JP2015087333A - Sensor element, force detection device, robot, electronic component conveyance device, electronic component inspection device and component processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor element capable of suppressing or preventing trouble caused by a temperature change, a force detection device, a robot, an electronic component conveyance device, an electronic component inspection device and a component processing device.SOLUTION: A sensor element 10 includes a laminate 110 including: first and second piezoelectric layers 121 and 123; third and fourth piezoelectric layers which are disposed in such a manner that a crystal axis (z) and a crystal axis (x) of the first and second piezoelectric layers 121 and 123 are orthogonal; fifth and sixth piezoelectric layers which are disposed in such a manner that a crystal axis (x) and a crystal axis (x) of the third and fourth piezoelectric layers are orthogonal; and a plurality of electrode layers including internal electrode layers provided between the piezoelectric layers. The sensor element 10 also includes a plurality of side surface terminals including side surface terminals 120-150 which are provided on side surfaces 110a-110d of the laminate 110 and connected to the electrode layers. A plurality of side surface terminals are provided on the side surfaces 110b and 110d with the crystal axis (z) of the first and second piezoelectric layers 121 and 123 as a normal.

Description

  The present invention relates to a sensor element, a force detection device, a robot, an electronic component transport device, an electronic component inspection device, and a component processing device.

  In recent years, industrial robots have been introduced into production facilities such as factories for the purpose of improving production efficiency. Such an industrial robot includes an arm that can be driven in the direction of one axis or a plurality of axes, a hand attached to the tip of the arm, an end effector such as a component inspection instrument, a component transport instrument, and a component processing tool. It is possible to perform various operations such as component assembly operations, component processing operations, component inspection operations such as component inspection operations, and component transfer operations.

In such an industrial robot, a force detection device is provided between the arm and the end effector. This force detection device includes a piezoelectric element (charge output element) that outputs electric charge according to an applied external force, and a conversion circuit (converter) that converts electric charge output from the piezoelectric element into a voltage. An external force applied to the element can be detected. An industrial robot uses such a force detection device to detect an external force generated during a component manufacturing operation or a component transfer operation, and controls the arm and the end effector based on the detection result. As a result, the industrial robot can accurately execute the parts manufacturing work or the parts transporting work.
As such a force detection device, a crystal-type piezoelectric sensor using a crystal as a piezoelectric element is widely used (for example, see Patent Document 1). The crystal-type piezoelectric sensor described in Patent Document 1 is widely used in industrial robots because it has excellent characteristics such as a wide dynamic range, high rigidity, high natural frequency, and high load resistance.

JP 2013-101020 A

  However, in such a crystal type piezoelectric element, since the electric charge output from the crystal is weak, the influence of output drift due to temperature change cannot be ignored. In particular, even when the external force is not applied, there is a possibility that stress is generated in the crystal due to thermal expansion or contraction due to temperature change. Due to this stress, there is a possibility that charges are detected in the quartz piezoelectric element even when the external force is not applied.

As described above, the conventional crystal piezoelectric element may have a problem that the detection accuracy is lowered due to the influence of the temperature change.
An object of the present invention is to provide a sensor element, a force detection device, a robot, an electronic component transport device, an electronic component inspection device, and a component processing device that can suppress or prevent problems due to temperature changes.

Such an object is achieved by the following application examples according to the present invention.
(Application example 1)
The sensor element of the present invention includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
The plurality of side surface terminals are provided on the side surface having the crystal axis z of the X-cut plate as a normal line.
This prevents or suppresses unnecessary detection as an external force without affecting the piezoelectric effect of the X-cut plate even when each side terminal is thermally deformed (thermal expansion or contraction). , The detection accuracy can be further increased.

(Application example 2)
In the sensor element of the present invention, it is preferable that each of the side terminals is connected to a plurality of internal electrodes in the thickness direction of the laminate.
As a result, a plurality of internal electrodes can be electrically connected together.
(Application example 3)
In the sensor element of the present invention, the side surface of the laminate includes two pairs of opposed surfaces,
It is preferable that the number of side terminals provided on one of the opposing surfaces is equal to the number of side terminals provided on the other opposing surface.
Thereby, the dispersion | variation in the mechanical strength in the arrangement | positioning direction of the side surface terminal of a sensor element can be reduced. As a result, even if each side terminal is thermally deformed, it is possible to effectively prevent or reduce the occurrence of twisting or the like in the laminate.

(Application example 4)
In the sensor element according to the aspect of the invention, the plurality of side surface terminals may include a first side surface terminal that outputs charges generated by the X-cut plate, and a second side surface that outputs charges generated by the first Y-cut plate. A pair of terminals, a third side terminal for outputting charges generated by the second Y-cut plate, and a fourth side terminal for grounding the stacked body. Preferably, two side terminals are provided on one opposing surface and two side terminals are provided on the other opposing surface.
Thereby, the dispersion | variation in the mechanical strength in the arrangement | positioning direction of the side surface terminal of a sensor element can be reduced more reliably.

(Application example 5)
In the sensor element of the present invention, it is preferable that the X-cut plate is provided between the first Y-cut plate and the second Y-cut plate.
Thereby, the external force (compression / tensile force) applied (received) along the thickness direction can be detected with higher sensitivity.

(Application example 6)
In the sensor element according to the aspect of the invention, it is preferable that the laminate includes a plurality of the X-cut plate, the first Y-cut plate, and the second Y-cut plate.
Thereby, the detection accuracy of the sensor element can be improved by increasing the output charge.

(Application example 7)
The sensor element of the present invention includes an X-cut plate, a first Y-cut plate arranged so that a crystal axis y and a crystal axis z of the X-cut plate are orthogonal, and the crystal of the first Y-cut plate. A laminate comprising a second Y-cut plate disposed so that the axis z and the crystal axis z are orthogonal to each other, and a plurality of electrode layers including an internal electrode layer provided between the cut plates, A laminate comprising side surfaces along the thickness direction;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the electrode layers;
The plurality of side terminals are provided in a region other than a surface having the crystal axis y of the X-cut plate as a normal line.
This prevents or suppresses unnecessary detection as an external force without affecting the piezoelectric effect of the X-cut plate even when each side terminal is thermally deformed (thermal expansion or contraction). , The detection accuracy can be further increased.

(Application example 8)
The sensor element of the present invention has three axes orthogonal to each other as an A axis, a B axis, and a C axis.
An X-cut plate that outputs charges according to an external force along the A-axis direction, a first Y-cut plate that outputs charges according to an external force along the B-axis direction, and the first Y-cut plate On the other hand, the second Y-cut plate, which is arranged in a state rotated by 90 ° around the axis in the thickness direction, and outputs electric charges according to the external force along the C-axis direction, and the cut plates A laminate comprising a plurality of electrode layers including the provided internal electrode layer, the laminate comprising side surfaces along the thickness direction of the laminate, and
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
The external force applied along the B-axis direction from the external force applied along the C-axis direction of the X-cut plate due to thermal deformation of the side terminal that contacts the X-cut plate among the plurality of side terminals. It is characterized in that it is provided in a region where becomes small.
This prevents or suppresses unnecessary detection as an external force without affecting the piezoelectric effect of the X-cut plate even when each side terminal is thermally deformed (thermal expansion or contraction). , The detection accuracy can be further increased.

(Application example 9)
The force detection device of the present invention includes an X-cut plate, a first Y-cut plate disposed so that a crystal axis z and a crystal axis x of the X-cut plate are orthogonal, and the first Y-cut plate. A laminated body comprising a second Y-cut plate disposed so that the crystal axis x and the crystal axis x are orthogonal to each other, and a plurality of electrode layers including an internal electrode layer provided between the cut plates. , A laminate comprising side surfaces along the thickness direction of the laminate, and
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
And an external force detection circuit that detects the external force based on the voltage output from the sensor element.
Thereby, the same effect as that of the sensor element of the present invention can be obtained, and an external force can be detected based on the electric charge output from the sensor element.
(Application Example 10)
In the force detection device of the present invention, it is preferable that three or more sensor elements are provided.
Thereby, the detection accuracy of the force detection device can be improved by the amount of three or more sensor elements.

(Application Example 11)
The robot of the present invention has a plurality of arms, and at least one arm connection body formed by rotatably connecting the adjacent arms of the plurality of arms;
An end effector provided on the distal end side of the arm coupling body;
A force detection device provided between the arm coupling body and the end effector for detecting an external force applied to the end effector;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
And an external force detection circuit that detects the external force based on the voltage output from the sensor element.

  Thereby, the same effect as the sensor element of the present invention can be obtained. Then, the external force detected by the force detection device can be fed back to perform the operation more precisely. Further, the contact of the end effector with the obstacle can be detected by the external force detected by the force detection device. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like, which are difficult with conventional position control, can be easily performed, and the work can be executed more safely.

(Application Example 12)
An electronic component transport apparatus according to the present invention includes a gripping unit that grips an electronic component,
A force detection device that detects an external force applied to the gripping portion;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
And an external force detection circuit that detects the external force based on the voltage output from the sensor element.

  Thereby, the same effect as the sensor element of the present invention can be obtained. Then, the external force detected by the force detection device can be fed back to perform the operation more precisely. In addition, contact of the grip portion with an obstacle can be detected by the external force detected by the force detection device. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like, which are difficult with conventional position control, can be easily performed, and the electronic component transport operation can be executed more safely.

(Application Example 13)
The electronic component inspection apparatus of the present invention includes a gripping unit that grips an electronic component,
An inspection unit for inspecting the electronic component;
A force detection device that detects an external force applied to the gripping portion;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
And an external force detection circuit that detects the external force based on the voltage output from the sensor element.

  Thereby, the same effect as the sensor element of the present invention can be obtained. Then, the external force detected by the force detection device can be fed back to perform the operation more precisely. In addition, contact of the grip portion with an obstacle can be detected by the external force detected by the force detection device. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like that are difficult with conventional position control can be easily performed, and an electronic component inspection operation can be performed more safely.

(Application Example 14)
The component processing apparatus of the present invention is equipped with a tool displacing unit for mounting a tool and displacing the tool,
A force detection device for detecting an external force applied to the tool;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
And an external force detection circuit that detects the external force based on the voltage output from the sensor element.

  Thereby, the same effect as the sensor element of the present invention can be obtained. Then, by feeding back the external force detected by the force detection device, the component processing device can execute the component processing operation more precisely. Further, contact of the tool with an obstacle can be detected by an external force detected by the force detection device. Therefore, an emergency stop can be performed when an obstacle or the like comes into contact with the tool, and the component processing apparatus can execute a safer component processing operation.

It is sectional drawing which shows 1st Embodiment of the force detection apparatus (sensor element) which concerns on this invention. It is a top view of the force detection apparatus (sensor element) shown in FIG. It is a circuit diagram which shows roughly the force detection apparatus shown in FIG. FIG. 2 is a cross-sectional view schematically showing the charge output element shown in FIG. 1. Conceptual diagram showing the state of the unit cell when viewed from the negative direction of the crystal axis z of the X-cut plate ((a) a natural state where no external force is applied, (b) a state where a compressive force is applied in the A-axis direction, ( c) A state in which a tensile force is applied in the A-axis direction). Conceptual diagram showing the state of the unit cell when viewed from the positive direction of the crystal axis z of the Y-cut plate ((a) natural state, (b) state where an external force is applied in the positive direction of the B axis, (c) B The external force is applied in the negative direction of the shaft). It is an expanded view of the electric charge output element which shows the arrangement | positioning state of a side terminal. It is a conceptual diagram which shows the shape of an electrode layer, and the relationship with a side terminal. It is the conceptual diagram which shows the state of a unit cell when it sees from the positive direction of the crystal axis z of a Y cut board ((a) natural state, (b) state where compressive force was applied to B-axis direction). It is an expanded view of the electric charge output element which shows the other arrangement | positioning state of a side terminal. It is an expanded view of the electric charge output element which shows the other arrangement | positioning state of a side terminal. It is a top view which shows 2nd Embodiment of the force detection apparatus (sensor element) which concerns on this invention. It is sectional drawing in the AA line in FIG. FIG. 13 is a circuit diagram schematically showing the force detection device shown in FIG. 12. It is a figure which shows an example of the single arm robot using the force detection apparatus (sensor element) which concerns on this invention. It is a figure which shows an example of the multi-arm robot using the force detection apparatus (sensor element) which concerns on this invention. It is a figure which shows an example of the electronic component inspection apparatus and electronic component conveyance apparatus using the force detection apparatus (sensor element) which concern on this invention. It is a figure which shows one example of the electronic component conveying apparatus using the force detection apparatus (sensor element) which concerns on this invention. It is a figure which shows one example of the component processing apparatus using the force detection apparatus (sensor element) which concerns on this invention. It is a figure which shows one example of the moving body using the force detection apparatus (sensor element) which concerns on this invention.

Hereinafter, a sensor element, a force detection device, a robot, an electronic component conveying device, an electronic component inspection device, and a component processing device according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<First Embodiment>
1 is a sectional view showing a first embodiment of a force detection device (sensor element) according to the present invention, FIG. 2 is a plan view of the force detection device (sensor element) shown in FIG. 1, and FIG. 4 is a circuit diagram schematically showing the force detection device shown in FIG. 4, FIG. 4 is a sectional view schematically showing the charge output element shown in FIG. 1, and FIG. 5 is a view from the negative direction of the crystal axis z of the X-cut plate. Schematic diagram showing the state of the unit cell ((a) a natural state where no external force is applied, (b) a state where a compressive force is applied in the A-axis direction, (c) a state where a tensile force is applied in the A-axis direction) FIG. 6 is a conceptual diagram showing the state of the unit cell when viewed from the positive direction of the crystal axis z of the Y-cut plate ((a) natural state, (b) state where an external force is applied in the positive direction of the B axis. (C) State in which an external force is applied in the negative direction of the B-axis), FIG. FIG. 9 is a conceptual diagram showing the state of the unit cell when viewed from the positive direction of the crystal axis z of the Y-cut plate ((a) natural state, ( b) State in which compressive force is applied in the B-axis direction), FIG. 10 and FIG. 11 are development views of the charge output element showing other arrangement states of the side terminals. The upper side of FIGS. 1 and 4 is also referred to as “upper (upper)” and the lower side is also referred to as “lower (lower)”.

  As shown in FIG. 1, the force detection device 1 includes a first substrate 2, a second substrate 3 that is disposed at a predetermined interval from the first substrate 2 and faces the first substrate 2, An analog circuit board (circuit board) 4 provided between the first board 2 and the second board 3, and an analog circuit board 4 provided between the first board 2 and the second board 3 A digital circuit board 5 electrically connected to the circuit board, a charge output element (sensor element) 10 that is mounted on the analog circuit board and outputs a signal according to an applied external force, and a package 60 that houses the charge output element 10 The sensor device 6 has two pressurizing bolts (fixing members) 71.

  As shown in FIG. 3, the analog circuit board 4 includes a conversion output circuit 90 a that converts the charge Qa output from the charge output element 10 of the mounted sensor device 6 into a voltage Va, and the output from the charge output element 10. A conversion output circuit 90b for converting the charge Qb into the voltage Vb and a conversion output circuit 90c for converting the charge Qc output from the charge output element 10 into the voltage Vc are provided. The digital circuit board 5 includes an external force detection circuit 40 that detects the applied external force. The digital circuit board 5 is disposed on the first board 2 side of the analog circuit board 4, that is, between the analog circuit board 4 and the first board 2.

  As shown in FIG. 1, the sensor device 6 is disposed on the surface of the analog circuit board 4 on the second board 3 side, and a convex portion 21 and a second board 3 described later provided on the first board 2. Is sandwiched between. That is, the charge output element 10 is sandwiched between the convex portion 21 and the second substrate 3 via the package 60 and is pressurized. Note that either the first substrate 2 or the second substrate 3 may be a substrate on which a force is applied, but in the present embodiment, the second substrate 3 is described as a substrate on which a force is applied. The charge output element 10 may be disposed on the surface of the analog circuit board 4 on the first substrate 2 side.

  The shapes of the first substrate 2, the second substrate 3, the analog circuit substrate 4, and the digital circuit substrate 5 are not particularly limited, but in the present embodiment, as shown in FIG. The outer shape of the second substrate 3, the analog circuit substrate 4, and the digital circuit substrate 5 is circular. In addition, as said other external shape in planar view of the 1st board | substrate 2, the 2nd board | substrate 3, the analog circuit board 4, and the digital circuit board 5, for example, polygons, such as a rectangle and a pentagon, an ellipse, etc. Is mentioned. Further, as the constituent materials of the first substrate 2, the second substrate 3, and the parts other than the respective elements and wirings of the analog circuit board 4, and the constituent elements of the respective parts of the digital circuit board 5 and other than the respective wirings, For example, various resin materials, various metal materials, and the like can be used.

<Sensor device>
The sensor device 6 includes a charge output element 10 and a package 60 that houses the charge output element 10.
The package 60 includes a base (first member) 61 having a recess 611 and a lid (second member) 62 joined to the base 61. The charge output element 10 is installed in the recess 611 of the base 61, and the recess 611 of the base 61 is sealed with a lid 62. Thereby, the charge output element 10 can be protected and the highly reliable force detection apparatus 1 can be provided. Note that the upper surface of the charge output element 10 is in contact with the lid 62. The lid 62 of the package 60 is disposed on the upper side, that is, the second substrate 3 side, and the base 61 is disposed on the lower side, that is, the first substrate 2 side, and the base 61 is the analog circuit board. 4 is fixed. With this configuration, the base 61 and the lid 62 are sandwiched between the convex portion 21 and the second substrate 3 and pressurized, and the charge output element 10 is sandwiched and applied by the base 61 and the lid 62. Pressed.

Moreover, it does not specifically limit as a constituent material of the base 61, For example, insulating materials, such as ceramics, etc. can be used. Moreover, it does not specifically limit as a constituent material of the cover body 62, For example, various metal materials, such as stainless steel, can be used. In addition, the constituent material of the base 61 and the constituent material of the lid 62 may be the same or different.
In addition, the shape of the package 60 is not particularly limited, but in the present embodiment, as illustrated in FIG. 2, the package 60 has a quadrangular shape in a plan view of the first substrate 2. Examples of the other shape in the plan view of the package 60 include other polygons such as a pentagon, a circle, and an ellipse. Moreover, when the shape of the package 60 is a polygon, the corner | angular part may be roundish, for example, and may be notched diagonally.

  Further, in this embodiment, the lid 62 has a plate shape, and the central portion 625 protrudes toward the second substrate 3 by bending a portion between the central portion 625 and the outer peripheral portion 626. Yes. The shape of the central portion 625 is not particularly limited, but in the present embodiment, the shape is the same as that of the charge output element 10 in a plan view of the first substrate 2, that is, a quadrangle. Note that the upper surface and the lower surface of the central portion 625 of the lid 62 are both flat.

A plurality of terminals 63 that are electrically connected to the charge output element 10 are provided at the end of the lower surface of the base 61 of the package 60. Each terminal 63 is electrically connected to the analog circuit board 4, whereby the charge output element 10 and the analog circuit board 4 are electrically connected. The number of terminals 63 is not particularly limited, but is four in the present embodiment, that is, the terminals 63 are respectively provided at four corners of the base 61.
The charge output element 10 is accommodated in such a package 60. The charge output element 10 will be described in detail later.

<Conversion output circuit>
As shown in FIG. 3, conversion output circuits 90 a, 90 b and 90 c are connected to the charge output element 10. The conversion output circuit 90a has a function of converting the charge Qa output from the charge output element 10 into a voltage Va. The conversion output circuit 90b has a function of converting the charge Qb output from the charge output element 10 into a voltage Vb. The conversion output circuit 90c has a function of converting the charge Qc output from the charge output element 10 into a voltage Vc. Since the conversion output circuits 90a, 90b, and 90c are the same, the conversion output circuit 90c will be typically described below.

  The conversion output circuit 90c has a function of converting the charge Qc output from the charge output element 10 into a voltage Vc and outputting the voltage Vc. The conversion output circuit 90 c includes an operational amplifier 91, a capacitor 92, and a switching element 93. The first input terminal (minus input) of the operational amplifier 91 is connected to the output electrode layer 122 of the charge output element 10, and the second input terminal (plus input) of the operational amplifier 91 is grounded to the ground (reference potential point). ing. The output terminal of the operational amplifier 91 is connected to the external force detection circuit 40. The capacitor 92 is connected between the first input terminal and the output terminal of the operational amplifier 91. The switching element 93 is connected between the first input terminal and the output terminal of the operational amplifier 91, and is connected in parallel with the capacitor 92. The switching element 93 is connected to a drive circuit (not shown), and the switching element 93 performs a switching operation in accordance with an on / off signal from the drive circuit.

  When the switching element 93 is off, the charge Qc output from the charge output element 10 is stored in the capacitor 92 having the capacitance C1, and is output to the external force detection circuit 40 as the voltage Vc. Next, when the switching element 93 is turned on, both terminals of the capacitor 92 are short-circuited. As a result, the electric charge Qc stored in the capacitor 92 is discharged to 0 coulomb, and the voltage V output to the external force detection circuit 40 is 0 volt. When the switching element 93 is turned on, the conversion output circuit 90c is reset. The voltage Vc output from the ideal conversion output circuit 90c is proportional to the amount of charge Qc output from the charge output element 10.

  The switching element 93 is a semiconductor switching element such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), for example. Since the semiconductor switching element is smaller and lighter than the mechanical switch, it is advantageous for reducing the size and weight of the force detection device 1. Hereinafter, a case where a MOSFET is used as the switching element 93 will be described as a representative example.

  The switching element 93 has a drain electrode, a source electrode, and a gate electrode. One of the drain electrode and the source electrode of the switching element 93 is connected to the first input terminal of the operational amplifier 91, and the other of the drain electrode and the source electrode is connected to the output terminal of the operational amplifier 91. The gate electrode of the switching element 93 is connected to a drive circuit (not shown).

  The same drive circuit may be connected to the switching element 93 of each of the conversion output circuits 90a, 90b, and 90c, or different drive circuits may be connected to each other. Each of the switching elements 93 receives an on / off signal that is all synchronized from the drive circuit. As a result, the operations of the switching elements 93 of the conversion output circuits 90a, 90b, and 90c are synchronized. That is, the on / off timings of the switching elements 93 of the conversion output circuits 90a, 90b, and 90c coincide with each other.

<External force detection circuit>
The external force detection circuit 40 detects the applied external force based on the voltage Va output from the conversion output circuit 90a, the voltage Vb output from the conversion output circuit 90b, and the voltage Vc output from the conversion output circuit 90c. It has the function to do. The external force detection circuit 40 includes an AD converter 401 connected to the conversion output circuits 90a, 90b, and 90c, and an arithmetic unit 402 connected to the AD converter 401.

The AD converter 401 has a function of converting the voltages Va, Vc, and Vb from analog signals to digital signals. The voltages Va, Vc, and Vb digitally converted by the AD converter 401 are input to the calculation unit 402.
That is, when an external force is applied in which the relative positions of the first substrate 2 and the second substrate 3 are shifted in the B-axis direction, the AD converter 401 outputs the voltage Vb. Similarly, when an external force is applied in which the relative positions of the first substrate 2 and the second substrate 3 are shifted in the C-axis direction, the AD converter 401 outputs the voltage Vc. Further, when an external force is applied in which the relative positions of the first substrate 2 and the second substrate 3 are shifted in the A-axis direction, the AD converter 401 outputs a voltage Va.

  The arithmetic unit 402 performs, for example, each process such as correction for eliminating the difference in sensitivity between the conversion output circuits 90a, 90b, and 90c on the digitally converted voltages Va, Vc, and Vb. The arithmetic unit 402 outputs three signals proportional to the accumulated amounts of the charges Qa, Qc, and Qb output from the charge output element 10. Since these three signals correspond to the triaxial force (shearing force and compression / tensile force) applied to the charge output element 10, the force detection device 1 detects the triaxial force applied to the charge output element 10. can do.

  As shown in FIGS. 1 and 2, in the force detection device 1, a convex portion (first convex portion) 21 is provided on the first substrate 2. The first substrate 2 and the second substrate 3 have the convex portion 21 on the inside, and the surface of the first substrate 2 and the surface of the second substrate 3 are opposed to each other with a space therebetween. The upper surface (surface facing the second substrate 3) 211 of the convex portion 21 is a flat surface. The convex portion 21 may be formed integrally with the first substrate 2 or may be formed by a separate member. In addition, the constituent material of the convex part 21 is not specifically limited, For example, it can be the same as that of the 1st board | substrate 2. As shown in FIG.

Further, the position of the convex portion 21 is not particularly limited, but in the present embodiment, the convex portion 21 is disposed at the central portion of the first substrate 2.
In addition, the shape of the convex portion 21 is not particularly limited, but in the present embodiment, the shape is the same as that of the charge output element 10 in the plan view of the first substrate 2, that is, a quadrangle. In addition, as said other shape in planar view of the convex part 21, polygons, such as a square and a pentagon, an ellipse etc. are mentioned, for example.

  In addition, a hole 41 into which the convex portion 21 is inserted is formed in a portion of the analog circuit board 4 where the charge output element 10 is disposed, that is, in the central portion. The hole 41 is a through hole that penetrates the analog circuit board 4. The shape of the hole 41 is not particularly limited, but in the present embodiment, the shape is the same as that of the convex portion 21 in the plan view of the first substrate 2, that is, a quadrangle. The analog circuit board 4 is supported by the convex portion 21.

Similarly, a hole 51 into which the convex portion 21 is inserted is formed in a portion of the digital circuit board 5 where the charge output element 10 is disposed, that is, in the central portion. The shape of the hole 51 is not particularly limited, but in the present embodiment, the shape is the same as that of the convex portion 21 in the plan view of the first substrate 2, that is, a quadrangle. The digital circuit board 5 is supported by the convex portion 21.
The analog circuit board 4 has two holes 42 through which the two pressurizing bolts 71 are inserted. Similarly, the digital circuit board 5 has two holes 52 through which the two pressurizing bolts 71 are inserted. Is formed.

  The protrusion 21 is inserted into the hole 41 of the analog circuit board 4 and 51 of the digital circuit board 5 and protrudes toward the charge output element 10. The sensor device 6 is sandwiched between the convex portion 21 and the second substrate 3, whereby the charge output element 10 is sandwiched between the convex portion 21 and the second substrate 3 via the package 60. . Note that the lower surface (surface facing the first substrate 2) 36 of the second substrate 3 is a flat surface, and the lower surface 36 abuts against the central portion of the lid 62 of the sensor device 6 and the upper surface of the convex portion 21. 211 abuts the base 61.

  Further, the dimension of the convex portion 21 is not particularly limited, but the area of the convex portion 21 is preferably equal to or larger than the area of the charge output element 10 in a plan view of the first substrate 2. It is more preferable that it is larger than the above. In the configuration shown in the figure, the area of the convex portion 21 is larger than the area of the charge output element 10. The charge output element 10 is disposed in the convex portion 21 in a plan view of the first substrate 2 (viewed from a direction perpendicular to the first substrate 2), and the center of the charge output element 10 The line and the center line of the convex portion 21 coincide with each other. In this case, the charge output element 10 does not have to protrude from the convex portion 21 in the plan view of the first substrate 2. As a result, a pressure can be applied to the entire charge output element 10, and an external force is applied to the entire charge output element 10 during force detection, so that more accurate force detection can be performed.

  The first substrate 2 and the second substrate 3 are fixed by two pressurizing bolts 71. The “fixing” by the pressurizing bolt 71 is performed while allowing a predetermined amount of movement of the two fixed objects. Specifically, the first substrate 2 and the second substrate 3 are fixed by two pressurizing bolts 71 while allowing a predetermined amount of movement in the surface direction of the second substrate 3 to be allowed. . This also applies to other embodiments.

  Each pressurizing bolt 71 is arranged so that its head 715 is on the second substrate 3 side, and is inserted from the hole 35 formed in the second substrate 3, and the hole 42 of the analog circuit board 4. The male screw 716 is inserted into the hole 52 of the digital circuit board 5 and screwed into the female screw 25 formed on the first board 2. Each pressurizing bolt 71 applies a predetermined amount of pressure in the A-axis direction (see FIG. 4), that is, pressurization, to the charge output element 10. In addition, the magnitude | size of the said pressurization is not specifically limited, It sets suitably.

  Further, the position of each pressurizing bolt 71 is not particularly limited, but in the present embodiment, each pressurizing bolt 71 is located on the first board 2, the second board 3, the analog circuit board 4, or the digital circuit board 5. Along the circumferential direction, they are arranged so as to face each other through the charge output element 10 in equiangular intervals (180 ° intervals), that is, in a plan view of the second substrate 3. As a result, the first substrate 2 and the second substrate 3 can be fixed with good balance, and pressure can be applied to each charge output element 10 with good balance. The number of pressurizing bolts 71 is not limited to two, and may be three or more, for example.

In addition, it does not specifically limit as a constituent material of each pressurization volt | bolt 71, For example, various resin materials, various metal materials, etc. can be used.
As described above, according to the force detection device 1, the analog circuit board 4 and the digital circuit board 5 are provided between the first board 2 and the second board 3. can do.

Further, the sensor device 6 is sandwiched between the convex portion 21 and the second substrate 3 without the analog circuit substrate 4 and the digital circuit substrate 5, that is, the charge output element 10 is sandwiched via the package 60. be able to. Thereby, a sufficient pressure can be applied to the charge output element 10, and the accuracy of force detection can be improved.
Further, since the central portion 625 of the lid 62 of the package 60 protrudes toward the second substrate 3, it is sufficient for the charge output element 10 even if the lower surface 36 of the second substrate 3 is flat. Pressurization can be applied, and it is possible to prevent external force from becoming difficult to be applied during force detection. And since the lower surface 36 of the 2nd board | substrate 3 is a plane, alignment with the 2nd board | substrate 3 and the charge output element 10 becomes unnecessary at the time of manufacture, and the force detection apparatus 1 can be manufactured easily.

Next, the charge output element 10 will be described.
The charge output element 10 has a function of outputting three charges Qa, Qb, and Qc according to external forces applied (received) along three axes (A axis, B axis, and C axis) orthogonal to each other. Have. As shown in FIG. 7, the charge output element 10 includes a stacked body 110 that outputs charges Qa, Qb, and Qc, a first side terminal 120 for taking out the charge Qa from the stacked body 110, and the stacked body 110. It has a second side terminal 130 for taking out the charge Qb, a third side terminal 140 for taking out the charge Qc from the laminate 110, and a fourth side terminal 150 for grounding the laminate 110. ing.
The shape of the stacked body 110 is not particularly limited, but in the present embodiment, the stacked body 110 has a quadrangular shape when viewed from the top of the first substrate 2, that is, from a direction perpendicular to the first substrate 2. In addition, as said other external shape in planar view of the laminated body 110, other polygons, such as a pentagon, circular, an ellipse, etc. are mentioned, for example.

  As shown in FIG. 4, the laminate 110 responds to four ground electrode layers 11, 15, 16, and 17 grounded to the ground (reference potential point) and an external force (compression / tensile force) parallel to the A axis. The first sensor 12 that outputs the charge Qa, the second sensor 13 that outputs the charge Qb according to the external force (shearing force) parallel to the B axis, and the external force (shearing force) parallel to the C axis. And a third sensor 14 that outputs a charge Qc. In the charge output element 10, the ground electrode layer 11, the third sensor 14, the ground electrode layer 15, the first sensor 12, the ground electrode layer 16, the second sensor 13, and the ground electrode layer 17 are sequentially arranged in the A axis. Stacked from the negative direction. In FIG. 4, the stacking direction of the sensors 12, 13, and 14 is the A-axis direction, and the directions orthogonal to the A-axis direction and orthogonal to each other are the B-axis direction and C-axis direction, respectively.

The first sensor 12 has a function of outputting a charge Qa in accordance with an external force (compression / tensile force) applied (received) along the A axis. The first sensor 12 is configured to output a positive charge according to a compressive force parallel to the A axis and to output a negative charge according to a tensile force parallel to the A axis.
As shown in FIGS. 4 and 7, the first sensor 12 includes a first piezoelectric layer 121, a second piezoelectric layer 123 provided to face the first piezoelectric layer 121, It has an output electrode layer (internal electrode layer) 122 that is provided between the first piezoelectric layer 121 and the second piezoelectric layer 123 and outputs a charge Qa.

In the present specification, first and second piezoelectric layers 121 and 123, third and fourth piezoelectric layers 131 and 133 described later, and fifth and sixth piezoelectric layers 141 described later are described. , 143 are each composed of quartz, that is, a case where a quartz plate is used as these piezoelectric layers will be described as a representative.
The first piezoelectric layer 121 is composed of an X-cut quartz plate having three crystal axes orthogonal to each other, that is, an x axis (crystal axis x), a y axis (crystal axis y), and a z axis (crystal axis z). ing. As a result, the x-axis direction and the A-axis direction match, the y-axis direction and the B-axis direction match, and the z-axis direction and the C-axis direction match.
The first piezoelectric layer 121 has a hexagonal unit cell in which Si atoms and O atoms are alternately arranged at six apexes when viewed from the positive direction of the C axis (FIG. 5). (See (a)). This unit cell is in a state in which one of the three diagonal lines connecting Si atoms and O atoms is substantially parallel to the thickness direction of the first piezoelectric layer 121.

  When a compressive force parallel to the A axis is applied to the surface of the first piezoelectric layer 121, the unit cell is deformed so as to be crushed in the A axis direction as shown in FIG. . For this reason, two Si atoms adjacent to the O atom adjacent to the output electrode layer 122 are brought closer to the output electrode layer 122 as shown in FIG. 5A and adjacent to the Si atom adjacent to the ground electrode layer 16. The matching two O atoms are brought closer to the ground electrode layer 16 as shown in FIG. As a result, the positive charge is biased near the surface of the first piezoelectric layer 121 on the output electrode layer 122 side, and the negative charge is biased near the surface of the first piezoelectric layer 121 on the ground electrode layer 16 side. .

  On the contrary, when a tensile force parallel to the A axis is applied to the surface of the first piezoelectric layer 121, the unit cell is stretched in the A axis direction as shown in FIG. To be deformed. For this reason, two Si atoms adjacent to the O atom adjacent to the output electrode layer 122 are separated from the output electrode layer 122 as shown in FIG. 5A and adjacent to the Si atom adjacent to the ground electrode layer 16. The matching two O atoms are separated from the ground electrode layer 16 as shown in FIG. As a result, negative charge is biased near the surface of the first piezoelectric layer 121 on the output electrode layer 122 side, and positive charge is biased near the surface of the first piezoelectric layer 121 on the ground electrode layer 16 side. .

The second piezoelectric layer 123 has the same crystal axis as that of the first piezoelectric layer 121, and is arranged in a state where the first piezoelectric layer 121 is rotated 180 ° around the C axis. ing. That is, in the second piezoelectric layer 123, the unit cell is vertically inverted with respect to the first piezoelectric layer 121 when viewed from the positive direction of the C axis.
Therefore, when a compressive force parallel to the A axis is applied to the surface of the second piezoelectric layer 123, positive charges are biased near the surface of the second piezoelectric layer 123 on the output electrode layer 122 side, In the vicinity of the surface of the second piezoelectric layer 123 on the ground electrode layer 15 side, negative charges are biased. On the contrary, when a tensile force parallel to the A axis is applied to the surface of the second piezoelectric layer 123, a negative charge is present in the vicinity of the surface of the second piezoelectric layer 123 on the output electrode layer 122 side. In the vicinity of the surface of the second piezoelectric layer 123 on the ground electrode layer 15 side, the positive charge is biased.

The output electrode layer 122 has a function of outputting positive charges or negative charges generated in the first piezoelectric layer 121 and the second piezoelectric layer 123 as charges Qa.
As described above, when a compressive force parallel to the A axis is applied to the surface of the first piezoelectric layer 121 or the surface of the second piezoelectric layer 123, a positive charge is biased near the output electrode layer 122. It becomes the state. As a result, in the output electrode layer 122, negative charges are collected on the first and second piezoelectric layers 121 and 123 side by electrostatic induction, and positive charges are on the opposite side to the first and second piezoelectric layers 121 and 123. Gather. Therefore, positive charge Qa is output from the output electrode layer 122.

  On the other hand, when a tensile force parallel to the A axis is applied to the surface of the first piezoelectric layer 121 or the surface of the second piezoelectric layer 123, the negative charge is biased near the output electrode layer 122. Become. As a result, in the output electrode layer 122, positive charges are collected on the first and second piezoelectric layers 121 and 123 side due to electrostatic induction, and negative charges are on the opposite side to the first and second piezoelectric layers 121 and 123. Gather. Therefore, the negative charge Qa is output from the output electrode layer 122.

The second sensor 13 has a function of outputting a charge Qb according to an external force (shearing force) applied (received) along the B axis. The second sensor 13 is configured to output a positive charge according to an external force applied along the positive direction of the B axis and to output a negative charge according to an external force applied along the negative direction of the B axis. Has been.
The second sensor 13 is arranged on the positive side of the first axis of the first sensor 12 so as to face the first sensor 12. The second sensor includes a third piezoelectric layer 131, a fourth piezoelectric layer 133 provided to face the third piezoelectric layer 131, the third piezoelectric layer 131, and the fourth piezoelectric layer 131. It has an output electrode layer (internal electrode layer) 132 that is provided between the piezoelectric layer 133 and outputs a charge Qb.

The third piezoelectric layer 131 is composed of a Y-cut quartz plate having three crystal axes that are orthogonal to each other, that is, an x axis (crystal axis x), a y axis (crystal axis y), and a z axis (crystal axis z). ing. As a result, in the third piezoelectric layer 131, the x-axis direction and the B-axis direction coincide with each other, the y-axis direction and the A-axis direction coincide with each other, and the z-axis direction and the C-axis direction coincide with each other. I'm doing it.
The third piezoelectric layer 131 has a hexagonal unit cell in which Si atoms and O atoms are alternately arranged at six vertices when viewed from the negative direction of the C axis (FIG. 6). (See (a)). This unit cell is in a state in which one of the three diagonal lines connecting Si atoms and O atoms is almost perpendicular to the thickness direction of the third piezoelectric layer 131.

  When an external force along the positive direction of the B-axis is applied to the surface of the third piezoelectric layer 131, the unit cell is inclined in the positive direction of the B-axis as shown in FIG. Deformed). Therefore, O atoms out of O atoms and Si atoms arranged in the direction (plane direction) substantially perpendicular to the thickness direction of the third piezoelectric layer 131 on the output electrode layer 132 side are shown in FIG. The Si atoms out of the O atoms and the Si atoms that are separated from the output electrode layer 132 and arranged in the plane direction of the third piezoelectric layer 131 on the ground electrode layer 17 side are grounded as shown in FIG. The state is separated from the electrode layer 16. As a result, the positive charge is biased near the surface of the third piezoelectric layer 131 on the output electrode layer 132 side, and the negative charge is biased near the surface of the third piezoelectric layer 131 on the ground electrode layer 17 side. .

  On the contrary, when an external force along the negative direction of the B axis is applied to the surface of the third piezoelectric layer 131, the unit cell has the B axis as shown in FIG. It deforms so as to incline (distort) in the negative direction. Therefore, Si atoms out of the O atoms and Si atoms arranged in the plane direction of the third piezoelectric layer 131 on the output electrode layer 132 side are in a state separated from the output electrode layer 132 from FIG. At the same time, O atoms among O atoms and Si atoms arranged in the plane direction of the third piezoelectric layer 131 on the ground electrode layer 17 side are in a state of being separated from the ground electrode layer 17 as shown in FIG. As a result, negative charges are biased near the surface of the third piezoelectric layer 131 on the output electrode layer 132 side, and positive charges are biased near the surface of the third piezoelectric layer 131 on the ground electrode layer 17 side. .

The fourth piezoelectric layer 133 has the same crystal axis as that of the third piezoelectric layer 131, and is arranged in a state where the third piezoelectric layer 131 is rotated by 180 ° around the B axis. ing. That is, in the fourth piezoelectric layer 133, the unit cell is vertically inverted with respect to the third piezoelectric layer 131 when viewed from the negative direction of the C axis.
Therefore, when an external force along the positive direction of the B axis is applied to the surface of the fourth piezoelectric layer 133, positive charges are biased near the surface of the fourth piezoelectric layer 133 on the output electrode layer 132 side. In the vicinity of the surface of the fourth piezoelectric layer 133 on the ground electrode layer 16 side, negative charges are biased. Conversely, when an external force along the negative direction of the B-axis is applied to the surface of the fourth piezoelectric layer 133, the surface of the fourth piezoelectric layer 133 near the output electrode layer 132 side is not present. Negative charge is biased, and the positive charge is biased near the surface of the fourth piezoelectric layer 133 on the ground electrode layer 16 side.

The output electrode layer 132 has a function of outputting positive charges or negative charges generated in the third piezoelectric layer 131 and the fourth piezoelectric layer 133 as charges Qb.
As described above, when an external force along the positive direction of the B axis is applied to the surface of the third piezoelectric layer 131 or the surface of the fourth piezoelectric layer 133, a positive charge is present in the vicinity of the output electrode layer 132. Becomes a biased state. As a result, in the output electrode layer 132, negative charges are collected on the third and fourth piezoelectric layers 131 and 133 by electrostatic induction, and positive charges are on the opposite side of the third and fourth piezoelectric layers 131 and 133. Gather. Therefore, positive charge Qb is output from the output electrode layer 132.

  On the other hand, when an external force along the negative direction of the B axis is applied to the surface of the third piezoelectric layer 131 or the surface of the fourth piezoelectric layer 133, negative charges are biased in the vicinity of the output electrode layer 132. It becomes a state. As a result, in the output electrode layer 132, positive charges are collected on the third and fourth piezoelectric layers 131 and 133 due to electrostatic induction, and negative charges are on the opposite side of the third and fourth piezoelectric layers 131 and 133. Gather. Therefore, the negative charge Qb is output from the output electrode layer 132.

The third sensor 14 has a function of outputting a charge Qc according to an external force (shearing force) applied (received) along the C axis. The third sensor 14 is configured to output a positive charge according to an external force applied along the positive direction of the C axis and to output a negative charge according to an external force applied along the negative direction of the C axis. Has been.
The third sensor 14 is provided on the opposite side of the first sensor 12 from the second sensor 13, that is, on the negative side of the A axis, facing the first sensor 12. The third sensor 14 includes a fifth piezoelectric layer 141, a sixth piezoelectric layer 143 provided to face the fifth piezoelectric layer 141, a fifth piezoelectric layer 141, and a sixth piezoelectric layer 141. And an output electrode layer (internal electrode layer) 142 that outputs a charge Qc.

The fifth piezoelectric layer 141 is composed of a Y-cut quartz plate having three crystal axes orthogonal to each other, that is, an x axis (crystal axis x), a y axis (crystal axis y), and a z axis (crystal axis z). Yes. As a result, in the fifth piezoelectric layer 141, the x-axis direction and the C-axis direction coincide with each other, the y-axis direction and the A-axis direction coincide with each other, and the z-axis direction and the B-axis direction coincide with each other. I'm doing it.
The fifth piezoelectric layer 141 has a unit lattice in the same state as described in the third piezoelectric layer 131 when viewed from the positive direction of the B axis.

When an external force along the positive direction of the C-axis is applied to the surface of the fifth piezoelectric layer 141, the output electrode layer 142 of the fifth piezoelectric layer 141 is the same as the third piezoelectric layer 131. The positive charge is biased near the side surface, and the negative charge is biased near the ground electrode layer 15 surface of the fifth piezoelectric layer 141. Conversely, when an external force along the negative direction of the C-axis is applied to the surface of the fifth piezoelectric layer 141, the surface of the fifth piezoelectric layer 141 near the output electrode layer 142 side is not The negative charge is biased, and the positive charge is biased near the surface of the fifth piezoelectric layer 141 on the ground electrode layer 15 side.
The sixth piezoelectric layer 143 has the same crystal axis as that of the fifth piezoelectric layer 141, and is arranged in a state in which the fifth piezoelectric layer 141 is rotated by 180 ° around the B axis. ing. That is, in the sixth piezoelectric layer 143, the unit cell is vertically inverted with respect to the fifth piezoelectric layer 141 when viewed from the positive direction of the B axis.

  When an external force along the positive direction of the C axis is applied to the surface of the sixth piezoelectric layer 143, the output electrode layer 142 of the sixth piezoelectric layer 143 is the same as the fourth piezoelectric layer 133. The positive charge is biased near the side surface, and the negative charge is biased near the ground electrode layer 11 side surface of the sixth piezoelectric layer 143. On the other hand, when an external force along the negative direction of the C axis is applied to the surface of the sixth piezoelectric layer 143, the surface of the sixth piezoelectric layer 143 is not near the output electrode layer 142 side surface. Negative charge is biased, and the positive charge is biased near the surface of the sixth piezoelectric layer 143 on the ground electrode layer 11 side.

The output electrode layer 142 has a function of outputting positive charges or negative charges generated in the fifth piezoelectric layer 141 and the sixth piezoelectric layer 143 as charges Qc.
As described above, when an external force along the positive direction of the C-axis is applied to the surface of the fifth piezoelectric layer 141 or the surface of the sixth piezoelectric layer 143, a positive charge is present in the vicinity of the output electrode layer 142. Becomes a biased state. As a result, in the output electrode layer 142, due to electrostatic induction, negative charges are collected on the fifth and sixth piezoelectric layers 141 and 143, and on the opposite side to the fifth and sixth piezoelectric layers 141 and 143, Charge collects. Therefore, positive charge Qc is output from the output electrode layer 142.

  On the other hand, when an external force along the negative direction of the C axis is applied to the surface of the fifth piezoelectric layer 141 or the surface of the sixth piezoelectric layer 143, negative charges are biased in the vicinity of the output electrode layer 142. It becomes a state. In the output electrode layer 142, positive charges gather on the fifth and sixth piezoelectric layers 141 and 143 side due to electrostatic induction, and negative charges gather on the opposite side to the fifth and sixth piezoelectric layers 141 and 143. . As a result, a negative charge Qc is output from the output electrode layer 142.

  Thus, the third sensor 14, the second sensor 13, and the first sensor 12 are stacked so that the force detection directions of the sensors are orthogonal to each other. Thereby, each sensor can induce an electric charge according to force components orthogonal to each other. Therefore, the charge output element 10 can output three charges Qa, Qb, and Qc according to external forces (strains) along the three axes (A axis, B axis, and C axis).

In particular, in the present embodiment, the first sensor 12 (X-cut plate) is between the second sensor 13 (first Y-cut plate) and the third sensor 14 (second Y-cut plate). Is provided. In the charge output element 10 having such a configuration, an external force (compression / tensile force) applied (received) along the A-axis direction can be detected with higher sensitivity.
In each of the sensors 12, 13, and 14, two piezoelectric layers are disposed in a state where the piezoelectric layers are rotated by 180 ° around the B axis or the C axis. Thereby, as compared with the case where each sensor is constituted by only one of the two piezoelectric layers and the output electrode layer, it is possible to increase the positive charge or the negative charge biased near the output electrode layer. As a result, the charges Qa to Qc output from the output electrode layer can be increased.

Each piezoelectric layer can be made of a material (piezoelectric material) having a crystal structure similar to that of quartz. Examples of such materials include topaz, barium titanate, lead titanate, lead zirconate titanate (PZT: Pb (Zr, Ti) O ₃ ), lithium niobate, lithium tantalate, and the like. These can be used alone or in combination of two or more. However, quartz is preferable because it has excellent characteristics such as a wide dynamic range, high rigidity, high natural frequency, and high load resistance.

The material used for the piezoelectric layer of the first sensor 12, the material used for the piezoelectric layer of the second sensor 13, and the material used for the piezoelectric layer of the third sensor 14 may be the same. Well, it can be different.
As illustrated in FIG. 7, the stacked body 110 includes four side surfaces 110 a to 110 d. Of these side surfaces, the two side surfaces 110a and 110c are side surfaces having the B axis (the crystal axis y of the first and second piezoelectric layers 121 and 123) as a normal line, and the two side surfaces 110b and 110d are , And the C axis (the crystal axes z of the first and second piezoelectric layers 121 and 123) are normal sides.

  As shown in FIGS. 7 and 8, in the present embodiment, the first side terminal 120 connected to the output electrode layer 122 for extracting the charge Qa and the output electrode layer 132 connected to extract the charge Qb. The second side surface terminal 130 is provided on the second side surface 110b. The fourth side surface is connected to the output electrode layer 142 and connected to the third side surface terminal 140 for taking out the charge Qc, and the ground electrode layers 11, 15, 16, and 17, and the laminated body 110 is grounded. A terminal 150 is provided on the fourth side surface 110d.

Further, each of the side terminals 120 to 150 has a long shape (a belt shape in a side view) along the thickness direction of the stacked body 110, and the output electrode layers 122, 132, 142 arranged in the same thickness direction. Etc. are electrically connected. With this configuration, electrical connection with a plurality of output electrode layers is possible at once.
As shown in FIG. 8, each electrode layer includes an electrode main body 191 and a connection portion 192 that protrudes laterally from the electrode main body 191 and is integrally formed with the electrode main body 191. Each electrode layer is selectively connected to the corresponding side terminals 120 to 150 by changing the position of the connecting portion 192. By setting it as this structure, it does not short-circuit between the side terminals 120-150.

  Here, conventionally, when the side terminals 120 to 150 are provided in the laminated body 110, as disclosed in Patent Document 1, it is common to provide one side terminal 120 to 150 on one side 110a to 110d. is there. In such a configuration, two of the side terminals 120 to 150 inevitably have the first piezoelectric layer 121 and / or the second piezoelectric layer 123 (hereinafter collectively referred to as “X-cut plate”). ”) Is in contact with the surface having the B axis (crystal axis y) as a normal line.

  In this case, when the side terminal is thermally deformed (thermal expansion or contraction), a compressive force or a tensile force in the B-axis direction is applied to the X-cut plate. When a compressive force in the B-axis direction is applied to the X-cut plate, as shown in FIG. 5C, the unit lattice in the X-cut plate is crushed in the B-axis direction (so as to be stretched in the A-axis direction). ) And positive charges are output from the output electrode layer 122. On the other hand, when a tensile force in the B-axis direction is applied to the X-cut plate, as shown in FIG. 5B, the unit lattice in the X-cut plate is stretched in the B-axis direction (pressed in the A-axis direction). As a result, the output electrode layer 122 outputs negative charges. Such a charge is detected as an unnecessary signal, and the force detection device 1 determines that an external force is applied to the charge output element 10 even though no external force is applied to the charge output element 10. End up.

  Therefore, in the present invention, the side terminals 120 to 150 are not provided on the side surfaces 110a and 110c whose normal is the B axis (crystal axis y) of the X cut plate, and the A axis (crystal axis z) of the X cut plate is used. They are provided on the side surfaces 110b and 110d that are normal lines. With this configuration, even if each of the side terminals 120 to 150 is thermally deformed, it can be prevented or reduced that the force detection device 1 determines that an external force has been applied to the charge output element 10. .

  In the Y cut plate constituting the X cut plate and the third and fourth piezoelectric layers 131 and 133, the O atom and the Si atom are arranged in a spiral shape in the C axis direction (z axis direction). (Not shown). Therefore, when a compressive force in the C-axis direction is applied to these cut plates, this spiral is only crushed in the C-axis direction, and the hexagonal unit cell as described above maintains its shape. For this reason, there is no or very small charge bias (piezoelectric effect) in the thickness direction.

  In addition, in the Y-cut plates constituting the fifth and sixth piezoelectric layers 141 and 143, as shown in FIG. 9, when a compressive force in the C-axis direction is applied, the above-described hexagonal unit cell becomes Y Although deformed so as to be crushed in a direction substantially perpendicular to the thickness direction of the cut plate, the O and Si atoms aligned in the plane direction on the output electrode layer 142 and ground electrode layers 11 and 15 side, the output electrode layer 142 and The distance to the ground electrode layers 11 and 15 hardly changes. For this reason, there is no or very small charge bias (piezoelectric effect) in the thickness direction.

  Thus, in the present invention, the side terminals 120 to 150 are provided on the side surfaces 110b and 110d having the z-axis of the X-cut plate as a normal line, in other words, the y-axis of the X-cut plate is defined as a normal line. By providing them in a region other than the surface to be charged, even if they are thermally deformed (thermal expansion or thermal contraction), the charge output element 10 is not detected as an unnecessary external force. That is, according to the present invention, the detection accuracy of the charge output element 10 can be further increased.

  Each of the side terminals 120 to 150 can be formed of, for example, Ag paste, Cu paste, Au paste, or the like, but it is particularly preferable to use Ag paste. Ag paste is easily available and has excellent handling properties. Moreover, the thermal expansion coefficient of Ag paste is extremely larger than the thermal expansion coefficient in the y-axis direction (B-axis direction) of the X-cut plate. Therefore, the effect of the present invention is particularly prominent when the side terminals 120 to 150 are formed of Ag paste.

  Further, in the present embodiment, the longest fourth side terminal 150 and the shortest third side terminal 140 are provided on the same side 110d, the second longest second side terminal 130, and the third The long first side surface terminal 120 is provided on the same side surface 110b. Further, the longest fourth side terminal 150 and the second longest second side terminal 130 are provided at diagonal positions in plan view of the laminate 110, and the shortest third side terminal 140, 3 The first long side surface terminal 120 is provided at a diagonal position in plan view of the laminate 110. With this configuration, the mechanical strength variation in the B-axis direction of the charge output element 10 can be reduced. As a result, even if the side terminals 120 to 150 are thermally deformed, it is possible to effectively prevent or reduce the occurrence of twisting or the like in the laminate 110.

  The first to third side terminals 120 to 140 are formed to have the same length as the fourth side terminal 150 from the viewpoint of particularly reducing variation in mechanical strength in the B-axis direction of the charge output element 10. May be. Even in such a configuration, as described above, each electrode layer is formed in a shape including the connection portion 192 that protrudes laterally from the electrode main body 191, and therefore, the first to fourth side terminals 120 to 150 are connected to each other. There is no short circuit between them.

In the present embodiment, two side terminals are provided on each of the second side face 110b and the fourth side face 110d, which are two opposing faces, but the second side face 110b and the fourth side face are provided. Four side terminals may be provided on one of the side surfaces 110d, and one side terminal may be provided on one side and three side terminals may be provided on the other side.
In addition to the side terminals 120 to 150, the second side face 110b and / or the fourth side face 110d may be provided with one or more dummy side terminals that are not intended for electrical connection. As a result, the mechanical strength of the charge output element 10 can be increased.

  Each of the side terminals 120 to 150 is a region other than the surface having the y-axis of the X-cut plate as a normal line, that is, the side terminals in contact with the X-cut plate (in this embodiment, the first, second, and fourth). The external force applied along the y-axis direction (B-axis direction) is smaller than the external force applied along the z-axis direction (C-axis direction) of the X-cut plate due to thermal deformation of the side terminals 120, 130, 150). For example, the following configuration may be employed.

  In the charge output element 10 shown in FIG. 10, a first side terminal 120 that is circular in a side view is provided at a position corresponding to the first sensor 12 on the second side surface 110b, and the second side of the third side surface 110c. A second side terminal 130 that is circular in a side view is provided at a position corresponding to the sensor 14, and a third side surface that is circular in a side view at a position corresponding to the third sensor 14 on the first side 110a. A terminal 140 is provided, and a belt-like fourth side terminal 150 is provided on the fourth side face 110d in a side view. According to such a configuration, since a rectangular metal foil (metal sheet) can be used for each electrode layer, the manufacturing cost of the charge output element 10 can be reduced.

  Further, in the charge output element 10 shown in FIG. 11, the shape of the laminate 110 in plan view is substantially circular (or elliptical), and the side terminals 120 to 150 are biased toward the upper side and the lower side in the figure. Is provided. According to this configuration, when the first, second, and fourth side terminals 120, 130, and 150 that contact the X-cut plate (first sensor 12) are thermally deformed, the y-axis direction (B Even if an external force is applied along the axial direction), the magnitude is much smaller than the external force applied along the z-axis direction (C-axis direction) of the X-cut plate.

Furthermore, at least the output electrode layer 122 and the ground electrode layers 15 and 16 provided in contact with the X-cut plate have a thermal expansion coefficient that is as large as possible in the B-axis direction (y-axis direction) of the X-cut plate. It is preferable to be close. As a result, when the charge output element 10 is thermally deformed, the X-cut plate, the output electrode layer 122, and the ground electrode layers 15 and 16 are deformed at an approximate contraction rate or elongation rate. For this reason, unnecessary compressive stress or shrinkage stress in the B-axis direction can be prevented or suppressed from being applied to the X-cut plate. As a result, the detection accuracy of the charge output element 10 can be further increased.
This difference in thermal expansion coefficient is preferably 10% or less of the thermal expansion coefficient along the y-axis direction of the X-cut plate, more preferably 8% or less, and even more preferably 5% or less. . As a result, the X-cut plate, the output electrode layer 122, and the ground electrode layers 15 and 16 are deformed at substantially the same shrinkage rate or elongation rate.

Examples of the constituent material of the electrode layer that can satisfy such conditions include Ni, Co, Bi, etc., and one or more of these can be used in combination. These materials are preferable because they have a thermal expansion coefficient close to that of the piezoelectric material (particularly, SiO ₂ ) as described above.
In addition, it is preferable to comprise all the electrode layers with the same material. Thereby, it can prevent or suppress more reliably that unnecessary compressive stress or shrinkage stress in the B-axis direction is applied to the X-cut plate.

Second Embodiment
12 is a plan view showing a second embodiment of the force detection device (sensor element) according to the present invention, FIG. 13 is a cross-sectional view taken along line AA in FIG. 12, and FIG. 14 is shown in FIG. It is a circuit diagram which shows a force detection apparatus roughly.
Hereinafter, the second embodiment will be described with a focus on the differences from the first embodiment described above, and the description of the same matters will be omitted.

The force detection device 1 of the second embodiment shown in FIGS. 12 and 13 has a function of detecting an external force (including moment), that is, a six-axis force (translation force component (shearing force) in the A, B, and C axis directions). And a function of detecting a rotational force component (moment) around the A, B, and C axes.
As shown in FIGS. 12 and 13, the force detection device 1 has four sensor devices 6 and four pressurizing bolts 71. Although the position of each sensor device 6 is not particularly limited, in this embodiment, each sensor device 6, that is, each charge output element 10, is arranged around the first substrate 2, the second substrate 3, and the analog circuit substrate 4. Along the direction, they are arranged at equiangular intervals (90 ° intervals). Thereby, an external force can be detected without deviation. And a six-axis force can be detected. In the present embodiment, all the charge output elements 10 face the same direction, but the present invention is not limited to this.
The first substrate 2 is provided with four convex portions 21 so as to correspond to the sensor devices 6. Since the convex portion 21 has been described in the first embodiment, the description thereof is omitted.

  The number of sensor devices 6 is not limited to the above four, and may be two, three, five, or more, for example. However, the number of sensor devices 6 is preferably plural, and more preferably three or more. In addition, if the force detection apparatus 1 has at least three sensor devices 6, it can detect a six-axis force. When there are three sensor devices 6, since the number of sensor devices 6 is small, the force detection apparatus 1 can be reduced in weight. Further, when there are four sensor devices 6 as shown in the figure, the 6-axis force can be obtained by a very simple calculation to be described later, so that the calculation unit 402 can be simplified.

<Conversion output circuit>
As shown in FIG. 14, conversion output circuits 90a, 90b, and 90c are connected to each charge output element 10 respectively. Since each of the conversion output circuits 90a, 90b, and 90c is the same as the conversion output circuit 90 of the first embodiment described above, description thereof is omitted.
<External force detection circuit>
The external force detection circuit 40 includes voltages Va1, Va2, Va3, Va4 output from each conversion output circuit 90a, voltages Vb1, Vb2, Vb3, Vb4 output from each conversion output circuit 90b, and each conversion output circuit 90c. Based on the output voltages Vc1, Vc2, Vc3, and Vc4, it has a function of detecting the applied external force. The external force detection circuit 40 includes an AD converter 401 connected to the conversion output circuits 90a, 90b, and 90c, and an arithmetic unit 402 connected to the AD converter 401.

  The AD converter 401 has a function of converting the voltages Va1, Vc1, Vb1, Va2, Vc2, Vb2, Va3, Vc3, Vb3, Va4, Vc4, and Vb4 from analog signals to digital signals. Voltages Va 1, Vc 1, Vb 1, Va 2, Vc 2, Vb 2, Va 3, Vc 3, Vb 3, Va 4, Vc 4, Vb 4 digitally converted by the AD converter 401 are input to the arithmetic unit 402.

  That is, when an external force is applied in which the relative positions of the first substrate 2 and the second substrate 3 are shifted in the A-axis direction, the AD converter 401 outputs the voltages Va1, Va2, Va3, and Va4. Similarly, when an external force is applied in which the relative positions of the first substrate 2 and the second substrate 3 are shifted in the C-axis direction, the AD converter 401 outputs voltages Vc1, Vc2, Vc3, and Vc4. Further, when an external force is applied in which the relative positions of the first substrate 2 and the second substrate 3 are shifted in the B-axis direction, the AD converter 401 outputs voltages Vb1, Vb2, Vb3, and Vb4.

Further, the first substrate 2 and the second substrate 3 are capable of relative displacement rotating around the A axis, relative displacement rotating around the B axis, and relative displacement rotating around the C axis. It is possible to transmit the external force accompanying to the charge output element 10.
The calculation unit 402 translates the translational force component Fa in the A-axis direction and the translation in the C-axis direction based on the digitally converted voltages Va1, Vc1, Vb1, Va2, Vc2, Vb2, Va3, Vc3, Vb3, Va4, Vc4, and Vb4. It has a function of calculating a force component Fc, a translational force component Fb in the B-axis direction, a rotational force component Ma around the A axis, a rotational force component Mc around the C axis, and a rotational force component Mb around the B axis. Each force component can be obtained by the following equation.

Fa = Va1 + Va2 + Va3 + Va4
Fc = Vc1 + Vc2 + Vc3 + Vc4
Fb = Vb1 + Vb2 + Vb3 + Vb4
Ma = k × (Vb4-Vb2)
Mc = j × (Vb3−Vb1)
Mb = k × (Va2−Va4) + a × (Vc1−Vc3)
Here, j and k are constants.
Thus, the force detection device 1 can detect six-axis forces.

Note that the arithmetic unit 402 may perform, for example, correction that eliminates the difference in sensitivity between the conversion output circuits 90a, 90b, and 90c.
As shown in FIGS. 12 and 13, the first substrate 2 and the second substrate 3 are fixed by four pressurizing bolts 71. The number of pressurizing bolts 71 is not limited to four, and may be two, three, five, or more, for example.

Further, the position of each pressurizing bolt 71 is not particularly limited, but in the present embodiment, each pressurizing bolt 71 is located on the first board 2, the second board 3, the analog circuit board 4, or the digital circuit board 5. They are arranged at equiangular intervals (90 ° intervals) along the circumferential direction. As a result, the first substrate 2 and the second substrate 3 can be fixed with good balance, and pressure can be applied to each charge output element 10 with good balance.
According to the force detection device 1, the same effect as that of the first embodiment described above can be obtained.

<Embodiment of single arm robot>
Next, based on FIG. 15, a single-arm robot which is an embodiment of the robot of the present invention will be described. Hereinafter, the present embodiment will be described with a focus on differences from the first and second embodiments described above, and descriptions of similar matters will be omitted.
FIG. 15 is a diagram showing an example of a single-arm robot using the force detection device (sensor element) of the present invention. 15 includes a base 510, an arm 520, an end effector 530 provided on the distal end side of the arm 520, and a force detection device 1 provided between the arm 520 and the end effector 530. Have In addition, as the force detection apparatus 1, the thing similar to each embodiment mentioned above is used.

The base 510 has a function of accommodating an actuator (not shown) that generates power for rotating the arm 520, a control unit (not shown) that controls the actuator, and the like. The base 510 is fixed on, for example, a floor, a wall, a ceiling, or a movable carriage.
The arm 520 includes a first arm element 521, a second arm element 522, a third arm element 523, a fourth arm element 524, and a fifth arm element 525, and rotates adjacent arms. It is configured by linking freely. The arm 520 is driven by being rotated or bent in a compound manner around the connecting portion of each arm element under the control of the control unit.

The end effector 530 has a function of gripping an object. The end effector 530 has a first finger 531 and a second finger 532. After the end effector 530 reaches a predetermined operating position by driving the arm 520, the object can be gripped by adjusting the distance between the first finger 531 and the second finger 532.
The end effector 530 is a hand here, but the present invention is not limited to this. Other examples of the end effector include, for example, a component inspection device, a component transport device, a component processing device, a component assembly device, and a measuring instrument. The same applies to the end effectors in other embodiments.

The force detection device 1 has a function of detecting an external force applied to the end effector 530. By feeding back the force detected by the force detection device 1 to the control unit of the base 510, the single-arm robot 500 can perform more precise work. Further, the single arm robot 500 can detect contact of the end effector 530 with an obstacle or the like by the force detected by the force detection device 1. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like, which are difficult with conventional position control, can be easily performed, and the single-arm robot 500 can perform work more safely.
In the illustrated configuration, the arm 520 includes a total of five arm elements, but the present invention is not limited to this. When the arm 520 is constituted by one arm element, when constituted by 2 to 4 arm elements, and when constituted by 6 or more arm elements, it is within the scope of the present invention. .

<Embodiment of double-arm robot>
Next, a multi-arm robot which is an embodiment of the robot of the present invention will be described with reference to FIG. Hereinafter, the present embodiment will be described focusing on the differences from the first and second embodiments described above and the single-arm robot embodiment, and description of similar matters will be omitted.
FIG. 16 is a diagram showing an example of a multi-arm robot using the force detection device (sensor element) of the present invention. The multi-arm robot 600 of FIG. 16 includes a base 610, a first arm 620, a second arm 630, a first end effector 640a provided on the distal end side of the first arm 620, and a second A second end effector 640b provided on the distal end side of the arm 630, and between the first arm 620 and the first end effector 640a and between the second arm 630 and the second end effector 640b. A force detection device 1 is provided. In addition, as the force detection apparatus 1, the thing similar to each embodiment mentioned above is used.

The base 610 has a function of accommodating an actuator (not shown) that generates power for rotating the first arm 620 and the second arm 630, a control unit (not shown) that controls the actuator, and the like. Have. The base 610 is fixed on, for example, a floor, a wall, a ceiling, or a movable carriage.
The 1st arm 620 is comprised by connecting the 1st arm element 621 and the 2nd arm element 622 so that rotation is possible. The second arm 630 is configured by rotatably connecting the first arm element 631 and the second arm element 632. The first arm 620 and the second arm 630 are driven by being complexly rotated or bent around the connecting portion of each arm element under the control of the control unit.

  The first and second end effectors 640a and 640b have a function of gripping an object. The first end effector 640a has a first finger 641a and a second finger 642a. The second end effector 640b has a first finger 641b and a second finger 642b. After the first end effector 640a reaches a predetermined operating position by driving the first arm 620, the object is grasped by adjusting the distance between the first finger 641a and the second finger 642a. Can do. Similarly, after the second end effector 640b reaches a predetermined operating position by driving the second arm 630, the distance between the first finger 641b and the second finger 642b is adjusted to thereby adjust the object. It can be gripped.

The force detection device 1 has a function of detecting an external force applied to the first and second end effectors 640a and 640b. By feeding back the force detected by the force detection device 1 to the control unit of the base 610, the multi-arm robot 600 can perform the operation more precisely. The multi-arm robot 600 can detect contact of the first and second end effectors 640a and 640b with an obstacle by the force detected by the force detection device 1. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like that have been difficult with conventional position control can be easily performed, and the multi-arm robot 600 can perform the operation more safely.
In the illustrated configuration, there are a total of two arms, but the present invention is not limited to this. The case where the multi-arm robot 600 has three or more arms is also within the scope of the present invention.

<Embodiments of Electronic Component Inspection Device and Electronic Component Transfer Device>
Next, based on FIG. 17, FIG. 18, the electronic component inspection apparatus and electronic component conveyance apparatus which are embodiment of this invention are demonstrated. Hereinafter, the present embodiment will be described with a focus on differences from the first and second embodiments described above, and descriptions of similar matters will be omitted.
FIG. 17 is a diagram illustrating an example of an electronic component inspection device and a component transport device that use the force detection device (sensor element) of the present invention. FIG. 18 is a diagram showing an example of an electronic component transport apparatus using the force detection device (sensor element) of the present invention.

  The electronic component inspection apparatus 700 of FIG. 17 includes a base 710 and a support base 720 provided upright on the side surface of the base 710. On the upper surface of the base 710, an upstream stage 712u on which the electronic component 711 to be inspected is placed and transported, and a downstream stage 712d on which the inspected electronic component 711 is placed and transported are provided. ing. Further, between the upstream stage 712u and the downstream stage 712d, an imaging device 713 for confirming the posture of the electronic component 711, and an inspection table 714 on which the electronic component 711 is set for inspecting electrical characteristics. And are provided. Examples of the electronic component 711 include semiconductors, semiconductor wafers, display devices such as CLD and OLED, crystal devices, various sensors, inkjet heads, various MEMS devices, and the like.

  Further, the support stage 720 is provided with a Y stage 731 that can move in a direction (Y (B) direction) parallel to the upstream stage 712u and the downstream stage 712d of the base 710. The arm portion 732 extends in the direction toward the base 710 (X (C) direction). An X stage 733 is provided on the side surface of the arm 732 so as to be movable in the X direction. The X stage 733 is provided with an imaging camera 734 and an electronic component transfer device 740 incorporating a Z stage movable in the vertical direction (Z (A) direction). In addition, a gripping portion 741 that grips the electronic component 711 is provided on the front end side of the electronic component transport apparatus 740. Further, the force detection device 1 is provided between the tip of the electronic component transport device 740 and the grip portion 741. Further, on the front side of the base 710, a control device 750 for controlling the overall operation of the electronic component inspection device 700 is provided. In addition, as the force detection apparatus 1, the thing similar to each embodiment mentioned above is used.

  The electronic component inspection apparatus 700 inspects the electronic component 711 as follows. First, the electronic component 711 to be inspected is placed on the upstream stage 712u and moved to the vicinity of the inspection table 714. Next, the Y stage 731 and the X stage 733 are moved to move the electronic component transport device 740 to a position immediately above the electronic component 711 placed on the upstream stage 712u. At this time, the position of the electronic component 711 can be confirmed using the imaging camera 734. Then, when the electronic component transport device 740 is lowered using the Z stage built in the electronic component transport device 740 and the electronic component 711 is gripped by the gripping portion 741, the electronic component transport device 740 is directly placed on the imaging device 713. The position of the electronic component 711 is confirmed using the imaging device 713. Next, the attitude of the electronic component 711 is adjusted using a fine adjustment mechanism built in the electronic component transport apparatus 740. Then, after moving the electronic component transport device 740 to above the inspection table 714, the Z stage built in the electronic component transport device 740 is moved to set the electronic component 711 on the inspection table 714. Since the attitude of the electronic component 711 is adjusted using the fine adjustment mechanism in the electronic component conveying apparatus 740, the electronic component 711 can be set at the correct position on the inspection table 714. Next, after the electrical characteristic inspection of the electronic component 711 is completed using the inspection table 714, the electronic component 711 is picked up from the inspection table 714, the Y stage 731 and the X stage 733 are moved, and the upper stage 712d is moved. The electronic component conveying device 740 is moved to the position, and the electronic component 711 is placed on the downstream stage 712d. Finally, the downstream stage 712d is moved to transport the electronic component 711 that has been inspected to a predetermined position.

  FIG. 18 is a diagram illustrating an electronic component transport device 740 including the force detection device 1. The electronic component transport device 740 includes a gripping portion 741, a six-axis force detection device 1 connected to the gripping portion 741, a rotating shaft 742 connected to the gripping portion 741 via the six-axis force detection device 1, A fine adjustment plate 743 is rotatably attached to the rotation shaft 742. The fine adjustment plate 743 is movable in the X direction and the Y direction while being guided by a guide mechanism (not shown).

  Further, a piezoelectric motor 744θ for rotation direction is mounted toward the end surface of the rotation shaft 742, and a driving convex portion (not shown) of the piezoelectric motor 744θ is pressed against the end surface of the rotation shaft 742. Therefore, by operating the piezoelectric motor 744θ, the rotation shaft 742 (and the gripping portion 741) can be rotated by an arbitrary angle in the θ direction. Further, a piezoelectric motor 744 x for X direction and a piezoelectric motor 744 y for Y direction are provided toward the fine adjustment plate 743, and each drive convex portion (not shown) is a surface of the fine adjustment plate 743. It is pressed against. For this reason, by operating the piezoelectric motor 744x, the fine adjustment plate 743 (and the gripper 741) can be moved by an arbitrary distance in the X direction. Similarly, the fine adjustment can be performed by operating the piezoelectric motor 744y. The plate 743 (and the gripping portion 741) can be moved by an arbitrary distance in the Y direction.

  Further, the force detection device 1 has a function of detecting an external force applied to the grip portion 741. By feeding back the force detected by the force detection device 1 to the control device 750, the electronic component transport device 740 and the electronic component inspection device 700 can perform work more precisely. Further, the contact of the gripping portion 741 with an obstacle can be detected by the force detected by the force detection device 1. Therefore, an obstacle avoidance operation, an object damage avoidance operation, and the like that were difficult with conventional position control can be easily performed, and the electronic component transport device 740 and the electronic component inspection device 700 can perform safer work. is there.

<Embodiment of component processing apparatus>
Next, an embodiment of the component processing apparatus of the present invention will be described based on FIG. Hereinafter, the present embodiment will be described with a focus on differences from the first and second embodiments described above, and descriptions of similar matters will be omitted.
FIG. 19 is a diagram showing an example of a component processing apparatus using the force detection device of the present invention. A component processing apparatus 800 of FIG. 19 is attached to a base 810, a support column 820 standing upright on the upper surface of the base 810, a feed mechanism 830 provided on a side surface of the support column 820, and a lift mechanism 830 that can be moved up and down. A tool displacement unit 840, a force detection device 1 connected to the tool displacement unit 840, and a tool 850 attached to the tool displacement unit 840 via the force detection device 1. In addition, as the force detection apparatus 1, the thing similar to each embodiment mentioned above is used.

  The base 810 is a base for mounting and fixing the workpiece 860. The column 820 is a column for fixing the feed mechanism 830. The feed mechanism 830 has a function of moving the tool displacement portion 840 up and down. The feed mechanism 830 includes a feed motor 831 and a guide 832 that raises and lowers the tool displacement portion 840 based on an output from the feed motor 831. The tool displacement unit 840 has a function of imparting displacement such as rotation and vibration to the tool 850. The tool displacement portion 840 includes a displacement motor 841, a tool attachment portion 843 provided at the tip of a main shaft (not shown) connected to the displacement motor 841, and a holder attached to the tool displacement portion 840 and holding the main shaft. Part 842. The tool 850 is attached to the tool attachment portion 843 of the tool displacement portion 840 via the force detection device 1 and is used for machining the workpiece 860 in accordance with the displacement given from the tool displacement portion 840. The tool 850 is not particularly limited, and is, for example, a wrench, a Phillips screwdriver, a flat-blade screwdriver, a cutter, a circular saw, a nipper, a cone, a drill, or a milling cutter.

  The force detection device 1 has a function of detecting an external force applied to the tool 850. By feeding back the external force detected by the force detection device 1 to the feed motor 831 and the displacement motor 841, the component processing device 800 can execute the component processing operation more precisely. Further, the contact of the tool 850 with an obstacle or the like can be detected by the external force detected by the force detection device 1. Therefore, an emergency stop can be performed when an obstacle or the like comes in contact with the tool 850, and the component processing apparatus 800 can execute a safer component processing operation.

<Embodiment of moving body>
Next, based on FIG. 20, embodiment of a moving body is described. Hereinafter, the present embodiment will be described with a focus on differences from the first and second embodiments described above, and descriptions of similar matters will be omitted.

FIG. 20 is a diagram showing an example of a moving object using the force detection device according to the present invention. The moving body 900 of FIG. 20 can move by the applied power. The moving body 900 is not particularly limited, and is, for example, a vehicle such as an automobile, a motorcycle, an airplane, a ship, or a train, a robot such as a bipedal walking robot, or a wheeled robot.
The moving body 900 detects a main body 910 (e.g., a vehicle casing, a robot main body, etc.), a power unit 920 that supplies power for moving the main body 910, and an external force generated by the movement of the main body 910. The force detection device 1 of the present invention and a control unit 930 are provided. In addition, as the force detection apparatus 1, the thing similar to each embodiment mentioned above is used.

  When the main body 910 is moved by the power supplied from the power unit 920, vibration, acceleration, and the like are generated with the movement. The force detection device 1 detects an external force caused by vibration, acceleration, or the like that occurs with movement. The external force detected by the force detection device 1 is transmitted to the control unit 930. The control unit 930 can execute control such as posture control, vibration control, and acceleration control by controlling the power unit 920 and the like according to the external force transmitted from the force detection device 1.

The sensor element, the force detection device, the robot, the electronic component transport device, the electronic component inspection device, and the component processing device of the present invention have been described based on the illustrated embodiments. However, the present invention is not limited to this. Instead, the configuration of each part can be replaced with any configuration having the same function. In addition, any other component may be added to the present invention.
In addition, the present invention may be a combination of any two or more configurations (features) of the embodiment.

In the present invention, the package may be omitted.
Further, in the present invention, instead of the pressurizing bolt, for example, one having no function of applying pressurization to the element may be used, or a fixing method other than the bolt may be adopted.
In addition, the robot of the present invention is not limited to an arm type robot (robot arm) as long as it has an arm, but is another type of robot such as a scalar robot, a legged walking (running) robot, or the like. Also good.
In addition, the force detection device (sensor element) of the present invention is not limited to a robot, an electronic component transport device, an electronic component inspection device, a component processing device, and a moving body, but other devices such as other transport devices and other inspections. It can also be applied to measuring devices such as devices, vibrometers, accelerometers, gravimeters, dynamometers, seismometers, inclinometers, and input devices.

DESCRIPTION OF SYMBOLS 1 ... Force detection apparatus 2 ... 1st board | substrate 21 ... Protruding part 211 ... Upper surface 25 ... Female screw 3 ... 2nd board | substrate 35 ... Hole 36 ... Lower surface 4 ... Analog circuit board 40 ... External force detection circuit 401 ... AD converter 402 ... Arithmetic unit 41, 42 ... hole 5 ... digital circuit board 51, 52 ... hole 6 ... sensor device 60 ... package 61 ... base 611 ... concave part 62 ... lid body 625 ... central part 626 ... outer peripheral part 63 ... terminal 71 ... pressure bolt 715: Head 716: Male screw 90a, 90b, 90c ... Conversion output circuit 91 ... Operational amplifier 92 ... Capacitor 93 ... Switching element 10 ... Charge output element 11, 15, 16, 17 ... Ground electrode layer 12 ... First sensor 121 ... first piezoelectric layer 122 ... output electrode layer 123 ... second piezoelectric layer 13 ... second sensor 131 ... third piezoelectric layer 1 DESCRIPTION OF SYMBOLS 2 ... Output electrode layer 133 ... 4th piezoelectric material layer 14 ... 3rd sensor 141 ... 5th piezoelectric material layer 142 ... Output electrode layer 143 ... 6th piezoelectric material layer 110 ... Laminated body 110a, 110b, 110c, 110d: Side surface 120 ... First side terminal 130 ... Second side terminal 140 ... Third side terminal 150 ... Fourth side terminal 191 ... Electrode body 192 ... Connection portion 500 ... Single-arm robot 510 ... Base 520 ... Arm 521: First arm element 522: Second arm element 523: Third arm element 524: Fourth arm element 525: Fifth arm element 530: End effector 531: First finger 532: Second Finger 600 ... double-arm robot 610 ... base 620 ... first arm 621 ... first arm element 622 ... second arm element 630 ... second arm 631 1st arm element 632 ... 2nd arm element 640a ... 1st end effector 641a ... 1st finger 642a ... 2nd finger 640b ... 2nd end effector 641b ... 1st finger 642b ... 2nd finger DESCRIPTION OF SYMBOLS 700 ... Electronic component inspection apparatus 710 ... Base 711 ... Electronic component 712u ... Upstream stage 712d ... Downstream stage 713 ... Imaging apparatus 714 ... Inspection table 720 ... Support stand 731 ... Y stage 732 ... Arm part 733 ... X stage 734 ... Imaging camera 740 ... Electronic component conveying device 741 ... Grip part 742 ... Rotating shaft 743 ... Fine adjustment plate 744x, 744y, 744θ ... Piezoelectric motor 750 ... Control device 800 ... Component processing device 810 ... Base 820 ... Post 830 ... Feed mechanism 831 ... Feeding motor 832 ... Guide 840 ... Tool displacement part 841 ... Position motor 842 ... holding portion 843 ... the tool mounting portions 850 ... tool 860 ... the processed part 900 ... mobile 910 ... body 920 ... power unit 930 ... control unit

Claims (14)

X-cut board,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
The sensor element, wherein the plurality of side terminals are provided on the side surface having the crystal axis z of the X-cut plate as a normal line.   The sensor element according to claim 1, wherein each of the side terminals is connected to a plurality of internal electrodes in the thickness direction of the laminate. The side surface of the laminate includes two pairs of opposed surfaces.
The sensor element according to claim 1, wherein the number of side terminals provided on one of the opposing surfaces is equal to the number of side terminals provided on the other opposing surface.   The plurality of side terminals include a first side terminal that outputs charges generated by the X cut plate, a second side terminal that outputs charges generated by the first Y cut plate, and the second side terminals. A third side terminal for outputting the electric charge generated in the Y-cut plate and a fourth side terminal for grounding the laminate, two of the two opposing faces, The sensor element according to claim 3, wherein the side terminal is provided on one opposing surface, and the two side terminals are provided on the other opposing surface.   The sensor element according to any one of claims 1 to 4, wherein the X-cut plate is provided between the first Y-cut plate and the second Y-cut plate.   The sensor element according to any one of claims 1 to 5, wherein the laminated body includes a plurality of the X-cut plate, the first Y-cut plate, and the second Y-cut plate, respectively. An X-cut plate, a first Y-cut plate arranged so that the crystal axis y and the crystal axis z of the X-cut plate are orthogonal, and the crystal axis z and the crystal axis z of the first Y-cut plate are A laminated body comprising a second Y-cut plate arranged so as to be orthogonal to each other and a plurality of electrode layers including an internal electrode layer provided between the cut plates, along the thickness direction thereof A laminate having a side surface;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the electrode layers;
The sensor element, wherein the plurality of side terminals are provided in a region other than a surface having the crystal axis y of the X-cut plate as a normal line. When the three axes orthogonal to each other are the A axis, B axis and C axis,
An X-cut plate that outputs charges according to an external force along the A-axis direction, a first Y-cut plate that outputs charges according to an external force along the B-axis direction, and the first Y-cut plate On the other hand, the second Y-cut plate, which is arranged in a state rotated by 90 ° around the axis in the thickness direction, and outputs electric charges according to the external force along the C-axis direction, and the cut plates A laminate comprising a plurality of electrode layers including the provided internal electrode layer, the laminate comprising side surfaces along the thickness direction of the laminate, and
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
The external force applied along the B-axis direction from the external force applied along the C-axis direction of the X-cut plate due to thermal deformation of the side terminal that contacts the X-cut plate among the plurality of side terminals. A sensor element characterized in that it is provided in a region where the size of the sensor becomes small. An X-cut plate, a first Y-cut plate arranged so that the crystal axis z and the crystal axis x of the X-cut plate are orthogonal, and the crystal axis x and the crystal axis x of the first Y-cut plate are A laminate including a second Y-cut plate arranged to be orthogonal to each other and a plurality of electrode layers including an internal electrode layer provided between the cut plates, the thickness direction of the laminate A laminate comprising side surfaces along
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
An external force detection circuit that detects the external force based on a voltage output from the sensor element.   The force detection device according to claim 9, wherein three or more sensor elements are provided. A plurality of arms, and at least one arm connecting body formed by rotatably connecting the adjacent arms of the plurality of arms;
An end effector provided on the distal end side of the arm coupling body;
A force detection device provided between the arm coupling body and the end effector for detecting an external force applied to the end effector;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
A robot comprising: an external force detection circuit configured to detect the external force based on a voltage output from the sensor element. A gripper for gripping electronic components;
A force detection device that detects an external force applied to the gripping portion;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
An electronic component transport apparatus comprising: an external force detection circuit configured to detect the external force based on a voltage output from the sensor element. A gripper for gripping electronic components;
An inspection unit for inspecting the electronic component;
A force detection device that detects an external force applied to the gripping portion;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
An electronic component inspection apparatus comprising: an external force detection circuit that detects the external force based on a voltage output from the sensor element. A tool displacing part for mounting the tool and displacing the tool;
A force detection device for detecting an external force applied to the tool;
The force detection device includes an X-cut plate,
The first Y-cut plate disposed so that the crystal axis z of the X-cut plate and the crystal axis x of the first Y-cut plate are orthogonal to each other;
The second Y-cut plate disposed so that the crystal axis x of the first Y-cut plate and the crystal axis x of the second Y-cut plate are orthogonal to each other;
A laminate including a plurality of electrode layers including an internal electrode layer provided between the cut plates, and a laminate including a side surface along a thickness direction of the laminate;
A plurality of side terminals including side terminals provided on the side surfaces of the laminate and connected to the internal electrode layers;
A plurality of side terminals provided on the side surface having the crystal axis z of the X-cut plate as a normal line;
A component processing apparatus comprising: an external force detection circuit configured to detect the external force based on a voltage output from the sensor element.

Images