Sensor device and film

Abstract

This sensor device enables the implementation of multiple strain gauges in a short time, regardless of the shape and material of the strain-generating body, and minimizes variations in the relative positions of the multiple strain gauges. [Solution] The sensor device (1) comprises a strain-generating body (11) and a film (12) on which a plurality of strain gauges (13) are formed, and the film (12) is bonded to the strain-generating body (11).

Description

Technical Field

[0001] The present invention relates to a sensor device that detects force and / or torque. The present invention also relates to a film used for such a sensor device.

Background Art

[0002] Sensor devices that detect force and / or torque, such as force sensors for detecting force, torque sensors for detecting torque, and force-torque sensors for detecting force and torque, are widely used. These sensor devices employ a configuration that electrically detects the strain of a strain generating body caused by the action of force and / or torque, using a plurality of strain gauges bonded to the strain generating body.

[0003] In order to manufacture such a sensor device, it is necessary to bond each of the plurality of strain gauges to the strain generating body individually. This leads to the problem that the mounting of the strain gauges takes time. In addition, it is necessary to individually determine the position at which each of the plurality of strain gauges is bonded to the strain generating body. This leads to the problem that variations easily occur in the positional relationship of the plurality of strain gauges. If variations occur in the positional relationship of the strain gauges, it becomes difficult to mass-produce highly accurate force-torque sensors.

[0004] Patent Document 1 is cited as a document disclosing a technique that may contribute to solving such problems. Patent Document 1 discloses a technique for detecting the strain of an insulating substrate that is a strain generating body, using a strain gauge directly formed on the surface of the strain generating body by a sputtering method.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0006] However, the sensor devices to which the technology described in Patent Document 1 can be applied are limited to sensor devices that use a substrate as a strain source on which strain gauges can be directly formed using the sputtering method. Therefore, a technology that can solve the above problems regardless of the shape and material of the strain source has not yet been realized.

[0007] One aspect of the present invention has been made in view of the above-mentioned problems, and one of its objectives is to realize a sensor device in which the time required to mount multiple strain gauges is short, regardless of the shape and material of the strain generating body, and in which variations in the positional relationship of the multiple strain gauges are less likely to occur. [Means for solving the problem]

[0008] A sensor device according to one aspect of the present invention comprises a strain-generating body and a film on which a plurality of strain gauges are formed, wherein the film is bonded to the strain-generating body.

[0009] A film according to one aspect of the present invention is a film that is laminated to a strain-generating body and has a plurality of strain gauges formed on it. [Effects of the Invention]

[0010] According to one aspect of the present invention, a sensor device can be realized in which the time required to mount multiple strain gauges is short, regardless of the shape and material of the strain generating body, and in which variations in the positional relationship of the multiple strain gauges are less likely to occur. [Brief explanation of the drawing]

[0011] [Figure 1] This is an exploded perspective view of a force sensor according to one embodiment of the present invention. [Figure 2] Figure 1 is a top view of the force sensor. [Figure 3] Figure 1 is a cross-sectional view of the force sensor. [Figure 4]Figure 1 shows a first modified example of the force sensor. (a) is a top view showing one of the films of the force sensor according to the first modified example. (b) is a top view showing the other film of the force sensor according to the first modified example. [Figure 5] Figure 4 is a cross-sectional view of the strain-generating body of the force sensor shown. [Figure 6] Figure 1 is an exploded perspective view showing a second modified example of the force sensor. [Modes for carrying out the invention]

[0012] In this embodiment, the configuration, effects, and modified examples of a force sensor, which is an example of a sensor device, will be described. However, the scope of application of the present invention is not limited to force sensors. That is, the present invention is applicable to any sensor device that electrically detects the strain of a strain-generating body using strain gauges. For example, in addition to force sensors that detect force and torque, the present invention is also applicable to force sensors that detect force and torque sensors that detect torque.

[0013] (Example configuration of a force sensor) A force sensor 1 according to the first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is an exploded perspective view of the force sensor 1, Figure 2 is a top view of the force sensor 1, and Figure 3 is a cross-sectional view of the force sensor 1.

[0014] The force sensor 1 comprises a strain-generating body 11, a film 12 bonded to the upper surface of the strain-generating body 11, and a film 14 bonded to the lower surface of the strain-generating body 11. Multiple strain gauges 13 are formed on the film 12. Multiple strain gauges 15 are formed on the film 14.

[0015] The strain generating body 11 is composed of a core part 11a, a frame part 11b, and a beam part 11c. Examples of the material of the strain generating body 11 include metal materials such as aluminum alloys and stainless steel alloys, or resin materials such as epoxy resins and polyurethane resins. In any case, the core part 11a, the frame part 11b, and the beam part 11c are integrally molded.

[0016] The core part 11a is a columnar structure. In the present embodiment, a structure having a circular cross section perpendicular to the central axis, that is, a cylindrical structure is used as the core part 11a, but the present invention is not limited thereto. That is, the cross-sectional shape of the core part 11a is arbitrary.

[0017] The frame part 11b is a cylindrical structure surrounding the core part 11a. The frame part 11b is arranged such that the central axis of the frame part 11b coincides with the central axis of the core part 11a, and the inner side surface of the frame part 11b faces the side surface of the core part 11a. In the present embodiment, a structure having an annular cross section perpendicular to the central axis, that is, a cylindrical structure is used as the frame part 11b, but the present invention is not limited thereto. That is, the cross-sectional shape of the frame part 11b is arbitrary.

[0018] The beam part 11c is a columnar structure that connects the core part 11a and the frame part 11b. The beam part 11c is arranged in a space sandwiched between the side surface of the core part 11a and the inner side surface of the frame part 11b such that the central axis of the beam part 11c is orthogonal to the central axis of the core part 11a. In the present embodiment, a structure having a rectangular cross section perpendicular to the central axis, that is, a quadrangular prism-shaped structure is used as the beam part 11c, but the present invention is not limited thereto. That is, the cross-sectional shape of the beam part 11c is arbitrary. Further, in the present embodiment, the core part 11a and the frame part 11b are connected by three beam parts 11c arranged such that the angle formed by the central axes is 120°, but the present invention is not limited thereto. That is, the number of the beam parts 11c is arbitrary.

[0019] On the inner side surface of the frame portion 11b, a convex portion 11d extending parallel to the central axis of the frame portion 11b is formed. In the present embodiment, the convex portion 11d having a semicircular cross section perpendicular to the central axis is used, but the present invention is not limited thereto. That is, the cross-sectional shape of the convex portion 11d is arbitrary. As will be described later, the convex portion 11d is a configuration for facilitating alignment between the strain generating body 11 and the film 12. Note that the upper surface of the convex portion 11d may be provided with a mounting hole for mounting a cover for covering the upper surface of the force sensor 1. Similarly, the lower surface of the convex portion 11d may be provided with a mounting hole for mounting a cover for covering the lower surface of the force sensor 1.

[0020] The film 12 is a film-like structure bonded to the upper surface of the strain generating body 11. Examples of the material of the film 12 include resin materials such as polyimide. In the present embodiment, an annular polyimide film whose inner peripheral radius matches the radius of the upper surface of the core portion 11a and whose outer peripheral radius matches the inner peripheral radius of the upper surface of the frame portion 11b is used as the film 12, but the present invention is not limited thereto. That is, the material and shape of the film 12 are arbitrary. A plurality of strain gauges 13 are formed on the upper surface of the film 12. The strain gauge 13 includes, for example, at least one pair of strain sensitive bodies, and may further include wiring connected to each strain sensitive body. Examples of the material of the strain gauge 13 include alloy materials such as chromium nitride, but the present invention is not limited thereto. In addition, a protective film (not shown) covering the strain gauges 13 may be deposited on the upper surface of the film 12.

[0021] In the strain generating body 11, with an arbitrary plane perpendicular to the central axis of the core portion 11a taken as a reference plane, the height Hb of the upper surface of the frame portion 11b is the same as the height Ha of the upper surface of the core portion 11a, and the height Hc of the upper surface of the beam portion 11c is lower than the heights Ha=Hb of the upper surfaces of the core portion 11a and the frame portion 11b (see FIG. 3). The film 12 is disposed in a space sandwiched between the side surface of the core portion 11a and the inner side surface of the frame portion 11b, and the lower surface of the film 12 is bonded to the upper surface of the beam portion 11c. The bonding between the lower surface of the film 12 and the upper surface of the beam portion 11c is performed using, for example, an adhesive.

[0022] Here, the film 12 is positioned so that each of the multiple strain gauges 13 overlaps with each of the multiple beam portions 11c, and then bonded to the upper surface of the beam portions 11c. To facilitate this positioning, a recess 12a is formed on the outer edge of the film 12. This positioning is achieved by rotating the film 12 appropriately so that the recess 12a formed on the outer edge of the film 12 engages with the protrusion 11d formed on the inner surface of the frame portion 11b.

[0023] Furthermore, the difference between the heights Ha=Hb of the upper surfaces of the core portion 11a and the frame portion 11b and the height Hc of the upper surface of the beam portion 11c, Ha-Hc=Hb-Hc, is greater than the total thickness of the film 12 including the strain gauge 13 and the protective film (see Figure 3). As a result, even if a cover is not provided to cover the upper surface of the force sensor 1, the entire film 12 is completely housed within the space sandwiched between the side surface of the core portion 11a and the inner surface of the frame portion 11b, making it less likely for the strain gauge 13 to be damaged by contact with an object.

[0024] Furthermore, the height Ha of the upper surface of the core portion 11a and the height Hb of the upper surface of the frame portion 11b may be the same or different. However, if the upper surface of the force sensor 1 is covered with a cover, it is preferable that the height Ha of the upper surface of the core portion 11a is less than or equal to the height Hb of the upper surface of the frame portion 11b.

[0025] The film 14 is a membrane-like structure bonded to the lower surface of the strain-generating body 11. In this embodiment, an annular polyimide film is used as the film 14, whose inner radius matches the radius of the lower surface of the core portion 11a and whose outer radius matches the inner radius of the lower surface of the frame portion 11b, but the invention is not limited to this. That is, the material and shape of the film 14 are arbitrary. A plurality of strain gauges 15 are formed on the lower surface of the film 14. The strain gauges 15 may include, for example, at least one pair of strain-sensing elements and wiring connected to each strain-sensing element. The material of the strain gauges 15 may be an alloy material such as chromium nitride, but the invention is not limited to this. In addition, the upper and lower surfaces of the film 14 may have a protective film (not shown) that covers the strain gauges 15.

[0026] In the strain-generating body 11, with an arbitrary plane perpendicular to the central axis of the core portion 11a as the reference plane, the height Hb' of the lower surface of the frame portion 11b is the same as the height Ha' of the lower surface of the core portion 11a, and the height Hc' of the lower surface of the beam portion 11c is higher than the height Ha'=Hb' of the lower surfaces of the core portion 11a and the frame portion 11b (see Figure 3). The film 14 is placed in the space sandwiched between the side surface of the core portion 11a and the inner surface of the frame portion 11b, and the upper surface of the film 14 is bonded to the lower surface of the beam portion 11c. The bonding of the upper surface of the film 14 to the lower surface of the beam portion 11c is performed, for example, using an adhesive.

[0027] Here, the film 14 is positioned so that each of the multiple strain gauges 15 overlaps with each of the multiple beam sections 11c, and then bonded to the lower surface of the beam sections 11c. To facilitate this positioning, a recess 14a is formed on the outer edge of the film 14. This positioning is achieved by rotating the film 14 appropriately so that the recess 14a formed on the outer edge of the film 14 engages with the protrusion 11d formed on the inner surface of the frame section 11b.

[0028] Furthermore, the difference Hc'-Ha'=Hc'-Hb' between the heights Ha'=Hb' of the lower surfaces of the core portion 11a and frame portion 11b and the height Hc' of the lower surface of the beam portion 11c is greater than the total thickness of the film 14, including the strain gauge 15 and the protective film (see Figure 3). As a result, even if a cover is not provided to cover the lower surface of the force sensor 1, the entire film 14 is completely housed within the space sandwiched between the side surface of the core portion 11a and the inner surface of the frame portion 11b, making it less likely for the strain gauge 15 to be damaged by contact with an object.

[0029] In this embodiment, a configuration is adopted in which a protrusion 11d is formed on the inner circumferential surface of the frame portion 11b and a recess 12a is formed on the outer edge of the film 12, but the present invention is not limited thereto. For example, a configuration may be adopted in which a recess is formed on the inner circumferential surface of the frame portion 11b and a protrusion is formed on the outer edge of the film 12.

[0030] Furthermore, the height Ha' of the lower surface of the core portion 11a and the height Hb' of the lower surface of the frame portion 11b may be the same or different. However, if the lower surface of the force sensor 1 is covered with a cover, it is preferable that the height Ha' of the lower surface of the core portion 11a is greater than or equal to the height Hb' of the lower surface of the frame portion 11b.

[0031] In this embodiment, a configuration is adopted in which multiple protrusions 11d of the same shape are formed on the inner circumferential surface of the frame portion 11b, and multiple recesses 12a of the same shape are formed on the outer edge of the film 12. However, the present invention is not limited thereto. A configuration may be adopted in which a single protrusion 11d is formed on the inner circumferential surface of the frame portion 11b, and a single recess 12a is formed on the outer edge of the film 12. Alternatively, a configuration may be adopted in which multiple protrusions 11d of different shapes are formed on the inner circumferential surface of the frame portion 11b, and multiple recesses 12a of different shapes are formed on the outer edge of the film 12. This eliminates the degree of freedom of rotation of the film 12 during alignment.

[0032] (Film manufacturing method) The film 12 (including the strain gauge 13) to be bonded to the upper surface of the strain generating body 11 can be manufactured, for example, as follows.

[0033] Step 1: A film (e.g., polyimide film) is bonded onto a glass substrate.

[0034] Step 2: Multiple strain gauges 13 are deposited onto the film simultaneously. At this time, terminals for connecting wiring to the strain gauges 13 may be deposited on the polyimide film together with the strain gauges 13.

[0035] Step 3: A protective film is formed on the film so as to cover the strain gauge 13. If terminals were formed in Step 2, the protective film should be formed so as not to cover the terminals, or the protective film should be formed to cover the terminals, and then the portion of the protective film that covers the terminals should be peeled off.

[0036] Step 4: Laser cut the film into the predetermined shape.

[0037] Step 5: Peel the laser-cut film from the glass substrate.

[0038] The film 14 (including the strain gauge 15) to be bonded to the lower surface of the strain generating body 11 can be manufactured in the same manner. The force sensor 1 is completed by bonding the film 12 (including the strain gauge 13) and film 14 (including the strain gauge 15) manufactured in this manner to the strain generating body 11.

[0039] (Effect of force sensor) Conventional force sensors required the individual bonding of each strain gauge to the strain-generating body during manufacturing. This resulted in the problem of time-consuming strain gauge implementation. Furthermore, the position for bonding each strain gauge to the strain-generating body had to be determined individually. This led to a problem of inconsistency in the relative positions of the strain gauges. When inconsistencies occur in the relative positions of the strain gauges, it becomes difficult to mass-produce high-precision force sensors.

[0040] On the other hand, in the force sensor 1 according to this embodiment, multiple strain gauges 13 can be mounted in the correct positions simply by attaching the film 12 to the upper surface of the strain generating body 11 during manufacturing. Similarly, multiple strain gauges 15 can be mounted in the correct positions simply by attaching the film 14 to the lower surface of the strain generating body 11. Therefore, the force sensor 1 according to this embodiment can eliminate the problem of time required to mount the strain gauges 13 and 15, and the problem of variations in the relative positions of the strain gauges 13 and 15.

[0041] In this embodiment of the force sensor 1, instead of individually attaching each of the multiple strain gauges 13 to the strain generating body 11, it is necessary to form each of the multiple strain gauges 13 on a film 12. Similarly, instead of individually attaching each of the multiple strain gauges 15 to the strain generating body 11, it is necessary to form each of the multiple strain gauges 15 on a film 14.

[0042] However, the process of forming each of the multiple strain gauges 13 on the film 12 can be carried out collectively by the film deposition process. Similarly, the process of forming each of the multiple strain gauges 15 on the film 14 can be carried out collectively by the film deposition process. Therefore, even considering the process of forming each of the multiple strain gauges 13 on the film 12 and the process of forming each of the multiple strain gauges 15 on the film 14, the time required to manufacture the force sensor 1 according to this embodiment is shorter than the time required to manufacture a conventional force sensor. Furthermore, the variation in the positional relationship of the multiple strain gauges 13 and 15 in the force sensor according to this embodiment is smaller than the variation in the positional relationship of the multiple strain gauges in a conventional force sensor.

[0043] (First modified example of a force sensor) A first modified example of the force sensor 1 (hereinafter referred to as "force sensor 1A") will be described with reference to Figures 4 and 5. Figure 4(a) is a top view of the film 12 provided by the force sensor 1A, and Figure 4(b) is a top view of the film 14 provided by the force sensor 1A. Figure 5 is a cross-sectional view of the beam portion 11c of the strain generating body 11 to which the films 12 and 14 are bonded.

[0044] The force sensor 1A according to this modified example comprises a strain-generating body 11, a film 12 attached to the upper surface of the strain-generating body 11, and a film 14 attached to the lower surface of the strain-generating body 11, similar to the force sensor 1 shown in Figure 1. The differences between the force sensor 1 shown in Figure 1 and the force sensor 1A according to this modified example are as follows.

[0045] Difference 1: As shown in Figure 1, the upper surface of the film 12 of the force sensor 1 has a strain gauge 13 formed on it, which is located on the upper surface of the beam portion 11c. In contrast, as shown in Figure 4(a), the upper surface of the film 12 of the force sensor 1A according to this modified example has a second strain gauge 13b formed on the side of the beam portion 11c, in addition to the first strain gauge 13a located on the upper surface of the beam portion 11c. The second strain gauge 13b is located in a second region 12d adjacent to the first region 12c where the first strain gauge 13a is located on the upper surface of the film 12 of the force sensor 1A.

[0046] Difference 2: As shown in Figure 1, the film 12 of the force sensor 1 does not have any notches formed on it. In contrast, as shown in Figure 4(a), the film 12 of the force sensor 1A according to this modified example has notches 12b formed on it that surround three sides of the second region 12d, excluding the boundary with the first region 12c.

[0047] Due to these differences, in the modified force sensor 1A, the film 12 can be folded so that the boundary line between the first region 12c and the second region 12d becomes a ridge. As a result, as shown in Figure 5, the first region 12c can be attached to the upper surface of the beam portion 11c, and the second region 12d can be attached to the side surface of the beam portion 11c. Therefore, the first strain gauge 13a can be placed on the upper surface of the beam portion 11c, and the second strain gauge 13b can be placed on the side surface of the beam portion 11c.

[0048] Difference 3: As shown in Figure 1, the lower surface of the film 14 of the force sensor 1 has a strain gauge 15 formed on it, which is located on the lower surface of the beam portion 11c. In contrast, as shown in Figure 4(b), the lower surface of the film 14 of the force sensor 1A has a third strain gauge 15a located on the lower surface of the beam portion 11c, as well as a fourth strain gauge 15b located on the side surface of the beam portion 11c. The fourth strain gauge 15b is located in a fourth region 14d adjacent to the third region 14c where the third strain gauge 15a is located on the lower surface of the film 14 of the force sensor 1A.

[0049] Difference 4: As shown in Figure 1, the film 14 of the force sensor 1 does not have a cut formed therein. In contrast, as shown in Figure 4(b), the film 14 of the force sensor 1A according to this modified example has a cut 14b formed therein that surrounds three sides of the fourth region 14d, excluding the boundary with the third region 14c.

[0050] Due to these differences, in the modified force sensor 1A, the film 14 can be folded so that the boundary line between the third region 14c and the fourth region 14d becomes a ridge. As a result, as shown in Figure 5, the third region 14c can be attached to the lower surface of the beam portion 11c, and the fourth region 14d can be attached to the side surface of the beam portion 11c (the side surface opposite to the side surface to which the second region 12d is attached). Therefore, the third strain gauge 15a can be placed on the lower surface of the beam portion 11c, and the fourth strain gauge 15b can be placed on the side surface of the beam portion 11c (the side surface opposite to the side surface to which the second strain gauge 12b is placed).

[0051] (Second modified example of the force sensor) A second modified example of force sensor 1 (hereinafter referred to as "force sensor 1B") will be described with reference to Figure 6. Figure 6 is an exploded perspective view of force sensor 1B.

[0052] The force sensor 1B according to this modified example comprises a strain-generating body 11, a film 12 attached to the upper surface of the strain-generating body 11, a plurality of strain gauges 13 formed on the upper surface of the film 12, a film 14 attached to the lower surface of the strain-generating body 11, and a plurality of strain gauges 15 formed on the lower surface of the film 14, similar to the force sensor 1 shown in Figure 1. The differences between the force sensor 1 shown in Figure 1 and the force sensor 1B according to this modified example are as follows.

[0053] Difference 1: In the force sensor 1 shown in Figure 1, a recess 12a is formed on the outer edge of the film 12, and a protrusion 11d is formed on the inner surface of the frame portion 11b. In contrast, in the force sensor 1B according to this modified example, no recess is formed on the outer edge of the film 12, and no protrusion is formed on the inner surface of the frame portion 11b. Instead, in the force sensor 1B according to this modified example, an alignment mark 12e is formed on the upper surface of the film 12, and an alignment mark 11e is formed on the inner surface of the frame portion 11b.

[0054] As a result, when laminating the film 12 to the upper surface of the beam portion 11c, the strain gauge 13 can be positioned in the correct location (directly above the beam portion 11c) by rotating the film 12 so that the alignment mark 12e formed on the film 12 aligns with the alignment mark 11e formed on the frame portion 11b. The method for forming the alignment marks 11e and 12e is, for example, printing, but is not limited to this. The method for forming the alignment marks 11e and 12e is arbitrary.

[0055] Difference 2: In the force sensor 1 shown in Figure 1, a recess 14a is formed on the outer edge of the film 14, and a protrusion 11d is formed on the inner surface of the frame portion 11b. In contrast, in the force sensor 1B according to this modified example, no recess is formed on the outer edge of the film 14, and no protrusion is formed on the inner surface of the frame portion 11b. Instead, in the force sensor 1B according to this modified example, an alignment mark 14e is formed on the lower surface of the film 14, and an alignment mark (not shown) is formed on the inner surface of the frame portion 11b.

[0056] As a result, when laminating the film 14 to the lower surface of the beam portion 11c, the strain gauge 15 can be positioned in the correct location (directly below the beam portion 11c) by rotating the film 12 so that the alignment mark 14e formed on the film 12 aligns with the alignment mark (not shown) formed on the frame portion 11b. The method for forming the alignment mark 14e is, for example, printing, but is not limited to this. The method for forming the alignment mark 14e is arbitrary.

[0057] (summary) A sensor device according to embodiment 1 of the present invention comprises a strain generating body and a film on which a plurality of strain gauges are formed, wherein the film is bonded to the strain generating body.

[0058] According to the above configuration, regardless of the shape and material of the strain-generating body, it is possible to realize a sensor device in which the time required to mount multiple strain gauges is short, and in which variations in the positional relationship of the multiple strain gauges are less likely to occur.

[0059] The sensor device according to embodiment 2 of the present invention is the sensor device according to embodiment 1, wherein the strain generating body has a columnar core portion, a cylindrical frame portion surrounding the core portion, and a beam portion connecting the core portion and the frame portion, and the film is bonded to the upper surface of the beam portion.

[0060] According to the above configuration, a sensor device is made which includes a strain-generating body having a core, a frame, and a beam, and which has a short time required for mounting multiple strain gauges and is less prone to variations in the positional relationship of the multiple strain gauges.

[0061] A sensor device according to embodiment 3 of the present invention is a sensor device according to embodiment 2, wherein the upper surface of the beam portion is lower than the upper surfaces of the core portion and the frame portion, and the film is arranged in a region sandwiched between the side surface of the core portion and the inner surface of the frame portion and is bonded to the upper surface of the beam portion.

[0062] With the above configuration, the entire film is completely housed within the space sandwiched between the side of the core and the inner surface of the frame, so even if the top surface of the sensor device is not covered with a cover, damage to the strain gauge due to contact with an object becomes less likely.

[0063] A sensor device according to aspect 4 of the present invention is a sensor device according to aspect 3, wherein a protrusion is formed on the inner surface of the frame portion and a recess is formed on the outer edge of the film that engages with the protrusion, or a recess is formed on the inner surface of the frame portion and a protrusion is formed on the outer edge of the film that engages with the recess.

[0064] With the above configuration, the alignment of the film and the strain-generating body, that is, the alignment of multiple strain gauges and the strain-generating body, can be easily achieved by appropriately rotating the film so that the recess formed on the outer edge of the film engages with the protrusion formed on the inner surface of the frame, or by appropriately rotating the film so that the protrusion formed on the outer edge of the film engages with the recess formed on the inner surface of the frame.

[0065] A sensor device according to aspect 5 of the present invention is a sensor device according to aspect 2 or aspect 3, wherein a first alignment mark is formed on the inner surface or upper surface of the frame portion, and a second alignment mark corresponding to the first alignment mark is formed on the upper surface of the film.

[0066] With the above configuration, by appropriately rotating the film so that the alignment marks formed on the upper surface of the film align with the alignment marks formed on the inner or upper surface of the frame, the alignment of the film and the strain generating body, that is, the alignment of multiple strain gauges and the strain generating body, can be easily achieved.

[0067] A sensor device according to embodiment 6 of the present invention is a sensor device according to any one embodiment of embodiments 2 to 5, wherein the film includes a first region on the upper surface of the beam portion where a first strain gauge is formed, and a second region on the side surface of the beam portion where a second strain gauge is formed, the second region being adjacent to the first region and surrounded by notches on three sides except for the boundary with the first region, and the film is folded such that the boundary line between the first region and the second region becomes a ridge line, the first region is bonded to the upper surface of the beam portion, and the second region is bonded to the side surface of the beam portion.

[0068] According to the above configuration, a sensor device in which strain gauges are arranged on the side of the beam section can be realized in which the time required to mount multiple strain gauges is short and in which variations in the relative positions of the multiple strain gauges are less likely to occur.

[0069] A sensor device according to embodiment 7 of the present invention further comprises another film on which other strain gauges are formed, the lower surface of the beam portion is higher than the lower surfaces of the core portion and the frame portion, and the other film is arranged in a region sandwiched between the side surface of the core portion and the inner surface of the frame portion and is bonded to the lower surface of the beam portion, as described in any one embodiment of embodiments 2 to 6.

[0070] According to the above configuration, a sensor device in which strain gauges are arranged on both sides of the strain generating body can be realized in which the time required to mount multiple strain gauges is short and in which variations in the relative positions of the multiple strain gauges are less likely to occur. Furthermore, since the entire film is completely housed inside the space sandwiched between the side of the core and the inner surface of the frame, damage to the strain gauges due to contact with objects is less likely to occur even if the bottom surface of the sensor device is not covered with a cover.

[0071] The film according to aspect 8 of the present invention is a film to be bonded to a strain-generating body, and has a plurality of strain gauges formed on it.

[0072] According to the above configuration, it is possible to realize a sensor device in which the time required to implement multiple strain gauges is short, and in which variations in the relative positions of the multiple strain gauges are less likely to occur.

[0073] [Additional Notes] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in each of the embodiments described above are also included within the technical scope of the present invention. [Explanation of symbols]

[0074] 1,1A,1B: Force sensor (sensor device), 11: Strain generating body, 11a: Core part, 11b: Frame part, 11c: Beam part, 11d: Convex part, 12,14: Film, 12a,14a: Concave part, 13,15: Strain gauge

Claims

1. Strain-generating body and, A film on which multiple strain gauges are formed, The film is bonded to the strain-generating body. Sensor device.

2. The strain generating body has a columnar core portion, a cylindrical frame portion surrounding the core portion, and a beam portion connecting the core portion and the frame portion. The film is bonded to the upper surface of the beam portion. The sensor device according to claim 1.

3. The upper surface of the beam portion is lower than the upper surfaces of the core portion and the frame portion. The film is positioned in a region sandwiched between the side surface of the core portion and the inner surface of the frame portion, and is bonded to the upper surface of the beam portion. The sensor device according to claim 2.

4. A protrusion is formed on the inner surface of the frame portion, and a recess is formed on the outer edge of the film that engages with the protrusion, or a recess is formed on the inner surface of the frame portion, and a protrusion is formed on the outer edge of the film that engages with the recess. The sensor device according to claim 3.

5. A first alignment mark is formed on the inner surface or upper surface of the frame portion, and a second alignment mark corresponding to the first alignment mark is formed on the upper surface of the film. The sensor device according to claim 2.

6. The film includes a first region on the upper surface of the beam portion where a first strain gauge is formed, and a second region on the side surface of the beam portion where a second strain gauge is formed, the second region being adjacent to the first region and surrounded by notches on three sides except for the boundary with the first region. The film is folded such that the boundary line between the first region and the second region becomes a ridge line, the first region is bonded to the upper surface of the beam portion, and the second region is bonded to the side surface of the beam portion. The sensor device according to claim 2.

7. Further comprising other films on which other strain gauges are formed, The lower surface of the beam portion is higher than the lower surfaces of the core portion and the frame portion. The other film is placed in the region sandwiched between the side surface of the core portion and the inner surface of the frame portion, and is bonded to the lower surface of the beam portion. The sensor device according to claim 2.

8. A film to be bonded to a strain-generating body, having multiple strain gauges formed on it. film.

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