is changed, so that the capacitor capacitance between the large electrode plate and the small electrode plate of each electrode plate group is changed. A strain-generating body for detecting force and moment. 9. The strain-flexing portion is composed of strip-shaped plates arranged at 90 ° angular intervals, and the arrangement position of the light-receiving body group or the light-emitting bodies is set on the strip-shaped plate. A flexure element for detecting force and moment according to any one of claims 1 to 4. 10. The strain-flexing portion is composed of strip-shaped plates arranged at 90 ° angular intervals, and the position of the electrode plate group or the large electrode plate is set on the strip-shaped plate. A strain-generating body for detecting force and moment according to any one of claims 5 to 8.