JP2013130432A - Sensor device, sensor module, force detection device and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor device, a sensor module, a force detection device and a robot, capable of cutting off a sensor element from external environment and increasing pressure sensitivity of the sensor element so that a force can be detected with high accuracy.SOLUTION: A sensor device 10 includes: a sensor element 42 having a piezoelectric body; a first member 12 at which the sensor element 42 is arranged; a second member 34 abutting on a second face opposite to a first face of the sensor element 42 on which the first member 12 abuts; and a coating part 40 that coats a side face different from the first and second faces of the sensor element 42. The coating part 40 coats part of the first member 12 and part of the side face of the second member 34.

Description

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

  Conventionally, the thing of patent document 1 was known as a force sensor using a piezoelectric material. As shown in FIG. 4 of Patent Document 1, the signal electrode 15 shown in FIG. 15 of Patent Document 1 is sandwiched by a crystal disk 16 that is a piezoelectric material, and is further sandwiched by a metal cover disk 17. A plurality of force sensors arranged by welding in the metal ring 14 is disclosed.

  FIG. 10 shows a conventional sensor device. As shown in FIG. 10, the sensor device 200 includes a sensor element 214 that sandwiches the electrode plate 218 with two crystal plates 216 having the same cut surface facing each other, and a metal device that houses the sensor element 214. The package 202 and the metal lid 204 that is bonded to the upper surface 224 that is the outer periphery of the opening 220 in the concave portion of the package 202 and that abuts on the crystal plate 216 constitute the whole. A coaxial connector 206 is attached to the side surface of the package 202. The coaxial connector 206 has an outer peripheral portion 208 and a center conductor 210, and an insulating resin 212 is filled between them, so that the outer peripheral portion 208 and the central conductor 210 are electrically insulated. The outer peripheral portion 208 is short-circuited with the package 202 and the lid 204, and the central conductor 210 is electrically connected to the electrode plate 218.

  The sensor device 200 is sandwiched between pressurization plates (not shown) and given pressurization, and the crystal plate 216 outputs (induces) electric charges to the electrode plate 218 due to the piezoelectric effect accompanying the pressurization. Then, the pressure applied to the crystal plate 216 changes according to the external force applied to the pressurizing plate. Therefore, the external force applied to the sensor device 200 can be detected by monitoring the change amount of the output charge due to the change in pressure through the coaxial connector 206.

  Here, in the sensor device 200, the sensor element 214 is sealed by the lid 204 in a state where the inside of the package 202 is filled with dry air so that the charge induced from the crystal plate 216 does not leak to the outside due to moisture or the like. ing.

Japanese Unexamined Patent Publication No. Hei 4-231827

  The force sensor disclosed in Patent Document 1 has a structure in which a signal electrode is sandwiched between crystal disks and this crystal disk is sandwiched between metal cover disks. When this is attached to the metal ring by welding, there is a dimensional error in individual parts such as signal electrodes, which becomes unevenness in the welded portion, and there is a possibility that a gap is generated in the welding. Therefore, in a situation where the external environment is inferior, such as high humidity, there is a possibility that the charge leaks to the outside due to the intrusion of moisture into the sensor element, making stable measurement difficult. Further, the method of sealing the measuring element by laser welding or the like is a complicated process and has a problem that it is difficult to apply to mass production.

  Further, the conventional sensor device shown in FIG. 10 has the following problems when the sensor element is accommodated in the package. In the manufacturing process of the package and the sensor element, the package has a dimensional error of several tens of μm, and the sensor element has a dimensional error of several μm, resulting in manufacturing variations based on such a dimensional error. For this reason, it has been difficult to adjust the internal height of the package (the height from the bottom surface of the package to the lid) and the height of the sensor element to be exactly equal.

  11A and 11B are explanatory views of a conventional sensor device in which manufacturing variations have occurred. FIG. 11A shows a case where the upper surface of the sensor element is lower than the position of the outer periphery of the opening of the recess of the package, and FIG. The case where the upper surface of an element becomes higher than the position used as the outer periphery of the opening part of the recessed part of a package is shown.

  As shown in FIG. 11A, when the height of the upper surface 222 of the sensor element 214 is lower than the height of the upper surface 224, when the lid 204 is joined to the package 202, the lid 204 and the upper surface 222 of the sensor element 214 are aligned. A gap 226 is formed without contact. 11B, when the height of the upper surface 222 of the sensor element 214 is higher than the height of the upper surface 224 that is the outer periphery of the opening 220 of the recess of the package 202, the lid 204 is bonded to the package 202. Then, as shown in FIG. That is, the center portion of the lid 204 is raised, and the periphery of the upper surface 222 of the sensor element 214 contacts the lid 204, but a gap 228 is formed between the center portion of the upper surface 222 of the sensor element 214 and the lid 204. Is done.

  Thus, when the upper surface of the sensor element is lower than the position that is the outer periphery of the opening of the recess of the package, the upper surface of the sensor element is higher than the position that is the outer periphery of the opening of the recess of the package. When applying a pressurizing pressure using a plurality of any one of the sensor devices that coincides with the position of the outer periphery of the opening of the concave portion of the package, it is difficult to apply the pressure evenly.

  For sealing the lid and the package, welding with high adhesion is used. The sensor element is housed in the package in close contact with the lid. For this reason, the heat generated during welding is very easily transmitted from the lid to the sensor element. Therefore, there is a possibility that the sensitivity characteristics of the sensor element are adversely affected by heat generated during welding.

  Therefore, in order to solve the above-described problems of the prior art, the present invention provides a sensor device, a sensor module, and a sensor device, which can perform high-precision force detection by blocking the sensor element from the external environment and increasing the pressure receiving sensitivity of the sensor element. The purpose is to provide a force detection device and a robot.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples.
Application Example 1 A sensor device of this application example is opposite to a sensor element having a piezoelectric body, a first member on which the sensor element is disposed, and a first surface on which the first member of the sensor element is in contact. A second member that contacts the second surface and a covering portion that covers a side surface different from the first and second surfaces of the sensor element are provided.
With the above configuration, the sensor element can be cut off from the external environment with an easy and inexpensive configuration. Accordingly, it is possible to obtain highly reliable and stable detection data that is free from measurement error due to moisture or the like. In addition, there is no risk of aging deterioration of the electrode due to the external environment. Moreover, since the 2nd member which covers one main surface of a sensor element is exposed from the coating | coated part, the applied pressurization can be directly transmitted to the pressure receiving surface of a sensor element via a 2nd member. .

Application Example 2 The sensor device according to Application Example 1, wherein the covering portion covers a part of the first member and a part of a side surface of the second member.
With the above configuration, the sensor element and the second member on the first member can be supported and the sensor element can be blocked from the external environment.

Application Example 3 In the planar view from the normal direction of the contact surface between the sensor element and the second member, the second member is positioned so that the periphery of the second member surrounds the periphery of the upper surface of the sensor element. The sensor device according to Application Example 1 or 2, wherein the sensor device is arranged.
With the above configuration, when the covering portion is filled, a layer is formed from the bottom surface of the first member. After covering the side surface of the sensor element, the side surface of the peripheral portion of the second member is covered more than the sensor element in plan view. The state in which the filling speed of the covering portion changes when the portion reaches can be easily confirmed from the opening side of the container. Therefore, after the covering portion covers the side surface of the sensor element, it can be easily confirmed whether it is sufficiently filled until it covers a part of the second member. There is no risk of measurement errors due to moisture and the like, and stable detection data with high reliability can be obtained.

Application Example 4 The sensor device according to any one of Application Examples 1 to 3, wherein the first member has a recess in which the sensor element and the second member are disposed.
With the above configuration, it is possible to make the sensor element difficult to be exposed to the external environment while increasing the rigidity of the first member.

Application Example 5 The sensor device according to any one of Application Examples 1 to 4, wherein the covering portion is made of an epoxy resin.
With the above configuration, it is possible to provide insulation, predetermined flexibility that does not hinder the piezoelectric effect of the sensor element, and predetermined rigidity that supports the sensor element including the piezoelectric body from the side surface.

Application Example 6 According to any one of Application Examples 1 to 5, wherein the covering portion encloses therein a wiring that connects the connection electrode of the first member and the electrode of the sensor element. Sensor device.
Thereby, the wiring which electrically connects the connection electrode and the electrode can be protected from the external environment. Moreover, it can prevent that wiring contacts.

Application Example 7 The sensor device according to any one of Application Examples 1 to 6, wherein a material of the second member is any one of ceramic, metal material, crystal, and glass.
With the above-described configuration, the pressurization can be sufficiently transmitted to the pressure receiving surface of the sensor element with a predetermined rigidity.

Application Example 8 The sensor device according to any one of Application Examples 1 to 7, wherein the material of the first member is ceramic.
With the above configuration, predetermined rigidity can be provided.

Application Example 9 When a stacking direction of the sensor elements in which a plurality of the piezoelectric bodies are stacked is a Z-axis direction, and directions orthogonal to the Z-axis direction and orthogonal to each other are an X-axis direction and a Y-axis direction, at least A first sensor element that detects a force in the X-axis direction, a second sensor element that detects a force in the Y-axis direction, and a third sensor element that detects a force in the Z-axis direction. The sensor device according to any one of Application Examples 1 to 8.
Even if it is a sensor device which detects the force of a triaxial direction by controlling the mutual position shift of the sensor element which detects the force of X direction, Y direction, Z direction, and what is called a triaxial direction by the above-mentioned composition. It can be stably maintained without impairing high detection accuracy.

Application Example 10 A sensor element having a piezoelectric body, a first member on which the sensor element is disposed, and a second surface that is in contact with a second surface opposite to the first surface on which the first member of the sensor element is in contact. A member, a covering portion that covers a side surface different from the first and second surfaces of the sensor element, a first plate that contacts the second member, a second plate that contacts the first member, and the first A sensor module comprising: a plate and a fastening portion that fastens the second plate.
With the above configuration, a predetermined pressurizing pressure can be applied to the sensor device.

Application Example 11 A force detection apparatus comprising the sensor device according to any one of Application Examples 1 to 9.
With the above configuration, the external force load can be easily calculated and measured based on the amount of charge and the sign of the charge. In addition, a triaxial force detection sensor can be obtained with a simple configuration. Furthermore, by using a plurality of sensor devices according to the application examples described above, for example, a six axis force detection device including torque measurement can be easily obtained. .

Application Example 12 A sensor element having a piezoelectric body, a first member on which the sensor element is disposed, and a second surface that is in contact with a second surface opposite to the first surface on which the first member of the sensor element is in contact. A force detection device comprising: a member; a covering portion that covers a side surface different from the first and second surfaces of the sensor element; and an electronic circuit that is electrically connected to the sensor element.
With the above configuration, the external force load can be easily calculated and measured based on the amount of charge and the sign of the charge.

Application Example 13 A robot provided with the force detection device according to Application Example 11.
With the above configuration, the detection of contact with obstacles and the contact force with the object that occur during a specified operation for the robot arm or robot hand that operates is detected reliably by the force detection device, and data is sent to the robot control device. By feeding back, safe and detailed work can be performed.

Application Example 14 A robot including a main body portion, an arm portion connected to the main body portion, and a hand portion connected to the arm portion, wherein a sensor device is connected to a connection portion between the arm portion and the hand portion. The sensor device includes: a first member on which the sensor element is disposed; a second member in contact with a second surface opposite to the first surface with which the first member of the sensor element contacts; And a covering portion that covers a side surface different from the first and second surfaces of the sensor element.
With the above configuration, the detection of contact with obstacles and the contact force with the object that occur during a specified operation for the robot arm or robot hand that operates is detected reliably by the force detection device, and data is sent to the robot control device. By feeding back, safe and detailed work can be performed. In addition, the robot can stably detect a highly accurate force even with a small amount of displacement.

It is sectional drawing of the sensor device which concerns on 1st Embodiment. It is a top view from the element lamination direction of the sensor device of this embodiment. It is a top view from the element lamination direction of the base member of this embodiment. It is a schematic diagram of the sensor element of this embodiment. It is sectional drawing of the sensor device which concerns on 2nd Embodiment. It is sectional drawing of the sensor device which concerns on 3rd Embodiment. It is sectional drawing of the sensor module of this embodiment. The force detection apparatus of this embodiment is shown, (a) shows a schematic diagram, (b) shows a top view. It is a schematic diagram of the robot carrying the force detection apparatus of this embodiment. It is a schematic diagram of the sensor device of a prior art. It is explanatory drawing of the sensor device which the conventional manufacture dispersion | variation produced, (a) shows the case where the upper surface of a sensor element becomes lower than the position used as the outer periphery of the opening part of the recessed part of a package, (b) is an upper surface of a sensor element. Is higher than the position of the outer periphery of the opening of the recess of the package.

Embodiments of a sensor device, a force detection apparatus, and a robot of the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 is a sectional view of a sensor device according to the first embodiment. FIG. 2 is a plan view from the element stacking direction of the sensor device of the present embodiment. FIG. 3 is a plan view of the base member of this embodiment from the element stacking direction.

  The sensor device 10 according to the first embodiment covers a sensor element 42 including a piezoelectric body, a first member 12 that supports the entire one main surface of the sensor element 42, and the other main surface of the other sensor element 42. The second basic member 34 that transmits external force to the sensor element 42 and the covering portion 40 that covers the side surface of the sensor element 42 are the main basic components.

  The first member 12 is a member that supports the lower surface of the sensor element 42. The shape of the 1st member 12 of this embodiment is a container type, and comprises base member 14 and side wall member 24 used as a crevice. Both the base member 14 and the side wall member 24 are formed of an insulating material such as ceramic. The base member 14 is a flat plate having a rectangular shape in plan view, and the sensor element 42 is disposed on the upper surface. The side wall member 24 has the same outer shape as the base member 14 in plan view (FIG. 2), and is disposed on the base member 14 so as to surround the sensor element 42 (ring shape).

  As shown in FIG. 3, a ground electrode 16 connected to the lower surface of the sensor element is disposed at the center of the upper surface of the base member 14. Further, side electrodes 20A, 20B, 20C, and 20D are disposed at the four corners of the side surface of the base member 14. The side electrodes 20A, 20B, 20C, and 20D are electrically connected to mounting electrodes on an electronic circuit (not shown), respectively.

  As shown in FIGS. 1, 2, and 3, connection electrodes 18 </ b> A, 18 </ b> B, 18 </ b> C, and 18 </ b> D are disposed on the upper surface of the base member 14. The connection electrodes 18A, 18B, 18C, 18D are arranged corresponding to the side electrodes 20A, 20B, 20C, 20D, respectively. On the other hand, the other ends of the connection electrodes 18A, 18B, and 18C are arranged at positions near the ground electrode 16. The other end of the connection electrode 18D is connected to the ground electrode 16.

As shown in FIG. 2, the side wall member 24 is laminated at a position on the base member 14. The side wall member 24 is disposed so as to cover the connection electrodes 18A, 18B, 18C, and 18D, but the other end side of the connection electrodes 18A, 18B, 18C, and 18D is exposed inside the side wall member 24, and the ground electrode 16 is also formed. The base member 14 is laminated in an exposed state.
The ground electrode 16 and the connection electrodes 18A, 18B, 18C, and 18D can be formed of a metal having conductivity.

As shown in FIG. 1, the sensor element 42 is formed of, for example, quartz, lead zirconate titanate (PZT: Pb (Zr, Ti) O ₃ ), lithium niobate, lithium tantalate or the like having piezoelectricity. In this embodiment, a quartz plate is used as the piezoelectric body. The sensor element 42 is formed by laminating a first sensor element 46, a third sensor element 58, and a second sensor element 52 in order from the top. The first sensor element 46 is formed such that the first quartz plates 48A and 48B sandwich the first detection electrode 50. The second sensor element 52 is formed such that the second crystal plates 54 </ b> A and 54 </ b> B sandwich the second detection electrode 56. The third sensor element 58 is formed so that the third crystal plates 60 </ b> A and 60 </ b> B sandwich the third detection electrode 62.

  A first ground electrode 64 serving as an electrode is disposed between the first sensor element 46 (first crystal plate 48B) and the third sensor element 58 (third crystal plate 60A), and the third sensor element 58 ( A second ground electrode 66 is disposed between the third crystal plate 60B) and the second sensor element 52 (second crystal plate 54A). Further, the upper surface of the first sensor element 46 (first crystal plate 48A) is the upper surface 44 of the sensor element 42. The second member 34 made of a conductive material is grounded in surface contact. When the insulating second member 34 is used, a contact electrode is disposed between the second member 34 and the upper surface of the sensor element 42 and grounded. The lower surface of the second sensor element 52 (second crystal plate 54B) is grounded by being connected to the ground electrode 16.

  As shown in FIG. 2, the first detection electrode 50, the second detection electrode 56, the third detection electrode 62, the first ground electrode 64, and the second ground electrode 66 are formed from stacked first to third crystal plates. Each part is arranged so that it protrudes. The first detection electrode 50 is connected to the exposed portion (the other end side) of the connection electrode 18A by the conductive wire 68A, and the second detection electrode 56 is connected to the exposed portion (the other end side) of the connection electrode 18B by the wire 68B. The third detection electrode 62 is connected to the exposed portion (the other end side) of the connection electrode 18C by a wire 68C. The first ground electrode 64, the second ground electrode 66, and the second member 34 are connected to the exposed portion (the other end side) of the connection electrode 18D by wires 68D, 68E, and 68F, respectively.

  By the above connection, the side electrode 20A is electrically connected to the first detection electrode 50 via the connection electrode 18A and the wire 68A. The side electrode 20B is electrically connected to the second detection electrode 56 through the connection electrode 18B and the wire 68B. The side electrode 20C is electrically connected to the third detection electrode 62 through the connection electrode 18C and the wire 68C.

  Further, the side electrode 20D is electrically connected to the ground electrode 16 through the connection electrode 18D. Further, the side electrode 20D is electrically connected to the first ground electrode 64 via a wire 68D connected to the connection electrode 18D, and is electrically connected to the second ground electrode 66 via a wire 68E connected to the connection electrode 18D. It is connected and electrically connected to the second member 34 via a wire 68F connected to the connection electrode 18D.

  As the materials for the various electrodes described above, a simple substance or an alloy such as gold, titanium, aluminum, copper, or iron can be used. For example, stainless steel can be used as the iron alloy, and it is preferably used because of its excellent durability and corrosion resistance.

  FIG. 4 is a schematic diagram of the sensor element of the present embodiment. In the present embodiment, the second member 34 is orthogonal to not only the force in the direction parallel to the normal direction (γ axis) of the upper surface 44 of the sensor element 42 but also the force in the surface direction of the upper surface 44, that is, the γ axis. In addition, forces in two directions (α axis and β axis) orthogonal to each other can be transmitted to the upper surface 44. The sensor element 42 can detect forces parallel to the α-axis, β-axis, and γ-axis, as will be described later.

  In the first sensor element 46, the first crystal plates 48A and 48B are formed of Y-cut crystal plates, and the X direction, which is the crystal orientation for generating the piezoelectric effect, is normal to the first crystal plates 48A and 48B (FIG. 4). The crystal orientation is perpendicular to the direction parallel to the γ-axis. The first crystal plates 48A and 48B are arranged so that the X directions are opposite to each other. Furthermore, the first crystal plates 48A and 48B are arranged so that the X direction is parallel to the α axis of the space orthogonal coordinates.

  In the second sensor element 52, the second crystal plates 54A and 54B are formed of Y-cut crystal plates, and the X direction is perpendicular to the normal line (the direction parallel to the γ axis) of the second crystal plates 54A and 54B. The crystal orientation is as follows. The second crystal plates 54A and 54B are arranged so that the X directions are opposite to each other. Further, the second crystal plates 54A and 54B are arranged so that the X direction is parallel to the β-axis of the space orthogonal coordinates.

  In the third sensor element 58, the third crystal plates 60A and 60B are formed by X-cut crystal plates, and the X direction is parallel to the normal line (the direction parallel to the γ axis) of the third crystal plates 60A and 60B. The crystal orientation is as follows. The third crystal plates 60A and 60B are arranged so that the X directions are opposite to each other. Furthermore, the third crystal plates 60A and 60B are arranged so that the X direction is parallel to the γ-axis of the space orthogonal coordinates.

  As shown in FIG. 4, the sensor device 10 according to the present embodiment uses the direction parallel to the γ-axis of the space orthogonal coordinates as the height direction of the sensor device 10. Then, the first pressurizing plate 70 and the second pressurizing plate 80 which will be described later are sandwiched from the direction of the γ-axis and applied with the pressure, and the sensor element 42 is applied via the second member 34 from the direction parallel to the γ-axis. Pressure is applied. As a result, the third crystal plates 60A and 60B receive pressure (compression force) from the X direction, so that charge is induced by the piezoelectric effect, and charge (Fz signal) is output to the third detection electrode 62.

  In the above configuration, when an external force in which the relative positions of the first pressurizing plate 70 and the second pressurizing plate 80 are shifted in a direction parallel to the α axis is applied to the sensor element 42 via the second member 34, An external force in a direction parallel to the α axis is applied. Then, since the first quartz plates 48A and 48B receive external force (shearing force) from the X direction, charges are induced by the piezoelectric effect, and charges (Fx signal) are output to the first detection electrode 50.

  Further, when an external force is applied in which the relative positions of the first pressurizing plate 70 and the second pressurizing plate 80 are shifted in the direction parallel to the β axis, the sensor element 42 is moved to the β axis via the second member 34. An external force in a parallel direction is applied. Then, since the second crystal plates 54A and 54B receive external force (shearing force) from the X direction, electric charges are induced by the piezoelectric effect, and electric charges (Fy signals) are output to the second detection electrodes 56.

  Further, when an external force is applied so that the relative positions of the first pressurizing plate 70 and the second pressurizing plate 80 are shifted in a direction parallel to the γ axis, the sensor element 42 is moved to the γ axis via the second member 34. An external force in a parallel direction is applied. Then, since the third crystal plates 60A and 60B receive an external force (compression force or tensile force) from the X direction, the amount of charge induced by the piezoelectric effect changes, and the charge output to the third detection electrode 62 ( The magnitude of the (Fz signal) changes.

  Therefore, the sensor device 10 of the present embodiment outputs the charge (Fx signal) output to the first detection electrode 50 via the side electrode 20A and the second detection electrode 56 via the side electrode 20B. The charge (Fy signal) and the charge (Fz signal) output to the third detection electrode 62 via the side electrode 20C can be monitored, respectively, an α axis (X-axis described later) orthogonal to each other, External forces (Fx, Fy, Fz) in a direction parallel to the β axis (Y-axis described later) and the γ-axis (Z axis described later) can be detected. The sensor element 42 has a laminated structure of the first sensor element 46, the second sensor element 52, and the third sensor element 58, but may be configured to use at least one of them.

  The second member 34 is formed in a substantially rectangular shape (a shape that is the same as or larger than the upper surface (pressure receiving surface) of the sensor element 42 in plan view) of ceramic, metal material, crystal, or glass. The second member 34 is placed so as to cover the entire area of the upper surface of the sensor element 42. Further, the second member 34 is exposed from the opening 30 of the concave portion of the first member 12. The thickness of the second member 34 is such that the upper surface of the second member 34 is the same height as the upper surface of the side wall member 24 in a state where the second member 34 is placed on the upper surface of the sensor element 42 disposed on the first member 12. The upper surface of the second member 34 is formed so as to be slightly higher than the upper surface of the side wall member 24. The second member 34 having such a configuration is in surface contact with the entire upper surface 44 serving as a pressure receiving surface of the sensor element 42 in a state where a pressure is applied by a first pressure plate 70 described later.

  The covering portion 40 is a covering that adheres to the first member 12, the sensor element 42, and the second member 34. The covering portion 40 preferably has insulating properties, predetermined flexibility that does not hinder the piezoelectric effect of the sensor element 42, and predetermined rigidity that supports the sensor element 42 including the piezoelectric body from the side surface. . In order to have such characteristics, in this embodiment, an ultraviolet curable or thermosetting epoxy resin is used as an example of the material of the covering portion 40. The covering portion 40 of this embodiment is filled on the base member 14 of the first member 12. At this time, the covering portion 40 is formed so as to adhere to a part of the first member 12, the entire region of the side surface of the sensor element 42, and a part of the second member 34. With this configuration, the sensor element 42 has the entire lower surface (one main surface) covered with the first member 12 and the upper surface (the other main surface) covered with the second member 34. Yes. Further, the entire side surface of the sensor element 42 is covered by the covering portion 40. Therefore, the sensor element 42 is cut off from the external environment, and there is no risk of measurement error due to humidity or the like. In addition, there is no risk of aging deterioration of the electrode due to the external environment. The covering portion 40 of this embodiment is configured not to adhere to the upper surface of the sensor element 42. This is because when the covering portion 40 is formed on the upper surface of the sensor element 42, the pressure is partially absorbed by the covering portion 40 due to the application of the pressurizing plate described later and affects the sensitivity. In addition, the resin is not susceptible to a load having the same load direction and a magnitude that changes with time, that is, a repeated load, and is not preferably formed on the pressure receiving surface of the detection element using the piezoelectric effect.

  The manufacturing method of such a sensor device 10 is performed as follows. First, the sensor element 42 is placed on the base member 14 of the first member 12, and the exposed portion (the other end side) of the connection electrode 18A and the first detection electrode 50 are connected by the conductive wire 68A. The exposed portion (the other end side) of the connection electrode 18B and the second detection electrode 56 are connected by the wire 68B. The exposed portion (the other end side) of the connection electrode 18C and the third detection electrode 62 are connected by the wire 68C. The first ground electrode 64, the second ground electrode 66, and the second member 34 are connected to the exposed portion (the other end side) of the connection electrode 18D by wires 68D, 68E, and 68F, respectively.

  Next, the covering portion 40 is formed inside the first member 12. As shown in FIG. 1, the covering portion 40 supplies resin from the opening 30 of the concave portion of the first member 12 until a part of the second member 34, that is, a part of the side surface of the second member 34 is covered. Formed. At this time, the wires 68A, 68B, 68C, 68D, 68E, and 68F are embedded in the covering portion 40. When the covering portion 40 is cured, the entire area of the upper surface of the sensor element 42 is covered with the second member 34, the entire area of the lower surface is covered with the first member 12, and the entire area of the side surface is covered with the covering portion 40. Is called. Further, the upper surface of the second member 34 is exposed from the opening 30 of the concave portion of the first member 12. The laminated structure of the second member 34 on the first member 12 and the sensor element 42 is maintained by the adhesive force of the covering portion 40. In addition, the wire that connects the connection electrode 18 of the first member 12 and the electrode of the sensor element 42 is sealed inside by the covering portion 40.

  According to the sensor device 10 having such a configuration, the sensor element 42 is covered by the second member 34 in the entire area of the upper surface, the entire area of the lower surface is covered by the first member 12, and the entire area of the side surface is covered 40. The sensor element 42 can be shut off from the external environment with an easy and inexpensive configuration. Accordingly, it is possible to obtain highly reliable and stable detection data that is free from measurement error due to moisture or the like. In addition, there is no risk of aging deterioration of the electrode due to the external environment.

  Further, the second member 34 that covers the upper surface of the sensor element 42 is exposed from the covering portion 40. For this reason, the pressurization applied from the pressurization plate can be directly transmitted to the sensor element via the second member 34. Accordingly, it is possible to prevent a decrease in the sensitivity of the pressurization that occurs when the coating portion 40 is passed through, and a decrease in the sensitivity that occurs due to a variation in thickness due to the coating portion 40 that is partially insufficiently filled.

  Furthermore, since the sealing of the package using the lid is not used to cut off the sensor element from the external environment, the sensor element is not affected by the manufacturing variation of the package due to the dimensional error. In addition, there is no problem that the sensor element is affected by heat generated during sealing of the package using welding.

  The covering portion 40 encloses a wire connecting the connection electrode of the first member 12 and the electrode of the sensor element. Thereby, the wiring which electrically connects the connection electrode and the electrode can be protected from the external environment. Moreover, it can prevent that wiring contacts.

  FIG. 5 is a cross-sectional view of a sensor device according to the second embodiment. The sensor device 10A according to the second embodiment uses a second member 34A that is larger in plan view than the second member 34 of the first embodiment. Other configurations are the same as those of the sensor device 10 of the first embodiment, and the same reference numerals are given and detailed description thereof is omitted.

  The second member 34A of the second embodiment is made of the same material as that of the second member 34, and has a peripheral portion 35 so as to surround the peripheral edge of the upper surface of the sensor element 42 in plan view. When the second member 34A is placed so as to cover the entire area of the upper surface (pressure receiving surface) of the sensor element 42, the peripheral edge 35 is horizontal from the upper surface of the sensor element 42 in plan view, in other words, the side wall member 24. Protrudes toward. A wire 68 </ b> F is connected to the lower surface of the peripheral portion 35. Further, the second member 34 </ b> A is exposed from the opening 30 of the concave portion of the first member 12. The thickness of the second member 34A is such that the upper surface of the second member 34A is the same height as the upper surface of the side wall member 24 in a state where the second member 34A is placed on the upper surface of the sensor element 42 disposed on the first member 12. The upper surface of the second member 34 </ b> A is formed to be slightly higher than the upper surface of the side wall member 24. The second member 34 </ b> A having such a configuration is in surface contact with the entire upper surface 44 serving as a pressure receiving surface of the sensor element 42 in a state where a pressure is applied by a first pressure plate 70 described later.

The covering portion 40 of the second embodiment is formed so as to adhere to a part of the side surface of the second member 34A, as in the first embodiment.
According to the sensor device 10A according to the second embodiment having such a configuration, a layer is formed from the bottom surface of the first member 12 when the covering portion 40 is filled, but after covering the side surface of the sensor element 42, The state in which the filling speed of the covering portion changes when the resin reaches the side surface of the peripheral edge portion 35 of the second member 34A rather than the sensor element 42 in plan view, in other words, the opening area of the recess of the first member 12 is the sensor element. Unlike the side surface of 42 and the side surface of the second member 34, it is possible to easily confirm from the opening side of the container 12 that the filling speed of the smaller opening area is increased. Therefore, after the covering portion 40 covers the side surface of the sensor element 42, it can be easily confirmed whether it is sufficiently filled until a portion of the second member 34 is covered. Therefore, it is possible to obtain highly reliable and stable detection data that is exposed to the external environment and does not cause a measurement error due to moisture or the like. Also, the sensor device 10A according to the second embodiment can achieve the same effects as the sensor device according to the first embodiment.

  FIG. 6 is a cross-sectional view of a sensor device according to the third embodiment. In the sensor device 10 </ b> B according to the third embodiment, the first member 12 is configured only by the base member 14, and the side wall member (not illustrated) is configured to be detachable from the base member 14. Other configurations are the same as those of the sensor device 10 of the first embodiment, and the same reference numerals are given and detailed description thereof is omitted.

  In the sensor device 10 </ b> B of the present embodiment, a ring-shaped side wall member (not shown) of the first member 12 is formed so as to be detachable from the base member 14. As the attaching / detaching means, a fitting structure of recesses and protrusions formed on the contact surfaces of the side wall member and the base member 14, an attaching / detaching means, and the like can be used. And after forming the sensor element 42 and the coating | coated part 40 on the 1st member 12 similarly to the sensor device 10 which concerns on 1st Embodiment, the side wall member is removed.

  According to the sensor device 10B according to the third embodiment having such a configuration, the same operational effects as those of the sensor device 10 according to the first embodiment can be obtained. And the structure of the 1st member is simplified and size reduction of the whole device can be achieved. In addition, the manufacturing cost can be reduced by reusing the side wall member.

  Note that the second member 34A according to the second embodiment may be applied to the configuration of the sensor device 10B according to the third embodiment, and the same operational effects as the sensor device according to the second embodiment are obtained.

  FIG. 7 is a cross-sectional view of the sensor module of the present embodiment. As shown in the figure, the sensor module 88 of the present embodiment has the sensor device of the first embodiment, the first plate, the second plate, and the fastening portion 86 as the main basic configuration.

  70 A of 1st pressurization plates used as the 1st plate of this embodiment are substantially rectangular plate plates larger than the 1st member 12 by planar view. The first pressurizing plate 70A is made of a metal material such as stainless steel, and has a predetermined strength and can be easily formed. Further, the first pressurizing plate 70A is formed with a through hole 74 into which a fastening portion 86 described later is inserted. The through hole 74 includes a first hole 74A into which the head of the fastening portion 86 is inserted, and a second hole 74B into which the shaft is inserted.

  The second pressurizing plate 80A serving as the second plate is a plate plate that is larger than the first member 12 in plan view and has substantially the same shape as the first pressurizing plate 70A. The second pressurizing plate 80A is formed with a screw hole 82 into which a male screw of a fastening portion 86 described later is screwed. The second pressurizing plate 80A is made of a metal material such as stainless steel, and has a predetermined strength and can be easily formed. Note that the first pressurizing plate 70A and the second pressurizing plate 80A may be formed in a disc, an ellipse, or a polygon in addition to a rectangular shape in plan view.

  The fastening portion 86 is a member that fastens the first pressurizing plate 70A and the second pressurizing plate 80A in a state where the sensor device 10 is sandwiched between the first pressurizing plate 70A and the second pressurizing plate 80A. The fastening part 86 of this embodiment is a fastening bolt. The fastening bolt is composed of a head and a shaft. The end of the shaft is formed with a threaded male screw and can be screwed into the screw hole 82 of the second pressurizing plate 80A. Such a fastening portion 86 only needs to be able to fix the sensor device 10 while pressurizing it between the first pressurizing plate 70A and the second pressurizing plate 80A. In the present embodiment, as an example, the sensor device 10 is sandwiched therebetween. Installed in two places.

In assembling such a sensor module 88, first, the sensor device 10 is placed on the mounting surface of the second pressurizing plate 80A. Then, the first pressurizing plate 70 </ b> A is disposed on the sensor device 10. Next, a fastening bolt serving as a fastening portion 86 is inserted from the through hole 74 of the first pressurizing plate 70A and screwed into the screw hole 82 of the second pressurizing plate 80A. At this time, the tightening amount of the fastening portion 86 can be adjusted so that a predetermined pressurizing pressure (for example, about 10 kN) is applied.
According to the sensor module 88 having such a configuration, a predetermined pressure can be applied to the sensor device 10.

  FIG. 8 shows a force detection device according to the present embodiment, where (a) shows a schematic view and (b) shows a plan view. The force detection device 90 of this embodiment has a configuration in which four sensor devices 10 are sandwiched between a first pressurizing plate 70 and a second pressurizing plate 80. The first pressurizing plate 70 and the second pressurizing plate 80 are both formed in a disc shape in plan view, and the four sensor devices 10 are arranged on lines that pass through the center and are orthogonal to each other. In the second pressurizing plate 80, four electronic circuit boards (not shown) are formed at locations where the sensor device 10 is disposed.

  In assembling such a force detection device 90, first, the sensor device 10 is placed on the second pressurizing plate 80, and the side electrodes 20A, 20B, 20C, 20D and the mounting electrodes of the electronic circuit board (not shown) are electrically connected. Connect. Then, the first pressurizing plate 70 is disposed on the sensor device 10. Next, the tightening amount of the fastening means (not shown) is adjusted in a state where the sensor device is sandwiched between the first pressurizing plate 70 and the second pressurizing plate 80, and a predetermined pressurizing force is applied to the sensor device 10. (For example, about 10 kN) is applied.

  The force detection device 90 having such a configuration is sandwiched between the first pressurizing plate 70 and the second pressurizing plate 80 in a state where all the four sensor devices 10 face in the same direction, and the pressurizing force is applied. For example, in the sensor device 10, the detection axis of the first sensor element 46 (FIGS. 1 and 4) is oriented in a direction parallel to Fx, and the detection axis of the second sensor element 52 (FIGS. 1 and 4) is parallel to Fy. In this direction, the detection axis of the third sensor element 58 (FIGS. 1 and 4) is oriented in a direction parallel to Fz.

  Here, when the relative position of the first pressurizing plate 70 and the second pressurizing plate 80 receives a force that shifts in the Fx direction, the sensor device 10 detects the forces of Fx1, Fx2, Fx3, and Fx4, respectively. When the relative position of the first pressurizing plate 70 and the second pressurizing plate 80 receives a force that is shifted in the Fy direction, the sensor device 10 detects the forces of Fy1, Fy2, Fy3, and Fy4, respectively. Furthermore, when the relative position of the first pressurizing plate 70 and the second pressurizing plate 80 receives a force that shifts in the Fz direction, the sensor device 10 detects the forces of Fz1, Fz2, Fz3, and Fz4, respectively.

  Therefore, in the force detection device 90, the rotational force Mx is set to a direction parallel to the forces Fx, Fy, Fz, and Fx orthogonal to each other, and the rotational force My and Fz is set to be parallel to the direction parallel to Fy. The rotational force Mz whose direction is the rotation axis can be obtained as follows.

  Here, a and b are constants. Therefore, the force detection device 90 according to the present embodiment can detect forces from all three dimensions (forces in six axes) and stably detect highly accurate forces even with a small amount of displacement. The force detection device 90 can be performed.

  FIG. 9 shows a robot equipped with the force detection device of this embodiment. As shown in FIG. 9, the robot 100 includes a main body 102, an arm 104, a robot hand 116, and the like. The main body 102 is fixed on, for example, a floor, a wall, a ceiling, or a movable carriage. The arm unit 104 is provided so as to be movable with respect to the main body unit 102. The main body unit 102 includes an actuator (not shown) that generates power for rotating the arm unit 104, and a control for controlling the actuator. Etc. (not shown) are incorporated.

  The arm unit 104 includes a first frame 106, a second frame 108, a third frame 110, a fourth frame 112, and a fifth frame 114. The first frame 106 is connected to the main body 102 so as to be rotatable or bendable via a rotating and bending shaft. The second frame 108 is connected to the first frame 106 and the third frame 110 via a rotating and bending shaft. The third frame 110 is connected to the second frame 108 and the fourth frame 112 via a rotating and bending shaft. The fourth frame 112 is connected to the third frame 110 and the fifth frame 114 via a rotating and bending shaft. The fifth frame 114 is connected to the fourth frame 112 via a rotating and bending shaft. The arm unit 104 is driven by each frame being rotated or bent in a compound manner around each rotation / bending axis under the control of the control unit.

  A robot hand unit 116 is attached to the tip of the fifth frame 114, and the robot hand 120 capable of grasping an object is connected via a robot hand connection unit 118 having a built-in motor (not shown) that rotates. Connected to the fifth frame 114.

  The robot hand connection unit 118 incorporates the above-described force detection device 90 (not shown in FIG. 9) in addition to the motor, and when the robot hand unit 116 is moved to a predetermined operation position under the control of the control unit. , Contact with an obstacle or contact with an object by an operation command beyond a predetermined position is detected as a force by the force detection device 90 and fed back to the control unit of the robot 100 to execute an avoidance operation. Can do.

  By using such a robot 100, it is possible to easily perform an obstacle avoidance operation, an object damage avoidance operation, etc., which cannot be dealt with by conventional position control, and obtain a robot 100 capable of safe and detailed work. Can do. Furthermore, the robot 100 can stably detect a highly accurate force even with a small amount of displacement. Further, the present invention is not limited to this embodiment, and can be applied to a double-arm robot.

10, 10A, 10B, 10C ......... sensor device, 12 ......... first member, 14 ......... base member, 16 ......... ground electrode, 18A, 18B, 18C, 18D ......... connection electrode, 20A, 20B, 20C, 20D ......... side electrode, 24 ......... side wall member, 30 ......... opening, 34, 34A ......... second member, 35 ......... peripheral portion, 40 ......... covering portion, 42... Sensor element 44 44 Upper surface 46 First sensor element 48A, 48B First crystal plate 50 First sensor electrode 52 Second sensor element 54A, 54B ......... Second crystal plate, 56 ......... Second detection electrode, 58 ......... Third sensor element, 60A, 60B ......... Third crystal plate, 62 ......... Third detection electrode, 64... First ground electrode 66 66 Second ground electrode 68A, 68B, 6 C, 68D, 68E, 68F ......... Wire, 70, 70A ......... First pressurizing plate, 80,80A ......... Second pressurizing plate, 88 ......... Sensor module, 90 ......... Force detector 96 ......... Mounting electrode, 100 ......... Robot, 102 ......... Main body, 104 ......... Arm, 106 ......... First frame, 108 ......... Second frame, 110 ......... Third Frame, 112 ......... Fourth frame, 114 ......... Fifth frame, 116 ......... Robot hand section, 118 ......... Robot hand connection section, 120 ......... Robot hand, 200 ......... Sensor device, 202 ......... Package, 204 ...... Lid, 206 ......... Coaxial connector, 208 ......... Outer peripheral part, 210 ......... Center conductor, 212 ......... Insulating resin, 214 ...... Sensor element 216 ......... quartz plate, 218 ......... electrode plate, 220 ......... opening 222 ......... top, 224 ......... top, 226 ......... gap, 228 ......... gap.

Claims (14)

A sensor element having a piezoelectric body;
A first member on which the sensor element is disposed;
A second member in contact with a second surface opposite to the first surface with which the first member of the sensor element contacts;
A sensor device comprising: a covering portion that covers a side surface different from the first and second surfaces of the sensor element.   The sensor device according to claim 1, wherein the covering portion covers a part of the first member and a part of a side surface of the second member.   The second member is disposed at a position in which the periphery of the second member surrounds the periphery of the upper surface of the sensor element in a plan view from the normal direction of the contact surface between the sensor element and the second member. The sensor device according to claim 1 or 2.   The sensor device according to any one of claims 1 to 3, wherein the first member has a recess in which the sensor element and the second member are disposed.   The sensor device according to claim 1, wherein the covering portion is made of an epoxy resin.   6. The sensor device according to claim 1, wherein the covering portion encloses therein a wiring that connects the connection electrode of the first member and the electrode of the sensor element. 7.   The sensor device according to claim 1, wherein a material of the second member is any one of ceramic, metal material, crystal, and glass.   The sensor device according to claim 1, wherein a material of the first member is ceramic.   When the stacking direction of the sensor elements in which a plurality of the piezoelectric bodies are stacked is the Z-axis direction and the directions orthogonal to the Z-axis direction and orthogonal to each other are the X-axis direction and the Y-axis direction, respectively, at least the X-axis direction A first sensor element for detecting the force in the Y-axis direction, a second sensor element for detecting the force in the Y-axis direction, and a third sensor element for detecting the force in the Z-axis direction. The sensor device according to any one of 1 to 8. A sensor element having a piezoelectric body;
A first member on which the sensor element is disposed;
A second member in contact with a second surface opposite to the first surface with which the first member of the sensor element contacts;
A covering portion covering a side surface different from the first and second surfaces of the sensor element;
A first plate in contact with the second member;
A second plate in contact with the first member;
A sensor module comprising: a fastening portion that fastens the first plate and the second plate.   A force detection apparatus comprising the sensor device according to claim 1. A sensor element having a piezoelectric body;
A first member on which the sensor element is disposed;
A second member in contact with a second surface opposite to the first surface with which the first member of the sensor element contacts;
A covering portion covering a side surface different from the first and second surfaces of the sensor element;
An electronic circuit electrically connected to the sensor element.   A robot comprising the force detection device according to claim 11. The main body,
An arm portion connected to the main body portion;
A hand unit connected to the arm unit,
It has a sensor device in the connection part between the arm part and the hand part,
The sensor device is
A first member on which the sensor element is disposed;
A second member in contact with a second surface opposite to the first surface with which the first member of the sensor element contacts;
And a covering portion covering a side surface different from the first and second surfaces of the sensor element.