JP2019152462A - Sensor device, force detector, and robot - Google Patents

Abstract

To provide a sensor device, a force detector and a robot with which it is possible to exhibit stable detection characteristics.SOLUTION: A sensor device comprises: a first member; a second member; a piezoelectric element arranged between the first and the second members; a first intermediate substrate arranged between the first member and the piezoelectric element; a second intermediate substrate arranged between the second member and the piezoelectric element; a first resin layer arranged between the first member and the first intermediate substrate; and a second resin layer arranged between the second member and the second intermediate substrate. A Young's modulus of the first resin layer is smaller than a Young's modulus of the first member and a Young's modulus of the first intermediate substrate, and a Young's modulus of the second resin layer is smaller than a Young's modulus of the second member and a Young's modulus of the second intermediate substrate.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sensor device, a force detection device, and a robot.

  The variable load detection pad, which is a sensor device described in Patent Document 1, includes a piezoelectric plate, a pair of electrode plates that sandwich the piezoelectric plate, a pair of insulating plates that sandwich the pair of electrode plates, and an electrode plate and an insulating plate. And an adhesive member for bonding them. In such a sensor device, when a compressive load in the thickness direction is received, a charge based on the magnitude of the received load is output from the pair of electrode plates.

JP 2011-43442 A

  Here, in order to improve the sensitivity of the sensor device as described above, the sensor device may be sandwiched between a pair of pressing members and used in a state where the sensor device is pressurized in the thickness direction. At that time, if the applied pressure is not uniformly applied to the surface of the sensor device, the output may become unstable.

  An object of the present invention is to provide a sensor device, a force detection device, and a robot that can exhibit stable detection characteristics.

One aspect of the present invention includes a first member,
A second member;
A piezoelectric element disposed between the first member and the second member;
A first intermediate substrate disposed between the first member and the piezoelectric element;
A second intermediate substrate disposed between the second member and the piezoelectric element;
A first resin layer disposed between the first member and the first intermediate substrate;
A second resin layer disposed between the second member and the second intermediate substrate,
The Young's modulus of the first resin layer is smaller than the Young's modulus of the first member and the Young's modulus of the first intermediate substrate,
The second resin layer is a sensor device having a Young's modulus smaller than that of the second member and Young's modulus of the second intermediate substrate.
As described above, the first resin layer is provided between the first member and the first intermediate substrate, and the second resin layer is provided between the second member and the second intermediate substrate. The uniformity of the pressure is increased, and the output value from the piezoelectric element is stabilized. Therefore, the sensor device can exhibit stable detection characteristics and can detect the received external force more accurately.

In one aspect of the present invention, it is preferable that the thickness of the first resin layer is equal to the thickness of the second resin layer.
As a result, the external force is transmitted in a balanced manner from both sides of the force detection element, so that the output value from the force detection element is stabilized. Therefore, the sensor device can exhibit stable detection characteristics and can detect the received external force more accurately.

In one embodiment of the present invention, the material of the first resin layer and the material of the second resin layer are preferably the same.
As a result, the external force is transmitted in a balanced manner from both sides of the force detection element, so that the output value from the force detection element is stabilized. Therefore, the sensor device can exhibit stable detection characteristics and can detect the received external force more accurately.

In one aspect of the present invention, it is preferable that the first resin layer and the second resin layer each contain a filler.
This makes it easy to control the thicknesses of the first and second resin layers and to control the characteristics (resin viscosity, coefficient of thermal expansion, etc.) of the first and second resin layers.

In one aspect of the present invention, the filler includes a first filler having a first maximum diameter, and a second filler having a second maximum diameter smaller than the first maximum diameter,
The Young's modulus of the first filler is preferably larger than the Young's modulus of the second filler.
Thereby, since a 1st filler functions as a gap material and it deform | transforms before a 1st filler deform | transforms when a 2nd filler receives a pressurization, a gap change (parallelism deviation | shift between planes) is suppressed.

In one aspect of the present invention, a frame-shaped member connected to the first member and the second member,
The frame member preferably has a frame shape surrounding the piezoelectric element.
This makes it difficult for pressure fluctuation factors to be applied from the outside when more pressure (pressurization) is applied.

In one aspect of the present invention, the first member and the second member are preferably made of a metal material.
As a result, the first member and the second member have relatively high rigidity and elastically deform appropriately when stress is applied. Therefore, an external force can be accurately transmitted to the piezoelectric element via the first member and the second member, and the risk of damage to the first member and the second member due to the external force can be reduced.

In one aspect of the present invention, it is preferable that the first resin layer and the second resin layer each have an insulating property.
Thereby, it can suppress that a force detection element and a 1st member conduct | electrically_connect through a 1st resin layer, and a force detection element and a 2nd resin layer conduct | electrically_connect through a 2nd resin layer. Therefore, the formation of an unintended electric path is suppressed, and the output value from the force detection element is stabilized. Therefore, the sensor device can exhibit stable detection characteristics, and can detect the received external force with higher accuracy.

In one aspect of the present invention, the first member and the first intermediate substrate are bonded via the first resin layer,
It is preferable that the second member and the second intermediate substrate are bonded via the second resin layer.
Thereby, since the attitude | position of the force detection element between a 1st member and a 2nd member is stabilized, an external force can be correctly transmitted to a force detection element via a 1st member and a 2nd member. Further, the pressure is uniformly applied to the force detection element, and the output value from the force detection element is stabilized. Therefore, the sensor device can exhibit stable detection characteristics and can detect the received external force more accurately.

In one aspect of the present invention, when the direction in which the first member and the second member are arranged is the first direction, and the direction orthogonal to the first direction is the second direction,
A conductive member disposed in line with the piezoelectric element in the second direction and in contact with the piezoelectric element;
It is preferable that the conductive member overlaps the second resin layer in plan view from the first direction.
Thereby, conduction between the second member and the connection member can be suppressed, and a highly reliable sensor device is obtained.

In one aspect of the present invention, it is preferable that each of the first intermediate substrate and the second intermediate substrate is made of quartz.
Thereby, it becomes the 1st, 2nd intermediate board which has high mechanical strength, and can transmit external force to a force detection element exactly.

In one aspect of the present invention, when the first direction is the direction in which the first member and the second member are aligned,
The piezoelectric element has a plurality of piezoelectric layers made of quartz arranged side by side in the first direction,
The crystal axis of the piezoelectric layer closest to the first intermediate substrate among the plurality of piezoelectric layers and the crystal axis of the first intermediate substrate coincide with each other,
It is preferable that the crystal axis of the piezoelectric layer closest to the second intermediate substrate among the plurality of piezoelectric layers and the crystal axis of the second intermediate substrate coincide with each other.
In this way, the thermal expansion of the first intermediate substrate is made to coincide with the crystal axis of the adjacent piezoelectric layer, and the crystal axis of the second intermediate substrate is made to coincide with the crystal axis of the adjacent piezoelectric layer. The coefficients can be made uniform, and the output drift due to thermal expansion can be effectively reduced.

In one aspect of the present invention, the first intermediate substrate has a thickness larger than the thickness of the piezoelectric layer closest to the first intermediate substrate among the plurality of piezoelectric layers,
It is preferable that the second intermediate substrate has a thickness larger than the thickness of the piezoelectric layer closest to the second intermediate substrate among the plurality of piezoelectric layers.
Thereby, a uniform pressure (pressurization) can be applied to the piezoelectric layer, and the impact resistance is also improved.

One aspect of the present invention includes a first base,
A second base;
And a sensor device according to one aspect of the present invention provided between the first base and the second base.
According to such a force detection device, since the sensor device according to one aspect of the present invention is provided, the external force can be detected with higher accuracy.

One embodiment of the present invention includes a base;
An arm connected to the base;
A force detection device according to one embodiment of the present invention.
According to such a robot, since the force detection device of one embodiment of the present invention is provided, more precise work can be executed.

1 is a plan view of a sensor device according to a first embodiment of the present invention. It is sectional drawing of the sensor device shown in FIG. It is sectional drawing of the force detection element which the sensor device shown in FIG. 1 has. FIG. 4 is a perspective view of the force detection element shown in FIG. 3. It is sectional drawing of the 1st resin layer and 2nd resin layer which the sensor device shown in FIG. 1 has. It is a perspective view of the force detection apparatus which concerns on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view of the force detection apparatus shown in FIG. It is a cross-sectional view of the force detection device shown in FIG. It is sectional drawing of the sensor device arrange | positioned at a force detection apparatus. It is a perspective view of the robot which concerns on 3rd Embodiment of this invention.

  Hereinafter, a sensor device, a force detection device, and a robot of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<First Embodiment>
First, the sensor device according to the first embodiment of the present invention will be described.

  FIG. 1 is a plan view of a sensor device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the sensor device shown in FIG. FIG. 3 is a cross-sectional view of a force detection element included in the sensor device shown in FIG. FIG. 4 is a perspective view of the force detection element shown in FIG. FIG. 5 is a cross-sectional view of the first resin layer and the second resin layer that the sensor device shown in FIG. 1 has.

  In the following, for convenience of explanation, three axes that are orthogonal to each other are referred to as an A axis, a B axis, and a C axis, and the tip side of an arrow indicating each axis is referred to as “plus side”, and the base end side is referred to as “minus side”. " The direction parallel to the A axis is the “A axis direction (first direction)”, the direction parallel to the B axis is the “B axis direction (second direction)”, and the direction parallel to the C axis is the “C axis direction”. That's it. Further, the positive side in the C axis direction is also referred to as “upper”, and the negative side in the C axis direction is also referred to as “lower”. Further, what is viewed from the C-axis direction (plan view of the base 21) is also referred to as “plan view”.

  A sensor device 1 illustrated in FIG. 1 includes a package 2 and a force detection element 3 (force detection unit) housed in the package 2. The sensor device 1 is used in a state where the force detection element 3 is pressurized with being sandwiched from the C-axis direction, for example, as in a force detection device 100 described later (see FIG. 9). Then, external forces (shearing force in the A-axis direction and shearing force in the B-axis direction) applied to the sensor device 1 are transmitted to the force detection element 3 via the package 2, and a signal (charge) based on the received external force is applied to the force detection element 3. Is output from.

  As shown in FIG. 1, the package 2 is substantially square in plan view. However, the planar view shape of the package 2 is not particularly limited, and may be any shape such as a circle, an ellipse, a triangle, a quadrangle other than a square (rectangle, parallelogram, trapezoid), a pentagon or more polygon, an irregular shape, and the like. There may be.

  As shown in FIG. 2, the package 2 includes a base body 21 and a lid body 24 (first member) joined to the base body 21. An airtight storage space S is formed inside the package 2, and the force detection element 3 is stored in the storage space S. By housing the force detection element 3 in the package 2, the force detection element 3 can be protected (dustproof and waterproof) from the outside. The atmosphere of the storage space S is not particularly limited, but is preferably in a vacuum state or a state close thereto (depressurized state). Specifically, the storage space S is preferably 0.01 Pa or more and 1000 Pa or less. However, the storage space S may be replaced with, for example, an inert gas such as nitrogen, argon, or helium in addition to the vacuum state.

  Further, as shown in FIG. 2, the base 21 has a base portion 22 (frame member) and a bottom member 23 (second member). The base 22 includes a recess 221 that opens to the upper surface, a recess 222 that opens to the lower surface, and a through-hole 223 that passes through the central portions of the bottom surfaces of the recesses 221 and 222. Therefore, the base 22 has a frame shape. The bottom member 23 has a plate shape and is joined to the bottom surface of the recess 222 so as to close the lower opening of the through hole 223. Therefore, the through hole 223 and the bottom member 23 form a recess 224 that opens at the center of the bottom surface of the recess 221. And the force detection element 3 is arrange | positioned so that it may insert in the recessed part 224. FIG.

  Further, as shown in FIG. 2, a plurality of internal terminals 27 are provided on the bottom surface of the recess 221, and a plurality of external terminals 28 electrically connected to the internal terminals 27 are provided on the bottom surface of the base 21. ing.

  The constituent material of the base 22 is preferably an insulating material. For example, oxide ceramics such as alumina and zirconia, carbide ceramics such as silicon carbide, and nitride ceramics such as silicon nitride. It is preferable to use various ceramics such as Thereby, it becomes the base 22 which has moderate rigidity and is excellent in insulation. Therefore, damage due to deformation of the package 2 hardly occurs, and the force detection element 3 housed inside can be reliably protected.

  In addition, the constituent material of the bottom member 23 is not particularly limited, and examples thereof include various metal materials such as stainless steel, Kovar, copper, iron, carbon steel, and titanium. Among them, Kovar is particularly preferable. . As a result, the bottom member 23 has a relatively high rigidity and elastically deforms moderately when stress is applied. Therefore, an external force can be accurately transmitted to the force detection element 3 via the bottom member 23, and the possibility of the bottom member 23 being damaged by the external force can be reduced. Further, since Kovar has a thermal expansion coefficient that is relatively close to that of the ceramic material that is the constituent material of the base portion 22, thermal stress (deflection due to the difference in thermal expansion coefficient between the base portion 22 and the bottom member 23) occurs in the base 21. It is difficult to effectively suppress output drift caused by thermal stress. There is also an advantage that it is easy to process into a flat surface at low cost.

  As shown in FIG. 2, the lid body 24 has a plate shape and is formed on the upper surface of the base portion 22 via the seal member 20 (joining member) so as to close the opening formed on the C axis plus side of the concave portion 221. It is joined. The sealing member 20 is not particularly limited as long as the base body 21 and the lid body 24 can be joined. For example, the sealing member 20 can be made of gold, silver, titanium, aluminum, copper, iron, or an alloy containing these. .

  The lid body 24 is located between the central portion 241, the outer edge portion 242 that surrounds the central portion 241 and forms a frame shape along the outer edge, and the connecting portion 243 that connects between the central portion 241 and the outer edge portion 242. And having. The lid body 24 is joined to the upper surface of the base portion 22 via the seal member 20 at the outer edge portion 242. Further, the central portion 241 is positioned so as to be shifted from the outer edge portion 242 to the side opposite to the bottom member 23 (C-axis direction plus side). The connecting portion 243 is inclined to connect the outer edge portion 242 and the central portion 241 and has a tapered shape whose width decreases toward the positive side in the C-axis direction. However, the shape of the lid body 24 is not particularly limited. For example, the connection portion 243 may have a straight shape with a constant width along the C-axis direction. Further, the lid body 24 may have a flat plate shape, or the central portion 241 may be recessed, contrary to the present embodiment.

  The constituent material of the lid 24 is not particularly limited, and includes various metal materials such as stainless steel, Kovar, copper, iron, carbon steel, titanium, etc., as in the case of the bottom member 23 described above. Particularly preferred is Kovar. As a result, as with the bottom member 23, the external force can be accurately transmitted by the force detection element 3, and damage to the lid body 24 due to the external force can be reduced. The constituent material of the lid 24 may be the same as or different from the constituent material of the bottom member 23, but is preferably the same. Thereby, the external force applied to the package 2 can be accurately transmitted by the force detection element 3.

  The force detection element 3 outputs a charge Qa (first charge) corresponding to the A-axis direction component of the external force applied to the force detection element 3 and a charge Qb (second charge) corresponding to the B-axis direction component. It has a function. As shown in FIG. 3, the force detection element 3 includes a piezoelectric element 30 and a pair of intermediate substrates 33 and 34 (first and second intermediate substrates) that sandwich the piezoelectric element 30 from the C-axis direction. The piezoelectric element 30 also outputs a first piezoelectric element 31 that outputs a charge Qa according to an external force (shearing force) in the A-axis direction, and a second piezoelectric element 30 that outputs a charge Qb according to an external force (shearing force) in the B-axis direction. And a piezoelectric element 32.

  The first piezoelectric element 31 has a ground electrode layer 311, a piezoelectric layer 312, an output electrode layer 313, a piezoelectric layer 314, a ground electrode layer 315, a piezoelectric layer 316, and an output electrode from the lower side (C-axis direction minus side). The layer 317, the piezoelectric layer 318, and the ground electrode layer 319 are stacked in this order. The second piezoelectric element 32 is laminated on the first piezoelectric element 31, and the ground electrode layer 321, the piezoelectric layer 322, the output electrode layer 323, and the piezoelectric layer from the lower side (minus side in the C-axis direction). 324, a ground electrode layer 325, a piezoelectric layer 326, an output electrode layer 327, a piezoelectric layer 328, and a ground electrode layer 329 are sequentially stacked. In the present embodiment, the ground electrode layers 319 and 321 are integrated (shared).

  The piezoelectric layers 312, 314, 316, 318, 322, 324, 326, 328 are each made of quartz. Thereby, the force detection element 3 having excellent characteristics such as high sensitivity, a wide dynamic range, and high rigidity is obtained. In the piezoelectric layers 312, 316, the X axis (electrical axis) that is the crystal axis of the crystal faces the right side (A axis direction plus side) in FIG. 3, and in the piezoelectric layers 314, 318, the X axis of the crystal is illustrated. 3 is directed to the left side (minus side in the A-axis direction). Further, in the piezoelectric layers 322 and 326, the X-axis of the crystal faces the back side (the B-axis direction plus side) in FIG. 3, and in the piezoelectric layers 324 and 328, the X-axis of the crystal is in FIG. It faces the near side (minus side in the B-axis direction). Each of these piezoelectric layers 312, 314, 316, 318, 322, 324, 326, 328 is constituted by a Y-cut quartz plate (a quartz plate having the Y axis (mechanical axis) of the quartz as a thickness direction). Yes.

However, the piezoelectric layers 312, 314, 316, 318, 322, 324, 326, and 328 may be configured using a piezoelectric material other than quartz. Examples of piezoelectric materials other than quartz include topaz, barium titanate, lead titanate, lead zirconate titanate (PZT: Pb (Zr, Ti) O ₃ ), lithium niobate, lithium tantalate, and the like.

  In addition, the ground electrode layers 311, 315, 319 (321), 325, and 329 are each electrically connected to a reference potential (for example, the ground potential GND). Then, the charge Qa corresponding to the component in the A-axis direction is output from the output electrode layers 313 and 317, and the charge Qb corresponding to the component in the B-axis direction is output from the output electrode layers 323 and 327. The constituent materials of the ground electrode layers 311, 315, 319 (321), 325, 329 and the output electrode layers 313, 317, 323, 327 are not particularly limited. For example, nickel, gold, titanium, aluminum, copper, Examples thereof include iron, chromium, alloys containing these, and the like, and one or more of these can be used in combination (for example, laminated).

  The pair of intermediate substrates 33 and 34 are arranged so as to sandwich the piezoelectric element 30 from above and below. Specifically, the intermediate substrate 33 is disposed on the upper surface of the piezoelectric element 30 and the intermediate substrate 34 is disposed on the lower surface. As a result, the ground electrode layers 311 and 329 can be covered with the intermediate substrates 33 and 34, and the ground electrode layers 311 and 329 can be protected, and the ground electrode layers 311 and 329 come into contact with the package 2 and are not intended. The occurrence of conduction can be suppressed. Further, the pressurization in the C-axis direction can be uniformly transmitted to the entire area of the piezoelectric element 30. The intermediate substrates 33 and 34 are bonded (bonded) to the piezoelectric element 30 via an adhesive or the like (not shown).

  The intermediate substrates 33 and 34 are made of quartz. Accordingly, the intermediate substrates 33 and 34 having high mechanical strength are obtained, and an external force can be accurately transmitted to the force detection element 3. Further, the intermediate substrate 33 has the same configuration as the adjacent piezoelectric layer 328. That is, the intermediate substrate 33 is formed of a Y-cut quartz plate like the piezoelectric layer 328, and the X-axis of the quartz faces the front side (the B-axis direction minus side) in FIG. Similarly, the intermediate substrate 34 has the same configuration as the adjacent piezoelectric layer 312. That is, the intermediate substrate 34 is formed of a Y-cut quartz plate like the piezoelectric layer 312, and the X-axis of the quartz faces the right side (A-axis direction plus side) in FIG. In this way, by making the crystal axis of the intermediate substrate 33 coincide with the crystal axis of the adjacent piezoelectric layer 328 and aligning the crystal axis of the intermediate substrate 34 with the crystal axis of the adjacent piezoelectric layer 312, these thermal expansions. The coefficients can be made uniform, and the output drift due to thermal expansion can be effectively reduced.

  The crystal axis of the intermediate substrate 33 and the crystal axis of the piezoelectric layer 328 coincide with each other when the crystal axis of the intermediate substrate 33 and the crystal axis of the piezoelectric layer 328 completely coincide with each other. This also includes the case where the crystal axis of the intermediate substrate 33 and the crystal axis of the piezoelectric layer 328 are slightly deviated (for example, within about 5 °) (for example, an error that may occur in manufacturing occurs). . Further, the crystal axis of the intermediate substrate 33 may not coincide with the crystal axis of the piezoelectric layer 328, and the crystal axis of the intermediate substrate 34 may not coincide with the crystal axis of the piezoelectric layer 312. In addition, each of the intermediate substrates 33 and 34 may be formed of a piezoelectric body other than quartz, or may be configured using a material having no electrical conductivity other than the piezoelectric body.

  Further, the intermediate substrate 33 has a thickness larger than the thickness of the piezoelectric layer 328 immediately below, and the intermediate substrate 34 has a thickness larger than the thickness of the piezoelectric layer 312 on the intermediate substrate 34 side immediately above. is doing. Therefore, a uniform pressure (pressurization) can be applied by the piezoelectric element 30, and the impact resistance is also improved.

  Moreover, as shown in FIG. 4, the whole shape of the force detection element 3 is a rectangular parallelepiped. That is, the force detection element 3 includes an upper surface 3a that is an upper surface of the intermediate substrate 33, a lower surface 3b that is a lower surface of the intermediate substrate 34, and four side surfaces 3c, 3d, 3e, and 3f that connect the upper surface 3a and the lower surface 3b. And having. However, the shape of the force detection element 3 is not particularly limited. For example, a cylindrical shape, a triangular prism shape, a quadrangular prism shape other than a square (rectangle, trapezoid, parallelogram, etc.), a polygonal prism shape more than a pentagonal prism shape, etc. Any shape is possible.

  On the side surface 3c facing the A-axis direction plus side, a connection electrode 391 electrically connected to each ground electrode layer 311, 315, 319 (321), 325, 329, and each output electrode layer 323, 327, Electrically connected connection electrodes 392 are provided side by side in the width direction (B-axis direction). Further, on the side surface 3e that faces the side surface 3c and faces the negative side in the A-axis direction, a connection electrode 393 electrically connected to the ground electrode layers 311, 315, 319 (321), 325, 329, and each output Connection electrodes 394 that are electrically connected to the electrode layers 313 and 317 are provided side by side in the width direction (B-axis direction).

  The connection electrode 391 is electrically connected to the internal terminal 27 via the connection member 261, the connection electrode 392 is electrically connected to the internal terminal 27 via the connection member 262, and the connection electrode 393 is connected to the internal terminal 27. The internal terminal 27 is electrically connected through the member 263, and the connection electrode 394 is electrically connected to the internal terminal 27 through the connection member 264. These connecting members 261, 262, 263, and 264 are not particularly limited, and for example, various metal pastes such as Ag paste, Cu paste, and Au paste can be used.

  However, the arrangement of the connection electrodes 391, 392, 393, and 394 is not particularly limited. For example, the connection electrodes 391, 392, 393, and 394 may be separately arranged on different side surfaces of the force detection element 3, or may be collectively arranged on one side surface of the force detection element 3. . Further, the connection electrodes 391, 392, 393, and 394 may be disposed on the upper surface 3a and the lower surface 3b of the force detection element 3.

  The force detection element 3 has been described above. As shown in FIG. 2, such a force detection element 3 is located between the bottom member 23 and the center portion 241 of the lid body 24, and a lower end portion thereof is inserted into the recess 224. A first resin layer 41 is provided between the force detection element 3 and the lid body 24, and a second resin layer 42 is provided between the force detection element 3 and the bottom member 23. Hereinafter, the first and second resin layers 41 and 42 will be described in detail.

  As shown in FIG. 2, the first resin layer 41 is located between the upper surface 3 a of the force detection element 3 (the upper surface of the intermediate substrate 33) and the central portion 241 of the lid body 24. Such a first resin layer 41 functions as an adhesive, and the upper surface 3 a of the force detection element 3 and the inner surface 240 of the lid body 24 are bonded (bonded) via the first resin layer 41. On the other hand, the second resin layer 42 is located between the lower surface 3 b (the lower surface of the intermediate substrate 34) of the force detection element 3 and the bottom member 23. Such a second resin layer 42 functions as an adhesive, and the lower surface 3 b of the force detection element 3 and the upper surface 231 of the bottom member 23 are bonded (bonded) via the second resin layer 42.

  In this manner, the force detection element 3 and the lid 24 are bonded using the first resin layer 41, and the force detection element 3 and the bottom member 23 are bonded using the second resin layer 42, whereby the package 2 The posture of the force detection element 3 inside is stabilized, and external force can be accurately transmitted to the force detection element 3 via the package 2 (the bottom member 23 and the lid body 24). Further, the pressure is applied uniformly to the force detection element 3, and the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can detect the received external force with higher accuracy. However, the first resin layer 41 does not have adhesiveness, and may be disposed between the force detection element 3 and the lid body 24 without being bonded thereto. Similarly, the second resin layer 42 does not have adhesiveness, and may be disposed between the force detection element 3 and the bottom member 23 without being bonded thereto.

  Further, the first resin layer 41 is arranged so as to include the entire area of the upper surface 3a in plan view. That is, the first resin layer 41 is bonded to the entire area of the upper surface 3a. Similarly, the 2nd resin layer 42 is arrange | positioned so that the whole region of the lower surface 3b may be included by planar view. That is, the second resin layer 42 is bonded to the entire area of the lower surface 3b. As a result, the local concentration of stress can be reduced (preferably prevented) more reliably, and the applied pressure is uniformly applied to the force detection element 3. Therefore, the output value from the force detection element 3 is stabilized, and the sensor device 1 can detect the received external force with higher accuracy. However, the first resin layer 41 may not be bonded to the entire area of the upper surface 3a, and the second resin layer 42 may not be bonded to the entire area of the lower surface 3b.

  The first resin layer 41 has a fillet portion 411 that goes around the side surfaces 3c, 3d, 3e, and 3f of the force detection element 3 and is bonded to the side surfaces 3c, 3d, 3e, and 3f. Similarly, the second resin layer 42 wraps around the side surfaces 3c, 3d, 3e, and 3f of the force detection element 3, and has a fillet portion 421 bonded to the side surfaces 3c, 3d, 3e, and 3f. Thereby, the force detection element 3, the cover body 24, and the bottom member 23 can be more firmly bonded. However, the first resin layer 41 may not have the fillet portion 411, and the second resin layer 42 may not have the fillet portion 421.

  Each of the first and second resin layers 41 and 42 has an insulating property. That is, each of the first and second resin layers 41 and 42 has a sufficiently high electric resistance value (for example, 100 MΩ or more). Thereby, it is suppressed that the force detection element 3 and the lid body 24 are electrically connected via the first resin layer 41 and the force detection element 3 and the bottom member 23 are electrically connected via the second resin layer 42. it can. Therefore, the formation of an unintended electric path is suppressed, and the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can detect the received external force with higher accuracy.

  As shown in FIGS. 1 and 2, the second resin layer 42 is located between the connection members 261, 262, 263, 264 and the bottom member 23, and further, the connection member 261, 262, 263, 264. Therefore, even if the connection members 261, 262, 263, 264 flow in the recess 224 and reach the bottom surface of the recess 224, the connection members 261, 262, 263, 264 and the bottom member are caused by the second resin layer 42. The contact with 23 is suppressed. Therefore, it is possible to effectively suppress the connection members 261, 262, 263, and 264 from being electrically connected via the bottom member 23, and the highly reliable sensor device 1 is obtained. In particular, in the present embodiment, since the second resin layer 42 is provided so as to cover the entire bottom surface of the recess 224, the bottom member 23 is not exposed in the recess 224, and the above-described effects are more remarkably exhibited. be able to. However, the second resin layer 42 may not overlap with the connection members 261, 262, 263, 264 in plan view.

  The first and second resin layers 41 and 42 may be made of the same material or may be made of different materials, but in the present embodiment, they are made of the same material. By configuring the first and second resin layers 41 and 42 with the same material, an external force is transmitted in a balanced manner from both sides of the force detection element 3, so that the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can detect the received external force with higher accuracy. Here, as will be described later, the first and second resin layers 41 and 42 have a resin material and a filler F dispersed in the resin material. 41 and 42 being made of the same material means that at least both use the same resin material, and preferably both use the same filler F and have the same content.

  Further, the thickness D1 of the first resin layer 41 and the thickness D2 of the second resin layer 42 are not particularly limited, but are preferably 1 μm to 100 μm, for example, and preferably 5 μm to 90 μm. Is more preferable. By using such thicknesses D1 and D2, force detection by providing the first and second resin layers 41 and 42 while sufficiently securing the mechanical strength of the first and second resin layers 41 and 42 is achieved. Transmission loss of external force to the element 3 can be reduced. Therefore, external force can be efficiently transmitted to the force detection element 3. The thickness D1 of the first resin layer 41 and the thickness D2 of the second resin layer 42 may be the same or different, but are the same in the present embodiment. That is, in the present embodiment, the relationship D1 = D2 is satisfied. Thus, by satisfying the relationship of D1 = D2, external force is transmitted in a balanced manner from both sides of the force detection element 3, so that the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can detect the received external force with higher accuracy.

  Note that the thickness D1 and the thickness D2 are equal to each other, for example, an error that may occur technically or an error that is unavoidable in manufacturing (for example, an error of about ± 5% or less). It means to include. Further, the thickness D1 means an average thickness of a portion of the first resin layer 41 sandwiched between the upper surface 3a of the force detection element 3 and the inner surface 240 of the lid 24. Similarly, the thickness D <b> 2 means the average thickness of the portion sandwiched between the lower surface 3 b of the force detection element 3 and the upper surface 231 of the bottom member 23 of the second resin layer 42.

  Further, the Young's modulus of the first resin layer 41 is smaller than the Young's modulus of the lid 24 (metal material) and the Young's modulus of the intermediate substrate 33 (quartz). The Young's modulus of the second resin layer 42 is smaller than the Young's modulus of the bottom member 23 (metal material) and the intermediate substrate 34 (crystal). The Young's modulus of the first and second resin layers 41 and 42 is not particularly limited as long as the above relationship is satisfied. For example, the pressure is 300 kg. In the case of the degree, it is preferably 1 GPa or more and 10 GPa or less, and more preferably 4 GPa or more and 6 GPa or less. By setting it as such a Young's modulus, an external force can be more efficiently transmitted to the force detection element 3. Moreover, it can suppress that the force detection element 3 and the base 22 are damaged by external force.

  As shown in FIG. 5, each of the first and second resin layers 41 and 42 includes a resin material and a filler F dispersed in the resin material. Moreover, the filler F has the 1st filler F1 and the 2nd filler F2. Each of the first and second resin layers 41 and 42 may appropriately include water, a solvent, a plasticizer, a curing agent, an antistatic agent, and the like.

  As the resin material, a material that can undergo a curing reaction is used. As such a resin material, for example, a plastic resin such as a thermoplastic resin or a thermoplastic resin, a curable resin such as a thermosetting resin, a photocurable resin, and an electron beam curable resin can be used. It is preferable to use a curable resin, and it is more preferable to use a thermosetting resin. Examples of the thermosetting resin include acrylic resins, phenolic resins, silicone resins, and epoxy resins. Among these, it is preferable to use epoxy resins. By using the epoxy resin, the first and second resin layers 41 and 42 having excellent tensile shear adhesive strength can be obtained.

  The first and second fillers F1 and F2 have different diameters, and the maximum diameter (maximum width, first maximum diameter) of the first filler F1 is the maximum diameter (maximum width, second width) of the second filler F2. Larger than the maximum diameter). Therefore, the first filler F1 functions as a gap material that controls the thicknesses D1 and D2 of the first and second resin layers 41 and 42. On the other hand, the second filler F2 has a function of controlling characteristics (elasticity, resin viscosity, coefficient of thermal expansion, etc.) of the resin material, not the thicknesses D1 and D2 of the first and second resin layers 41 and 42.

  Further, the Young's modulus of the first filler F1 is larger than the Young's modulus of the second filler F2. Thereby, when the 2nd filler F2 receives a pressurization, since it deform | transforms before the 1st filler F1 deform | transforms, a gap change (shift in parallelism between surfaces) is suppressed.

The constituent materials of the first and second fillers F1 and F2 are not particularly limited. For example, inorganic materials such as inorganic oxides such as silica (SiO ₂ ) and alumina (Al ₂ O ₃ ), ceramics, and glass can be used. It is preferable to use a filler, and one or more of these can be used in combination. Of these, silica, alumina, and hollow glass beads are preferably used as the constituent materials of the first and second fillers F1 and F2. Thereby, the mechanical strength and heat resistance of the first and second resin layers 41 and 42 can be increased. Further, the first and second fillers F1 and F2 are preferably non-conductive (insulating). Especially as the second filler F2. It is preferable to use hollow glass beads. Thereby, the thermal expansion coefficient of the 1st, 2nd resin layers 41 and 42 can be reduced, suppressing the increase in the elasticity modulus of the 1st, 2nd resin layers 41 and 42. FIG. Moreover, the residual stress of the 1st, 2nd resin layers 41 and 42 can also be reduced.

  The shape of the first and second fillers F1 and F2 is not particularly limited, but is preferably spherical. By making the first and second fillers F1 and F2 spherical, it is easy to classify the first and second fillers F1 and F2 to make the diameters uniform. Therefore, the thicknesses D1 and D2 of the first and second resin layers 41 and 42 can be controlled with higher accuracy, and the characteristics of the first and second resin layers 41 and 42 can be controlled with higher accuracy. . However, the shape of the first and second fillers F1 and F2 is not limited to a spherical shape, and for example, a rectangular shape, a plate shape, a needle shape, a leaf shape, or the like can be used. The first and second fillers F1 and F2 may be dense bodies or porous bodies.

  The sensor device 1 has been described above. As described above, the sensor device 1 includes the lid 24 (first member), the bottom member 23 (second member), and the piezoelectric element disposed between the lid 24 and the bottom member 23. 30, an intermediate substrate 33 (first intermediate substrate) disposed between the lid 24 and the piezoelectric element 30, and an intermediate substrate 34 (second intermediate substrate) disposed between the bottom member 23 and the piezoelectric element 30. An intermediate substrate), a first resin layer 41 disposed between the lid 24 and the intermediate substrate 33, and a second resin layer 42 disposed between the bottom member 23 and the intermediate substrate 34. Have. The Young's modulus of the first resin layer 41 is smaller than the Young's modulus of the lid 24 and the Young's modulus of the intermediate substrate 33, and the Young's modulus of the second resin layer 42 is the Young's modulus of the bottom member 23 and the Young's modulus of the intermediate substrate 34. Less than rate. As described above, the first resin layer 41 is provided between the lid 24 and the intermediate substrate 33, and the second resin layer 42 is provided between the bottom member 23 and the intermediate substrate 34. The uniformity of the pressurization increases, the pressurization is applied uniformly, and the output value from the piezoelectric element 30 is stabilized. Therefore, the sensor device 1 can exhibit stable detection characteristics and can detect the received external force with higher accuracy.

  Further, as described above, in the sensor device 1, the thickness D1 of the first resin layer 41 and the thickness D2 of the second resin layer 42 are equal. Thus, by satisfying the relationship of D1 = D2, external force is transmitted in a balanced manner from both sides of the force detection element 3, so that the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can exhibit stable detection characteristics and can detect the received external force with higher accuracy.

  Further, as described above, in the sensor device 1, the material of the first resin layer 41 and the material of the second resin layer 42 are the same. As described above, by configuring the first resin layer 41 and the second resin layer 42 with the same material, the external force is transmitted in a balanced manner from both sides of the force detection element 3, so that the output value from the force detection element 3 is stable. To do. Therefore, the sensor device 1 can exhibit stable detection characteristics and can detect the received external force with higher accuracy.

  Further, as described above, each of the first resin layer 41 and the second resin layer 42 includes the filler F. Thereby, the thicknesses D1 and D2 of the first and second resin layers 41 and 42 are controlled, and the characteristics (resin viscosity, thermal expansion coefficient, etc.) of the first and second resin layers 41 and 42 are controlled. It becomes easy.

  Moreover, as described above, the filler F includes the first filler F1 having the first maximum diameter and the second filler RF2 having the second maximum diameter smaller than the first maximum diameter, and the first filler The Young's modulus of F1 is larger than the Young's modulus of the second filler F2. As a result, the first filler F1 functions as a gap material, and the first filler F1 is deformed before it is deformed when the second filler F2 is pressurized. Is done.

  Further, as described above, the sensor device 1 includes the base portion 22 (frame member) connected to the lid body 24 and the bottom member 23, and the base portion 22 has a frame shape surrounding the piezoelectric element 30. This makes it difficult for pressure fluctuation factors to be applied from the outside when more pressure (pressurization) is applied.

  As described above, the lid body 24 and the bottom member 23 are made of a metal material. As a result, the lid 24 and the bottom member 23 have relatively high rigidity and elastically deform appropriately when stress is applied. Therefore, it is possible to accurately transmit an external force to the force detection element 3 via the lid 24 and the bottom member 23, and it is possible to reduce the risk of the lid 23 and the bottom member 23 being damaged by the external force.

  Further, as described above, each of the first resin layer 41 and the second resin layer 42 has an insulating property. Thereby, it is suppressed that the force detection element 3 and the lid body 24 are electrically connected via the first resin layer 41 and the force detection element 3 and the bottom member 23 are electrically connected via the second resin layer 42. it can. Therefore, the formation of an unintended electric path is suppressed, and the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can exhibit stable detection characteristics and can detect the received external force with higher accuracy.

  Further, as described above, the lid body 24 and the intermediate substrate 33 are bonded via the first resin layer 41, and the bottom member 23 and the intermediate substrate 34 are bonded via the second resin layer 42. ing. Thereby, since the attitude | position of the force detection element 3 in the package 2 is stabilized, external force can be accurately transmitted to the force detection element 3 via the package 2 (the bottom member 23 and the cover body 24). Further, the pressure is applied uniformly to the force detection element 3, and the output value from the force detection element 3 is stabilized. Therefore, the sensor device 1 can exhibit stable detection characteristics and can detect the received external force with higher accuracy.

  As described above, when the direction in which the lid body 24 and the bottom member 23 are arranged is the C-axis direction (first direction) and the direction orthogonal to the C-axis direction is the A-axis direction (second direction), the sensor The device 1 includes connecting members 261, 262, 263, and 264 (conductive members) that are arranged side by side with the piezoelectric element 30 and are in contact with the piezoelectric element 30. The connection members 261, 262, 263, and 264 overlap with the second resin layer 42 in plan view from the C-axis direction, respectively. Therefore, even if the connection members 261, 262, 263, 264 flow to the bottom member 23 side and reach the bottom member 23, the connection members 261, 262, 263, 264 and the bottom member are caused by the second resin layer 42. The contact with 23 can be suppressed. Therefore, it is possible to effectively suppress the connection members 261, 262, 263, and 264 from being electrically connected via the bottom member 23, and the highly reliable sensor device 1 is obtained.

  Further, as described above, each of the intermediate substrate 33 and the intermediate substrate 34 is made of quartz. Accordingly, the intermediate substrates 33 and 34 having high mechanical strength are obtained, and an external force can be accurately transmitted to the force detection element 3.

  Further, as described above, when the direction in which the lid body 24 and the bottom member 23 are arranged is the C-axis direction (first direction), the piezoelectric element 30 includes a plurality of quartz crystals arranged in the C-axis direction. Piezoelectric layers 312, 314, 316, 318, 322, 324, 326, and 328. Of the plurality of piezoelectric layers 312, 314, 316, 318, 322, 324, 326, 328, the crystal axis of the piezoelectric layer 328 closest to the intermediate substrate 33 and the crystal axis of the intermediate substrate 33 are The crystal axis of the piezoelectric layer 312 closest to the intermediate substrate 34 among the plurality of piezoelectric layers 312, 314, 316, 318, 322, 324, 326, 328, the crystal axis of the intermediate substrate 34, Match. In this way, by making the crystal axis of the intermediate substrate 33 coincide with the crystal axis of the adjacent piezoelectric layer 328 and aligning the crystal axis of the intermediate substrate 34 with the crystal axis of the adjacent piezoelectric layer 312, these thermal expansions. The coefficients can be made uniform, and the output drift due to thermal expansion can be effectively reduced.

  Further, as described above, the intermediate substrate 33 is larger than the thickness of the piezoelectric layer 328 that is closest to the intermediate substrate 33 among the plurality of piezoelectric layers 312, 314, 316, 318, 322, 324, 326, and 328. The intermediate substrate 34 has a thickness larger than the thickness of the piezoelectric layer 312 closest to the intermediate substrate 34 among the plurality of piezoelectric layers 312, 314, 316, 318, 322, 324, 326, and 328. Have Therefore, a uniform pressure (pressurization) can be applied by the piezoelectric layers 312, 314, 316, 318, 322, 324, 326, and 328, and the impact resistance is improved.

Second Embodiment
Next, a force detection device according to a second embodiment of the present invention will be described.

  FIG. 6 is a perspective view of a force detection device according to the second embodiment of the present invention. 7 is a longitudinal sectional view of the force detection device shown in FIG. FIG. 8 is a cross-sectional view of the force detection device shown in FIG. FIG. 9 is a cross-sectional view of a sensor device arranged in the force detection device.

  Also, in the following, for convenience of explanation, the three axes orthogonal to each other are referred to as an α axis, a β axis, and a γ axis, the tip side of the arrow indicating each axis is referred to as “plus side”, and the base end side is referred to as “minus side”. . A direction parallel to the α axis is referred to as “α axis direction”, a direction parallel to the β axis is referred to as “β axis direction”, and a direction parallel to the γ axis is referred to as “γ axis direction”. The positive side in the γ-axis direction is also referred to as “upper”, and the negative side in the γ-axis direction is also referred to as “lower”. Also, what is viewed from the γ-axis direction is called “plan view”.

  A force detection device 100 illustrated in FIG. 6 is a six-axis force sensor that can detect a six-axis component of an external force applied to the force detection device 100. The six-axis component includes translational force (shearing force) components in directions of three axes orthogonal to each other (the α-axis, β-axis, and γ-axis in the figure), and rotational force around each of these three axes. (Moment) component.

  The force detection apparatus 100 accommodates a plurality (four in this embodiment) of sensor devices 1 arranged at equal intervals (90 ° intervals) around the central axis A1 (γ axis), and these sensor devices 1. A case 5. The force detection device 100 outputs detection signals corresponding to the external force received by each sensor device 1 and processes those detection signals to detect six-axis components of the external force applied to the force detection device 100. Can do. Hereinafter, each part with which the force detection apparatus 100 is provided is demonstrated.

[Case]
As shown in FIG. 6, the case 5 includes a first case member 6, a second case member 7 disposed at a distance from the first case member 6, and the first case member 6 and the second case. And a side wall portion 8 provided on the outer peripheral portion of the member 7.

  As shown in FIG. 7, the first case member 6 is provided on the top plate 61 (first base) and the lower surface of the top plate 61, and is arranged at equal intervals (90 ° intervals) around the central axis A1. And four wall portions 62 (first pressurizing portions). Further, the top plate 61 is formed with a through-hole 611 along the central axis A1 at the center thereof. Further, as shown in FIG. 8, each wall portion 62 is formed with a plurality of through holes 621 into which pressurizing bolts 50 described later are inserted. Further, the inner wall surface 620 (inner surface) of each wall portion 62 is a plane perpendicular to the top plate 61.

  Further, as shown in FIG. 7, the second case member 7 is provided on the bottom plate 71 (second base) and the top surface of the bottom plate 71 and around the central axis A1 so as to face the four wall portions 62 described above. And four wall portions 72 (second pressurizing portions) arranged at equal intervals (90 ° intervals). Further, the bottom plate 71 is formed with a through hole 711 along the central axis A1 at the center thereof. Moreover, each wall part 72 has the protrusion part 73 protruded toward the wall part 62 side which opposes, The top surface 730 of this protrusion part 73 is parallel to the inner wall surface 620, and with respect to the inner wall surface 620, They face each other at a predetermined distance (a distance at which the sensor device 1 can be inserted). Further, as shown in FIG. 8, each wall portion 72 is formed with a plurality of female screw holes 721 into which the tip ends of the pressurizing bolts 50 are screwed.

  Further, the side wall portion 8 has a cylindrical shape, and the upper end portion and the lower end portion thereof are fixed to the first case member 6 and the second case member 7 by, for example, screwing or fitting. Further, in the space S1 (internal space of the force detection device 100) surrounded by the side wall portion 8, the top plate 61 of the first case member 6 and the bottom plate 71 of the second case member 7, four sensor devices 1 are provided. It is stored.

  In the case 5 as described above, the upper surface 60 of the first case member 6 functions as an attachment surface attached to, for example, an end effector 1700 (attached member) included in the robot 1000 described later, and the lower surface 70 of the second case member 7. However, for example, it functions as an arm attachment surface that is attached to a robot arm 1200 included in the robot 1000 described later.

  Note that the outer shapes of the case 5 in plan view are each circular, but are not limited thereto, and may be any shape such as a polygon such as a triangle, a quadrangle, and a pentagon, an ellipse, and an irregular shape. . In the present embodiment, each wall 62 is formed as a member separate from the top plate 61 and is fixed to the top plate 61, but is not limited thereto, and is formed integrally with the top plate 61. Also good. Similarly, in the present embodiment, each wall portion 72 is formed as a separate member from the bottom plate 71 and is fixed to the bottom plate 71, but is not limited thereto, and may be formed integrally with the bottom plate 71. .

  Moreover, it does not specifically limit as a constituent material of the 1st case member 6, the 2nd case member 7, and the side wall part 8, respectively, For example, metal materials, such as aluminum and stainless steel, ceramics, etc. can be used. In addition, the constituent material of the 1st case member 6, the 2nd case member 7, and the side wall part 8 may mutually be the same, and may differ.

  As shown in FIG. 8, the four sensor devices 1 are arranged so as to be symmetric with respect to a line segment CL that passes through the central axis A1 and is parallel to the β axis in plan view. Further, as shown in FIG. 7, each sensor device 1 is located between the top plate 61 and the bottom plate 71. Each sensor device 1 is positioned between the wall portion 62 and the wall portion 72 (projecting portion 73), and is sandwiched between the wall portion 62 and the wall portion 72 (projecting portion 73). Specifically, as shown in FIG. 9, each sensor device 1 has the wall portions 62, 72 with the base 21 of the package 2 facing the wall portion 72 and the lid 24 facing the wall portion 62. It is arranged between. Further, the bottom member 23 of the base 21 is in contact with the top surface 730 of the protruding portion 73, and the central portion 241 of the lid body 24 is in contact with the inner wall surface 620 of the wall portion 62.

  As shown in FIG. 8, the pressurizing bolt 50 connects the wall portion 62 and the wall portion 72, and thereby the first case member 6 and the second case member 7 are fixed. In addition, when the pressurizing bolt 50 is tightened, the sensor device 1 (force detecting element 3) positioned between the wall portion 62 and the wall portion 72 is pressurized. That is, in the natural state, a compressive force in the direction indicated by the arrow P in FIG. In this way, by preloading the force detection element 3 in the natural state, it is possible to accurately detect the six-axis components of the external force applied to the force detection device 100. The pressurizing force applied to the force detecting element 3 can be adjusted by appropriately adjusting the fastening force of the pressurizing bolt 50.

  A pair of pressurizing bolts 50 are provided for each sensor device 1, and the pair of pressurizing bolts 50 are located on both sides of the sensor device 1. However, the arrangement of the pressurizing bolt 50 is not particularly limited. Further, the pressurizing bolt 50 may be provided as necessary, and may be omitted if unnecessary.

  Such a force detection device 100 has an external force detection circuit (not shown), and the external force detection circuit is based on the signals (charges Qa and Qb) output from each sensor device 1 and translate force components in the α-axis direction. Fα, translational force component Fβ in the β-axis direction, translational force component Fγ in the γ-axis direction, rotational force component Mα around the α-axis, rotational force component Mβ around the β-axis, and rotational force component Mγ around the γ-axis are detected (calculated) )can do. The external force detection circuit includes, for example, an analog circuit including a charge / voltage conversion circuit that converts charges Qa and Qb into voltages, an AD converter that converts an output from the analog circuit into a digital signal, and a CPU connected to the AD converter And a digital circuit provided with an arithmetic circuit such as the above.

  The force detection device 100 has been described above. As described above, the force detection device 100 includes the top plate 61 (first base), the bottom plate 71 (second base), and the sensor device 1 (the main device) provided between the top plate 61 and the bottom plate 71. An inventive sensor device). According to such a force detection apparatus 100, since the sensor device 1 is provided, an external force can be detected with higher accuracy.

<Third Embodiment>
Next, a robot according to a third embodiment of the invention will be described.

  FIG. 10 is a perspective view of a robot according to the third embodiment of the present invention.

  The robot 1000 shown in FIG. 10 can perform operations such as feeding, removing, transporting, and assembling of precision instruments and objects such as parts constituting the precision equipment. This robot 1000 is a single-arm robot, and is a so-called 6-axis vertical articulated robot. The robot 1000 includes a base 1100, a robot arm 1200 rotatably connected to the base 1100, a force detection device 100, and an end effector 1700.

  The base 1100 is a part fixed on, for example, a floor, a wall, a ceiling, and a movable carriage. The robot arm 1200 includes an arm 1210 (first arm), an arm 1220 (second arm), an arm 1230 (third arm), an arm 1240 (fourth arm), an arm 1250 (fifth arm), and an arm 1260 (sixth arm). Arm). These arms 1210 to 1260 are connected in this order from the proximal end side to the distal end side. Each arm 1210 to 1260 is rotatable with respect to an adjacent arm or base 1100.

  The force detection device 100 is connected to the tip of the arm 1260. The force detection device 100 detects a force (including a moment) applied to the end effector 1700 attached to the tip of the force detection device 100. The end effector 1700 is an instrument that performs work on a target object that is a work target of the robot 1000, and includes a hand that has a function of gripping the target object. The end effector 1700 may be an instrument according to the work content of the robot 1000, and is not limited to a hand. For example, the end effector 1700 is a screw tightening instrument that performs screw tightening or a fitting instrument that performs fitting. Also good.

  Although not shown, the robot 1000 includes a drive unit including a motor that rotates one arm with respect to the other arm (or the base 1100). The robot 1000 includes an angle sensor that detects the rotation angle of the rotation shaft of the motor, although not shown.

  The robot 1000 has been described above. As described above, the robot 1000 includes the base 1100, the robot arm 1200 (arm) connected to the base 1100, and the force detection device 100 (the force detection device of the present invention). Since the robot 1000 includes the force detection device 100, for example, an external force detected by the force detection device 100 is fed back to a control unit (not shown) having a function of controlling the robot 1000. Thus, the work can be executed more precisely. Further, the robot 1000 can detect contact of the end effector 1700 with an obstacle by the external force detected by the force detection device 100. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like can be easily performed, and the robot 1000 can perform work more safely.

  The force detection device 100 may be provided between adjacent arms (for example, between the arms 1240 and 1250). The robot 1000 may be another robot such as a scalar robot or a double-arm robot. The number of arms that the robot 1000 has is six in this embodiment, but is not limited thereto, and may be 1 to 5 or 7 or more.

  As described above, the sensor device, the force detection device, and the robot of the present invention have been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each unit may be any arbitrary function having the same function. It can be replaced with that of the configuration. In addition, any other component may be added to the present invention. In addition, the sensor device and the force detection device of the present invention can be incorporated in equipment other than the robot, and may be installed in a moving body such as an automobile.

  DESCRIPTION OF SYMBOLS 1 ... Sensor device, 2 ... Package, 20 ... Sealing member, 21 ... Base | substrate, 22 ... Base part, 221, 222, 224 ... Recessed part, 223 ... Through-hole, 23 ... Bottom member, 231 ... Top surface, 24 ... Cover body, 240 ... inner surface, 241 ... central portion, 242 ... outer edge portion, 243 ... connection portion, 261, 262, 263, 264 ... connection member, 27 ... internal terminal, 28 ... external terminal, 3 ... force detection element, 3a ... upper surface, 3b ... lower surface, 3c, 3d, 3e, 3f ... side face, 30 ... piezoelectric element, 31 ... first piezoelectric element, 311, 315, 319 ... ground electrode layer, 312, 314, 316, 318 ... piezoelectric layer, 313, 317 ... output electrode layer, 32 ... second piezoelectric element, 321, 325, 329 ... ground electrode layer, 322, 324, 326, 328 ... piezoelectric layer, 323, 327 ... output electrode layer, 33, 34 ... intermediate group , 391, 392, 393, 394 ... connection electrode, 41 ... first resin layer, 411 ... fillet part, 42 ... second resin layer, 421 ... fillet part, 5 ... case, 50 ... pressurizing bolt, 6 ... first Case member 60 ... Upper surface 61 ... Top plate, 611 ... Through hole, 62 ... Wall portion, 620 ... Inner wall surface, 621 ... Through hole, 7 ... Second case member, 70 ... Lower surface, 71 ... Bottom plate, 711 ... Through Hole: 72 ... Wall part, 721 ... Female screw hole, 73 ... Projection part, 730 ... Top face, 8 ... Side wall part, 100 ... Force detection device, 1000 ... Robot, 1100 ... Base, 1200 ... Robot arm, 1210, 1220, 1230, 1240, 1250, 1260 ... arm, 1700 ... end effector, A1 ... central axis, CL ... line segment, D1, D2 ... thickness, F ... filler, F1 ... first filler, F2 ... second filler GND ... ground potential, P ... arrows, Qa, Qb ... charge, S ... accommodation space, S1 ... space

Claims (15)

A first member;
A second member;
A piezoelectric element disposed between the first member and the second member;
A first intermediate substrate disposed between the first member and the piezoelectric element;
A second intermediate substrate disposed between the second member and the piezoelectric element;
A first resin layer disposed between the first member and the first intermediate substrate;
A second resin layer disposed between the second member and the second intermediate substrate,
The Young's modulus of the first resin layer is smaller than the Young's modulus of the first member and the Young's modulus of the first intermediate substrate,
A sensor device, wherein the Young's modulus of the second resin layer is smaller than the Young's modulus of the second member and the Young's modulus of the second intermediate substrate.   The sensor device according to claim 1, wherein a thickness of the first resin layer is equal to a thickness of the second resin layer.   The sensor device according to claim 1, wherein a material of the first resin layer and a material of the second resin layer are the same.   The sensor device according to any one of claims 1 to 3, wherein each of the first resin layer and the second resin layer includes a filler. The filler includes a first filler having a first maximum diameter, and a second filler having a second maximum diameter smaller than the first maximum diameter,
The sensor device according to claim 4, wherein the Young's modulus of the first filler is larger than the Young's modulus of the second filler. A frame-like member connected to the first member and the second member;
The sensor device according to claim 1, wherein the frame-shaped member has a frame shape surrounding the piezoelectric element.   The sensor device according to claim 1, wherein the first member and the second member are made of a metal material.   The sensor device according to claim 1, wherein each of the first resin layer and the second resin layer has an insulating property. The first member and the first intermediate substrate are bonded via the first resin layer,
The sensor device according to claim 1, wherein the second member and the second intermediate substrate are bonded via the second resin layer. When the direction in which the first member and the second member are arranged is the first direction, and the direction orthogonal to the first direction is the second direction,
A conductive member disposed in line with the piezoelectric element in the second direction and in contact with the piezoelectric element;
The sensor device according to claim 1, wherein the conductive member overlaps the second resin layer in a plan view from the first direction.   The sensor device according to any one of claims 1 to 10, wherein each of the first intermediate substrate and the second intermediate substrate is made of quartz. When the direction in which the first member and the second member are aligned is the first direction,
The piezoelectric element has a plurality of piezoelectric layers made of quartz arranged side by side in the first direction,
The crystal axis of the piezoelectric layer closest to the first intermediate substrate among the plurality of piezoelectric layers and the crystal axis of the first intermediate substrate coincide with each other,
The sensor device according to claim 11, wherein a crystal axis of a piezoelectric layer closest to the second intermediate substrate among the plurality of piezoelectric layers and a crystal axis of the second intermediate substrate coincide with each other. The first intermediate substrate has a thickness larger than the thickness of the piezoelectric layer located closest to the first intermediate substrate among the plurality of piezoelectric layers,
The sensor device according to claim 12, wherein the second intermediate substrate has a thickness larger than a thickness of the piezoelectric layer that is closest to the second intermediate substrate among the plurality of piezoelectric layers. A first base;
A second base;
A force detection device comprising: the sensor device according to claim 1 provided between the first base and the second base. The base,
An arm connected to the base;
A robot comprising: the force detection device according to claim 14.

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