WO2018189981A1

WO2018189981A1 - Force sensor

Info

Publication number: WO2018189981A1
Application number: PCT/JP2018/002935
Authority: WO
Inventors: 鈴木　隆史; 池田　隆男
Original assignee: 日本電産コパル電子株式会社
Priority date: 2017-04-14
Filing date: 2018-01-30
Publication date: 2018-10-18
Also published as: JP2018179806A; JP6817875B2

Abstract

Provided is a force sensor capable of independently setting the sensitivity and allowable torque of a strain sensor or the mechanical strength of a torque sensor. A flexible third region 13 connects a first region 11 and a second region 12 to each other. A plurality of strain sensors 14, 15, 16, 17 are provided between the first region 11 and the second region 12. Each of the strain sensors is provided with: a substrate that is provided between the first region and the second region; and a plurality of resistors that are provided on the surface of the substrate.

Description

Force sensor

The embodiment of the present invention relates to a force sensor applied to, for example, a robot.

The force sensor (also referred to as a 6-axis force sensor) includes forces Fx, Fy, and Fz in the X-axis, Y-axis, and Z-axis directions, and moments Mx, My, This is a sensor capable of measuring Mz (see, for example, Patent Document 1 and Patent Document 2).

In Patent Document 1 and Patent Document 2, the force sensor has a force sensor chip as a strain generating body. The force sensor chip has a frame-shaped support part, a square-shaped action part, and a T-shaped connection part that connects the support part and the action part, and the plurality of strain resistance elements include a connection part, an action part, Is provided on the surface of the boundary.

JP 2010-25736 A JP 2008-292510 A

In the force sensor chip, a plurality of strain resistance elements are directly arranged on the surfaces of the connecting portion and the action portion. For this reason, it has been difficult to independently set the sensitivity and allowable torque (maximum torque) of the strain resistance element as the strain sensor and the mechanical strength of the force sensor chip as the strain generating body.

The embodiment of the present invention provides a force sensor capable of independently setting the sensitivity and allowable torque of the strain sensor and the mechanical strength of the strain generating body.

The force sensor of the present embodiment includes a first region, a second region, a plurality of flexible third regions that connect the first region and the second region, and the first region. A plurality of strain sensors provided between the second regions, each of the plurality of strain sensors comprising: a substrate provided between the first region and the second region; and And a plurality of resistors provided on the surface.

According to the present invention, it is possible to provide a force sensor capable of independently setting the sensitivity and allowable torque of the strain sensor and the mechanical strength of the strain generating body.

The top view which shows an example of the force sensor which concerns on 1st Embodiment. The top view which takes out and shows one of the distortion sensors shown in FIG. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. The top view shown in order to demonstrate the relationship between the 1st distortion sensor thru | or 4th strain sensor shown in FIG. 1, and a some bridge circuit. The figure which shows concretely the bridge circuit contained in the 1st distortion sensor thru | or 4th distortion sensor shown in FIG. The figure which shows concretely the bridge circuit contained in the 1st distortion sensor thru | or 4th distortion sensor shown in FIG. The figure which shows the relationship between each bridge circuit and a resistor. The figure which shows the relationship between each bridge circuit and 6 axes. The figure which shows an example of operation | movement of a bridge circuit. The figure which shows the other example of operation | movement of a bridge circuit. The top view which shows the modification of 1st Embodiment. The perspective view which shows an example of the force sensor which concerns on 2nd Embodiment. The perspective view which shows a part of FIG.

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

(First embodiment)
FIG. 1 shows a force sensor according to the first embodiment. The force sensor (also referred to as a first strain body) 10 includes a first strain sensor 14, a second strain sensor 15, a third strain sensor 16, and a fourth strain sensor 17.

The first strain body 10 includes a first structure (first region) 11, a second structure (second region) 12, and a third structure (third region) 13 as a plurality of connecting portions. A first strain sensor 14, a second strain sensor 15, a third strain sensor 16, and a fourth strain sensor 17 are disposed between the first structure 11 and the second structure 12.

The first structure 11 has, for example, a substantially quadrangular frame shape, and has four corners and four sides. Each of the four corners of the first structure 11 has a first insertion port 11a for inserting a bolt (not shown), for example. The first structure 11 is fixed to a first movable body (not shown) as a force sensor main body by a bolt inserted into each first insertion port 11a. The first movable body is fixed to, for example, one of the joints (not shown) of a robot arm (not shown) as the body to be measured.

Each of the four sides of the first structure 11 has a first protrusion 11b. Specifically, each first protrusion 11b is provided on the inner surface at substantially the center of each of the four sides. The height of the surface of the first protrusion 11 b is equal to the height of the first structure 11. That is, the thickness of each side of the first structure 11 is equal to the thickness of the first protrusion 11b.

The second structure 12 has, for example, a substantially cross shape, and the height of the surface of the second structure 12 is equal to the height of the surface of the first structure 11. That is, the thickness of the second structure 12 is equal to the thickness of the first structure 11.

The second structure 12 has four second protrusions 12a, and each second protrusion 12a is opposed to each first protrusion 11b of the first structure 11 with a predetermined interval. The second structure 12 has a second insertion port 12b for inserting, for example, a bolt (not shown) corresponding to each second protrusion 12a. The 2nd structure 12 is fixed to the 2nd movable body which is not illustrated as a force sensor main part with the volt | bolt inserted in each 2nd insertion port 12b. The second movable body is fixed to, for example, the other joint of a robot arm (not shown) as a measured body.

For example, the four third structures 13 are provided between the four corners of the first structure 11 and the four corners of the second structure 12, respectively. Each third structure 13 has, for example, a substantially rectangular frame shape and has four corners. The first corner of each third structure 13 is provided at the corner of the first structure 11, and the third corner opposite to the first corner of the third structure 13 is the second structure. 12 are provided at corners between two adjacent second protrusions 12a.

The first structure 11, the second structure 12, and the third structure 13 are made of metal, for example, stainless steel (SUS), and have substantially the same thickness along the Z-axis direction in the drawing. However, the present invention is not limited to this, and the thicknesses of the first structure 11, the second structure 12, and the third structure 13 may be set. The first structure 11 and the third structure 13 have a predetermined width in the illustrated X-axis and Y-axis directions.

Since the third structure 13 has a rectangular frame shape, it can be deformed in multiple directions including the X-axis, Y-axis, and Z-axis directions shown in the figure. That is, the third structure 13 has flexibility. For this reason, the second structure 12 can be moved in multiple directions with respect to the first structure 11 by the third structure 13.

Between the four first protrusions 11b of the first structure 11 and the four second protrusions 12a of the second structure 12, a first strain sensor 14, a second strain sensor 15, and a third strain sensor 16 are provided. And a fourth strain sensor 17 are provided. The first strain sensor 14 to the fourth strain sensor 17 detect forces Fx, Fy, and Fz in the X-axis, Y-axis, and Z-axis directions, and moments Mx, My, and Mz around the X-axis, Y-axis, and Z-axis. The

FIG. 2 shows a part extracted from FIG. 1 and shows a mounting portion of the first strain sensor 14. The configuration of the mounting portion of the second strain sensor 15, the third strain sensor 16 and the fourth strain sensor 17 is the same as the configuration of the mounting portion of the first strain sensor 14, and the second strain sensor 15 and the third strain sensor 16. Since the configuration of the fourth strain sensor 17 is the same as the configuration of the first strain sensor 14, a description thereof will be omitted.

In FIG. 2, the first strain sensor 14 includes a substrate (second strain generating body) 21, a plurality of resistors 22 constituted by, for example, thin film resistors as strain gauges, a plurality of wiring patterns 23, and a plurality of terminals. 24.

The substrate 21 is made of a rectangular metal plate, for example, stainless steel (SUS). The rigidity of the substrate 21 is smaller than the rigidity of the third structure 13. One end of the substrate 21 is welded to the first protrusion 11b, and the other end is, for example, welded to the second protrusion 12a. A symbol Wp indicates a welded portion.

The method of attaching the substrate 21 to the first protrusion 11b and the second protrusion 12a is not limited to welding, and may be bonded by, for example, an adhesive.

Since one end of the substrate 21 is fixed to the first protrusion 11b and the other end is fixed to the second protrusion 12a, an intermediate portion between the one end and the other end can be deformed. .

The plurality of resistors 22, the plurality of wiring patterns 23, and the plurality of terminals 24 are provided in an intermediate portion of the substrate 21.

One end and the other end of each resistor 22 are connected to one end of the wiring pattern 23, respectively, and the other end of each wiring pattern 23 is connected to the terminal 24.

The plurality of resistors 22 include four resistors Sa1, Sa2, Sb1, and Sb2 on the four first structures 11 side and four resistors Ra1, Ra2, Rb1, and Rb2 on the four second structure bodies 12 side. Contains.

The eight first terminals 24a and the eight second terminals 24b are arranged between the four resistors Sa1, Sa2, Sb1, Sb2 and the four resistors Ra1, Ra2, Rb1, Rb2. Each of the first terminals 24a is connected to one end and the other end of the resistors Sa1, Sa2, Sb1, and Sb2 by the wiring pattern 23, and each of the second terminals 24b is connected to the resistors Ra1, Ra2, and Rb1 by the wiring pattern 23. , Rb2 are connected to one end and the other end, respectively.

By appropriately connecting each of the first terminals 24a and each of the second terminals 24b, two bridge circuits to be described later are formed by the resistors Sa1, Sa2, Sb1, and Sb2 and the resistors Ra1, Ra2, Rb1, and Rb2. Is configured.

FIG. 3 shows a cross section taken along line III-III shown in FIG.

The first strain sensor 14 includes, for example, a substrate 21, an insulating film 21a, a resistor 22, an adhesive film 21b, a wiring pattern 23, an adhesive film 21c, and a glass film 21d as a protective film.

Specifically, an insulating film 21a is provided on the substrate 21, and a resistor 22 made of, for example, Cr—N is provided on the insulating film 21a. A wiring pattern 23 made of, for example, copper (Cu) is provided on the resistor 22 with an adhesive film 21b interposed. An adhesive film 21c is provided on the wiring pattern 23, and the adhesive film 21c, the wiring pattern 23, the adhesive film 21b, the resistor 22 and the insulating film 21a are covered with, for example, a glass film 21d. The adhesive film 21b enhances the adhesion between the wiring pattern 23 and the resistor 22, and the adhesive film 21c enhances the adhesion between the wiring pattern 23 and the glass film 21d. The adhesive films 21b and 21c are conductive films containing, for example, chromium (Cr).

In addition, the structure of the 1st distortion sensor 14 thru | or the 4th distortion sensor 17 is not limited to this, It can deform | transform.

The resistors Sa1, Sa2, Sb1, Sb2 and the resistors Ra1, Ra2, Rb1, Rb2 have the same configuration, but may have different configurations.

FIG. 4 shows two bridge circuits included in each of the first strain sensor 14 to the fourth strain sensor 17. The first strain sensor 14 includes bridge circuits Ba1 and Bb1, the second strain sensor 15 includes bridge circuits Ba2 and Bb2, the third strain sensor 16 includes bridge circuits Ba3 and Bb3, and a fourth strain sensor 17. Includes bridge circuits Ba4 and Bb4.

5A and 5B schematically show two bridge circuits included in the first strain sensor 14 to the fourth strain sensor 17, respectively.

FIG. 5A shows the bridge circuits Ba1, Ba2, Ba3, Ba4, and FIG. 5B shows the bridge circuits Bb1, Bb2, Bb3, Bb4.

5A and 5B, resistors Sa1, Sa3, Sa5, Sa7, Sa2, Sa4, Sa6, Sa8, Sb1, Sb3, Sb5, Sb7, Sb2, Sb4, Sb6, Sb8, and resistors Ra1, Ra3, Ra5, Ra7, Ra2, Ra4, Ra6, Ra8, Rb1, Rb3, Rb5, Rb7, Rb2, Rb4, Rb6, Rb8 are the first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor, respectively. 17 resistors are shown.

Since the configurations of the first strain sensor 14 to the fourth strain sensor 17 are the same, the first strain sensor 14 will be described.

In the first strain sensor 14, the bridge circuit Ba1 includes resistors Sa1 and Sa2 and resistors Ra1 and Ra2, and the bridge circuit Bb1 includes resistors Sb1 and Sb2 and resistors Rb1 and Rb2.

In the bridge circuit Ba1 shown in FIG. 5A, one end of the resistor Sa1 is connected to one end of the resistor Ra1, and one end of the resistor Sa2 is connected to one end of the resistor Ra2. The other end of the resistor Sa1 is connected to the other end of the resistor Ra2, and the power source E is supplied to the connection point between the resistor Sa1 and the resistor Ra2. The other end of the resistor Sa2 and the other end of the resistor Ra1 are grounded. The output voltage V− is output from the connection point between the resistor Sa1 and the resistor Ra1, and the output voltage V + is output from the connection point between the resistor Sa2 and the resistor Ra2.

In the bridge circuit Bb1 shown in FIG. 5B, one end of the resistor Sb1 is connected to one end of the resistor Sb2, and the power source E is supplied to the connection point between the resistor Sb1 and the resistor Sb2. One end of the resistor Rb1 is connected to one end of the resistor Rb2, and the connection point between the resistor Rb1 and the resistor Rb2 is grounded. The other end of the resistor Sb1 is connected to the other end of the resistor Rb1, and an output voltage V− is output from a connection point between the resistor Sb1 and the resistor Rb1. The other end of the resistor Sb2 is connected to the other end of the resistor Rb2, and an output voltage V + is output from a connection point between the resistor Sb2 and the resistor Rb2.

FIG. 6 schematically shows the bridge circuits Ba1, Bb1, bridge circuits Ba2, Bb2, bridge circuits Ba3, Bb4, and bridge circuits Ba4, Bb4 included in the first strain sensor 14 to the fourth strain sensor 17.

In the above configuration, when a force and / or moment (torque) is applied to the first structure 11 and the second structure 12, the third structure 13 is deformed and the first structure 11 is The position of the two structures changes. For this reason, the first strain sensor 14 to the fourth strain sensor 17 are deformed. Along with the deformation of the first strain sensor 14 to the fourth strain sensor 17, the bridge circuits Ba1, Bb1, the bridge circuits Ba2, Bb2, the bridge circuits Ba3, Bb4, and the bridge included in the first strain sensor 14 to the fourth strain sensor 17. The balance between the output voltage V− and the output voltage V + of the circuits Ba4 and Bb4 is lost, and a signal corresponding to the applied force and / or moment is detected.

FIG. 7 shows the relationship between the bridge circuit and the detected force and moment.

As shown in FIG. 7, the force Fx in the X-axis direction is detected by the bridge circuits Bb1 and Bb3. The force Fy in the Y-axis direction is detected by the bridge circuits Bb2 and Bb4. The force Fz in the Z-axis direction is detected by the bridge circuits Ba1, Ba2, Ba3, Ba4.

The moment Mx around the X axis is detected by the bridge circuits Ba1 and Ba3. The moment My around the Y axis is detected by the bridge circuits Ba2 and Ba4. The moment Mz around the Z axis is detected by the bridge circuits Bb1, Bb2, Bb3, Bb4.

FIG. 8 shows an example of the operation of the bridge circuit Bb1, for example. The bridge circuit Bb1 detects a force in the main plane of the strain generating body 10 (X direction and / or Y direction shown in FIG. 4). The output voltage Vout of the bridge circuit Bb1 is obtained from the output voltage V + and the output voltage V− by the equation (1).

Vout = (V +-V-)
= (R1 / (R1 + R2) −R3 / (R3 + R4)) · E (1)
In FIG.
R1 is the resistance value of the resistor Sb1, R2 is the resistance value of the resistor Sb2, R3 is the resistance value of the resistor Rb2, and R4 is the resistance value of the resistor Rb1, and no force and moment are applied and there is no distortion. In this case, R1 = R2 = R3 = R4 = R. ΔR is the value of change in resistance value.

FIG. 9 shows an example of the operation of the bridge circuit Ba1, for example. The bridge circuit Ba1 detects a force perpendicular to the main surface of the strain body 10 (Z-axis direction). The output voltage Vout of the bridge circuit Ba1 is obtained from the output voltage V + and the output voltage V− by the equation (1).

In FIG.
R1 is the resistance value of the resistor Sa1, R2 is the resistance value of the resistor Sa2, R3 is the resistance value of the resistor Ra2, and R4 is the resistance value of the resistor Ra1, and no force and moment are applied and there is no distortion. In this case, R1 = R2 = R3 = R4 = R. ΔR is the value of change in resistance value.

(Effect of 1st Embodiment)
According to the first embodiment, the first structure 11 and the second structure 12 are connected by the third structure 13, and the third structure 13 has a substantially rectangular frame shape and is deformed in multiple directions. Is possible. For this reason, the first structure 11 and the second structure 12 are movable in the multiaxial direction via the third structure 13. The first strain sensor 14 to the fourth strain sensor 17 each including two bridge circuits are provided between the first structure 11 and the second structure 12. For this reason, sensor outputs in six-axis directions can be obtained from the output voltages of the first strain sensor 14 to the fourth strain sensor 17.

In addition, the first strain sensor 14 to the fourth strain sensor 17 are provided separately from the third structure 13, and a substrate (second strain body) constituting the first strain sensor 14 to the fourth strain sensor 17. The rigidity of 21 is smaller than the rigidity of the third structure 13. Therefore, regardless of the configuration of the substrate 21 provided in the first strain sensor 14 to the fourth strain sensor 17 that determines the sensitivity of the force sensor, the first structure 11 and the second structure as the first strain body. The rigidity of the force sensor 10 can be determined only by the body 12 and the third structure 13. Therefore, the structural design of the force sensor 10 can be facilitated.

Furthermore, the first strain sensor 14 to the fourth strain sensor 17 can be uniquely designed regardless of the first structure 11, the second structure 12, and the third structure 13. The sensitivity of the fourteenth to fourth strain sensors 17 can be improved. Therefore, multiaxial force and moment can be measured with high accuracy.

The first strain sensor 14 to the fourth strain sensor 17 can be attached between the first structure 11 and the second structure 12 by welding. For this reason, it is possible to simplify manufacture.

Further, in the first strain sensor 14 to the fourth strain sensor 17, a plurality of terminals 24 are arranged in the center portion of the substrate 21, and two terminals 24 can be appropriately connected to form two bridge circuits. Has been. For this reason, it is possible to easily form two different bridge circuits.

(Modification)
In the first embodiment, the third structure 13 has a rectangular frame shape. However, it is not limited to this.

FIG. 10 shows a modification of the first embodiment.

In FIG. 10, the third structure 31 is S-shaped, one end of the third structure 31 is provided at the corner of the first structure 11, and the other end is the second structure 12. It is provided at a corner between two adjacent second protrusions 12a.

In the present modification, the third structure 31 is S-shaped, and can be deformed in multiple directions including the X-axis, Y-axis, and Z-axis directions shown in the figure. For this reason, the second structure 12 can be moved in multiple directions with respect to the first structure 11 by the third structure 13. Therefore, the effect similar to 1st Embodiment can be acquired also by the structure of a modification.

Furthermore, as the shape of the third structure 31, for example, an L shape, a ring shape or the like can be applied.

(Second Embodiment)
11 and 12 show a second embodiment.

In the first embodiment, the first strain sensor 14 to the fourth strain sensor 17 are arranged at positions different from the third structure 13. In contrast, in the second embodiment, the first strain sensor 14 to the fourth strain sensor 17 and the third structure 41 are arranged at the same position.

11 and 12, the force sensor (also referred to as a first strain body) 40 includes a first strain sensor 14, a second strain sensor 15, a third strain sensor 16, and a fourth strain sensor 17. Yes.

The first strain body 40 includes a first structure (first region) 41, a second structure (second region) 42, and a third structure (third region) 43 as a plurality of connecting portions. The first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor 17 are disposed between the first structure 41 and the second structure 42.

As in the first embodiment, the first structure 41 has, for example, a substantially quadrangular frame shape, and has four corners and four sides. Each of the four corners of the first structure 11 has a first insertion port 11a for inserting, for example, a bolt (not shown). The first structure 11 is fixed to a first movable body (not shown) as a force sensor body by, for example, a bolt (not shown) inserted into each first insertion port 11a. The first movable body is fixed to, for example, one of the joints (not shown) of a robot arm (not shown) as the body to be measured.

The intermediate part of each side of the first structure 41 has a first protrusion 11b. The height of the surface of the first protrusion 11 b is equal to the height of the first structure 41. That is, the thickness of each side of the first structure 41 is equal to the thickness of the first protrusion 11b.

The second structure 42 is, for example, substantially rectangular, and the height of the surface of the second structure 12 is equal to the height of the surface of the first structure 11. That is, the thickness of the second structure 12 is equal to the thickness of the first structure 11.

The second structure 42 has second insertion ports 12b for inserting, for example, bolts (not shown) at four corners. The 2nd structure 12 is fixed to the 2nd movable body which is not illustrated as a force sensor main part with the volt | bolt inserted in each 2nd insertion port 12b. The second movable body is fixed to, for example, the other joint of a robot arm (not shown) as a measured body.

The third structure 43 is provided between the first protrusion 11b of the first structure 11 and the middle part of each side of the second structure 42, respectively.

As shown in FIG. 12, one end of the third structure 43 is connected to the first protrusion 11 b of the first structure 41, and the other end is connected to the second structure 42.

The height of the surface 43 a of the third structure 43 is lower than the height of the surfaces of the first structure 11, the first protrusion 11 b, and the second structure 12. That is, the thickness of the third structure 43 is made thinner than the thickness of the first structure 11, the first protrusion 11 b, and the second structure 12.

Both side surfaces adjacent to the surface 43a of the third structure 43 have recesses 43b. For this reason, the width | variety of the 3rd structure 43 is made narrower than the width | variety of the 1st protrusion 11b.

Thus, the width of the third structure 43 is narrower than the width of the first protrusion 11b, and the thickness is lower than the thickness of the first structure 11, the first protrusion 11b, and the second structure 12. Yes. Therefore, the third structure 43 can be deformed in multiple directions with respect to the force applied to the first structure 41 and the second structure 42, and the second structure 12 The three structures 13 are movable in multiple directions including the illustrated X axis, Y axis, and Z axis directions with respect to the first structure 11.

The first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor 17 are provided between the first structure body 11 and the second structure body 12, respectively. Specifically, a plurality of protrusions 44 are provided on the surface of the first protrusion 11 b of the first structure 11 and the surface of the second structure 12 corresponding to the first protrusion 11 b, respectively. One end and the other end of the first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor 17 are held. The intermediate portion provided with the resistor 22 of the first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor 17 is separated from the third structure 43.

In this state, the first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor 17 are fixed to the first protrusion 11b and the second structure 12 by welding, for example. The fixing method is not limited to this, and for example, fixing with an adhesive can be used.

The configurations of the first strain sensor 14, the second strain sensor 15, the third strain sensor 16, and the fourth strain sensor 17 may be the same as or different from those of the first embodiment.

In the above state, when a force and / or moment (torque) is applied to the first structure 41 and the second structure 42, the third structure 43 is deformed and the first structure 41 is The position of the two structures changes. For this reason, the first strain sensor 14 to the fourth strain sensor 17 are deformed. Along with the deformation of the first strain sensor 14 to the fourth strain sensor 17, the bridge circuits Ba1, Bb1, the bridge circuits Ba2, Bb2, the bridge circuits Ba3, Bb4, and the bridge included in the first strain sensor 14 to the fourth strain sensor 17. The balance between the output voltage V− and the output voltage V + of the circuits Ba4 and Bb4 is lost, and a signal corresponding to the applied force and / or moment is detected.

(Effect of 2nd Embodiment)
According to the second embodiment, the same effect as that of the first embodiment can be obtained.

Moreover, in the second embodiment, the third structure 43 is provided in the middle part of each side of the first structure 41 and the middle part of each side of the second structure 42. For this reason, if the length of one side of the second structure 42 is equal to the length of one side of the second structure 12 shown in the first embodiment, the length of one side of the first structure 41 is changed to the first embodiment. It can be shorter than the length of one side of the first structure 11 shown. Therefore, the size of the first strain body 40 can be reduced.

In addition, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The force sensor according to the embodiment of the present invention can be applied to a joint of a robot arm, for example.

DESCRIPTION OF

SYMBOLS

10, 40 ... Force sensor (1st strain body) 11, 41 ... 1st structure (1st area | region) 12, 42 ... 2nd structure (2nd area | region), 13, 43 ... 3rd structure Body (third region), 14 ... first strain sensor, 15 ... second strain sensor, 16 ... third strain sensor, 17 ... fourth strain sensor, 21 ... substrate (second strain body), 22 ... resistor , Ba1, Bb1, Ba2, Bb2, Ba3, Bb3, Ba4, Bb4... Bridge circuit.

Claims

A first region;
A second region;
A plurality of flexible third regions connecting the first region and the second region;
A plurality of strain sensors provided between the first region and the second region;
Comprising
Each of the plurality of strain sensors is
A substrate provided between the first region and the second region;
A force sensor comprising: a plurality of resistors provided on a surface of the substrate.
The force sensor according to claim 1, wherein each of the strain sensors includes a first bridge circuit and a second bridge circuit configured by the plurality of resistors.
The force sensor according to claim 2, wherein the first bridge circuit detects a force in a direction perpendicular to the surface of the substrate, and the second bridge circuit detects a force in a direction along the surface of the substrate. .
The force sensor according to claim 1, wherein rigidity of the substrate is smaller than rigidity of the third region.
The force sensor according to claim 1, wherein the plurality of strain sensors are provided in a portion different from the third region.
The force sensor according to claim 1, wherein the plurality of strain sensors are provided in the same portion as the third region.
The first region is a first frame having four first corners and four first sides,
The force sensor according to claim 1, wherein each of the plurality of third regions connects the four first corners to the second region.
The force sensor according to claim 7, wherein each of the plurality of third regions is a second frame body having four second corners and four second sides.
The force sensor according to claim 7, wherein each of the plurality of third regions is S-shaped.
8. Each of the plurality of third regions connects a central portion of the four first sides and the second region, and has a thickness smaller than the thickness of the first region and the second region. Force sensor.
The force sensor according to claim 10, wherein each of the plurality of strain sensors is provided between the first region and the second region above each of the plurality of third regions.
The force sensor according to claim 1, wherein each of the plurality of strain sensors includes a welded portion welded to the first region and the second region.