JP2021060349A - Torque sensor - Google Patents

Abstract

To provide a fixing device for a strain sensor that can prevent reduction of the performance of the sensor and increase of the size of a device structure and that can fix the strain sensor to the structure without fail, and to provide a torque sensor using the fixing device.SOLUTION: A plurality of third structures 13 connect a first structure 11 and a second structure 12 to each other. A strain body 21 forming a strain sensor is provided between the first structure and the second structure. A first positioning part A is provided in the first structure and determines the position of a first end part of the strain body to the first structure. A second positioning part B is provided in the second structure and determines the position of a second end part of the strain body to the second structure.SELECTED DRAWING: Figure 7

Description

An embodiment of the present invention relates to, for example, a torque sensor provided at a joint of a robot arm.

The torque sensor has a first structure to which torque is applied, a second structure to which torque is output, and a plurality of strain generating portions as beams connecting the first structure and the second structure. However, a plurality of strain gauges as sensor elements are arranged in these strain generating portions. A bridge circuit is composed of these strain gauges (see, for example, Patent Documents 1, 2 and 3).

Japanese Unexamined Patent Publication No. 2013-096735 Japanese Unexamined Patent Publication No. 2015-049209 Japanese Unexamined Patent Publication No. 2017-172983

Generally, a strain sensor is provided with a plurality of strain gauges as sensor elements on a metal strain generating body. As a method of fixing the strain sensor to the torque sensor, for example, there are a method using welding, a method using an adhesive, and a method using a plurality of screws.

However, when the strain sensor is fixed to the structure by welding, the temperature of the strain-causing body is rapidly increased by welding. Therefore, the composition and shape of the strain-causing body and the strain gauge may change, which may affect the performance of the strain sensor.

Further, when the strain sensor is fixed to the structure using an adhesive, a low-rigidity adhesive is interposed between the strain-causing body and the structure. Therefore, the deformation of the structure is not directly transmitted to the strain-causing body, which may reduce the sensitivity of the strain sensor.

On the other hand, when the strain sensor is fixed to the structure using screws, a pressing member is provided on the strain generating body, and the pressing member is fastened to the structure with screws. It is fixed. In the case of such a configuration, since the pressing member and the strain-causing body are in surface contact with each other, the pressing member needs to maintain a high pressing force with respect to the strain-causing body. In order to maintain a high pressing force, it is necessary to increase the size and rigidity of the pressing member, increase the size of the screw, and increase the number of screws. Therefore, it is difficult to reduce the size and thickness of the torque sensor provided with the holding member and the screw.

The present embodiment provides a torque sensor capable of reliably fixing the strain sensor to the structure by preventing deterioration of sensor performance and enlargement of the device configuration.

The torque sensor of the embodiment includes a first structure, a second structure, a plurality of third structures connecting the first structure and the second structure, and the first structure and the first structure. A strain generating body provided between the two structures and forming a strain sensor, and a first end portion provided in the first structure and positioning the first end portion of the strain generating body with respect to the first structure. It includes one positioning portion and a second positioning portion provided on the second structure and positioning the second end portion of the strain-causing body with respect to the second structure.

The perspective view which shows the torque sensor to which this embodiment is applied. The plan view which shows except for a part of FIG. The perspective view which takes out the attachment part of the strain sensor shown in FIG. 2 and shows it enlarged. A plan view showing a part of FIG. 2 taken out and enlarged. FIG. 4 is a cross-sectional view taken along the line VV of FIG. FIG. 3 is an enlarged perspective view showing a fixing plate as a fixing member shown in FIG. The plan view which shows the positioning part of the strain-causing body which concerns on this embodiment. FIG. 7 is a cross-sectional view taken along the line VIII-VIII of FIG. FIG. 5 is a plan view showing a state in which a strain-causing body is mounted on the positioning portion shown in FIG. 7. FIG. 9 is a cross-sectional view taken along the line XX of FIG.

Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same parts are designated by the same reference numerals.

1 and 2 show an example of a torque sensor 10 to which this embodiment is applied. The configuration of the torque sensor 10 is not limited to this, and can be applied to torque sensors having various configurations. Further, the present embodiment can be applied not only to a torque sensor but also to a force sensor using a strain gauge or the like.

In FIG. 1, the torque sensor 10 includes a first structure 11, a second structure 12, a plurality of third structures 13, a plurality of waterproof caps 14, a case 15, a bush 16, and a cable 17.

The first structure 11 and the second structure 12 are formed in an annular shape, and the diameter of the second structure 12 is smaller than the diameter of the first structure 11. The second structure 12 is arranged concentrically with the first structure 11, and the first structure 11 and the second structure 12 are connected by a third structure 13 as a plurality of beams arranged radially. Has been done. The number of the third structure 13 is, for example, eight, and the eight third structures 13 are arranged at equal intervals. The number of the third structure 13 is not limited to eight.

The first structure 11 is connected to, for example, the object to be measured, the second structure 12 is connected to another structure (not shown), and the plurality of third structures 13 are connected to the first structure 11 to the second structure. Torque (moment (Mz) shown in FIG. 2) is transmitted to the structure 12. On the contrary, the second structure 12 is connected to the measured body, the first structure 11 is connected to another structure (not shown), and a plurality of third structures are connected from the second structure 12 to the first structure 11. Torque may be transmitted through the body 13.

In the case of the force sensor, the first structure 11, the second structure 12, and the third structure 13 are deformed three-dimensionally, and the three orthogonal axes (x, y, z) shown in FIG. 2 are related to each other. Forces (Fx, Fy, Fz) and moments (Mx, My, Mz) are detected.

The first structure 11, the second structure 12, and the plurality of third structures 13 are made of metal, for example, stainless steel, but if mechanically sufficient strength can be obtained with respect to the applied torque. , It is also possible to use materials other than metal.

As shown in FIG. 2, a strain sensor 20 described later is arranged corresponding to each third structure 13, and each strain sensor 20 is covered with a cap 14. In FIG. 2, one cap 14 is removed to expose the strain sensor 20. In the present embodiment, the number of strain sensors 20 is the same as the number of the third structure 13, but the number is not limited to this, and the number of strain sensors 20 is the number of the third structure 13. May be less.

The configuration of each strain sensor 20 is the same. The strain sensor 20 is provided between the first structure 11 and the second structure 12. That is, as will be described later, one end of the strain sensor 20 is joined to the first structure 11, and the other end of the strain sensor 20 is joined to the second structure 12.

The second structure 12 has a hollow portion 12a, and the case 15 is attached to the second structure 12 around the hollow portion 12a. Inside the case 15, a processing circuit (not shown) is provided that processes an electric signal supplied from the strain sensor 20 and generates a torque detection signal as a sensor signal.

A bush 16 for holding the cable 17 is provided in a part of the case 15. One end of the cable 17 (not shown) is connected to a processing circuit in the case 15, and the other end of the cable 17 is passed through, for example, a hollow portion 12a. The cable 17 supplies power to the processing circuit from the outside, and outputs a sensor signal processed by the processing circuit to the outside. Since the configuration of the processing circuit is not the essence of the present embodiment, the description thereof will be omitted.

3, FIG. 4, and FIG. 5 show the strain sensor 20 and the mounting structure of the strain sensor 20.

FIG. 3 shows the configuration of the mounting portion of the strain sensor 20. A recess 30 is integrally formed in the first structure 11, the second structure 12, and the plurality of third structures 13. At the bottom of the recess 30, a portion corresponding to the first structure 11 is provided with a first bottom 31a and a second bottom 32a lower than the first bottom 31a. As shown in FIG. 5, the difference in depth between the first bottom portion 31a and the second bottom portion 32a is substantially equal to the thickness of the strain generating body 21.

In the bottom portion of the recess 30, a first bottom portion 31b and a second bottom portion 32b lower than the first bottom portion 31b are also provided in a portion corresponding to the second structure 12. The difference in depth between the first bottom portion 31b and the second bottom portion 32b is also substantially equal to the thickness of the strain generating body 21.

At the bottom of the recess 30, a third bottom 33 lower than the second bottoms 32a and 32b is provided at a portion corresponding to the third structure 13.

An opening 34a is provided in a substantially central portion of the second bottom portion 32a corresponding to the first structure 11, and a screw thread is provided in the opening 34a. An opening 34b is also provided at substantially the center of the second bottom portion 32b corresponding to the second structure 12, and a screw thread is provided inside the opening 34b.

As shown in FIG. 4, the strain sensor 20 is provided between the first structure 11 and the second structure 12 in the recess 30. The strain sensor 20 includes, for example, a metal strain generating body 21 and a plurality of strain gauges 22 as sensor elements arranged on one surface of the strain generating body 21.

The strain gauge 22 is, for example, a thin film resistance element, and its resistance value changes as the strain generating body 21 is deformed. The plurality of strain gauges 22 form a bridge circuit (not shown), and the change in resistance value is detected as an electric signal by the bridge circuit. The plurality of strain gauges 22 are connected to one end of a flexible substrate 23 (shown in FIGS. 2 and 5) provided at the center of the strain generating body 21. The other end of the flexible substrate 23 is connected to the processing circuit in the case 15. The electric signal output from the bridge circuit is supplied to the processing circuit via the flexible substrate 23, and the processing circuit generates a torque detection signal as a sensor signal.

The strain-causing body 21 has, for example, a rectangular shape, and the length of the strain-causing body 21 is longer than the length of the third bottom portion 33. The strain-causing body 21 is fixed to the first structure 11 and the second structure 12 by the fixing device 40a and the fixing device 40b in a state of being arranged in the recess 30.

Specifically, as shown in FIG. 5, the first end portion of the strain generating body 21 is placed on the second bottom portion 32a of the first structure 11, and the second end portion of the strain generating body 21 is It is placed on the second bottom 32b of the second structure 12. That is, the strain-causing body 21 is arranged between the opening 34a of the second bottom 32a of the first structure 11 and the opening 34b of the second bottom 32b of the second structure 12.

The first end portion of the strain generating body 21 is fixed to the first structure 11 by a fixing device 40a arranged in a portion corresponding to the first structure 11 of the recess 30, and the second end portion of the strain generating body 21 is fixed to the first structure 11. , It is fixed to the second structure 12 by the fixing device 40b arranged in the portion corresponding to the second structure 12 of the recess 30.

The fixing device 40a and the fixing device 40b have the same configuration, and the fixing device 40a and the fixing device 40b each include a fixing plate 41 as a fixing member and a screw 42. In the fixing device 40a, the fixing plate 41 is attached to the first structure 11 by a screw 42 screwed into the opening 34a. In the fixing device 40b, the fixing plate 41 is attached to the second structure 12 by a screw 42 screwed into the opening 34b.

The screw 42 is inserted from above the fixing plate 41 and screwed into the opening 34a of the first structure 11 or the opening 34b of the second structure 12.

When the screw 42 of the fixing device 40a is tightened, the first end portion of the strain generating body 21 is fixed to the first structure 11 by the fixing plate 41, and when the screw 42 of the fixing device 40b is tightened, the strain generating body 21 The second end is fixed to the second structure 12 by the fixing plate 41.

(Structure of fixed plate)
FIG. 6 shows one form of the fixed plate 41 according to the present embodiment.

The fixing plate 41 is made of, for example, the same metal as the first structure 11, but is not limited to this, and may be made of another material.

The fixed plate 41 has, for example, a rectangular parallelepiped main body 41a. The fixed plate 41 and the main body 41a are the same, and the fixed plate 41 is also simply referred to as the main body 41a. A first protrusion 41c is provided along the first side of, for example, the bottom surface 41b of the main body 41a, and a second protrusion 41d is provided along the second side parallel to the first side. The first protrusion 41c and the second protrusion 41d are linear and project from the bottom surface 41b in the same direction. Therefore, the bottom surface 41b is arranged at a position away from the line connecting the first protrusion 41c and the second protrusion 41d. Further, the main body 41a has an opening 41f penetrating from the surface 41e to the bottom surface 41b.

The width W1 of the fixed plate 41 is narrower than the width W2 of the recess 30 (shown in FIG. 4), and the length L1 of the fixed plate 41 is the length L2 of the portion of the recess 30 corresponding to the first structure 11 (FIG. 4). The length of the portion of the recess 30 corresponding to the second structure 12 is shorter than L3. Here, the relationship between L2 and L3 is, for example, L2 <L3, but the relationship is not limited to this. That is, the length of the fixing plate 41 allows the fixing plate 41 to come into contact with the first bottom portion 31a and the first end portion of the strain generating body 21 when the screw 42 is tightened, or the first bottom portion 31b and the strain generating body 21. It may be long enough to contact the second end of the.

Specifically, as shown in FIGS. 4 and 5, in a state where the two fixing plates 41 are inserted into the portion of the recess 30 corresponding to the first structure 11 and the portion corresponding to the second structure 12. It is sufficient that the first protrusion 41c of each fixing plate 41 can make line contact with the first bottom portion 31a or the first bottom portion 31b, and the second protrusion 41d can make line contact with the first end portion or the second end portion of the strain generating body 21.

In this way, in a state where the two fixing plates 41 are inserted into the recesses 30, the screws 42 are inserted into the openings 41f of each fixing plate 41, and the openings 34a of the first structure 11 or the second structure By being screwed into the opening 34b of the body 12, the first protrusion 41c of the fixing plate 41 is in line contact with the first bottom 31a or the first bottom 31b, and the second protrusion 41d is the first end of the strain generating body 21. Line contact with the portion or the second end.

As shown in FIG. 6, the first protrusion 41c of the fixing plate 41 is linear, and the first protrusion 41c is in line contact with the first bottom portion 31b. However, the present invention is not limited to this, and for example, as shown by the broken line in FIG. 6, the first protrusion 41c may be a point-like protrusion, and the first protrusion 41c may make point contact with the first bottom portion 31b. The point-shaped first protrusion 41c is provided at substantially the center of the first side, but for example, two first protrusions may be provided at both ends of the first side. Alternatively, three first protrusions may be provided at the center of the first side and at both ends.

(Structure of positioning part of strain-causing body)
7 and 8 show the configuration of the positioning portion of the strain generating body 21 according to the present embodiment.

In the present embodiment, at the bottom of the recess 30 integrally provided in the first structure 11, the second structure 12, and the third structure 13, the portion corresponding to the first structure 11 is the first. A positioning portion A is provided, and a second positioning portion B is provided in a portion corresponding to the second structure 12. The first positioning portion A has a fourth bottom portion 35a, and the second positioning portion B has a fourth bottom portion 35b.

The fourth bottom 35a of the first positioning portion A is provided between the second bottom 32a and the third bottom 33, and the fourth bottom 35b of the second positioning portion B is between the second bottom 32b and the third bottom 33. It is provided in. The fourth bottom 35a is provided at a position deeper than the second bottom 32a and shallower than the third bottom 33, and the fourth bottom 35b is provided at a position deeper than the second bottom 32b and shallower than the third bottom 33.

The depth of the fourth bottom portion 35a and the fourth bottom portion 35b may be determined, for example, according to the thickness of the strain generating body 21, and the strain generating body 21 is arranged at the fourth bottom portion 35a and the fourth bottom portion 35b. In the state, the surface of the strain generating body 21 may substantially coincide with the first bottom portion 31a and the first bottom portion 31b.

On the side surface adjacent to the fourth bottom portion 35a, three first protrusions 35a-1, 35a-2, 35a-3 (3) capable of contacting three adjacent sides of the first end portion of the strain generating body 21 ( The first protrusion group) is provided.

On the side surface adjacent to the fourth bottom portion 35b, three second protrusions 35b-1, 35b-2, 35b-3 (3) capable of contacting three adjacent sides of the second end portion of the strain generating body 21 ( The second protrusion group) is provided.

9 and 10 show a state in which the strain generating body 21 is arranged in the recess 30. The first end portion of the strain generating body 21 is arranged in the fourth bottom portion 35a, and the second end portion is arranged in the fourth bottom portion 35b. In the fourth bottom 35a, the three adjacent sides located at the first end of the strain generating body 21 are in contact with the first protrusions 35a-1, 35a-2, 35a-3, respectively, and in the fourth bottom 35b. In, three adjacent sides located at the second end of the strain generating body 21 are in contact with the second protrusions 35b-1, 35b-2, and 35b-3, respectively.

Specifically, the three adjacent sides located at the first end of the strain generating body 21 are line-contacted with the first protrusions 35a-1, 35a-2, 35a-3 in the z direction, and the strain generating body 21 is formed. The three adjacent sides located at the second end of the above are in line contact with the second protrusions 35b-1, 35b-2 and 35b-3 in the z direction.

Therefore, in the strain generating body 21, the first end portion is placed on the fourth bottom portion 35a and the second end portion is placed on the fourth bottom portion 35b, and the strain generating body 21 is placed in the three axes (x, y, z) directions. Positioned. That is, the first end portion of the strain generating body 21 has three axes (x, y) with respect to the first structure 11 by the first protrusions 35a-1, 35a-2, 35a-3, and the fourth bottom portion 35a. , Z) The second end of the strain generating body 21 is positioned with respect to the second structure 12 by the second protrusions 35b-1, 35b-2, 35b-3, and the fourth bottom 35b. It is positioned in three axes (x, y, z) directions.

In this state, as shown in FIG. 4, the fixing plate 41 is placed on the first bottom portion 31a of the first structure 11 and the first end portion of the strain generating body 21, and the first structure 12 is the first. The fixing plate 41 is placed on the bottom portion 31b and the second end portion of the strain generating body 21. These fixing plates 41 are fastened to the first structure 11 and the second structure 12 by screws 42, respectively. Therefore, the first end portion of the strain generating body 21 is fixed to the first structure 11, and the second end portion is fixed to the second structure 12.

(Effect of embodiment)
According to the above embodiment, the first positioning portion A has first protrusions 35a-1, 35a-2, 35a-3 on the side surface adjacent to the fourth bottom portion 35a provided in the first structure 11. The second positioning portion B has second protrusions 35b-1, 35b-2, and 35b-3 on the side surface adjacent to the fourth bottom portion 35b provided in the second structure 12. The three adjacent side surfaces of the first end portion of the strain generating body 21 are line-contacted with the first projections 35a-1, 35a-2, and 35a-3 of the first positioning portion A, respectively, and the second side surface of the strain generating body 21 is second. The three adjacent side surfaces of the end portions are in line contact with the second protrusions 35b-1, 35b-2, and 35b-3 of the second positioning portion B, respectively. Therefore, in the strain generating body 21, the first structure 11 and the second structure 12 are simply placed with the first end portion placed on the fourth bottom portion 35a and the second end portion placed on the fourth bottom portion 35b. The positions in the three axes (x, y, z) directions with respect to the relative are determined. Therefore, it is possible to improve the positional accuracy of the strain generating body 21 with respect to the first structure 11 and the second structure 12.

Moreover, at the first end and the second end of the strain generating body 21, the three adjacent sides are the first protrusions 35a-1, 35a-2, 35a-3, and the second protrusions 35b-1, 35b-. Line contact is made with 2, 35b-3, respectively. If the first end portion and the first structure 11 of the strain generating body 21 and the second end portion and the second structure 12 of the strain generating body 21 are positioned by surface contact, respectively, the strain generating body 21 and the first structure are positioned. The contact area with the 1 structure 11 and the 2nd structure 12 is large. Therefore, other axis interference may occur due to a force or moment applied to the first structure 11 and the second structure 12 in directions other than the x and y directions. However, as in the present embodiment, the strain generating body 21 and the first protrusions 35a-1, 35a-2, 35a-3, and the second protrusions 35b-1, 35b-2, and 35b-3 are in line contact with each other, respectively. In this case, the contact area between the strain generating body 21 and the first structure 11 and the second structure 12 can be reduced, so that interference with other axes can be suppressed and the detection accuracy of the torque sensor can be improved. It is possible.

Further, the first positioning portion A and the second positioning portion B are arranged in the recesses 30 provided in the first structure 11, the second structure 12, and the third structure 13, and the first positioning portion A is The second positioning portion B is composed of fine second protrusions 35b-1, 35b-2, and 35b-3. Therefore, it is possible to prevent the first structure 11, the second structure 12, and the third structure 13 from becoming larger and the torque sensor 10 from becoming larger.

Further, the strain generating body 21 is positioned only by placing the first end portion on the fourth bottom portion 35a and the second end portion on the fourth bottom portion 35b. Therefore, it is not necessary to separately prepare a jig for positioning, and it is possible to facilitate the assembly work.

Further, the strain generating body 21 has first projections 35a-1, 35a-2, 35a-3 as the first positioning portion A, and second projections 35b-1, 35b-2, 35b as the second positioning portion B. -Three lines are in contact. Therefore, the deformation of the first structure 11 and the second structure 12 is directly transmitted to the strain generating body 21. Therefore, it is possible to reduce the fastening force of the screw 42 for fixing the strain generating body 21 by the fixing plate 41, and it is possible to reduce the fastening force of the fixing plate 41 to the strain generating body 21.

Further, even if the fastening force of the fixing plate 41 to the strain generating body 21 is reduced, the deformation of the first structure 11 and the second structure 12 can be directly transmitted to the strain generating body 21. Therefore, the fixing plate 41 can be fixed to the first structure 11 and the second structure 12 by means such as caulking or bonding with an adhesive instead of fastening with screws 42. Alternatively, the strain generating body 21 can be fixed to the first structure 11 and the second structure 12 by means such as caulking or bonding without using the fixing plate 41.

(Modification example)
In the above embodiment, the first positioning portion A and the second positioning portion B are provided in the fourth bottom portion 35a and the fourth bottom portion 35b. However, the present invention is not limited to this, as shown by the broken line in FIG.
The fourth bottom portion 35a and the fourth bottom portion 35b are not provided, and for example, on the second bottom portion 32a of the first structure 11, line contact can be made with three adjacent sides of the first end portion of the strain generating body 21. One protrusion 37 may be provided. The shape of these protrusions 37 is, for example, a cylinder, but the shape is not limited to the cylinder. Similarly, the second structure 12 side is provided with three protrusions 37 (not shown) capable of line contact with three adjacent sides of the second end portion of the strain generating body 21.

The same effect as that of the above embodiment can be obtained by the above modification.

Further, as shown in FIGS. 7 and 9, a pair of fixing plates 41 are positioned with respect to the first structure 11 at a portion corresponding to the fourth bottom portion 35a of the first structure 11 on the side surface of the recess 30. A pair of protrusions 36a-1 and 36a-2 are provided, and the fixing plate 41 is positioned with respect to the second structure 12 at a portion corresponding to the fourth bottom portion 35b of the second structure 12 on the side surface of the recess 30. The protrusions 36b-1 and 36b-2 are provided.

As shown in FIG. 4, the protrusions 36a-1 and 36a-2 position the end portion of the fixed plate 41 on the strain generating body 21 side with respect to the first structure 11, and the protrusions 36b-1 and 36b-2 , The end of the fixing plate 41 on the strain generating body 21 side is positioned with respect to the second structure 12. Specifically, as shown in FIG. 5, the protrusions 36a-1 and 36a-2 are in contact with the side surface of the fixing plate 41 in the z direction, and the protrusions 36b-1 and 36b-2 are on the side surface of the fixing plate 41. Contact in the z direction.

The second protrusion 41d of the fixing plate 41 positioned by the protrusions 36a-1 and 36a-2 is in line contact with the first end portion of the strain generating body 21 in a direction orthogonal to the longitudinal direction of the strain generating body 21. Similarly, the second protrusion 41d of the fixed plate 41 positioned by the protrusions 36b-1 and 36b-2 is also line-contacted with the second end of the strain generating body 21 in the direction orthogonal to the longitudinal direction of the strain generating body 21. ..

By providing the protrusions 36a-1 and 36a-2 and the protrusions 36b-1 and 36b-2 in the recess 30, the positioning of the fixing plate 41 can be facilitated.

In addition, the present invention is not limited to each of the above embodiments 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 each of the above embodiments. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.

10 ... Torque sensor, 11 ... First structure, 12 ... Second structure, 13 ... Third structure, 21 ... Distortion body, 30 ... Recession, 31a, 31b ... First bottom, 32a, 32b ... Second Bottom, 33 ... 3rd bottom, 35a, 35b ... 4th bottom, 35a-1, 35a-2, 35a-3 ... 1st protrusion, 35b-1, 35b-2, 35b-3 ... 2nd protrusion, 41 ... Fixed plate, 42 ... screw, A ... first positioning part, B ... second positioning part.

Claims (10)

The first structure and
The second structure and
A plurality of third structures connecting the first structure and the second structure,
A strain generating body provided between the first structure and the second structure and forming a strain sensor,
A first positioning portion provided on the first structure and positioning the first end portion of the strain-causing body with respect to the first structure.
A second positioning portion provided on the second structure and positioning the second end portion of the strain-causing body with respect to the second structure.
A torque sensor characterized by being provided with. The first positioning portion is provided on the first structure and includes a first protrusion group that can come into contact with three adjacent sides of the first end portion of the strain-causing body. 1. The torque sensor according to 1. The second positioning portion is provided in the second structure and includes a second projection group that can come into contact with three adjacent sides of the second end portion of the strain generating body. 1. The torque sensor according to 1. The torque sensor according to claim 2, wherein the first protrusion group makes line contact with the first end portion in the thickness direction of the strain-causing body. The torque sensor according to claim 3, wherein the second protrusion group makes line contact with the second end portion in the thickness direction of the strain-causing body. The first structure and
The second structure and
A plurality of third structures connecting the first structure and the second structure,
A strain generating body provided between the first structure and the second structure and forming a strain sensor,
A recess provided integrally with the first structure, the second structure, and the third structure,
At the bottom of the recess, a first bottom provided in each of the first structure and the portion corresponding to the second structure, and
The second bottom, which is lower than the first bottom,
A third bottom portion, which is provided in a portion corresponding to the third structure and is lower than the second bottom portion,
A fourth bottom portion between the second bottom portion and the third bottom portion, which is provided in each of the first structure and the portion corresponding to the second structure,
A first positioning portion provided on a side surface of the first structure adjacent to the fourth bottom portion and positioning the first end portion of the strain generating body, and a first positioning portion.
A second positioning portion provided on a side surface of the second structure adjacent to the fourth bottom portion and positioning the second end portion of the strain generating body, and a second positioning portion.
A torque sensor characterized by being provided with. The first positioning portion is provided on the first structure and includes a first protrusion group that can come into contact with three adjacent sides of the first end portion of the strain-causing body. 6. The torque sensor according to 6. The second positioning portion is provided in the second structure and includes a second projection group that can come into contact with three adjacent sides of the second end portion of the strain generating body. 6. The torque sensor according to 6. The torque sensor according to claim 7, wherein the first protrusion group makes line contact with the first end portion in the thickness direction of the strain-causing body. The torque sensor according to claim 8, wherein the second projection group makes line contact with the second end portion in the thickness direction of the strain-causing body.

Images